Question Answer
Total amount of blood volume in the venous system is? 64%
Venous return is the amount of blood volume returning to the? Right heart.
CI is CO based on? Actual body size.
End systolic pressure is? The amount of blood in the ventricle after ejection.
End diastolic pressure is? The amount of blood in the ventricle after filling.
Indexed measurements allow the normals to be standardized therefore account for the patients different body sizes. True.
Patients who develop A-fib or 3rd degree heart block, lose their atrial kick and? CO decreases.
Cardiac Tamponade Restricts the blood entering the heart.
Fick equation CO= VO2/C(a-v)O2 x 10
Right atrium pressure. (RAP) Measured with CVP or Swans.2 to 6 torr.
Right ventricle pressure. (RVP) Measured with Swans.20 to 30/2 to 6 torr.
Pulmonary artery pressure. (PAP) Measured with Swans.20 to 30/6 to 15 torr.Waveform has diacrotic notch.
Pulmonary capillary wedge pressure. (PCWP) Measured with Swans. 4 to 12 torr.
Ejection fraction. EF= SV/EDV If in the 30% range intolerance to exersise.
PAP looks at? lungs.
PCWP looks at? Left heart.
CVP looks at? Right atrial pressure or fluid levels. Norm 2-6 torr.
Systemic Artery Blood Pressure (SABP)looks at? Blood pressure thoughout the body.
Ventricular stroke work. Amount of blood ejected with each beat.
CVP norm? 2-6torr.
Cardiac Output QT norm? 4-8 L/M
Cardiac Index (CI) 2.5-4.5
Preload The stretch on the ventricle muscle fibers before contraction.
Afterload The resistance of external factors that oppose ventricular contraction.
Stroke volume is determined by? Preload, afterload, and contractility.
Preload is created by? End diastolic volume.
If there is no narrowing or dysfunction of the valve… Pressures in the atrium will be the same as in the ventricles at the end of diastole.
Atrial contraction is… 30% of cardiac output.
Afterloads two opposing factors? Tension and impedance.
Intrathoracic become more negative.(vacume effect) Increases filling and increases resistance to emptying of ventricles.
Increase in Ca causes? spastic heart.
Decrease in K+ and Na causes? Atrial fibrillation.


Question Answer
Identifying marks for an arterial wave form? the vertical scale has higher numbers
Identifying marks for the CVP waveform? small thin line, lower to the horizontal scale line.
Identifying marks for the RV waveform? waveform hits the top and the bottom of the scale.
Identifying marks for the PAP waveform? peak is up tall but it never reaches the bottom.
Identifying marks for the PWP waveform? the line is thin and wiggly but higher on the scale than the CVP.
Normal value for Arterial? Sys 90-140 torr, Dia 60-90 torr, Mean 70-105
Normal value for CVP? 2-6 torr
Normal value for RAP? < 6 torr
Normal value for RV? sys 20-30 torr, dia 2-6 torr,
Normal value for PAP? sys 20-30 torr, dia 8-15 torr, mean 10-20 torr
Normal value for PWP? 4-12 torr
Normal value for CI? 2.5-4.5 L/min/m2
Normal value for QT? 4-8 L/m
Normal value for C(a-v)O2? 4-6 Vol%
Normal value for Stroke volume? 60-130ml/beat
Normal value for ejection fraction? 65-70%
Discuss preload? stretch of the ventricle before the contraction. Venous return is most important.
Discuss afterload? resistance that opposes ventricular ejection.
Procedure for placing an arterial line? assemble equipment, perform Allen’s test, drape pt, inject 1% lidocaine, catheter inserted 30 degree angle, hold needle and advance catheter, remove needle and secure, attach drip and observe waveform.
Procedure for placing a pulmonary catheter? done by physician, check ballon for patency, inserted into selceted sight until reaches R atrium then inflate balloon with 1.5cc’s.
Common sites for placing pulmonary catheter? subclavian or internal jugular
Common sites for placing arterial catheter? radial, brachial, or femoral.
Equipment needed for a pulmonary catheter? bedside cardiac monitor, pressurized saline bag, pressure amplifier/monitor, BTFD catheter, pressure transducer system.
Equipment needed for an arterial line placement? arterial catheter, flush device, hepranized saline bag, transducer, 4×4 sterile squares, lidocaine, betadine/alcohol, tape to secure.
What pressure is your hepranized bag placed at and what is the rate of your drip? pressurized to 300 torr and set to drip 2-4ml per hour.
Thermodilution method for measuring QT? dextrose or saline injected at room temp into the proximal port of pulmonary cath. measures heat loss in relation to blood flow. done several times to get and average.
Fick method for measuring QT? requires I and E gases as well as mixed, gold standard, but rarely used.
Pulse Contour C.O. monitoring? simultaneous measurements of art pressure and C.O. by other methods for a baseline. If art prssure goes up them C.O. will go up.
Estimated C.O. monitoring? central venous blood used. If C(a-v)O2 is up then C.I. will be down and vice versa. Keep sats above 95%.
Discuss SVR? Systemic Vascular Resistance- pressure on the vessel’s throughout the body (from aorta).
Discuss PVR? Pulmonary Vascular Resistance- pressure on the pulmonary artery
Discuss vascular resistance? component of afterload determined by elasticity (compliance of vessel), size (radius), viscosity (how thick), changes in pressure (from one end of vessel to the other).
Discuss Ejection Fraction? fraction of end diastolic volume ejected with each beat. EF=SV/EDV. <30% exercise tolerance severly limited.
Discuss EDV? End Diastolic Volume- amount of blood before the contraction. Preload, or systole.
Discuss ESV? End Systolic Volume- amount of blood after the contraction. Afterload or diastole.
Discuss Cardiac Work? energy the heart uses to eject blood against the aortic or pulmonary pressures. Correlates with O2 requirments of heart. L ventricle has to work 6X harder then the R.
Calculate CaO2, CvO2, C(a-v)O2, C.O., and EF? CaO2- (Hbx1.34)(SaO2)+(PaO2x0.003), CvO2- (Hbx1.34)(SvO2)+(PvO2x0.003), C(a-v)O2- CaO2-CvO2, C.O.- HRxSV or VO2/C(a-v)O2 x 10, EF- SV/EDV.
Discuss factors that affect contractility of the heart? coronary blood flow, sympathetic nerve stimulation, Inotropic drugs, Physiologic depressants, damage to heart.
Discuss performance ability of the heart? HR and SV
Index measurements? measurements based on body size.
Left atrial filling pressures? preload and PWP
Right atrial filling pressures? amount of blood in R atrium or CVP
What do parameters do these reflect: CVP, PAP, PWP, C.O.? CVP- R heart, fluid management; PAP- lungs, mixed venous blood; PWP- L heart; C.O. blood pumped in one minute.
Discuss LCWI? amount of work on the left side of heart.
Discuss RCWI? amount of work on the right side of the heart.
Discuss LVSWI? directly related to SVR, mycardial mass, viscosity.
Discuss RVSWI? directly related to PVR, myocardial mass, viscosity.
Both LVSWI and RVSWI increase with? tachycardia, hypoxemia, and poor contractility.
