Question Answer
What are the advantages of negative pressure ventilator? We breathe negative pressure
What are the disadvantages of negative pressure ventilator? Limited effectiveness in volume produced, low cardiac output in hypovolemic patients, can facilitate upper airway obstruction
Define Transpulmonary Pressure (PL) pressure difference between alveolus and pleural space. Prevents atelectasis.
A patient with this disease has his Transpulmonary pressure. Congestive Heart Failure
Define Transairway Pressure (PTA) pressure between mouth and the alveolus
A patient with this diseaswe has high transairway pressure Asthma
Define Peak Pressure highest pressure recorded or seen on manometer at end of inspiration.
Define plateau pressure pressure at end of inspiration following a 0.5 to 1.0 second hold.
Define static compliance determines stiffnes of the lung at full inspired ventilator breath
What is the normal lung compliance for an intubated male? 40-50 ml/cmH2O
What is the normal lung compliance for an intubated female? 35-45 ml/cmH2O
What is the normal lung compliance for a non-intubated person 50-170 ml/cmH2O
Define time constant The rate at which lungs are filled
Define Dynamic Compliance determines overall stiffness of lungs to ventilation
Define Airway resistance frictional forces associated with ventilation due to lung tissue viscosity, the anatomical structure of the conducting airways and adjacent tissues and organs.
Normal RAW for non-intubated person .6-2.4L/sec
Normal RAW for intubated patient 6 cmH2O/L/sec
Calculation for static compliance Vt/Plt-PEEP
Calculation for dynamic compliance Vt/PIP-PEEP
Calculation for Airway Resistance [(PIP-PLT)/Insp flow]*60
Control Panel AKA User interface
Control Circuit Brain. Logical decision making unit of the vent. aka microprocessor
Control Variable Variables remain constant with any change in lung mechanics
Conditional Variable Variable changes with changes in lung mechanics
Phase Variable 3 phases of breath: Trigger, Limit, & Cycle
What is trigger variable Beginning of inspiration, can be patient or machine. machine>time. patient>pressure or flow
What is limit variable Max value
What is cycle variable End of Inspiration
Examples of electrically powered ventilator Bear I & Mac I
Examples of pneumatically Powered ventilator Bird Mark 14 & Monoghan
Examples of combined electrically/pneumatically ventilator Evita Dragger, Servo, Servo 300, 840, Sechrist, star, Bear 1000, viasys
Question Answer
GUI (graphic user interface) top screen of ventilator. (monitor area)
Sandbox bottom part of GUI, area where you set the settings
BDU (breath delivery unit) on/off switch. high pressure gas connections, insp/exp filters, humidifier (lower box where the air is coming out of )
BPS (back up power source) Power to BDU and GUI only, 30 min limit, Switches to BPS automatically when power is interupted
SST (short self test) Perform when changing circuit, changing humidifier type, prior to new pt
What to do for SST select SST and test button (on side) within 5 seconds. CAN NOT RUN WHILE ON PT.
SVO (safety valve open) allows pt to breath room air unassisted by vent ,
Modes on 840 SIMV, A/C, spontaneous, BiLevel
If pt disconnects the flow drops to 5 lpm to avoid spraying fluid collected in circuit
If pt is connect to vent before set up is complete Procedure error!, then vent goes to SVO
When does ventilation begin when pt is attached- until then it will stay in “standby”
What color is Spontaneous breath orange
what color is mandatory breath green
Pt vent check Assess pt, note vent type, tube placement, additional equipment (humidifier, suction, check tube), suction, drain tubing, check cuff pressure, measure weaning parameters, complete check form
A-a gradient [(Pb-47) FiO2 ] – PaCO2 x 1.25 all that minus PaO2
When adjusting PEEP MUST HAVE ORDER , ↓/↑ in increments of 2., check change PIP alarm and low PEEP alarm, assess with ABG, (t
Adjusting PEEP can cause decrease in venous return
Compliance equation Vt / (plateau pressure- PEEP) This shows sign of improvement or deteriation of pt.
When pt is getting worse its a decrease in compliance (stiff)
HIGH PIP alarm will go off if pt coughs, bites tube, fights tube, needs suctioning, air trapping, obstructed tube, lungs stuff…
The Low exhaled volume alarm can go off if exhaled volume measured is less that the set, leak, disconnect, pt is in spontaneous mode and not breathing as deep as when the alarm was set.
Question Answer
FIO2 to acive a result of what PaO2 of 60 and SAT of 90%
Tidal vol. set at 8 to 10 kgs of IBW
Rate (Fequency) 12 to 16
Pleautau presure <30
I:E ratio 1:2 higher E value for COPD patients
PEEP set at 3 to 5
Flow set at 60 to 80
high preasure alarm 10 above PIP that pt. does
low presure alarm 10 below PIP that pt. does
high tidal vol. alarm 100 above what tech. sets
low tidal vol. alarm 100 below what tech. sets
apnea alarms intervals 20 to 30 seconds
PEEP alarm 2 to 3 below set PEEP
High respiratory rate alarm double what pt. is doing
Question Answer
What is is the definition of mechanical ventilation An intervention classification defined as the use of an artificial device to assist the patient to breathe.
What are the indications of MV -apnea- acute respiratory failure- impending respiratory failure sever hypoxemia
What is considered acute respiratory failure hypercapnia and hypoxemia
What are the general goals of MV Provide adequate ALVEOLAR ventilation, provide adequate oxygenation, avoid ALVEOLAR over distention, maintain ALVEOLAR recruitment, avoid auto peep, use the lowest possible FIO2
What are the requirements for spontaneous ventilation Size of the tidal volume and rate or initiation
In phase 1 of MV what is the summary of what’s going on Establish the need, connecting the patient to the vent for the first time after the first blood gas is the end of phase 1
In phase 2 of MV what is the summary of what’s going on Stabilize arterial blood gases as much as possible.
