Question Answer
Characteristics of CF? Chronic obstruction and infection of airways Exocrine pancreatic insufficiency (maldigestion and small bowel obstruction) elevated sweat chloride concentrations
Diagnosis of CF Sweat chloride, CFTR gene analysis, nasal electrical potential difference, newborn screening
Tx of disease? the medications usually were given? SABA, Hypertonic saline (SABA can be mixed together with hypertonic) Vest/flutter/etc, Pulmozyme (not to be mixed) TOBI (always given last)
Physiological objectives for neo/ped MV? decrease VILI, decrease WOB, optimize lung volume, improve oxygenation and manipulate alveolar ventilation
Importance of MAP Average pressure exerted on airway and lungs from the beginning of inspiration until the beginning of next inspiration, an important tool to monitor babies oxygenation, babies are very much affected by increases with MAP ( increased MAP can lead to hemorrhaging)
definition of opening pressure the lower inflection point, to open an alveolus a certain amount of pressure must be applied to alveoli
definition of driving pressure created b the ventilator, difference b/w the PEEP and PIP, basically the delta P responsible for Vt, important for dynamic compliance
Normals for Compliance for a newborn about 2.5 – 5 ml/cmH2o
Normals for resistance about 20 -30 cmH2o/L/sec in a spontaneously breathing neonate, basically driving pressure needed to move gases through aw at a constant flow rate
Clinical application of Resistance the RADIUS of the aw is the most powerful influence on airway resistance, uncuffed tubes in neo/peds means always a leak, always a little loss in volume
Factors that increase airway resistance? Bronchospasm, airway secretions, edema of aw walls, inflammation, ETT or trach tubes
Hinski “reasons” for MV (VOPS) Ventilation, Oxygenation, Protection, Secretions
Partial Ventilatory Support modes? CPAP, PSV, SIMV
CPAP for neonates/peds methods of application? neonates: nasal pharyngeal or nasal prongs Pediatrics: nasal or full face mask
Indication for CPAP for neonates RR greater than 30% of normal, paradoxical chest wall movement, grunting, nasal flaring and cyanosis, CO2 less than 60 and PH greater than 7.25
Contraindications for neonates of CPAP prolonged apnea, untxd pneumo, hemodynamically unstable, unilateral pulmonary problem, mouth/face abnormalities or post surgery
Hazards of CPAP make PPHN worse, Increased ICP, decreased CO, may be ineffective if neonate weighs less than 1,000-1,200 grams
CPAP settings for infants? “Perfect World” 4-6 cmH2o starting point, flow rate of 8LPM (5cmcpap), higher Fio2 initially (wean down ASAP) increased levels by increments of 1 or2 cm, levels of 8-9 begin to show need for MV and level of 12cmH2o is max pressure attainalbe
CPAP weaning? Pt stable, no incidents of apnea, acceptable ABGs and CXR, decrease Fio2 1% at a time (until 0.4 maybe 0.6) then pressure incrememnts of 1-2 cm H20 until 2-3 cmH2o are reached
Si PaP? “sigh” positive aw pressure, allows infant to breath spontaneously at two seperate CPAP levels
Most useful blade type for intubation of neo/peds? Miller blade: of larger tongue and high epiglottis make straight blade most useful
Suctioning parameters suction level for neonates: -60 t0 -80 larger infants and children : -80 to -100 1 minute of preoxygenation required Peds: 100% o2 Neonates: increase fio2 by 10-15%
Most commonly used mode for peds and infants? infants: PCV-SIMV w/PS Peds: VCV-SIMV or PCV-SIMV both w/ PS
Targeted tidal volumes for infants and children? Infant: 5-7 ml/kg children: 6-8 ml/kg
freq and i times? RR set: 20, actual : 40-60 bpm passsive hyercapnia (45-55 mmhg Co2) Insp times: infants: >0.3 sec older children: up to 1 second
Parameters for neonates with normal lungs? Vt:6-7ml/kg PIP:10-20 cm Frq:10-20 itime: >0.3 sec etime: >0.5 sec PEEP: none unless 2-4 cm Insp Flow:5-8 L/min Fio2:0.4 Flow HAS to be 2X minute ventilation!