Question Answer
Positive pressure inspiration affects venous return by inc, dec, same decrease
Positive pressure inspiration affects pulm capillary flow by inc, dec, same decrease
Positive pressure inspiration affects Pulm Vascular resistance by inc, dec, same increase
Positive pressure inspiration affects cardiac output by inc, dec, same decrease
Negative pressure inspiration affects venous return by inc, dec, same increase
what are the central chemoreceptors medulla oblongotta
what does the medulla oblongotta primary stimulus responsive to increase PCO2 and decrease in pH
what are the 2 peripheral chemoreceptors located and what stimulates them Glassopharyngeal and vagus (9 and 10 nerve) sensitive to decrease in PaO22
what chemoreceptor primiarily stimiulates breathing for those without CO2 retention? Central Chemo Receptor
What torr level are peripheral receptors set? 60 torr PO2
What is airway resistance anything that impedes the airways
Where is RAW primarily located? airways
3 general factors that affect RAW length, diameter and flow (sometimes visosity)
Normal range for RAW 0.5 – 3 cwp/l/s
Formula for Raw PIP-PLAT/Flow
Raw is a problem on inspiration or exhalation exhalation
what type of a problem is RAW a restrictive or obstructive obstructive
on a vent,an increase in RAW will increase PIP, Plat or both PIP
Increase in RAW increases WOB
what is static compliance true measurement without air moving
what is dynamic compliance measurement with air moving
what type of complaince do we use for trending of chest wall compliance static
static compliance shows collective compliance in what 3 areas chest wall, pleural space, and parenchyma
Formula for static compliance Exh Vt/Plat-peep
Formula for dynamic compliance exh Vt/pip-peep
Normal value for static compliance 70-100 ml/cwp
normal value for dynamic compliance 50-80 ml/cwp
what does emphysema do to static compliance increase
what does restrictive disorders do to static compliance decease
on a vent, decreased static compliance will increase pip increase plat or both both
name 4 diseases with decreased compliance ARDS, Pulm Fibrosis, Plum Effusion, obesity
what zone has the most natural alveolar dead space one
which zone has the best blood flow three
normal value for VQ ratio 0.8
deadspace is the opposite of shunting
gas in the conducting airways not involved in gas exhange anatomical deadspace
anatomical deadspace = 1 ml/lb
describe alveolar deadspace pt is ventilating but not perfusing
2 examples of alveolar deadspace hyperinflation and pulm embolism
severe restrictive disorder pts Vd/Vt would increase decrease same increase
pt exercising their Vd/Vt would increase, decrease same decrease
formula for Vd/Vt PaCO2-PeCO2/PaCO2
normal range for Vd/Vt 25-40%
whend does deadspace become critical >60%
CaO2 formula (Hb x 1.34x SaO2)+(PaO2 x 0.003)
normal value for CaO2 20 vol %
CvO2 formula (Hb x 1.34x SvO2)+(PvO2 x 0.003)
Normal Value for CvO2 15 vol %
Formula for O2 transport CaO2 x CO x 10
Normal value O2 transport 1000 ml/min
C(a-v)O2 normal value 5%
O2 consumption formula C(a-v)O2 x CO x 10
O2 consumption normal value 250 ml/min
if Hb is low how does it affect tissue oxygenation decreases it
if CO decreases what does SvO2 do? decrease
CO increases SvO2 increases
CO decreases C(a-v)O2 increases
CO increases C(a-v)O2 decreases
pt is febrile the C(a-v)O2 increases
Pt is febrile the SvO2 decreases
pt is hypothermic the SvO2 increases
pt is febrile O2 consumption increases
pt is exercising O2 consumption increases
CO decreases O2 consumption stays the same
Normal SvO2 68-77%
Normal PvO2 40 torr
Room air norm for P(A-a)O2 0-20 torr
norm for P(A-a)O2 on 100% FiO2 30-50 torr
what is the normal PaO2/FiO2 ratio 380-475
at what point is the PaO2/FiO2 ratio critical? <200
What is the normal shunt range 2-5 up to 10%
formula for shunt (Qs/Qt) CcO2-CaO2/CcO2-CvO2
at what level do we treat a shunt? greaster than 20%
2 treatments to correct a shunt increase PEEP and FIO2
2 examples for shunt Pulm embolism, CHF
what type of shunt doesnt comein contact wtih alveoli true shunt
what type of shunt does capillary perfusion in excess of alveolar ventilation shunt like
which shunt is more treatable true or shunt like shunt like
what is the opposite of shunting deadspace
which is a shunt pulm embolism or pneumonia pneumonia
indication of nasopharyngeal airway freq sux
indication of oropharyngeal airway pt biting on ETT
hazard of oropharyngeal airway damage to oropharynx
ETT how long do we pre-oxygenate 3-5 min
ETT how long do we oxygenate between attempts 1-2 min
how long do we attempt ETT 30 sec
which hand do we hold laryngoscope left
what is a miller strait blade
4 ways to initially verify placement of ETT Listen to stomach and lungs, watch for chest rise, CO2 detector, Tube condensation
what is the average depth of ETT markings 21-23 cm
what is the average depth for Nasotracheal intubation 26-28 cm
how many cm above the carina should the ETT be placed 5-7 cm
how many fingers between tube holder and pt neck one
how many days till a pt should be considered for a trach 21
2 types of procedures for trach surgical and percutaneous
softening of trhe cartilaginoal rings and causes trahcea to collapse tracheomalacia
narrowing of trhe trachea due to scarring tracheostenosis
average range ETT cuff should be kept in torr and cwp 20-25 torr 25-30 cwp
2 contradictions of HME thick secretions spontaneous Ve >10 lpm
formula for calculating suction cath ETT x 2 = then the next size smaller
what is the max time spent sux a pt 15 sec
where should the sux pressure be kept 100-120 torr
absolute contradiction of sux epiglottitis
container used for collection sample luken trap
ABG shows pt is hypoventilating and hypoxemic, in vol vent CMV name 2 ways to fix hypoventilation increase rate increase volume
ABG shows pt is hypoventilating and hypoxemic, in vol vent SIMV name 3 ways to fix hypoventilation increase rate, increase Vt add PS
ABG shows pt is hypoventilating and hypoxemic, in pressure control vent name 2 ways to fix hypoventilation Increase PIP Increase I-time
ABG shows pt is hypoventilating and hypoxemic, in vol vent name 2 ways to fix hypoxemia increase FiO2 add PEEP
In PC/CMV list 3 ways to fix hypoxemia increase PEEP, Increase PIP, Increase I-Time
what is the best way to fix airtrapping without changing acid base balance Increase PIF
if high pressure alarm is sounding you would expect to also see what alarm Ve
if secretions are causing high pressure alarms, you would expect delivered Vt to be higher, lower or the same as set lower
Pt has Pulm Edema, Dr gives a diuretic you would expect inspiratory pressure to increase, decrease or stay the same same
Pt has Pulm Edema, Dr gives a diuretic you would expect Vt to increase, decrease or stay the same increase
Weaning: minumum acceptable value for RR 25
Weaning: minumum acceptable value for Vt >5 ml/kg IBW
Weaning: minumum acceptable value for Ve 5-10 LPM
Weaning: minumum acceptable value for VC 10-15 ml/kg/IBW
Weaning: minumum acceptable value for NIF/MIP -20 cwp
Weaning: minumum acceptable value for RSBI <105, 80+90% sucess
Question Answer
Blood pressure a. Normal Systolic = 90-140 b. Normal Diastolic = 60-90 c. As BP increases CO & CI usually decrease b. As BP decreases CO and CI usually increase
Pulse Pressure a. Systolic BP minus Diastolic BP b. Normal = 40 mmHg c. greater than 40 indicates decreased Stroke Volume (SV)
SV (Stroke Volume): a. Cardiac Output divided by Heart Rate b. Normal = 60 – 130 ml/beat c. It’s the volume ejected per beat
CO (Cardiac Output): a. Heart Rate times SV b. Normal = 4.8 LPM c. More reliable than Mean Airway Pressure (MAP)
CI (Cardiac Index): a. Cardiac Output divided by Body Surface Area (BSA) b. Normal = 2.5 LPMm2 or simply CO/2 c. Decreased with shock, dehydration, cardiac fail, PE. d. Increased with hypoxia, low BP. e. More reliable measurement than CO.
EF(Ejection Fraction): a. % of blood volume pushed out of heart per beat. b. Normal = 65 – 75% c. Reduced with ventricular damage
MAP (Mean Arterial Pressure): a. systolic BP + (Diastolic*2)/3 b. Normal = 70 – 105
Define Preload Blood that returns to ventricles at end diastolic, & refers to stretch of myocardial fibers after it is filled with blood.
PCWP (Pulmonary Capilary Wedge Pressure 1. Measures left heart function 2. Normal = 5 – 12 mmHg (same as PAP diastolic) 3. greater than 18 = edema forming in lungs (if no signs CHF think ARDS) 4. greater than 25 = edema in lungs from left heart failure (CHF) 5. greater t
Question Answer
What are artifacts spikes or shifts in values not constant with pt clinical status Ex: pt moving lines
Factitious real events that may require attention. Ex: changes in BP
How do you determine tissue oxygenation through ABG or pulse ox Depends on PIO2, PAO2, CaO2, DO2, tissue perfusion and O2 uptake
What ways can you monitor Spo2 Pulse OX, monitor, and ABG
What can cause errors in messuring SPO2 motion from shivering, seizure activity, pressure on senor, or patient transport, probe site placement, intense light, anemia, colored skin, carboxyhemo, methemoglobin, dark nail polish, some blood born dyes
normal value O2 consumption 250/ml
what causes O2 consumption to increase activity, stress, and temperature
Method used to mesure O2 consumpttion Fick method Qt=VO2/(CAO2-CVO2) VO2=QT/(CAO2-CVO2)
normal range for P(A-a)O2 5 to 15mm hg
equation for estimating % of shunt breathing 100% [P(A-a)O2]/20
If I have a P(A-a)O2 of 300 mm hg while on 100% o2, what is estimated shunt? 15%
normal PaO2/FIO2 ratio ALI ARDS 400mg to 500mg normal <300 ALI <200 ARDS
parameters considered most accurate and reliable measure of oxygenation efficiency 5 to 15 mm hg
normal range for VD/VT dead space/tidal volume ratio 0.20 to 0.40
best messure of efficiency of gas exchange in the lungs VD/VT ratio Paco2-Peco2/Paco2
which disorders will cause an increase in VD/VT CHF, PE, ALI, Pulmonary hypertension, and Pt’s undergoing mech. ventilation.