In phase 3 of MV what is the summary of what’s going on Weaning of the machine
What are the guidelines to EST. The need for phase 1 and acceptable values Vt= 5-8ml/kg, RR <35, Vc >15ml kg or 2x Vt, Nip or Mop < 20cmh2o -30 or -40 is better, Ve >10L
What are the initial settings on the vent Pplt pressure <30 cmh20, full support mode for the first 24 hours, Vt 5-8 ml/kg, f: 8-12/ min, FIO2 < or equal to 60
What are the things that the vent needs to know What is the oxygen requirements, what is the mandatory RR, mode, Vt, how fast and what fashion such as the I:E ratio
What are the 2 modes of ventilation Volume ventilation, pressure ventilation, pressure is most often used in neonatal due to the anatomy of the baby body not needing a cuff
What are the different types of breaths Controlled- vent respond. For both rate and volume Assisted- patient is respond for rate and initiating and vent is reps for volume, Spontaneous- patient is reps. For both rate and volume.
What are the different types of modes Control, assist, assist/control, SIMV, CPAP
CPAP Works on all spontaneous breaths, can’t leave patient unless know they can intiate and provide all volume.
Strategies to improve vent. According to the NBRC Decrease dead space, increase tidal volume, increase RR, increase the spontaneous tidal volume, increase the pressure support, beware of the CO2 retainer
Strategies to improve oxygenation assure that the adequate vent., increase FIO2, add/increase PEEP
What are some causes of height alarm sounding Cough, secretions, biting the tube, pneumothorax, patient distress
What are some causes of low alarm sounding leak, cuff leak, disconnect, extubtion, patient fatigue
Different waveforms Square, sine, decelerating
Square waveform pattern: Produces a constant flow throughout insp. Used mostly in non compliant lungs
Sine waveform pattern: Flow begins slowly and increases to a peak then decrease at the end of inspiration, gives good distribution of ventilation
Decelerating flow pattern: Flow is fast during the beginning of insp peak, then gradually decreases useful for people who need high flow rates
What is dynamic compliance: identifies changes in the airway, change in volume usually Vt as the dynamic compliance decreases the airway is getting more narrow.
What is plateau pressure The pressure that is at during a inspiratory hold, once the Vt is delivered you hold the insp. And the pressure at the hold is the pplat
What is static compliance Identifies the condition of the lungs, normal is 60-100 ml/cmh2o
What is resistance This is increased as the air way grows more narrow, normal is 0.6-2.4 cmh20/l/sec
What is the formula for Tidal volume You take the IBW and times it by 5 and by 8 to get the range of tidal volume you need. 105+5(ht”-60)/2.2 for female and 106 for male.
What is the formula for dynamic compliance Cd Change in volume/PIP-PEEP Peak insp. Pressure- positive end exp. pressure
What is the formula for static compliance Cs Change in volume/Pplat-PEEP Plateau pressure- positive end exp. pressure
What is the formula for RAW PIP-Pplat/FLOW(60)
Question Answer
Describe the changes is delivered volume with the following changes in the patient’s lung compliance and airway resistance (pressure remains the same) DECREASE COMPLIANCE Volume Change DECREASE
Describe the changes is delivered volume with the following changes in the patient’s lung compliance and airway resistance (pressure remains the same) INCREASE COMPLIANCE Volume Change INCREASE
Describe the changes is delivered volume with the following changes in the patient’s lung compliance and airway resistance (pressure remains the same) INCREASE AIRWAY RESISTANCE VOLUME CHANGE DECREASE
Describe the changes is delivered volume with the following changes in the patient’s lung compliance and airway resistance (pressure remains the same) DECREASE AIRWAY RESISTANCE VOLUME CHANGE INCREASE
Describe the changes is delivered volume with the following changes in the patient’s lung compliance and airway resistance (pressure remains the same) DECREASE COMPLIANCE,INCREASE RESISTANCE DECREASE Volume Change
Describe the changes is delivered volume with the following changes in the patient’s lung compliance and airway resistance (pressure remains the same) INCREASE COMPLIANCE,DECREASE RESISTANCE INCREASE Volume Change
What situations would cause the system to lose pressure? Leak,Insufficient Flow
Excessive pressure could be caused by? Obstruction Excessive Flow
If the PT is trying to initiate a breath but the machine will not cycle into inspiration, what adjusments should the therapist make to correct the problem? Adjust Sensitivity Tight Seal Aroud Mouthpiece
While receiving IPPB therapy, the PT is having a problem with the machine not cycling off. What would cause this to occur? LEAK, Mouthpiece/Mask Seal, Cuff Leaking Fenestrated Trach Tube Open Loose Equipment Connection
List the purpose of USING CPAP Increase Oxygenation, Support Oxygenation at Lower Fi02
what types of PT might benefit from USE OF CPAP CO Poisoning, Pneumonia, Post-OP Atelectasis
NASAL CPAP This device is useful for what type of PT? Useful with Neonates since they are obligate nose breathers
NASAL CPAP What happens to the CPAP level if the PT opens his mouth? Can lose CPAP
The Respiratory Therapist notices that a CPAP unit is losing pressure. What could cause this problem to occur? Readjust Nasal Prongs
What should the therapist look for as a possible cause of increased pressure? Obstruction With excessive flow, a continuous venting of the pop-off Vavle will Occur
What kind of PT would be a candidate for a non-invasive pressure ventilation? COPD,CHF,Pulmonary Edema Neuromuscular Disease,Restrictive Chest Wall Disease,Central/Obstructive Sleep Apnea
What kind of PT would NOT be a candidate for a non-invasive pressure ventilation? Acute Respiratory Failure
Non-invasive postive pressure ventilation is contraindicated for a PT who has _____? PT with Dysphagia
Expiratory positive airway pressure helps to improve____? Oxygenation
Inspiratory positive airway pressure is used to help maintain ______? PT Airway inObstructive Sleep Apnea
In th ST mode, timed breaths are controlled by what two parameters? Respiratory Rate and an Inspiratory Time