Parameters for neonates with LOW COMPLIANCE? Vt:5-7 ml/kg PIP:25-30 cm Freq:30-60 bpm I:E: 1:1 or 1:2 PEEP: 2-4 cm or up to 8-10 cm Insp. flow: 5-8 L/min Fio2: 0.4 (may need to be increased)
HFOV freq and settings? freq: 3-15 Hz, MAP up to 20, power set enought to get a “wiggle”, power 2-7 amps, increased power=increased vt
Inhaled Nitric Oxide? selective pulmonary vasodilator, initial dose of 20 ppm, more than 20 does nothing but increase risk of methohemoglobin, decreased SLOWLY bc of High incidence of rebound pulmonary hypertension
O. I. (oxygen Index) values and formula? if OI is >25, indication for INO MAPxFio2% /PaO2
What is ECMO? prolonged but temporary heart and lung support, used for pts with severe, REVERSIBLE resp/cardiac failure
VV ECMO? Veno-Venous ECMO, pulmonary bypass ONLY, only 1 surgical site(jugular), blood drained and goes back to RA, VVECMO requires good cardiac function, Avoids cannulation of carotid artery Disadvantages: doesn’t provide direct circulatory support/systemic 02
VA ECMO? Veno-arterial ECMO, heart and lungs bypassed, 2 surgical sites (RA and R carotid artery) provides lung and cardiac support, carotid artery doesn’t ever heal or work again! Disadvantages: ABG interp, two vessels used
Selection criteria for ECMO? >34 wks gestational age >1.8 Kg REVERSIBLE disease MV for less than 14 days staticus asthmaticus Failure of max medical management (nothings worked)
Excluded from ECMO a lot of neurological problems major IC hemorrage lethal malformation severe neuro injury uncontrollable coagulopathy poor prognosis
clincial indications for ECMO OI >40 on 2 or more ABG Pao2 <40 for 4hrs on 100%fio2 can’t fix metabolic acidosis pulmonary or cardiac failure, progressive inability to come off cardiopulmonary bypass
ECMO complications Hemorrhage, CNS damage, SZ, edema, cardiac dysrhythmia, renal failure, hyperbilirubemia, sepsis
Pediatric ECMO Managament: Pulmonary? goals: decrease further lung damage, oxygen toxicity, get “lung rest”. Peak Press: limited to 30 cm, Vt 4-6 ml/kg, RR 5-10 bpm, PEEP 12-15, goal Fio2 0.21, CO2 55-65, Spo2 >88%, 3-5 days min for ARDS, NO bagging!
Weaning off ECMO? increasing pts sats, decrease ECMO flow, adequate ABG, Trial off(clamp it, see if baby circulates their own blood), improved BP, perfusion, weaning pressor support, serial ECHOS show improving function
Question Answer
Describe dynamic compliance? the amount of force needed to overcome airway resistance and inflate the lung w/ a volume. (= Vt/PIP-PEEP)
Describe static compliance? inspiratory hold of air w/ a Pplat giving the C of the lungs. (= Vt/Pplat-PEEP)
How will Cstat and Cdyn change under ↑ Raw and stiffness? They will become less compliant
What changes in pt’s status can affect Cstat and Cdyn? Cstat will decrease w/ resistance or ↑ w/ air-trapping; Cdyn will decrease or become less C w/ an obstruction
Define the term “cycle” end of inhalation (i.e. machine stops at end of inhalation)
List the various factors used to trigger ventilator breaths. Pressure and Flow (pt.), Timed (vent.), Manuel (operator)
Describe mean airway pressure, the pressure maintained in the airways in an entire respiratory cycle. ↑in Paw then an ↑ in PaO2
What ventilator parameters (i.e. PEEP, Ti) that affects Paw. Can be increased w/ PIP, PEEP***, I-Time.
What is the advantage of SIMV vs. IMV? SIMV prevents breath stacking, IMV will give a pt a breath no matter where they are in a spontaneous breath.
What blood gas value is the primary indicator of adequate ventilation? PaCO2
Describe the possible negative impacts of PEEP therapy. barotraumas, ↓ venous return, Qt and renal blood flow, ↑ WOB, PVR, ICP, deadspace, mean airway pressure.
Describe the negative physiological effects of positive pressure vent. barotraumas*, ↓ venous return, Qt*, renal blood flow, urine output, and gastrointestinal function (due to ↓ blood flow), also an ↑ in ICP, PVR, deadspace and mean airway pressure.