What VD/VT value indicate that weaning is not likely >0.60 is predicitive of lack of success
what will lead to an increased end-tidal PCO2 *increased effective ventilation >VT >VE >VA *Marked < in effective ventilation *< carbon dioxide production (VCO2)(sedation, sleep, cooling) *< in lung perfusion (PE,
lung compliance and normal range measure of stiffness of the lungs 60 to 100ml/cm H2O
RAW and normal RAW Airway resistance determined by simutaneous measurments of airway flow and presure. normal RAW 1 to 2 cm Hg Intubated pt. 5 to 10 cm Hg
equation for RAW Diffrence between airway opening Pao2 and the alveoli PALV R = (Pao2-Palv)/flow
condition associted with an increased lung compliance improvement in atelectasis, pneumonia, Pulmonary edema, ALI, ARDS, pnemothorax, fibrosis, bronchial intubation, increased thoracic compliance, improved obesity, ascites, chest wall deformaties like flailed chest
What are caused of increased airway resistance *small ET tube, plug in ET tube, bitting on ET tube *Bronchospasm and mucosal edema *secretions *airway obstruction *high gas flow rate
What are the limits for plateau airway pressure in a pt. receiving MV? Why? not exceed 30mg hg because elevated Pplat increases chances of vent induced lung injury
factors associated with an increased risk for auto peep? dynamic hyperinlation can develop even at low VE alters trigger sensitivity on vent
factors that contribute to development of auto peep Expiratory muscle weekness, mech ventilated patients with COPD Pt with high VE, ARDS
peak presure increases due to? either increased resistance or decreased compliance. if they move up together the problem is compliance. when peak pressure increases and plateau stays the same problem is airway resistance.
breathing pattern suggesting resp. muscle decompensation? Cheney Stokes
What bedside parameters are used to assess resp mucle strength? VC >or= 70ml kg <10 to 15 muscle weakness MIP maximal inspiratory pressure >-20 to -30
normal VC 70ml/kg
what does decreased capacity indicate muscle weakness
why do we use ventilatory graphics to monitor pt’s vent interaction. allow rapid determination of mode, B pattern, auto peep, excessive presure, secretions in airway, synchrony, and triggering efforts, and WOB
what is MAP and MAP normal ranges Mean arterial Blood pressure 90mm hg (80-100)
what is CVP and CVP normal ranges central venous pressure. same as right arterial ranges 2 to 6mm hg
range for mean pulmonary artery pressure? 15mm hg
what is cardiac output and normal CO vol of blood pumped per minute by the heart normal 5 L/min (4-8)
what is PCWP and what is PCWP normal range? Pulmonary capillary wedge pressure 5-10mm Hg (<18)
What is CVP associated with increase CVP fluid overload, R ventricular failure, pulmonia, hypercapnia, valvular stenosis, PE cardiac tamponade, pneumothorax, PPV, PEEP, L ventricular failure
What is associated with increased PAP pulmonary hypercapnia, left ventricular failure, fluid overload
What is associated with increased PCWP left ventricular failure, fluid overload, > 20 intersticial edema, >25 alveolar filling, >30 frank pulmo. edema
Question Answer
What is it called when your heart skips a beat, has irregular rhythm, normal P waves and QRS complex missing? 2nd Degree Heart Block
How is 2nd Degree Heart Block Treated? Atropine and and electrical pacemaker
What is it when the PR interval cannot be determined and the QRS complex is widened? 3rd Degree Heart Block
How is 3rd Degree Heart block treated Electrical Pacemaker
What degree of block slows you down, pauses between the P wave to the QRS complex? 1st Degree Heart block
How is 1st Degree Heart block treated Atropine
What does an inverted T-wave mean Myocardial Ischemia
What does significant Q waves mean? Myocardial Infarction
What do elevated S-T segments mean Myocardial Injury
Where is the SA Node located? Upper right hand corner of the heart.
How does the electrical impulse travel through the heart Moves through atria causing contraction (P-wave), then it is received by AV node, delayed (P-R interval). Stimulus is sent through bundle of His and L&R bundle branches to purkjunke fibers (QRS) after short delay (S-T) the heart depolarizes (T-wave).
How do you treat Asystole Confirm in 2 leads first, epinephrine , Atropine and CPR
How do you treat Sinus Bradycardia Oxygen, Atropine
How do you treat Sinus Tachycardia Oxygen
How do you treat PVC Oxygen, Lidocaine
How do you treat multifocal PVC Oxygen, Lidocaine
How do you treat Ventricular Tachycardia If no pulse De-fibrillate If pulse Lidocaine, Cardioversion
How do you treat Ventricular Fibrillation De-fibrillate
Where do you place the Chest Electrodes V1 for an EKG 4th intercostal space on R side of sternum
Where do you place the Chest Electrodes V2 for an EKG 4th intercostal space on L side of sternum
Where do you place the Chest Electrodes V3 for an EKG Between V2 and V4 on left side
Where do you place the Chest Electrodes V4 for an EKG 5th intercostal space,left mid-clavicular line
Where do you place the Chest Electrodes V5 for an EKG Between V4 and V6 on left side
Where do you place the Chest Electrodes V6 for an EKG 5th intercostal space, left mid-axillary line
Two factors that affect the direction of the axis Hypertrophy and Infarction
What is the normal axis of the hearts electrical impulse Down and to the left
What are the 4 Chambers of the Heart Left Ventricle Right Atria Right Ventricle Left Atria
The Left Ventricle serves what branch systemic arteries
The Right Atria serves what branch systemic veins
The Right ventricle serves what branch pulmonary arteries
The Left Atria serves what branch pulmonary veins
What are the 3 factors which control blood pressure Heart, Blood and vessels
How does the heart increase BP when the rate increases
How does blood increase BP when there is fluid overload
How do vessels increase BP when there is constriction of the vessels
How does the heart decrease BP When it is not pumping hard enough
How does blood decrease BP Loss of blood
How do the vessels decrease BP when there is dilation of the vessels
List two methods used for measuring MAP Indwelling arterial catheter with a pressure transducer.
The left heart is associated with what disease CHF
The right heart is associated with what disease Cor Pulmonale
What is pulse pressure The difference between the systolic and diastolic pressure
What is Cardiac Output (QT) Measures the output of the left ventricle to systemic arterial circulation
What is SVR-Systemic Vascular Resistance The pressure gradient across the systemic circulation divided by the cardiac output
What is PVR – Pulmonary Vascular Resistance The pressure gradient across the pulmonary circulation divided by the cardiac output
What causes PVR to increase hypoxia, pulmonary hypertension and lung disease
What is the Normal Cardiac output range 4-8 LPM
What is the normal Cardiac Index range 2.5-4.0 liters/min/m2
The first heart sound S1 is created by what Normal closure of the mitral and tricuspid valves at the beginning of ventricular contraction
The second heart sound S2 is created by what Systole ends. The ventricles relax and the pulmonic and aortic valves close.
Question Answer
What is Preload? Myocardial fiber length at end diastole
What is Afterload? total force opposing ventricular ejection
What is Contractility and how does it affect Preload and Afterload? Force of ventricle contraction on each breath cycle, venous return will decrease
What pressures best represent the four areas of the heart? RA – CVP/RV – PVR/ LA – PCWP/ LV – Qt (SVR)
Calculation and range of CVP obtained via central catheter; normal range = 2-6 mmHg / 4-12 cmH2O
Calculation and range of MPAP Systole + Diastole (2)/3; normal range = 12 – 18
Calculation and range of PVR MPAP – PCWP/Qt x 80; normal range = 90-250 dynes
Calculation and range of PCWP obtained via Swan-Ganz; normal range = 4-12 mmHg
Calculation and range of MAP systole + diastole (2)/3; normal range = 70-100
Calculation and range of Qt = SV x f; normal range = 4 – 8 L/min
Calculation and range of SVR = MAP – CVP/Qt x 80; normal range = 800 – 1600 dynes
What does and ↑ or ↓ in CVP represent? ↑ Fluid overload, L-R shunt, Cor pulmonale, + an ↑in PVR see PVR; ↓ Hypovolemic Shock
What does and ↑ or ↓ in PAP represent? ↑ Hypervolemia, Pul. HTN, Pul. Emboli, hypoxiema, LVF; ↓ hypovolemia
What does and ↑ or ↓ in PVR represent? ↑ w/ cor pulmonale, hypoxia, pul. HTN, PE
What does and ↑ or ↓ in PCWP represent? ↑ cardiac tamponade, hypervolemia, LVF, Mitral regurg.; ↓ hypovolemia
What does and ↑ or ↓ in SVR represent? ↑ (vasoconstriction) HTN, Hypovolemia; ↓ (vasodilation) vasodilator therapy, shock
RHF vs. Cor Pulmonale (Causes and Diff.?) Cor Pulmonale is a pulmonary problem therefore an ↑ in PVR is seen, RHF the PVR is normal.
CHF; what happens in it’s most severe state? Where the LHF leads to a RHF, which is hard to diagnose due to false apparnent improvement
Pul Edema vs. Non Cardio Pul. Edema (ARDS) PCWP > 12 is Non-Cardiogenic Pulmonary Edema (ARDS); PCWP > 18 is Cardiogenic Pulmonary Edema (CHF)
Dicrotic notches in catheter waveforms represent closure of what valves? Aortic semi-lunar valve (A-line); Pulmonic semi-lunar valve (Swan-Ganz)
Arterial Line (aortic) continuously monitors BP from intra-arterial
PAC/ Swan-Ganz (pulmonic) provides rapid, beat to beat information of hemodynamic status.  (PCWP)
What are the 3 main catheters used for pressure readings? Complications? Type of Blood? 1. A-lines 2. CVP lines 3. Swan-Ganz
Complications of the 3 main catheters? 1. A-line = hemorrhage, embolism, infection 2. CVP lines = arrhythmias, perforation of chamber 3. Sw-Gz = insertion trauma (pneumo), arrhythmias, embolism, infection, art. damage
Type of blood surrounding the 3 main catheters? 1. A-line = arterial 2. CVP lines = Mixed Venous 3. Sw-Gz = Mixed Venous
Polysomnography is the study of what? the polygraphic recording during sleep of multiple physiologic variables related to the state and stages of sleep to assess possible biological causes of sleep disorders.