In the Timed mode, can the PT initiate additional breaths? PT cannot Trigger Additional Breaths
What level of pressure generally helps aPT with Obstructive sleep apnea? Generally find relief with EPAP pressures of 5-10 CmH20
PT with Neromuscular disease usually do well with pressures at what level? Usually do well with Inspiratory Pressures of 10-15 cmH20
How is Oxygen supplied to the PT using this type of device? must be titrated into the system to achieve a desired Fio2
The Respiratory is following established protocols in monitoring a PT using his incentive spirometer. The PT exhales completely then places the mouthpiece in his mouth and inhales maximally as he performs his therapy. The therapist should recommend that Inhale Maximally from resting Exhalation
The Primary indication for sustained maximal inspiration is to Treat Collapsed Alveoli
A PT enters the emergency department complaining od dyspnea and orthopnea. A quick check of her oxygenation status with pulse Oximetry reveals a saturation of 89%. Which of the following positions would facilitate oxygenation? Fowler’s
After undergoing aortic aneurrysm repair, a female PT is unable to reach her pre-operative incentive spriometry goal. The therapist sets goal to lower level and the PT complains of pain when performing the therapy. The therapist should Have the PT splint her chest with a pillow during therapy
During intermittent postive breathing therapy, a PT is achieving a pressure level of 22 cmH20 at a frequency of 17-19bpm. PT complains of lightheadedness with tingling sensations in the fingers of his left wrist. the therapist should instruct the PT to Decrease his breathing rate and pause between breaths
A new order for IPPB therapy is received for a PT who is recovering from a C-section delivery.Respiratory therapist instructs the PT on proper technique, he notices that the pressure manometer is hesitating during inspiration.Therapist should corect how Increase the flow
The Oxygen concentration supplied to PT while performing intermittent positive breathing would increase by making which of the following changes? Increase the Pressure Decrease the Terminal Flow
While administering intermittent positive pressure therapy with a Bird Mark 7 ventilator, the respiratory therapist determines that the volume delivered to the PT needs to be increased. This can be accomplished by increasing the. Inspiratory Pressure
Terminally ill PT presents to the ED in servere pain and respiratory distress.PT does not want to be intubated,Physician support this PT. Which device is best for the therapist to recommend? Non-invasive Ventilation
PT on Bi-level POS-Pressure ventilation is determined to have an arterial oxygen saturation ranging between 84-88% RR at 12-14bpm. The insp-pressure level is set at 17cmH20 with an Exp-Pres level of 5cmh20. Which adjustments should be made?
Question Answer
What is the humidity temperature range for humidification? 31-35 degrees celsius
How much dead space does the HME create? 500-100 ml deadspace
If you have a tidal volume of less than 400 the tidal volume goes directly to active humidity
What are contra indications for the HME? presence of thick, copious, bloody secretions. Can create resistance. VTe is less than 70% of inhaled Vt or there is no ET cuff. Temperature below 32 degrees celcius. Spontaneous VE is greater than 10 L/M Aerosolized medication is given. A very small
In order to do the leak test on the MA1 the following settings should be used. Vt-200 ml Rate 12 bpm flow 40 LPM Pressure MAX All other parameters off
To perform the leak test you should allow the ventilator to trigger occluding the wye and exhalation side of the circuit Then, observe the pressure manometer and the pressure should plateau and hold
Lost volume is gas volume that does not reach the patient
What can cause lost volume? small circuit leaks gas leak at ETT cuff Tubing compliance or system compressibility
Lost volume is not a concern when it is less than 5% of the VT
What is the compression factor for a neonatal circuit? 1 ml/cmH20
What is the compression factor for a pediatric circuit? 2 ml/cmH20
What is the compression factor for an adult circuit 3 ml/cmH20
How do you find the circuit compression factor? (Cfac) Put in the preset setting and occlude the wye only. Observe the PIP and exhalved VT. Calculate by exhaled Vt/PIP
In order to calculate compressible volume set the ventilator to appropriate patient settings and attach to patients airway. Observe PIP and spirometer.
In order to then calculate the compressible volume (lost volume) Circuit Compression Factor * (PIP-PEEP)
The final step is to find the patients corrected Vt by exhaled VT-Compressible volume
Tubing compliance (Ct) is now measured and corrected on most newer vents
What are causes of the high pressure alarm going off? Coughing secretions kink in tubing pneumothorax
What are causes of low pressure alarms? circuit disconnection cuff leak/tube too small chest tube leak Open lavage Port
In control mode the ventilator delivers a machine (preset) breath at a specific time interval
In control mode the ventilator controls rate, VT or pressure and the patient does not have control
The control mode of the ventilator should only be used when the patient has been properly medicated
What are indications for control mode? To provide full ventilatory support (patient fighting the ventilator, tetanus/seizures, complete rest, crushed chest injury/paradoxical movement)
What is a complication of the control mode? Patient is ventilator dependent
In Assist Control Mode the patient can control the rate, but the Vt or Pressure is controlled by the ventilator. A minimum rate is set
What are indications of assist control? To provide full ventilatory support
What are the advantages of assist control mode? Patients can control rate which controls VE, Low WOB
What are complications of Assist control mode? Hyperventilation (stress, anxiety, pain)
For Intermittent Mandatory Ventilation the ventilator delivers a set number of breaths at a set tidal volume or pressure but allows the patient to breath spontaneously in between at their own Vt.