What will be the result of an ↑ Raw or a ↓ in compliance on a volume cycled ventilator? Volume stays and pressure changes.
What will be the result of an ↑ Raw or a ↓ in compliance on a pressure, time cycled ventilator? Pressure, time stays the same as volume ↓’s. Less VE then pt could become hypercapnic
HME % humidity? 70%
Heated Wick % humidity? 100%
High Pressure Alarm Setting? 10 above pt’s set PIP
High rate alarm setting? 35
Low Volume alarm setting? (on assist control and SIMV) 10-15 below set Vt
Low minute ventilation alarm setting? 4
Apnea alarm setting? < 20 sec
I:E alarm setting? I is > E (check peak flow)
What are the various ways you can adjust I:E on a vol-cycled vent? flow* or I-Time* or Vt or even RR (changes TCT)
Highest PIP on a volume ventilator that can occur before possible damage? 30
Maximum setting that should be selected for the high respiratory rate alarm? 30
What FIO2 limit is considered dangerous in regards to possible O2 toxicity? 0.50 %
What settings on a ventilator are used to ↑ or ↓ the PaO2? FIO2, PEEP, I-Time
Describe how PEEP ↑ blood oxygenation. alveoli recruitment by allowing positive pressure at the end of expiration before inhalation restoring a person’s FRC.
Describe how ↑ the TI can improve blood oxygenation. this allows for a longer inhalation time for longer contact time for diffusion to take place.
Calculate the corrected Vt for the following pt: PIP = 50, Cmech = 2.5 ml/cmH20, delivered Vt = 900 ml. 1. Ct=Vol/P 2. V-lost= Ct x pt’s Pip 3. Corrected Vt= Vt – V-lost (775)
What is the appropriate action for any ventilator problem that is not immediately identified and corrected? remove from ventilator and begin bagging the pt.
What ventilator changes could be made to correct a respiratory acidosis? Increase Vt or RR (Adjust Vt first, but if Vt is ideal then go w/ RR)
What ventilator changes could be made to correct a respiratory alkalosis? decrease Vt or RR
What 3 changes could be made to correct a low PaO2? Increase concentration (FIO2), Increase lung diffusion area (inspiratory time or PEEP)
What 2 changes could be made to correct a high PaO2? ↓ FIO2 and/or I-Time
What is the goal for the PaCO2 and pH when mechanically ventilating a COPDer w/ chronic hypercapnea? get them to their baseline (Pa CO2 are usually acidic and ph as well)
Identify the normal Vt ranges. 6-10 ml/kg
What factors are to be optimized before considering a pt. for weaning off a vent? Is the problem that caused the respiratory failure resolved (Primary)? Blood gases stable? (PaCO2 baseline,PaO2 adequate on .40 or less), Cardiac condition stable? Is the patient afibrile? Respiratory mechanics stable? Proper nutrition and sleep?
Describe the criteria (tests) that are done daily w/ pt.’s undergoing weaning from a vent. (+ values) RSBI 105(predicts spontaneous breathing), SBT, MEP + 40,MIP = >-20 to -30 cmH2O, VE = < 10 L, VC = >10 – 15 ml/Kg, Spontaneous tidal volume = > 300 ml, Respiratory rate = < 25/min
Describe how a pt is weaned using SBT trials. Spontaneous breathing trial, off vent w/ T-Piece/CPAP (both spontaneous), SIMV (decrease to 2), PSV (basically CPAP)
Describe how a pt is weaned using SIMV. Gradual ↑ on pt’s ventilatory load by decresing the rate, Machine breaths are decreased by 2 breaths at a time (incremental changes), Patient takes over with spontaneous efforts to maintain the VE needed to stabilize PaCO2
Why would PSV be added to this mode? PSV can be added to help “fine tune” incremental changes and maintain adequate spontaneous Vt (>300 ml)
What is the most common setting for initiation of apnea ventilation? 20 seconds
What techniques are used to monitor the possible cardiac effects from positive pressure ventilation? A-line, Continuous BP monitor, Swan-Ganz
Describe possible advantages of pressure control ventilation over volume control ventilation. prevent barotrauma
What is the rationale for permissive hypercapnea? think barotrauma; only let go of maintaining CO2 for the sake of the lungs.