EEG’s purpose? measures brain waves to determine state of sleep
Sleep Stages? Stage one: drowsiness. Stage two: Light sleep. Stage three and four: Deep sleep (blood pressure & body temperature decrease).  REM (active sleep – brain rejuvenation)
REM? Comprises about 25% of sleep time (4 – 6 stages per night). Active phase of sleep where Breathing becomes irregular, Eyes move rapidly, Body twitches and Heart rate becomes irregular. Most large muscle are nearly paralyzed.
What is considered sleep apnea and what are the different types? interruption of breathing during sleep.
Central Sleep Apnea? no chest movement w/o nasal flow
Obstructive Sleep Apnea? chest movement w/o nasal flow
Narcoleptic Sleep Apnea? disturbed nocturnal sleep and an abnormal daytime sleep pattern, characterized by excessive daytime sleepiness (EDS)
Capnography is the study of what? study of the body’s CO2 levels (i.e. to prevent hypoxia)
Describe a waveform of an esophagus intubation. waveform would be rounded and slowly dissipate.
Describe a waveform of hypercapnea. waveform would show a square-ish shape that would steadily enlarge
How does Deadspace relate to capnography? Capnography provides information about CO2 production, pulmonary perfusion, alveolar ventilation (i.e. deadspace), respiratory patterns, and elimination of CO2
Deadspace equation?
What is a colorimetric capnometer? device that is used to verify placement of ET tube, Starts purple and should turn to gold if CO2 is present.
Pulse Oximeter usages and factors that interfering? SpO2, things that may interfere is poor perfusion in peripheral areas, movement, nail polish, etc..
What does a co-oximeter analyze? SaO2 (via ABG analysis)
Sanz electrode measures? pH
Severinghouse electrode measures? CO2
Clark electrode measures? O2
How is a TCM used and what does it analyze? Used to measure O2 and CO2 in infants.
What is third spacing? Veins have a higher osmotic pressure (i.e. “Vampire Veins”), osmotic meaning they suck in fluids and whatever they can’t get the lymphatic sys grabs and if it’s overwhelmed it enters the interstitial space (i.e. 3rd space).
Question Answer
Components of a Fluid Filled monitoring system intravascular catheter, low compliance tubing, transducer, amplifier/monitor, continuous flush system
The intravascular catheter is semi- ___ and provides access to ___ ____, _____ rigid;central veins, arteries
The low compliance/____ tubing connects what to what? rigid; intravascular catheter to transducer
Max length of the low compliance tubing should be no greater than 3-4 ft
This receives low voltage electrical signal from the transducer and increases the signal amplitude to be displayed on the monitor Amplifier/monitor
The amplifier/monitor responds rapidly to changes, creating real time display correlating with ___ ECG
The flush system continuously flushes fluid through the system at a rate of __ml/hr 3
Each beat of the heart generates a __ ___ __ (arterial pulse) complex pressure wave
The arterial pressure is propagated through systemic circulation at a given ____ frequency (bpm)(
The resulting sine wave is called the first ___ harmonic
Phase I of the arterial pressure waveform = early systole, inotropic component
The steepness, rate and height of the anacrotic rise in Phase I are related to stroke volume and LV contraction
What is Phase II of the arterial pressure waveform? Systole, Volume displacement curve, Continued ejection of SV from ventricle
What is Phase III of the arterial pressure waveform? Late systole and Diastole, Sloping decline, dicrotic notch
This Phase of the arterial pressure waveform has the anacrotic notch and volume displacement curve Phase II
This Phase of the arterial pressure waveform consists of the anacrotic rise (inotropic component) Phase I
What is Damping? Friction that slows down and reduces the amplitude of oscillations
What are the 3 damping factors? Elasticity(compliance of pressure tubing), Mass of fluid in tubing and cath, and Friction(viscosity and flow of the fluid/blood)
Underdamped waveform appears narrow, peaked
Effects of underdamped waveforms on BP measurements Overestimates/Inaccurately high SBP; Underestimates/inaccurately low DBP
What can cause an underdamped waveform? long tubing
Overdamped waveform appears how Widened and slurred, dicrotic notch not clearly visible
Overdamped effects on BP measurements underestimates/inaccurately low SBP, Overestimates/inaccurately high DBP
Causes of overdamped waveform air bubbles, overly compliant tubing, kinks, clots, stopcocks
The ability of a fluid filled monitoring system to accuraely reproduce the true pressure pulse on the monitor is called Dynamic response
What is the name of the test for dynamic response? Square wave/fast flush/snap test
If the fast flush test generates numerous oscillations that extend below baseline, what kind of system does that indicate? underdamped
If the fast flush test generates no oscillations below the baseline (no “ringing” after flush), what kind of system does that indicate? overdamped
Use ___, not SBP or DBP for monitoring bc ___ is less subject to error MAP
2 reasons for having an A-Line frequent blood draws and BP monitoring
4 ways to insure accuracy of fluid filled monitoring system unobstructed, zeroed, leveled, and calibrated properly
What is the number 1 cause there is no waveform? stopcock turned off to patient
Troubleshooting: no waveform, what do you do? check for kink, clot(aspirate first, do not flush), Check stopcock not off to pt, check pressure bag setting, check for loose connections, verify zero and level
What causes artifact? catheter whip
If you see Artifact what should you do? check pt movement, perform dynamic response testing to determine underdamping
Steps to assemble A-line collect equipment, puncture flush bag, attach pressure bag, tighten connections, prime press. tubing with flush soln changing stopcocks as you progress, inflate bag to 300mmHg, inspect for kinks/bubbles, connect to monitor, level and zero, connect to pt.
Blood pressure is _____ at all points in the arterial system, _____ affects BP not equal; gravity
ABP ____ downward from the heart level and _____ upwards from the heart level increases; decreases
Why should all BP measurements be taken at the heart level? to eliminate the affect of gravity on hydrostatic pressure
Leveling eliminates this type of pressure hydrostatic
This is an accurate reference to establish a standard neutral level for all measured pressures zeroing
Zeroing eliminates this type of pressure atmospheric
Where is the phlebostatic axis? midaxillary line, level of RA, 4 ICS, 1/2 AP diameter
Intravascular volume(Preload), Pump efficiency, SVR, and PVR(afterload) are all effected by what during Systole? Stroke volume
What is stroke volume? the volume of blood ejected from the heart with each beat
These factors influence ABP during Diastole Vascular resistance(SVR, PVR), vascular tone, heart rate
How does heart rate affect diastolic pressure? it changes the duration of diastole and the pressure continues to fall until next systole
SVR equation and Norm SVR=[(MAP-CVP/CO) x80] Norm: 770-1500 dynes/sec/cm-5
PVR equation and Norm PVR=[(MPAP-PWP/CO) x80] Norm: 20-120 dynes/sec/cm-5
What causes ABP to decrease? Hypovolemia, vasodilation(shock, vagal stimulation), cardiac failure
What causes ABP to increase? Vasoconstriction(sympathetic stimulation, vasopressors), improvement in circulating volume, Increase in Stroke Volume
What is compensatory vasoconstriction? vasoconstriction maintains ABP within acceptable range even though significant decreases in intravascular volume or SV may be present
What may still exist with compensatory vasoconstriciton? organ hypoperfusion
This is an early sign of changes in circulating blood volume? Changes in Pulse pressure
Pulse pressure is directly related to what? acute changes in SV; SV increases=PP increases, SV decreases=PP decreases
Normal PP range 25-80mmHg
Mean PP 40mmHg
low pulse pressures can indicate what 2 things? CHF and shock
What can cause high pulse pressures Stiff arteries, aortic regurgitation
What is the average driving force in the arterial system throughout the cardiac cycle known as? Mean arterial pressure
MAP is used to calculate what? SVR and PVR
Normal MAP is 70-105
MAP below 60 indicates circulation to vital organs may be compromised and poor tissue perfusion
Why does SBP become progressively higher toward the peripheral arteries? bc they are narrower
MAP is less affected by what 2 things ? motion artifact and damping factors
When is MAP not reliable? HR > 120
Systolic measurements by cuff may be __mmHg lower than arterial SBP 20mmHg
Diastolic measurements by cuff may be generally __ than arterial DBP higher
indications for Arterial cannulation hemodynamically unstable pt, pt on vasoactive drips (EPI, dopamine), pt with IAB, Perioperative pt
Contraindications of arterial cannulation hemorrhagic disorders, anticoagulant therapy, thrombolytic agents, Site specific: dialysis shunt, infection, grafts, vascular surgery, negative allens test
This insertion site is the largest vessel, useful in cardiopulmonary arrest femoral
Order of arterial insertion sites radial, brachial, pedal or femoral, axillary
Hazards of arterial cannulation hemorrhage, thrombus, air embloli, systemic infection, site infection, arterial spasm, vascular occlusion
Question Answer
why is invasive hemodynamic monitoring needed? clinical assessment alone may not accurately predict hemodynamics
what must be considered before a catheter is placed in a pt? risk-benefit ratio of invasive monitoring
what is hemodynamic monitoring performed to do? evaluate: intravascular fluid vol, cardiac/vascular function; identify sudden changes in hemodynamics
why is invasive monitoring needed? obtain an accurate evaluation of hemodynamics
what type of pt may a physician place an arterial catheter? significant hemodynamic instability or freq arterial blood draws