What is the indication of IMV mode? To provide partial ventilatory support (post-op patients, weaning)
What are the advantages of IMV? Maintains muscle strength Facilitates Weaning Less positive pressure Reduces V/Q mismatch
What are complications of IMV Mode? stacking of breaths muscle fatigue increased work of breathing
What Ventilator Settings are prescribed by the physician? Mode, VT, Fi02
What are the basic ventilator settings/alarms? mode, Vt, Rate, Flow,Fi02, I:E ratio, Sensitivity, FIO2 Alarm, High pressure alarm, Low pressure alarm, Low exhaled VT alarm.
What is the basic setting for VT? 10 ml/kg
What is the basic setting for rate? 8-12 breaths per minute
What is the basic setting for flow? 40-60 LPM
What is the basic setting for Fi02? 40%
What is the basic setting for I:E 1:2; 1:3
What is the basic setting for sensitivity? Pressure trigger (-2 cm H20) Flow trigger (2-4 L/Min)
What is the alarm setting for fi02? +/- 5%
What his the high pressure alarm setting? 10-15 cmH20 above PIP
What is the low pressure alarm setting? 10-15cmH20 below PIP
What is the low exhaled Vt setting? 100 mL below exhaled vT *consider spontaneous VT *Check for leak
Flow will affect PIP
For COPD patients you may choose to set the flow at 50-60 LPM
Positive End Expiratory Pressure increases the end-expiratory pressure to a value greater than atmospheric
What are the indications of PEEP? TO improve FRC Improve oxygenation
What are complications of PEEP? worsens the effects of positive pressure, bauraotrauma, airtrapping, pneumothorax, decrease invenous return, decreased urine output
What is the companion to PEEP? COntinuous positive airway pressure
CPAP is applied to spontaneous breaths
PEEP is used to help with oxygenation
What is the PEEP/Fi02 Rule? If the patient is on greater than 60% fi02 without PEEP, add it in
Before ventilators were designed that incorporated PEEP systems inside the unit PEEP was added externally by placing a device on the expiratory limb of the patient circuit
What are examples of external PEEP devices? Underwater Seal, Water Column, Boehringer Valve, Spring loaded valve (Down’s Valve)
What is the pro of the underwater Seal PEEP system? Low cost, non invasive
What is the CON of the underwater Seal PEEP System? loss of peep with evaporation Bubbling
What is the emerson Water Column? It is similar to the underwater seal but it’s diaphram reduces bubbling
The Boehringer Valve has a ball that creates pressure
What is the pro of the Boehringer Valve? No H20 is needed
What are Cons of the Boehringer Valve? Must remain upright. PEEP only goes to a certain value.
The Down’s Valve and Spring valve are similar in that they both contain a spring
What is the pro of the spring/downs valve? They work in any position
What is the con of the spring/downs valve? There is a limited amount of PEEP that can be reached
What is the PEEP that can be achieved with the down’s valve? 2.5-15 cm H20
What is the PEEP that can be achieved with the screw down valve? 0-20 cm H20
What is the formula to calculate Inspiratory Time (Sec(? Vt/Flow (Flow must be converted to Liters per second) Vt must be in Liters.
What is the calculation for RCT? 60/Respiratory Rate
What is the calculation for Et(Sec) RCT-I time
What is the calculation for I:E ratio? IT/IT:Et/IT
What is Peak Inspiratory Pressure? The amount of pressure required to deliver the Vt overcoming the airway resistance.
What is PIP used for? to calculate dynamic compliance which is a reflection of lung compliance and airway resistance.
The Ppl (plateau pressure) is caused by inspiratory hold and stops flow.
The Ppl corresponds with Phase 2 of the respiratory cycle
The Ppl is the amount of pressure required to maintain lung inflation in the absence of airflow.
How do you obtain the Ppl? Inspiratory Hold which will lengthen the I time.
Ppl is used to calculate static compliance which is a reflection of lung complaince.
What are other uses for an inspiratory hold? Improve oxygenation, administer MDI therapy.
Resistance holds no bearing on plateau pressure
What is Cdyn? Reflects lung compliance and/or airway resistance.
How do you calculate Cdyn? Corrected vT/(PIP-PEEP)
What is the normal values for Cdyn? 30-40 ml/CmH20
What does Cstat do? Reflects lung compliance only and cannot reflect airway reesistance because there is no gas flow.
What is the formula for cStat? corrected VT/(Ppl-PEEP)
Compliance is equal to Change in V/ Change in P
Compliance reflects the degree of lung volume per unit of pressure
In a normal healthy patient Cstat is 70-100 ml/cm H20
In a male on a ventilator Cstat should be about 40-50 ml/cm H20
In a female on a ventilator Cstat should be 35-45 ml/cmH20
cL is the abbreviation for lung compliance
What are conditions that decrease lung compliance? Atelectasis ARDS Pneumothorax
When there is a decrease in lung compliance PIP and Ppl both increase. This in turn decreases static and dynamic compliance.
An increase in airway resistance may be due to bronchospasm kinking/biting of ETT Airway obstruction
With an increase in Airway resistance there will be an increase only in the PIP. Dynamic compliance will be decreased only.
Airway resistance obsructs airflow.