Describe the 2 diff types of res. failure. What disease processes are associated w/ each? Type I: Hypoxic Type II: Hypercapnic
A/C mode, 600 Vt w/ a rate of 12, w/o spont.efforts: 7.25/CO2 55/HCO3 23/PaO2 80/ at an FIO2 .35 Respiratory Acidosis w/ normal oxygenation; Increase Vt or RR.
A/C mode, 600 Vt w/ a rate of 12, w/o spont.efforts: 7.37/CO2 55/HCO3 32/PaO2 50/ at an FIO2 .35 Compensated Respiratory Acidosis w/ moderate hypoxia; Increase FIO2
A/C mode, 600 Vt w/ a rate of 12, w/o spont.efforts: 7.51/CO2 25/HCO3 23/PaO2 90/ at an FIO2 .45 Respiratory Alkalosis w/ normal oxygenation; Decrease VE (Vt or RR) or sedate w/ propaphal
A/C mode, 600 Vt w/ a rate of 12, w/o spont.efforts: 7.38/CO2 43/HCO3 22/PaO2 120/ at an FIO2 .65 Normal ABG; except the PaO2, so lower the FIO2. It’s over the toxic level anyway.
A/C mode, 600 Vt w/ a rate of 12, w/o spont.efforts: 7.36/CO2 65/HCO3 38/PaO2 100/ at an FIO2 .45 (COPD pt being considered for weaning) Compensated Respiratory Acidosis w/ normal oxygenation; don’t touch the PaCO2. However, the O2 is at toxic level for a COPDer. Drop FIO2 until he starts to breath on his own.


Question Answer
Definition of positive pressure ventilator the machine creates a positive intrapulmonary pressure in which turns creates a pressure gradient between the pt’s lungs and the atmosphere
Definition of negative pressure ventilator creates a negative extrathoracic pressure which creates a pressure gradient between the pt lung and the atmosphere
Pressure trigger the pt generates an insp effort that drops pressure in the system therefore triggers the machine into inspiration
Time trigger the machine begins inspiration as a result of pre determined time
Flow trigger the pt generates an insp effort that changes flow in the system therefore triggers the machine into inspiration
What are basic settings for flow trigger 1-3 lpm (the lower the # the easier it is for the pt to trigger the machine
Advantage of flow vs pressure trigger flow is more sensitve to pt effort
Volume trigger the trigger threshold corresponds with a volume of 0-3 ml. When a particular volume moves across the sensor the ventilator to is triggered into inspiration
What is the importance of the exhalation circuit functions to direct the flow of the gas the pt. Closes on inspiration. At end of insp, valve opens and allows pt to exhale passively.
Without a proper functionally exhalation valve, that machine will will not deliver a positive pressure breath
Time cycled inspiration ends when a set time has expired
Flow cycled inspiration ends when a minimum flow is met
pressure cycled inspiration ends when a pre set pressure is reached
volume cycled inspiration ends when a pre set volume is delivered
IE ratio prevents the ventilator from delivering breaths with an IE ratio of less than 1:1
Pressure limit sets a maximum insp pressure that can be delivered to the pt. (stops inspiration)
inflation/plateu at peak inspiration, holds the pressure or volume for a period of time (increase insp time)(increase IE ratio)
Pressure limiting relief valve (high pressure alarm) releases any pressure in the system by venting any volume remaining (ALLOWS VOLUME TO ESCAPE)
PEEP WORKS BY INCREASING FRC. on expiration, pressure is held at an elevated baseline above atmosphere
CPAP when used with ventilator, it is the same as PEEP except that the pt must be taking spontaneous breaths (used to treat sleep apnea when CPAP machine is used)
mode control that selects how the machine will deliver inspiration or create expiration (HOW WE DELIVER THE BREATH)
Sensitivity (trigger) determine ease with which pt can begin inspiration (like IPPB)
inverse IE ratio insp time is set to be greater than exp time whcih reverses the normal
PEEP positive pressure is held at an elevated baseline at the end of expiration. Used to aid in elevating the pt’s PAO2 and does not contribute to remvoing PaCO2
CPAP purely spontaneous mode, cannot be used for pts’ with apneic. Used to elevate the pt’s PaO2 and does not contribute to removing PaCO2
PIP/MIP pressure it takes to ventilate the lung, aka peak airway pressure
IMV mode of ventilation that allows pt to spontaneously ventilate and receive assitance from the ventilator ALLOWS PT TO TAKE OWN BREATH BUT ALSO HAVE HELP FROM MACHINE
SIMV similar mode to IMV with a sig improvement. DOES NOT STACK BREATHS
What does does not stack breaths mean It will allow pt to take over that breath that the machine tried to start (so it will have different volume and not the set one)
PSV purely spontaneous mode of ventilation that is used for weaning. They are pt triggered, pressure limited, and flow cycled. It provides support to the pt during inspiration to overcome resistance caused by artificial airway, secretions, bronchospasm, oth
Spontaneous breathing pt triggered modes where pt determines their RR, insp flow rate, and size of breath (volume).