what conditions are likely candidates for arterial pressure monitoring? severe hypotension (shock) or HTN; respiratory failure
what pts may benefit from arterial pressure monitoring? pts in need of meds that affect BP (vasodilators/inotropic agents)
how many arterial catheter sizes are in common use and what is selection determined by? two; planned insertion site
where is the smaller catheter ideal for use? where is it not adequate? radial/small arteries; femoral/large arteries
how do arterial catheter walls compare with central venous catheters? thin and stiff
where is the arterial catheter usually placed? radial, ulnar, brachial, axillary, femoral
where is the arterial line most often placed and why? radial; readily accessable/adequate collateral circulation
the radial site is easy to _______ and what does it provide? monitor; stable site for blood withdrawal
what does the femoral artery provide? pressure measurements less affected by peripheral vasoconstriction; leakage of blood occurs
the _________ technique is used for most arterial catheter insertions. “Seldinger”
what should the arterial pressure waveform include? clear upstroke on left, w/ dicrotic notch (aortic valve closure) on downstoke to right
what happens if the dicrotic notch is not present? pressure tracing dampened, inaccurate; numbers are lower that actual pressure
the dicrotic notch disappears in some pts when the systolic pressure drops below __-__ mmHg. 50-60
the left side of the pressure wave may become straight and even pointed on the top when there is an increase in…? when else does this happen? circulating catecholamines that causes an increased inotropic response; stiff aorta
increases in HR and vascular resistance _______ diastolic pressure. increase
what can cause the diastolic pressure to drop? vasodilation that decreases vascular resistance
because approx ___% of coronary artery perfusion occurs during the diastolic phase, coronary arterial perfusion may be compromised if the diastolic pressure falls below ___ mmHg. 70%; 50
what must be considered when respiratory variation in the arterial pressure waveform is seen? cardiac tamponade or other causes of paradoxical pulse
when are increases in arterial pressure during inspiration seen? after heart surgery; pts w/ LV failure with MV and PEEP
what can cause variations in the height and shapes of the waveforms? dysrhythmias and pulsus alternans
what is the normal arterial pressure in the adult? 120/80 mmHg
what values are considered hypertensive? >160/90 mmHg
what values are considered hypotensive? <90/60 mmHg
arterial pressure is only a general sign of _________ status. circulatory
what is pressure the product of? flow and resistance
what is low blood pressure a late sign of? deficits in blood volume or cardiac function
what is earlier evidence of decreased blood volume or CO? cold, clammy extremities (caused by catecholamine-mediated peripheral vasoconstriction)
what are the causes of hypotension? low blood vol (bleeding), cardiac failure/shock (heart attack), vasodilation (sepsis)
during administration of what drugs should diastolic pressure be watched carefully? vasodilators such as sodium nitroprusside
what values of diastolic pressure may result in compromised coronary perfusion? diastolic pressures <50 mmHg; mean pressure <60 mmHg
what are the causes of hypertension? improvement in circulatory vol/function, sympathetic stimulation, vasoconstriction, vasopressors
administration of ________ _____ may or may not increase BP. inotropic agents
what inotropic agent can cause vasodilation? isoproterenol (isuprel)
besides systolic/diastolic pressures, what else does arterial pressure monitoring allow assessment of? pulse and mean arterial pressures
what is pulse pressure? and what is the normal? difference b/t systolic and diastolic pressure; 30-40 mmHg
what is pulse pressure reflection of? SV by the LV and arterial system compliance
what is a decreasing pulse pressure a sign of? low SV
what is an increasing SV in a pt receiving fluid therapy consistent with? improved preload
what is mean arterial pressure? avg of pressures pushing blood through the systemic circulation (most important of arterial pressures)
what is mean arterial pressure an indicator of? tissue perfusion
what is the normal MAP? 80-100 mmHg
what is the MAP calculation? systolic pressure + (diastolic pressure x 2)/3
when is circulation to the vital organs compromised? MAP <60 mmHg
what is elevated MAP associated with? increased risk of stroke and heart failure (need vasodilators or negative inotropics)
what is MAP use to calculate? SVR, LVSW, cardiac work
what is a major compication of direct arterial monitoring? ischemia resulting from embolism, thrombus, or arterial spasm
what is this complication evidenced by? pallor distal to the insertion site; pain and paresthesias
what can ischemia result in? tissue necrosis (if catheter is not repositioned or removed)
what is thrombosis prevented by? irrigation w/ diluted heparanized solution
__________ is possible if the line becomes disconnected or a stop cock is left open. hemorrhage
what else can occur at the insertion side especially if the catheter was placed through a needle? bleeding and hematoma
as with all invasive lines, the presence of an arterial catheter increases the risk of _________. infection
_______ in pts with invasive lines must trigger questions about the necessity of the lines and their role as a cause of the infection process. fever
_______ _______ ________ is the pressure of the blood in the RIGHT atrium or vena cava, where the blood is returned to the heart from the venous system. central venous pressure
what does CVP also represent? RVEDP and preload (filling vol) for RV
when is CVP monitoring indicated? assess circulating blood vol (filling pressures), degree of venous return, assess RV function
what pts need a CVP catheter? pts w/ major surgery or trauma, severe dehydration; pulmonary edema; pts with damage to RV from MI
what are the most common central venous catheters? 7-french, 3-lumen catheters w/ one distal port and two pots 3-4 cm from the distal end of catheter
what does the multiple-lumen catheter allow? infusion of blood samples and medications
what catheters are less commonly associated with infection? those impregnated with antibiotics
what are the common sites for introduction of central venous catheters? subclavian, internal jugular, femoral veins
what is an advantage of the subclavian vein approach? results in stable catheter after placement
what is a disadvantage of the subclavian vein approach? more difficult to find
what approach is easier because there is nearly a straight shot for the guidewire to reach the superior vena cava and less risk for pneumothorax and hematomas are easier to see and control? internal jugular vein approach
what are the disadvantages of the internal jugular vein approach? catheter less stable, subject to kinking, breakage, and accidental removal
what central venous catheters are the easiest to place and have the least risk for complications, but they provide less reliable hemodynamic info b/c the catheter tip is far from RA, pressure waveforms often dampened? femoral central venous catheters
what should be performed after subclavian or internal jugular central venous line insertion? CXR (ensure placement/rule out pneumothorax)
where is the subclavian vein entered? edge of the distal third of the clavicle
where is the internal jugular vein entered? head of the clavicle or a site behind the brachial artery
where is the femoral vein entered? just medial to the femoral artery in the groin
what is the only difference b/t these techniques? the head of the pt’s bed is lowered for subclavian/internal jugular vein insertions
what does doing this cause? increases size of vein, making it easier; decreases risk of air embolism
what do CVP waveforms reflect? what is it equivalent too? pressure changes in the R atrium; PAWP (approximates L atrial pressure)
what do CVP and PAWP waveforms both include? three waves – a, c, v
what does the a wave result from and occur during? atrial contraction; ventricular diastole
when the atrium contracts against a closed valve, as occurs during atrioventricular dissociation or w/ some junctional or ventricular pacemaker rhythms, what occurs? large a waves called cannon waves
what does the downslope of the a wave (x descent) result from? decrease in atrial pressure
when does the c wave occur? AV valve closure; represents movement of AV valve back toward atrium during V contraction
what does the v wave result from? atrial filling while the AV valve is closed during ventricular systole
when does the downslope of the v wave occur? when tricuspid and mitral valves open and the ventricle begins to fill with blood
what is it referred to as when the AV valve does not close all the way and some of the blood is ejected backward into the atrium during systole? tricuspid regurgitation (exaggerated v waves and elevated CVP measurement)
what are the most likely causes of no respiratory artifact seen on the trace and the pt is not holding their breath? kink/air in tube, stopcoack turned in wrong direction, small clot/kink in catheter
what should happen to the waveform if the patient is asked to take a deep breath? fall below baseline as intrathoracic pressure falls w/ inspiration
when does CVP decrease and increase? d: spontaneous inspiration, i: MV
how can a mean venous pressure without resp artifact be obtained if spontaneously breathing? on MV? suspend breathing; disconnect ventilator
what are hte two ways CVP can be obtained? transducer system (mmHg) or a water manometer (cmH2O)
which method is more accurate assessment of mean CVP or right atrial pressure and also allows observation of the CVP waveform? transducer
what are the advantages of the water manometer? inexpensive, does not require electric equipment, easy to use
when is CVP ideally read and why? end of expiration, spontaneous inspiration causes pressure to fall and MV causes it to rise