Airway resistance is increased when the diameter or patency of the airway is reduced
Airway resistance can be caused by changes inside the airway (retained secretions), in the wall of the airway (inflammation), or outside the airway (ie, tumors)
What is normal RAW on an unintubated patient? .6-2.4 cmH20/L/Sec
What is the normal Raw on an intubated patient with a flow of 30 L/Min? 6 cmH20/L/SeC
How do you calculate Raw(cmH20/L/Sec) PIP-Ppl/Flow(l/s)
In order to calculate RAW flow must be in Liters per second and constant. It is the limit variable.
Waveforms are graphical representations of the control or phase variables in relation to time.
Observation and assessment of waveforms during mechanical ventilation can provide useful information, such as inadvertant PEEP, WOB, resistance and compliance changes, patient/ventilator dyscynchrony, and leaks
The descriptors used to describe each waveform are based upon their respective shape
What is the function of the expiratory retard and sigh controls on the MA-1? The expiratory retard is a PEEP knob. The sigh controls are to give a large VT breath.
The sources that illuminate the lights on the control panel of the MA 1 are Assist Pressure Ratio Sigh Oxygen
What is a range for Ppl to use on graphics? 0.1-1.3 seconds and must correspond with Vt and Flow
Adding an inspiratory hold or plateau will do what to inspiratory time? increase
Increasing the inspiratory rate on the MA-1 will do what to I time? NOt change
Increasing tidal volume on the MA-I will do what to the Inspiratory time? increase
Increasing the respiratory rate on the MA-I will do what to the I:E ratio? decrease
Increasing the respiratory rate on the MA-I will do what to the peak pressure? NOt Change
Increasing the tidal volume on the MA-I will do what to the peak pressure? Increase
Increasing the flow rate on the MA-I will do what to the peak pressure? Increase
In the presence of normal compliance and resistance an MA-I produces what kind of wave form? Flow wave form
What three factors impact I time? Rate, VT and VE?
Question Answer
Orders for the vent VT,pressure (if in PC), MODE, FiO2, RR,
As a RT what can you change based on your pt. flow, IE ratio, I time
What is the Pt unit where gas mixes, where gas is delivered to pt. (BIG BOX ON BOTTOM OF VENT)
What is the front panal Where you select the settings, (MONITOR)
Where is the power switch on back of the front panal
Where is the deadspace From the Y connector to the pt.
Where is the circuit connected to left side of the ventilator to the pt.
Temp prob is on which circuit inhalation tube
How is the Servo powered electrically and pneumatically
If there is a power failure how long is the battery 3 hours ( 30 min for each battery) ( 6 batteries)
If there is no battery power what happens high priority alarm sounds and the insp/exp valves open up (let pt breath room air)
Cycle methods Used to end inspiration…. Volume, pressure, flow, time
Servo has what kind of check Pre – use
When is the pre use check done Between pts, when circuit change (if using tubing compliance)
What does tubing compliance mean adjusts delivered volume for loss of volume during circuit compression, NOT USED IN INFANTS OR Pressure control or pressure support.
Steps for new pt Admit pt, enter info, select infant or adult, mode, set parameters and alarms
Modes on Servo Volume control, Pressure control, pressure support, and CPAP, PRVC, VS
Pressure regulated volume control (PRVC) pressure cycled breathing, desired VT or VE can be used. (default mode, like A/C)
PRVC varying pressures so machine can deliver volume @ lowest pressure possible… 1st breath is volume controlled test breath using desired VT or VE with pause time then pause pressure is used as the insp (PIP) level for following breaths
Volume support Pt triggered, flow cycled Pressure support increases until targeted volume is reached. After 3 start up breaths, support increases and decreases within 3 cm to deliver targeted volume
Automode Pairs support and control modes to automatically switch between the 2. Volume control(machine) and volume support (pt)… Pressure control and pressure support
Trigger setting turn left to negative number (pressure triggered) turn right to positive number (flow triggered)
Pressure control above PEEP sets peak insp pressure for pressure control ventilation. Max is 120 cm H20 pressure
Pressure support above PEEP sets pressure support level in modes where available
Insp rise time allows slow rise to full flow or pressure at beginning of breath. Adjustable in % of total cycle time or in seconds. Whats comfortable for pt.
Insp cycle off determines how low flow drops before inspiration ends
Trigger timeout max time elapsing before controlled ventilation takes over in automode (really sick pt)
Start breath delivers manually activated breath at set parameters
O2 breaths delivers 100% O2 for 1 min or until button is pushed again (used for suctioning)
Insp hold to find plateau pressure (to get compliance)
Alarm silence silence for 2 min
Question Answer
Different types of ventilation devices self inflating, non-self inflating (flow inflating), and pneumatic-powerdered
List 2 types of patient valves found in self inflating manual ventilation devices spring loaded valves (disc and ball) diaphragm valves (duckbill and leaf)
15 mm connector attaches to ETT/artificial airways
22 mm connector attaches to mask
non rebreather mask directs flow to patient during bag compression, directs exhaled air away from bag during releases
reservoir system increases delivered FIO2
pressure relief valve prevents accidental use of high pressures with infants and children
5 factors which affect FIO2, when using a self inflating resuscitation bag use of reservoir, oxygen flowrate, bag refill time, stroke volume, ventilation rate
How to assess the effectiveness and adequacy of ventilation when using a manual resuscitation device monitor chest rise and fall, listen to breath sounds, pulse ox or ABG
Question Answer
What are the standard connections 15 mmID (inside) for ET tube, or trach tube and 20 mmOD (outside)for resuscitation mask
Uses for bag Ventilate patients during CPR, hyperventilate before and after suctioning, ventilate during transport, management of mechinially ventilated patients
What does FIO2 depends on oxygen input flow, reservoir volume, delivered stroke volume and rate, bag refill time
Parts of Bag patient valve, bag, inlet valve, oxygen nipple, reservoir, pressure pop-off
Size of adult bag 1500-2000 ml volume no pressure pop off needed
Size of pediactric bag 250-500 ml volume Pressure pop off at 40 cmH20 pressure (+-10 required)
Size of neonate bag 250 ml volume comes with 40 cmH20 pressure (+-5 cmH20 pressure pop-off)
Ideal stroke volume for Adult 800 ml avg (1500-2000 max)
Ideal stroke volume for infant 240 ml
Spring loaded mechanism NOT sensitive to patient effort and spontatneous breathing WILL NOT open valve to allow patient to breath from bag
Diaphragm (duckbill) these valves are flexible and EASILY OPENED by pressure from bag compression, or by the pt spontaneous breathing effort
Diaphragm (leaf) spontaneous breathing WILL open valve to allow patient breath from bag
Charcteristics of good self inflating bag Easy to clean..standard connections…self inlfating.. nonrebreathing valve…available in different sizes
Function of pop off valve (pressure relief valve) prevents delivery of excessive pressure with infants/pediactrics pts.