Pressure support ventilation works in S, weaning mode, Flow is provided at level of necessary to acheive the set pressure, pressure maintained thru insp, machine cycles off when flow delivered slows down, pt has control of RR and volume
Levels of 7 and below simply overcome airway resistance and make breathing easier. (pt will be getting that volume on their own)
Levels of 7 and above can add to spontaneous tidal volume
What basic parameters must be ordered on a ventilator volume, rate, mode, initial FiO2
Question Answer
Square Constant wave
How is the square created by using high pressure source greater than resistance of lungs
Square charcteristics flow on insp peaks up and stays constant, flow is not affected by changes in airway resistance and lung compliance, decreases insp time, aids in air distribution
Caution for square can increase peak insp pressure and may increase overall mean airway pressure (MAP)
Sine non constant
Sine charcteristics produces some pattern breath after breath, flow picks ups then slows down, slower flow, less resistance is created; therefore usually get lower peak insp pressures.
Caution for sine may result in a decrease in mean airway pressure (MAP)
Tapered decelerating
Tapered picture flow rate at the beginning of insp is high then decreases
Tapered charcteristics tapered wave decelerates flow and decreases peak insp pressures (help keep MAP low)
Caution for tapered may increase insp time to the point that the result is an overall MAP increase
Question Answer
Mode How we deliver the breath. How the machine will deliver insp and create expiratory
sensitvity determine ease with which pt can begin inspiration (flow or pressure sensitivity)
Inverse IE ratio pt usually sedated
PIP Peak inspiratory pressure/ MIP Pressure that is required to deliver the set volume on the ventilator. (HOW MUCH PRESSURE YOU NEED TO VENTILATE THE LUNG)
MAP mean airway pressure average airway pressure over a resp cycle an increase in MAP helps with oxygenation. You use it if there is to much dead space (to much pressure)
Negative pressure Creates a negative extrathoracic pressure
Positive pressure creates a positive intrapulmonary pressure
Internal circuit pathway for air inside the machine
external circuit has exhaltion valve which functions to direct the flow of the gas to the pt wye.
External circuit will not function properly without a exhalation valve, machine would not deliver a positive pressure breath
Assist pt initiates all breaths (machine is not set to deliver timed breaths)
control machine is set to deliver ALL breaths based on time, pt CANNOT take assisted breaths
What makes the ventilator begin a breath for the pt time, pressure, flow, volume triggers
Flow triggering used instead of pressure triggering, more senstive to pt effort. Decreased WOB, base flow rate is set through the pt circuit., as pt reduces that flow by an amount (trigger flow) machine delivers pt breath.
The variable that is measured and used to end expiration cycle variable
Pressure cycled inspiration ends when a pre set pressure is reached. pressure stays constant
Volume cycled inspiration ends when a pre set volume is delivered. Volume and flow are constant. Needs to hit Vt to exhale
Time cycled inspiration ends when a set time expired. Pressure is constant.
What effects expiratory time flow, rate, volume
Flow cycled inspiration ends when a min flow is met. Breath in and when you are filled that flow drops (stops) and makes you exhale
Pressure limited/time cycled allows the therapist to preset peak airway pressure and insp ends due to the set time. Tidal volume is variable depending on total system resistance and compliance
How pressure limited/time cycled works ventilator adjusts flow to meet set pressure, flow is tapered or decreased,
IE ratio limit prevents the ventilator from delivering breaths with an IE ratio of less than 1:1
Pressure limit sets a maximum inp pressure that can be delivered to the pt. Stops inspiration, (SAFETY PRESSURE LIMIT WE SET)
Inflation hold (plateau) at peak insp, holds the pressure or volume for a period of time, increase IE ratio.