what does the criteria for interpretation of CVP by water manometer include? 1. X-ray 2. IV fluid 3. ability to easily aspirate blood sample 4. rapidly falling H2O column 5. small oscillations at top of H2O column 6. larger oscillations w/ respiration
what does the comparison of water manometer methods w/ transduccer methods demonstrate? water manometer method usually overestimates transducer-determined mean RA pressure (CVP)
what CVP regulated by? balance b/t ability of heart to pump blood out of RA and V and amount of blood returned to the heart by venous system (venous return)
when the pumping ability of the right heart is increased, CVP ________; when pumping ability decreases, CVP _________. decreases; increases
what are 6 causes of increased CVP? fluid overload, R/L heart failure, pulmonary HTN, tricuspid valve stenosis, pulm embolism, increased venous return
what are 4 causes of decreased CVP? vasodilation, reduced circulating blood vol, leaks in pressure system/air bubbles, spontaneous inspiratino
what does the CVP reflect when a pt is hypovolemic but has pulmonary HTN with decreased RV function? elevated pressure from the loss of ventricular function, does not fall to level that are expected
when is this most commonly seen? cor pulmonale who become dehydrated and hypovolemic
when can CWP be used to estimate LV filling pressures and performance? pts w/ an EF >0.50, no cardiopulmonary disease
what is CVP a reasonable option for the management of? intraoperative fluid levels, postop fluid levels, vol replacement in young pts w/ no hx of heart disease or HTN
who may benefit from monitoring of both the left and right heart pressures? pulmonary HTN disease
what problems can placement of the catheter cause? bleeding, pneumothorax
when is bleeding more likely? when pt is taking heparin or low platelet count; subclavian artery penetrated
when can pneumothorax occur? catheter punctures the pleural lining
what is the most common complication associated with use of the catheter over time? what is a less common complication? infection; thrombus around the catheter
what can accidental opening of the central venous line stopcock allow and result in? air to enter vein, air embolus
what does the PAC allow the assessment of? filling pressures of the left side of the heart
what does the PAC allow the assessment of? LV filling pressures (via PADP/PCWP); PVR (via PA mean systolic pressures/PCWPs), SVR (via systemic arterial mean pressure/PAEDP); CO; arteriovenous O2 difference, mixed venous O2 levels
what is the only place w/ swan-ganz catheter to get the most accurate assessment of oxygenation? arteriovenous O2 difference; mixed venous O2 levels
PAC is more a risk than CVP because why? need for catheter to pass through the R side of the heart and into PA (may cause dysrhythmias or other complications)
what are common factors to consider when placing a PAC? experience of physician, availability of proper equipment/personnel, diagnosis, cardiac/pulm hx
what are the common situations in which PAC monitoring is considered? severe cardiogenic pulm edema; ARDS (hemodynamically unstable); major thoracic surgery; cardiogenic/septic shock pts
what are PACs also called? swan-ganz catheters
what is the balloon at the tip of the catheter used for? float the catheter into position (into the R side of heart and into PA) and obtain wedge pressure measurements
what is another name for the catheter? balloon-tipped, flow-directed catheter
what are the catheters available for children? what is most commonly used for adults? 4- and 5-french catheters w/ 2 or 3 lumens; 7-french w/ 3-lumens (air channel for balloon)
the distal lumen terminates at the tip of the catheter, what is it used for? measuring PA pressures, aspirating mized venous blood samples, injecting meds
what might the balloon help prevent? PVCs
what is the proximal port used for? aspirating blood samples, measuring CVP, injecting drugs, injecting thermal bolus used for thermodilution CO measurements
some catheters have 2 lumens ending in the RA, what are these used for? 1. routine infusion of drugs/continuous pressure monitoring 2. infusion of thermodilution materials/periodic injections
what are the most popular sites for PAC used in ICU? subclavian/internal jugular veins
the PAC can be positioned used __________, but is more often…? fluoroscopy; floated into place using pressure waveforms to indicate position
what is the insertion technique for PAC? 1. balloon inflated at superior vena cava or RA 2. catheter floats through R side, into PA 3. wedges into place, balloon deflated
what are seen as catheter passes through the RA, RV, PA, and into wedge position? distinctive waveforms
what is the normal pressure for RA? RV? PA? PCWP? RA: 2-6 mmHg; RV: 20-30/0-5 mmHg; PA: 20-30/6-15 mmHg (mean pressures: 10-20 mmHg); PCWP: 4-12 mmHg
in most adults, catheters inserted through the subclavian or jugular vein are positioned in the PA when approximately ___cm of catheter is inserted into the pt. 50
what is entry into the PA recognized by? change in the diastolic portion of the wavefomr
PA maintains pressure throughout the cardiac cycle so that the basline pressure usually increases to ___-___ mmHg over RV diastolic pressures. 8-15
PA _______ pressure is the highest pressure created when the RV ejects blood through the pulmonary valve and into the PA and lungs. systolic
what is normal PA systolic pressure? 20-30 mmHg
when does PA pressure decrease? increase? d: vol of blood from RV decreases, decreased PVR; i: pulm blood flow increases, PVR increases
what can resistance to pulmonary flow (increased PVR) be caused by? constriction, obstruction, or compression of the pulmonary vasculature or backpressure from the L heart
what conditions cause increased PVR? pulmonary emboli; acute/chronic lung disease; cardiac tamponade; L heart failure
what is the normal PA diastolic pressure? what does it reflect? 8-15 mmHg; pulm venous, LA, LVEDP
what is a PADP-PCWP gradient >5 mmHg a characteristic of? ARDS, sepsis, excessive PEEP, anything that increases PVR
what is normal PCWP? what is PCWP also called? and what is it used to monitor? 4-12 mmHg; pulmonary artery occlusion pressure; LV filling during diastole
what will hx of MI cause? stiff LV and lead to higher pressures
in the normal heart, optimal SV is obtained with a PCWP of ___-___ mmHg. in the pt with LV hypertrophy, a PCWP of ___ mmHg or higher may be needed to optimize SV. 10-12; 18
when does PCWP increase? LV failure (common cause); mitral valve regurgitation; pulm venous circulation obstructed w/ tumor
what is the most common cause of a decreased PCWP? what also decreases PCWP? hypovolemia; severe dehydration
what is zone I? no blood flow b/c alveolar pressure exceeds both pulmonary venous pressure and MAP
what is zone II? alveolar pressure exceeds venous pressure but is less than MAP
what is zone III? area of lung where both PA and venous pressures exceed alveolar pressure
what does the catheter in zone II measure? PAP w/ balloon deflated but reflects alveolar pressure when it is wedged
zone II conditions dominate in ________ pts. supine
to measure L heart pressure accurately, the catheter tip must be in zone ___. III
when can zone III areas convert to zone I or II? when intravascular vol decreases or alveolar pressure increases
alterations in ventilatory patterns cause fluctuations in __________ _______. intrapleural pressure
wedge pressure readings normally are about __ mmHg lower than pulmonary diastolic pressure readings b/c blood flows from high pressure to low pressure. 2
what is transmural pressure? the net distending pressure within the ventricle
how is the transmural pressure calculated? subtracting the pressure around the heart from the measure filling pressure of the heart
what is wedge pressure used to estimate? LV filling pressure inside the heart
what is used to approximate the pressure pushing on the heart from the outside? intrapleural or esophageal pressure
what are the 2 ways PEEP is subtracted from wedge pressures? 1. compliant lungs: 1/2 of PEEP from PCWP 2. noncompliant lungs: 1/4 of PEEP from PCWP
what complications of PA catherization is possible during cannulation of a central vein? pneumothorax; hydrothorax; hemothorax; air embolism; damage to the vein, arteries, nerves
what can movement of the catheter inside the heart trigger? bundle-branch block; supraventricular or ventricular dysrhythmia
constant movement of the catheter with heartbeat, breathing, and pt movement can result in ________ _________. catheter migration
_________ ___________ and even PA rupture can result from overfilling the balloon while obtaining a wedge pressure, as well as from catheter migration. pulmonary infarction
what should be immediately available at both insertion adn removal? lidocaine and emergency resuscitation equipment
what should be optimized to decrease the risk of dysrhythmia? blood gases and serum electrolytes
what is not normal and is an indication for obtaining a CXR to assess the cause? catheter resistance
Question Answer
The factors that control blood pressure The Heart, Blood/Fluid & Vessels
The amount of blood pumped out of the left ventricle in a minute Cardiac Output
Cardiac Output normal range 4-8 LPM
Formula for Cardiac Output CO= HR X SV (Must be in liters)
Volume or amount of blood ejected with each beat Stroke Volume
Stroke Volume Normal range 60-130 mL/Beat
Formula for stroke volume SV= CO / HR (answer in mL)
Amount ejected from heart depends on 3 things Preload, Afterload & Contractility
Amount of stretch on Ventricle at filling before contraction (End Diastole) Preload
Resistance to ventricular emptying Afterload
RV pumps against PVR (Pulmonary vascular resistance)
LV pumps against SVR (Systemic Vascular Resistance)
Relates to the amount of stretching of the heart. Starlings Law
What happens to contraction of the heart with increased stretching stronger contraction which will increase cardiac output.