Effect of ventilation on RATE Faster=lower FiO2…..Slower = increased FiO2
Effect of ventilation on O2 FLOW higher the flow = increased FIO2 slower the flow = decreased FIO2
Effect of ventilation on Reservoir capacity no reservoir = 35-40 % at O2 flow of 10-15 lpm…up to 100% at O2 flow of 10-15 lpm… size of reservoir = increased size – Increased FIO2 reservoir present =
Effect of ventilation on REFILL TIME increased time = increased FIO2 decreased time = decreased FIO2
Effect of ventilattion on STROKE VOLUME (squeezing) increased stroke volume = decreased FIO2 decreased stroke volume = increased FIO2
Observations to assure ventilation rise and fall of chest, breath sounds, ABG, and oximetry
Hazards with bags gastric insufflation, vomiting/aspiration, barotrauma, hypoventilation
What to do if you get gastric insufflation intubate ASAP
what to do if vominting or aspiration occurs intubate ASAP, this causes decreased compliance (expansion stiffens)
What to do if barotrauma happens don’t squeeze bag until pop-off–slow down and not as hard
what to do if hypoventilation occurs use both hands, and check for breath sounds
Advantage for mouth to mask ventilation no direct person to person contact
Limitations for mouth to mask ventilation maintain airtight seal, gastric inflation
Demand valve gas powered, pressure relief set at 40, you get 100% FIO2 with 50 psi outlet, THEY CAN GENERATE A BREATH
PEEP valves used to keep back pressure open…pressure to overcome refractory hypoxemia (decreased FRC) (it’s not responding to oxygen help
Hazards for demand valve barotrauma because you won’t feel compliance, tank runs out to fast, limits pop, don’t know tidal volume
Question Answer
stroke volume size of the breath delivered to the pt when the bag is compressed
ventilation rate (frequency) the faster one ventilates the patient, the less time the bag reservoir has to refill with 100%, the lower the delivered FIO2.
reservoir capacity collect the oxygen so that when the bag refills it does so with 100% oxygen, the larger the reservoir the larger or greater the oxygen percentage delivered
refill time length of time for reinflation, reifll of the resuscitator after each compression of the device…. The less time the bag has to refill, the lower the percentage of oxygen delivered to the patient
oxygen liter flow the higher the oxygen flow rate, the higher the delivered FIO2
Question Answer
Without oxygen 21%
with oxygen, no reservoir 40-50%
with oxygen and reservoir 90-95 % can be 100%
with demand valve attachment 100%
Should not contain a pop off valve on Adults
Newborns pop off set at 30-45 cmH2O
Question Answer
The operating principles of self filling resuscitator bags 1. Portable, 2. delivery positive pressure 3. can deliver room air, O2 or combi 4. O2-inlet nipple, 5. O2 reservoir 6. Have standard in and out connection
Common uses of self filling bag 1. ventilate during CPR, 2. Hypervintaliting before and after suctioning 3. ventilate during transport 4. management of mechanically ventilated patients
Standard fittings of a pt valve on a bag and explain why they are specific 15 mmID (inside for connection to ET or trach)…20 mmOD (outside for connection to bag)
Spring loaded mechanism are NOT sensitive to pt effort and spontaneous breathing WILL NOT open valve to allow pt breath from bag
Diaphragm valve which are duckbill/fish mouth or leaf type
Duckbill these valves are flexible and EASILY OPENED by pressure from bag compression, or by pt’s spontaneous breathing effort
Leaf valve spontaneous breathing WILL open valve to allow patient to breath from bag
Demand valve gas powered device
Characteristics of good self inflating bag Easy to clean, standard connections, delivers O2 concentrations at high stroke volume/rates, self in flating, non-rebreathing valve, available in adult,peds, and neonates
Common equipment failure issues and how to correct them. If bag fills rapidly and collapses easily-check for absent inlet valve or if stuck open it up. 2. If bag becomes hard to compress-pt valve may be stuck open or closed 3. Excessively high flow to device may cause valves to jam.
Function and purpose of pop off or pressure relief valve on bag prevents delivery of excessive pressure with infants/pediatric patients…prevents barotrauma/lung damage….prevents pneumothorax
Which bags have a pressure relief valve Adults only!!!