Pressure limiting relief valve alarm Releases any pressure in the system by venting any volume remaining (ALLOWS VOLUME TO ESCAPE)
PEEP on expiration, pressure is held at an elevated baseline above atmosphere, WORKS BY INCREASING FRC. (RAISE BASELINE,OPENS AIRWAY)
CPAP when used on ventilator, it is same as PEEP except that the pt must be taking only SPONTANEOUS breaths.
Assist/control use when pt is breathing some on their own but not effiecient enough
assist pt must be initiating breaths on their own
control pt cannot initiate breath on their own
IMV/SIMV pt must be breathing spontaneously, used as weaning mode
Pressure support affects spontaneous breath only, used with SIMV or CPAP mode
Pressure control pressure limited, time cycled (USE PRESSURE LIMIT THAT PRESSURE AND TIME CYCLES IT OFF)
IMV ventilator is set to deliver a specific # of breaths at a set volume. In btwen the set # of breaths the pt can take as many additional OWN breaths as they want (whatever volume they get is what they get)
SIMV same as IMV but if pt has started to take OWN breath and it’s time for a machine breath the machine will wait and allow pt to take control. (will not stack breaths)
CMV continous mandatory ventilation assist/control mode on some ventilators, each breath delivered to the pt is at the volume set on the machine
PSV pressure support ventilation NO SET, pt has control of RR and volume. FLow is provided at a level necessary to acheive the set pressure. Pressure is then maintained throughout inspiration. Machine cycles off when flow delivered slows down.
IN PSV what effects volume muscle, pressure, flow, compliance and resistance
Flow cycled on PSV machine cycles off when flow slows
Pressure limited on PSV will not go above pressure set
Assisted ventilation on PSV breath only happens when pt triggers machine
On PSV when breath starts it helps push up until it drops (flow drops)
Levels of 7 and below overcome airway resistance and make breathing easier. They will be getting that volume on their own
Levels of 7 and above can add to spontanous tidal volume
Goal of pressure support PSV overcome airway resistance, increase until WOB decreases and ventilatory pattern improves
If you increase pressure you will get close to volume that is set
How does PSV help pt Decrease WOB, increase spontaneous tidal volume, can decrease RR, increase Vt, reduces resp muscle activity, can decrease oxygen consumption (how body is using it)
Pt not breathing on their own (spontaneously) or not strong enough to initiate an assisted breath Use assit/control or CMV
Pt strong enough to assist ventilator in assist/control use SIMV
If pt’s tidal volume is large but has low PaO2 use PEEP or CPAP
Pt strong enough to assist ventilator but has low Vt in spontaneous breaths use PSV
When oxygenation is poor and pressure control does not work try inverse ratio ventilation
The key to selecting flow pattern is to select the one that will best ventilate the pt, low peak airway pressure, low mean airway pressure, IE ratio of at least 1:2 or less
On Volume cycled ventilators if you increase the flow decrease I time/increase E time
On volume cycled ventilators if you decrease the flow increase I time/decrease E time
If you increase the volume increase I time/ decrease E time
if you decrease the volume decrease I time/ increase E time
If you the pt fights the machine work of breathing will increase
Question Answer
The key to selecting a flow pattern is to select the one that will best ventilate the pt, low peak airway pressure, low mean airway pressure, and IE ratio of 1:2 or less
Square wave Utilizes high pressure source (from machine), flow peaks and stays constant, uninfluenced by changes in resistance and compliance. FAST AND HARD
Square wave use use with pts with non-compliant (stiff) lungs and increased resp rates. decreases I time, better air distribution/gas exchange
Caution of square wave could increase peak airway pressure and mean airway pressure. It pushes to quickly Use the lowest possible pressure
Sine wave same pattern breath after breath but flow is not constant. Most like normal breathing
Sine wave use decreases airway resistance by decreasing flow, decreases peak airway pressures,
Caution of sine wave use may result in decrease in mean airway pressure (MAP)
Tapered or decelerating wave Flow rate on inspiration is high then tapers(WANT TO GET AS MUCH IN THEN SLOW IT DOWN TO SLOWLY LET IT OUT)
Tapered sine wave use decreases PAP, increases I time,