Volume of blood returning to the right atrium Venous Return
Used to describe flow output taking into consideration body size. Cardiac Index
Formula for Cardiac Index QT/BSA =CI
Cardiac Index Normal range 2.5-4.0 L/min/m2
BSA Formula (4 X KG) +7 / Kg +90
Numbers that represent the afterload for each of the ventricles PVR & SVR
PVR Formula (MPAP-PCWP)/CO X 80
This happens when BP is too low tissues wont recieve O2
This happens when BP is too high Strain the heart and will eventually cause failure
The pump that creates BP Heart
Question Answer
What 2 types of catheters are inserted into central veins for direct pressure monitoring of central circulation? Central venous catheter(CVP), and Pulmonary artery cath (BTFDC)
What is BTFDC? Balloon tipped flow directed catheter
Central venous catheters have how many lumens? they can have single, double or triple lumens
Central venous catheters sit at what junction in the body? at the SVC and RA junction
What are the indications for central venous caths? RAP monitoring, drug/fluid/nutrition/electrolyte infusion, blood and blood product admin, phlebotomy access, and lack of accessible veins
What can cause a lack of accessible veins? trauma, sclerosis, thrombosis, or inflamed peripheral veins
The site of insertion for a CVC is dependent upon what? physician preference, regional trauma, or burns
Specific circumstances of insertion sites are? anticoagulation, coagulation abnormalities, presence of lung hyperinflation secondary to airway obstruction
What are the 3 main insertion sites for a CVC? internal jugular, subclavian, and femoral veins
What are the advantages of inserting a CVC into the subclavian vein? easy to access, maintain sterility and intact dressing, unrestricted movement and less likely to develop thrombus d/t rapid venous blood flow
What are the disadvantages of subclavian central venous access? Risks of air emboli, pneumothorax, hemothorax, nerve injury, tracheal puncture, ETT cuff puncture and puncture or laceration of subclavian artery
Advantages of Internal jugular central venous access short, direct pathway; reliable site, unlikely to be displaced, less likely to develop thrombus d/t rapid blood flow, and lower risk of art puncture and pneumo than subclavian site
Disadvantages of Internal jugular central venous access risk of air emboli, puncture of common carotid artery, pneumothorax (more common in left), and thoracic duct injury (left IJ only)
Advantages of femoral vein central venous access readily accessible, familiar site (used for central access longer than any other site), greater ease of insertion, no risk of pneumo and minimal risk of air emboli
Disadvantages of femoral central venous access inadvertent cannulation of smaller veins, increased risk of infection, difficult to maintain intact dressing, difficult to locate in obese patients, high risk of thrombus and PE, and difficulty immobilizing
What is a PICC line? peripherally inserted central catheter used for long periods of time
What are PICC lines used for? ABT regimen, chemotherapy
5 Complications of PICC lines catheter occlusion, phlebitis, infection, hemorrhage, and thrombus
What is the main reason for a Pulmonary Artery Cath? measure PA pressure
What is a Swan-Ganz or BTFDC? multi lumen catheter inserted through central vein and passively directed into a brach of the PA
The PAC is __-__cm in length 60-110cm
The PAC is marked in __cm increments 10cm
A PAC, Swan-Ganz or BTFDC usually has how many lumens/ports? 5
What are the 5 ports of the PAC? Proximal infusion port, Proximal injectate port, Distal port, Balloon inflation port and Thermistor connector
The proximal injectate and infusion ports open to a lumen that terminates how far from the tip? 30cm
The opening of the lumen for the injectate and infusion ports lies where within the body? RA when the tip is in the PA
What pressure can you measure through the proximal ports? RAP(CVP)
What can you administer through the proximal ports of the PAC? medications, fluid, electrolytes, blood and blood products
What can you take samples of therough the proximal ports of a PAC? RA blood
This opening of the proximal ports inside the RA receive the injectable solution for what measurement? CO
What does the distal port of the PAC open to? a lumen that runs the length of the catheter abd ebds at the cath tip
What pressures can you measure at the opening of the distal port within the body? PAP and PCWP (upon inflation of the balloon)
The distal port samples what type of blood? mixed venous
What cant you use the distal port of a PAC for and why? admin of meds d/t PA segment rupture, vascular and tissue reaction and damage
What is the thermistor? temp sensitive wire that terminates 4-6cm from tip of PAC and measures core temp
What does the thermistor allow for determination of and how? CO using thermodilution technique
Describe thermodilution technique Inject 10cc of solution less than body temp into proximal port then measure the magnitude of temp change over time to predict CO
An average of __ injections that produce a CO of no more than __% difference 3 injections; < 10% diff
When do you Inflate the balloon on a Pulm Artery Cath? for insertion from RA-PA and to measure the PCWP
What is the safety feature on the balloon inflation port? special syringe to only allow 1.5cc air and port lock to prevent inadvertent inflation
Overinflation of the ballon on a PAC can cause what 3 things? PA segment rupture, balloon herniation over cath tip resulting in erroneous pressure reading, and balloon rupture
What does it indicate if you have a PCWP wave w/o inflation of the balloon and how do you fix it cath too far into PA segment, withdraw until PAP appears
What does it mean if you don’t get a PCWP with inflation and how do you fix it cath not in far enough or balloon not intact, floar cath or advance in unless rupture suspected
How does CCO work thermal filament warms surrounding blood causing a washout curve, the area under curve is proportional to CO
How does a PAC help assess pulmonary status It allows you to see changes in PASP/PADP to assess for COPD, ARDS, Pulm Htn, Pulm emboli, Pulm edema
PAC indications for use Peripoperative monitor, fluid and drug admin, lack of peripheral veins, emergency placement of transvenous pacemaker
Large veins used for PAC allow what to occur that doesnt in peripheral veins dilution of caustic or hypertonic soultions (KCL, Levophend, hyperalimentation, Chemo)
What type of heart block called for emergency placement of transvenous pacemaker thru PAC third degree
Contraindications for PAC use severe coagulation defects, Prosthetic right heart valve, pacemaker, severe peripheral vascular disease, high pneumo risk, and pulm htn
What causes a high rick of pneumothorax to happen on PAC insertion increased PEEP, emphysema, air-trapping and subclavian insertion
What happens during Pulmonary Htn that makes it a contraindicaiton for PAC PA is distended causing an increased risk of rupture
What port is located at the 30cm mark and what does it do proximal port in RA, monitors fluid volume status, CVP/RAP/ Preload of RV, estimates venous return, intravascular volume
What 5 problems can we monitor for/ or progression of with the proximal port trauma, burns, hypovolemia, sepsis, renal failure
CVP estimates ______ and cannot be used as an estimate in what disorders RVEDP; tricuspid valve disorders
Formula for PVR and normals PVR=(MPAP-PCWP)/CO x 80 Norms: 20-120 dynes/sec/cm-5
Formula for SVR and Normal range SVP=(MAP-CVP)/CO x80 Norm:770-1500 dynes/sec/cm-5
PVR is an indications of what RV afterload and myocardial work
CVP=RVEDP= Formula RVEDP= (LVEDP-2mmHg)/2
LEVDP formula (RVEDPx2)+2
How do you assess and treat for hemorrhage from PAC oozing at site, bruising, swelling treat with pressure and decrease number of attempts
What is the most common bacteria for nosocomial infection of PAC Staph aureus
How do you assess and treat for nosocomial infection of PAC fever, redness, swelling, increased WBC, treat with proper sterile/aseptic technique, keep dressing and line dry, ABT and culture tip
How do you assess for and treat a pneumothorax d/t PAC dyspnea, elevated HR and RR, decreased BP and SpO2, increased PIP, decreased Vt and BS, treat with chest tube
How can a PAC cause arrhythmia and how do you assess and treat irritation of endocardium d/t migration into RV or during insertion. assess:presusre tracing, ecg, loc. Treat:reposition PAC, and antiarrythmics
What can cause a thromboembolism to form?# kinks in PAC tubing and decreased pressuree in bag
Assess and treat for thromboembolism chest pain, dyspnea, tachy, dampened waveform, poor med infusion, inability to aspirate from port. Trea:heparin therapy, removal of cath
How can you prevent a thromboembolism if port not used for continuous med infusion aspirate and flush port QS
What is one way to decreased risk of air embolism during PAC insertions place pt in trendelenburg
AIr embolism treatment place pt left side down to prevent air from moving into pulm circulation, aspirate air from RA into cath, PPV 100% hyperbaric to enhance air reabsorption
How do you assess for balloon rupture absence of normal resistance felt during inflation, blood in balloon lumer, failure to wedge, syringe does not fill with air when released
Tx for balloon rupture label cath port, notify MD and use PADP to estimate PCWP
Where is knotting or looping most likely to occur RV
What causes knotting or looping of PAC repeated advances and withdraws, dilated cardiac chambers, excessively long cath
Assess for knotting or looping ventricular arrythmias, dampened waveform, PA distal reads CVP wave, difficulty aspirating or flushing, CXR
Treatment for knotting or looping PAC undo under fluoroscopy, surgical removal
What causes Rupture of PA segment advancing PAC with balloon deflaated, rapid or forceful ballon inflation, spontaneous migration of cath
How do you assess for and treat PA segment rupture hemoptysis(blood in ETT), treat by pulling cath back, control airway, O2, place effected side down to prevent blood from entering other lung, PEEP to compress hemorrhage and surgery
What can cause pulmonary infarct or ischemic injury in relation to PAC PA occlusion by clot or persistently wedged cath
What is the RT job when assisting physician with insertion of PAC set up bag, zero, check ports, inflate balloon, deflate balloon
Describe the Seldinger technique constant, negative pressure on syringe so that a flash of blood will be observed upon vein entry.