Pressure relief valves fucntion at what pressure Pediatric pop off at 40 cmH20 (+- 10 required) Neonate comes with 40 cmH20 (+-5 pressure pop off)
how to check bag for proper function occlude the bag and see if it has a little squeeze….squeeze the bag to make sure there is a fall and a rise…..feel for air leaking out of outlet
Observations to assure ventilation when using a manual resuscitator chest rise, breath sounds, ABG, and oximetry
Hazards and how they can be minimized Gastric insufflation, vomitting/aspiration, barotrauma, hypoventilation
Purpose of the demand valve Gas powered, pressure relieve is set at 40, you get 100% oxygen delivered on a 50 psi outlet, inspiration can be started by manual button or pt generating negative pressure (PATIENT CAN GENERATE A BREATH
Advantages of using demand valve 100% FiO2, flows at least 40 lpm, one person can ventilate
Disadvantages of using demand valve Requires 50 psi outlet, does not provide a feel for chest compliance, barotrauma caused by overventilating, oxygen tanks drain quickly, should not be used with intuabted pts, ADULTS ONLY
Troubleshoot potential hazards of demand valve hyper or hypo ventilate, and barotrauma
Use and indications for PEEP attachments Used for pts that have refractory hypoxemia (not responding to given O2). They have decreased FRC
What does the PEEP do to FRC It overcomes the decreased FRC and keeps back pressure open (alveoli open)
When do you use PEEP To improve oxygenation when increasing FIO2 when it’s not sufficient Also when the pt is on a ventilator and it is hooked up with PEEP
If PEEP works on bag what will it do to PaO2? It will increase it
Effect of aspiration on ventilating a patient with a bag if aspiration occurs while using a bag that junk can get in the lungs, it will cause decreaed compliance
Steps for initial response when a pt is not responseive do typical CPR steps… If not responsive use rescue breath (breath for them) 30 chest compressions to 2 breaths.
Question Answer
Respiratory rate can be determined by the: ventilator ,patient
Tidal volume can be delivered as a fixed: volume, pressure
Define Tidal Volume settings: If the ventilator is set to deliver a volume (let’s say 500 cc), then no matter what (within reason), the ventilator will push 500 cc through its tubing into the patient.
Define Respiratory rate: The breaths can be triggered by either time or alternatively, if the patient tries to take a breath, the breath can be triggered by the patient’s inspiratory effort.
Define Flow rate: The flow rate is how fast the air enters the patient. In a volume regulated mode the ventilator controls how fast the breath is delivered.
SIMV synchronized intermittent mandatory ventilation
MMV mandatory minute ventilation
PCV pressure control ventilation plus
A/C assist control
Question Answer
Peak Flow preset inspiratory time is controlled by peak flow tidal volume flow waveform pause time
Peak Flow Preset I:E ratio is controlled by peak flow tidal volume flow waveform pause time master rate
Inspiratory Time % Preset inspiratory time is controlled by IT% Master Rate Pause Time
Inspiratory Time % preset I:E ratio is controlled by Inspiratory time% Pause Time
Peak flow in It% is controlled by Inspiratory time% Tidal Volume Master Rate Flow Wave Form
If Peak Flow is preset you can calculate I time in square waveform as It=(VT/Flow)+Pause
If Peak flow is preset and not in square wave form you can calculate as It=RCT/Total parts of I:E ratio
If inpsiratory Time% is preset you calculate It as RCT*(IT%+Ptime%)
In order to calculate Peak Flow in It% the VE is preset and based on a master rate and tidal volume. IT can also only be done with a square wave form VE preset/IT%
In the 900c in order to calculate peak flow based on accelerated flow you can estimate it by VE/IT%(1.5)
IT% of 80= I:E 3:1
IT% of 67= I:E 2:1
IT% of 50%= I:E 1:1
IT% of 33%= I:E 1:2
IT% of 25%- I:E 1:3
IT% of 20%= I:E 1:4
The Servo 900C is powered pneumatically and electrically
The bellows in the servo 900c provide a working pressure for the patient circuit
THe single circle manometer shows the patient working pressure
The alarm silence is active for two minutes and cannot be reset
The apnea alarm alarms after greater than 15 seconds goes by between breaths
If the alarm is yellow it means that it is not set properly
if the alarm is red it means that it is alarming
There are 2 small silver buttons on the PEEP know this is used as a safety precaution
The gas change button allows for free flow gas flush
The master rate must be set higher than the set or SIMV rate
The alarm types on the servo 900c include high/low minute volume, apnea alarm, fio2 alarm, upper pressure alarm and the gas supply alarm
What are the modes that are available on the servo 900 c Volume control, Volume Control +sigh, Pressure control, pressure support ventilation, SIMV, SIMV +PS, CPAP and manual.
What is the TLC for VC? T- RCT L-Flow C-IT
What is set in VC? A master rate, VE, IT%,Pause %, PEEP, Sensitivity, Fi02
What is set in SIMV mode? SIMV Rate, Master Rate, IT%, Pause %, Fi02, VE, Sensitivity, PEEP
What is the TLC in SIMV mode? T- RCT/Pt(pressure) L-Flow/Pressure C-It/ETS(preset at 25%)
The SIMV Cycle is the period of time between mandatory breaths
The SIMV Period is the time alloted for each mandatory breath
The spontaneous breath is equal to the SIMV cycle-SIMV period
There is one sigh breath every 100 breaths
In SIMV + Pressure support the TLC is T-RCT/Pt Pressure L Flow/ pressure C It/ETS
In SIMV +pressure support you set the Master rate, SIMV rate, fio2 It%, Pausse %, Sensitivity, PEEP, Inspiratory pressure level, VE
In pressure support you set the sensitivity, inspiratory pressure above PEEP, PEEP, fi02
The TLC for pressure support is T- Pt. PRessure L-Pressure C-ETS
Manual mode on the servo900c is typically use with anesthesia and there is no apnea alarm.