After entrance into the vein and intravenous position of needle confirmed what happens a guide wire is passed thru needle and threaded to a distance of no more than 20cm
MPAP formula and normal value MPAP=[(PADPx2)+PASP]/3 norm:10-15mmHg
Cardiac index formula and norm CI=(CO/BSA) Norm: 2.5-4.2 LPM/m2
4 things to remember when measuring hemodynamic pressures with PAC HOB no greater than 30 degrees, remain consistent, level and zero QS, and measure at end-exhalation
CVP measureswhat 3 things intravascular volume, venous return and RV preload
CVP reflects ____ in the absence of ___ ____ disorders RVEDP; Tricuspid valve disorders
PAC waveform: This wave indicates late ventricular diastole, RA contraction; atrial kick; and occurs after P wave A
PAC waveform: This indicates waveform descent; atrial relaxation X wave
__ wave= small crest that distorts descent; upward bulging of the AV valves during early systole C wave
Whay is the C wave not usually visibile? due to damping
__wave= atrila filling during ventricular systole; occurs after QRS V wave
__ wave= atrium emptying; filling ventricle with pressure gradient Y wave
What causes increased CVP? fluid overload, RV failure, Right sided valve disorders, cardiac tamponade/ effusion, and Obstructive RA tumor
What causes decreased CVP? hypovolemia and shock
What test can you perform to determine true volume status in response to fluid therapy? fluid challenge
Fluid challege = ___-___ml bolus 300-500
CVP response to fluid challene in normovolemic patient is CVP increased 2-4mmHg and returns to baseline within 10-15 mins
CVP response to fluid challenge in hypervolemic patient cvp rapidly increases but does not return to baseline within 10 mins
CVP response to fluid challene in hypovolemic patient CVP fails to increase
This pressure is normally only measured on insertion of PAC RVP
What does the RVP waveform look like? no dicrotic notch, lg ventricular wave, sharply contrasted to small RA waveform
What is the anacrotic rise early systol, inotropic component
What is the anacrotic nothc? volume displacement curve= indicator of SV; mid systole
Waht is the sloping descent? late systole, diastole
What is the dicrotic nothc? end systole, begin diastol, closure of aortic valve
What causes increased PAP? lung dysfunction, LH failure, hypervolemia
PCWP is an indication of what? LV preload/ LVEDP
PCWP>18= pulmonary vascular congestion
PCWP>30= pulmonary edema
When can PADP be used as an estimate of PCWP? in the absence of pulmonary disease and with a normal PVR
When is the balloon inflated to measure PCWP? exhalation
Wha causes increased PCWP? LH failure, intravascular volume overlaod, cardiac tamponade/effusion, Obstructive LA tumor
Anytime PADP is higher than PCWP it indicates what? increased PVR
High PCWP with normal PADP= LV problem not yet affecting lungs
High PCWP and PADP= LV causing lung dysfunction
High PADP with normal PCPW= lung dysfunction
A wide PADP, PCWP gradient = lung dysfunction and increased SVR
Where do you get mixed venous blood sample? Distal port of PAC
Normal Mixed venous Blood gas is 7.3-7.4/41-50/40/65-75%what
Question Answer
3 ways to maximize ventricular performance? Alter pre load, after load and contractility
How does increasing pre load volume affect PVR/SVR ? Decreases PVR/SVR AND Heart rate
How do we decreases pre load volume? Use of diuretics OR reduction of intravascular volume
What are two methods of altering ventricular afterload? Vasodilator therapy & Vasopressor therapy
When would we use vasodilator therapy? When SVR/PVR is HIGH
What is the result of vasodilator therapy? Decreased SVR/PVR, decreased afterload AND decreased preload !
The result of stimulation of vasopressors on alpha receptors is: peripheral vasoconstriction
When do we use vasopressor therapy? When SVR/PVR is LOW
What is the result of vasopressor therapy? INCREASED afterload, Increased SVR/PVR and increased preload
What are two ways we can alter Contractility? With a positive inotrope or a negative inotrope
A Positive Inotrope ___________ the force of myocardial contractility in order to ___________ cardiac output increases, increase (improve)
4 examples of Positive inotrope Dopamine, Dobutamine, Epinephrine & milrinone
What does a negative inotrope do? Decreases force of myocardial contractility and O2 requirements of the heart
Examples of negative inotropes beta blockers & calcium channel blockers
Factors(conditions) which can cause increased PVR: hypoxemia, acidosis, PPV/PEEP & vasoconstrictors
Factors which can decrease PVR: Oxygen, Nitrogen, Alkalosis & vasodilators
Factors (conditions) which INCREASE SVR? hypovolemia (aka compensatory vasoconstriction), certain shocks & vasoconstrictive drugs
Factors which DECREASE SVR? Vasodilators, morphine, certain shocks
Normal values for CVP? 2 – 6 mmHg
Normal values for RAP? 2 – 6 mmHg
Normal values for RVP? 20-30 / 0-5 mmHg
Normal values for PAP? 15-25 / 8-15
Normal values for MPAP? 10-20 mmHg
Normal values for PCWP? 5-12 mmHg
Normal values for PP? 30-50 mmHg
Normal values for MAP? 85-115 mmHg
Normal values for PVR? 155 – 255 dynes*sec/cm5
Normal values for SVR? 950 – 1300 dynes*sec/cm5
Normal EF 50 – 60%
Normal EDV? 120-180 mL
How do we increase preload volume? Infusion of I.V. Fluids
What are the indications for PAC? severe cardiogenic pulm. edema, non cardiogenic pulmo. edema (ARDS), major thoracic surgery (CABG) & Septic or cardiogenic shock
Complications of a PAC: 1. Same as CVP (pain, bleeding, infection etc.) 2.Irritation to heart (causing dysrhythmia) 3.Perforation of heart or pulm. artery 4.Pulmonary rupture from overfilling balloon
What do PAC’s measure? CVP, PAP, PAWP/PCWP/PAOP, PVR, SVR & C.O.
What are the uses of a PAC? Measure cardiac output(thermodilution), route for mixed venous sampling, administration of drugs and pacing
How many lumens do PAC catheters have? 4-6
Which part of a PAC measures cardiac output The Thermistor Lumen
Which part of the PAC rests in the right atrium (for CVP measurement)? Proximal Lumen
Where does the distal lumen rest? In the pulmonary artery
Which lumen measures the PAP, PCWP and obtains mixed venous samples? Why this lumen? The distal lumen, because it is in the pulmonary artery
When inserting a PAC, when do we inflate the balloon? As it enters the right atrium
When inserting a PAC, how do we know we’re in the right atrium? Pressure should read 2-6 mmHg ( CVP)
When will the CVP wave form appear, during a PAC insertion? Once the tip reaches the vena cava
How do we know when the catheter is in the right ventricle? There will be a huge pressure change/ increased wave form – and the downstroke will still come back down to zero
How do we know when we are in the pulmonary artery w/ a PAC ? Pressures increase by 6-15 mmHg and the down stoke DOES NOT come back down to zero
Once in the pulmonary artery, what does the dicrotic notch on the wave form represent? Pulmonic valve closure
When in wedge position, what pressure is being measured? The back pressure from the left ATRIUM
It takes ___________ cc’s to wedge a balloon. 0.8 – 1.5 cc’s
When do PAP’s increasE? When PVR increases and when pulmonary blood flow increases
What pressures does PA diastolic reflect? Left atrial pressure, pulmonary venous and left VEDP
What pressure measures left ventricular filling? (Preload) PCWP
Describe optimal PCWP The pressure at which any increase shows little or no improvement in C.O. or stroke volume
Under what conditions does the PCWP reflect the LEFT ATRIAL pressure? blood flow must be uninterupted b/w the catheter tip and the let heart. this ONLY OCCURS IN ZONE 3
Which part of the breathing cycle should we measure PCWP? end expiration
What is a complication of PCWP measurements during PPV? The PCWP can be OVER ESTIMATED, b/c of transmission of pos. press. to the catheter
PCWP should be measured when pleural pressure is ___________ zero/close to zero
How does negative pressure affect the heart? It INCREASES venous return AND preload !
What can cause increased PCWP? Left ventricular failure, hypervolemia, Mitral valve stenosis, and technical causes
What would be seen on an x ray w/ a PCWP > 18 mmHg? onset of pulmonary vascular congestion
What would be seen on an x ray w/ a PCWP > 25 mmHg? Obvious pulmonary edema
What can causes decreased PCWP? Hypovolemia (blood loss) or shock !
What 3 things do CVP and PCWP BOTH reflect? Vascular volume, vascular volume to venous tone relationship, & ability of ventricles to pump blood.
What is normal JVD? < 3 cm above sternal angle
When do we use a CVP? To assess circulating blood volume & assess right Ventricular function
Possible routes of access for a CVP? Jugular vein or subclavian vein, Femoral is rare!
Which CVP insertion site has a more serious risk for a pneumo? Subclavian
Risks and Complications of a CVP? Infection, bleeding, pain, air embolism, thrombus & pneumo
What does the a wave represent on a CVP and atrial waveform? Atrial contraction ( and it follows the P wave)
What does the x descent represent on a CVP and atrial waveform? Fall in right atrial pressure as the atria relax and the ventricles fill
What does the c wave represent on a CVP and atrial waveform? Closure of the AV valve (ventricular systole)
What does the v wave represent on a CVP and atrial waveform? The filling of the atrium DURING ventricular systole ( AV valves are closed)
What does the down slope of the v wave represent on a CVP and atrial waveform? Fall in atrial pressure when AV valve opens and fills the ventricle!