Question Answer
Dynamic The study of forces in action.
Dynamic re: lungs Refers to the movement of gas in and out of the lungs and the pressure changes required to move the gas.
Passive Dilation During normal inspiration in which the < in intrapleural pressure causes the bronchial airways to lengthen & increase in diameter.
Passive Constriction During normal expiration in which the > in intrapleural pressure causes the bronchial airways to shorten & decrease in diameter.
Poiseuille’s Law What the tube size does to the flow & pressure.
Poiseuille’s Law for v (flow) v = ^Pr4 – Flow = Change in pressure times r to the 4th power.
Poiseuille’s Law for P (pressure) P = v/r4 – Pressure = flow divided by r to the 4th power.
If radius > 2x then, v (flow) > 16x and P (pressure) < 1/16
If radius < 1/2 then, v (flow) < 1/16 and P (pressure) > 16x
Time Constants Time that is required to inflate a specific lung region 60% of its filling capacity. Determined by Cl & Raw.
Increase in Raw &/or Cl Increase time to inflate = long time constant
Decrease in Raw &/or Cl Decrease time to inflate = short time constant
Dynamic Compliance How readily a lung region fills with gas during a specific period of time. Measured DURING a period of gas flow. ^V/^Ptp
Positive end-expiration pressure – PEEP When during rapid ventilatory rates, small airways w/high Raw don’t have sufficient time to fully deflate during expiration and the pressure in the alveoli distal to these airways still have +pressure when the next inspiration begins.
auto-PEEP Caused by inadequate expiratory time and causes increase in pt WOB. AKA air trapping, intrinsic PEEP, occult PEEP, inadvertent PEEP & covert PEEP.
auto-PEEP & pt FRC increase When FRC increases, pt breaths at a higher, less compliant point on the volume pressure curve, thus causing > WOB.
auto-PEEP & pt diaphragm Air trapping causes diaphragm to push downward, causing > WOB. Pa is higher at beginning inspiration (ie +4 > ambient pressure) causing > WOB.
Ventilatory Pattern Consists of 1) tidal volume, 2)the ventalory rate, and 3) the time relationship between insp. & exh. (pause). 1:2
Tidal Volume The volume of air that normally moves into and out of the lungs in one quiet breath.
Normal Vt 7 – 9 mL/kg 3 – 4 mL/lb 500 mL total average
Ventilatory Rate Normal = 12-20 breaths per minute
Dead space ventilation Amount of gas that DOESN’T reach the alveoli and DOESN’T partake in gas exchange.
Alveolar ventilation Amount of gas that actually DOES reach the alveoli and DOES partake in gas exchange.
Effective Ventilation Va = Vt – Vds; measuring ONE breath only!
Minute alveolar ventilation v(flow)a = Vt – Vds x RR; measuring one MINUTE!
Ventilatory Pattern Consists of 1) tidal volume, 2)the ventalory rate, and 3) the time relationship between insp. & exh. (pause). 1:2
Tidal Volume The volume of air that normally moves into and out of the lungs in one quiet breath.
Normal Vt 7 – 9 mL/kg 3 – 4 mL/lb 500 mL total average
Ventilatory Rate Normal = 12-20 breaths per minute
Dead space ventilation Amount of gas that DOESN’T reach the alveoli and DOESN’T partake in gas exchange.
Alveolar ventilation Amount of gas that actually DOES reach the alveoli and DOES partake in gas exchange.
Effective Ventilation Va = Vt – Vds; measuring ONE breath only!
Minute alveolar ventilation v(flow)a = Vt – Vds x RR; measuring one MINUTE!
Anatomic dead space Amount of air in the conducting airways (upto but not including resp bronchioles). Equals about 1mL/lb IBW. Dilutes oxygen concentration of gas entering lungs.
Physiologic dead space The sum of the anatomic dead space and the alveolar dead space.
An increased depth of breathing, is far more effective than an equivalent increase in breathing rate in increasing an individual’s total alveolar ventilation.
Increase in tidal volume beyond anatomic dead space, goes entirely toward increasing alveolar ventilation.
Apnea Complete absence of spontaneous ventilation.
Eupnea Normal, spontaneous breathing.
Biot’s Short episodes of rapid, uniformly deep inspirations, followed by 10 to 30 seconds of apnea.
Hyperpnea Increased depth (volume) of breathing with or without an increased frequency.
Tachypnea A rapid rate of breathing.
Cheyen-Stokes Ten to 30 seconds of apnea, followed by a gradual increase in volume and frequency of breathing, then a gradual decrease in volume until another period of apnea occurs.
Kussmaul’s Both an increased depth (hyperpnea) and rate of breathing. Associated w/diabetic acidosis (ketoacidosis).
Orthopnea A condition in which an individual is able to breath most comfortably only in the upright position.
Dyspnea Difficulty in breathing, of which the individual is aware.
Alveolar Deadspace Alveolus ventilated by not perfused; due to clots, tumors, etc.
Question Answer
VE exhaled minute ventilation this value is usually used to assess the pt’ability to tolerate weaning
Vt Tidal volume indicates pt’s ability to move air in and out of the lung
VC vital capacity indicates the pt has or does not have a ventilatory reserve should they become stressed
NIF negative inspiratory force indicates respiratory muscle strength
PEFR peak expiratory flow rate used to indicate effectiveness of therapy
IC insipiratory capacity to help determine the appropriateness of the treatement
RSBI resp index or breathing index index to show chances of weaning from vent