Peep continued Flashcards
PaCO2 and VA or alveolar ventilation are \_\_\_\_ \_\_\_\_\_ related. A. Directly B. Inversely C. Linearly
B. Inversely related
spontaneous ventilation results in gas distribution to which regions of the lungs? A. Non dependent lung regions B. Dependent lung zones C. Peripheral lung zones D. A,B, C E. B&C F. A&C G. B only
E. Both B & C; spontaneous ventilation results in gas distribution to dep and peripheral regions
PPV ventilation results in gas distribution to which regions? A. Non dependent lung regions B. Dependent lung zones C. Peripheral lung zones D. A,B, C E. B&C F. A&C
A PPV distributes to non dependent lung zones because of inactivity of muscles & diaphragm
What is a normal value for PvCO2?
45 mmHg
In emphysema, formation of bullae is cause of destruction of pulmonary capillaries the result is:
A. poor perfusion & ventilation
B. Increased perfusion & ventilation
C. Poor perfusion & normally ventilated alveoli
C. Poor perfusion & normally ventilated alveoli
When previously collapsed alveoli are reopened what is the outcome? A. FRC improves B. Surface area increases C. PaO2 increases D. all of the above
D. all of the above
After a recruitment maneuver what is the best way to determine the optimal peep?
decremental peep trial
When increased mean airway pressure occurs what does it do to cardiac output?
What will decrease mean pressure?
Reduced venous return occurs and causes reduced cardiac output/you can reduce mean pressures with decrease in inspiratory time, rate, peep, or PIP.
If you need to absolutely control your patients minute ventilation which mode should you use?
Volume control
If a patient is on PC-SIMV and you see his WOB is high and PaCO2 high indicating respiratory acidosis, what besides changing frequency or driving pressure could be done to help reduce this PaCO2?
Add PSV
Of the four types of hypoxia which type is attributed to altitude and/or hypoventilation A. Hypoxemic hypoxia B. Anemic hypoxia C. Circulatory hypoxia D. Histotoxic hypoxia
A. Hypoxemic hypoxia
When looking at your a/v difference if you find your value is below the normal of 5 what does this mean? A. Patient not oxygenating B. Patient consuming too much O2 C. Patient may have hyperthermia D. Both B & C
A. Patient is not oxygenating if you a/v difference is below normal of 5; conditions can include cyanosis or hypothermia
If you are using more O2 (for example in fever) what would you expect would happen to your a/v difference?
A. Increase
B. Decrease
If your O2 consumption increases then your a/v difference would increase
What is your normal oxygen extraction ratio?
25%
What is your normal venous oxygenation?
75%
In a normal patient when analyzing your FIO2 what would you expect your PaO2 to be?
5x the FIO2 value in normal lungs
What is the formula for PAO2?
PAO2= FIO2(Pb-47) - (PaCO2/.8)
Pb= barometric press=760
Water vapor pressure = 47
What is the oxygen content formula?
CaO2=(SaO2xHBx1.34)+(PaO2x.003)
What is the shunt formula?
Qs/Qt=CcO2-CaO2/CcO2-CvO2
What is your formula for CcO2?
CcO2=(Hbx1.34x1.0)+(PAO2x.003)
What is the formula for CvO2?
CvO2=(Hbx1.34xSvO2)+(PvO2x.003)
The goal of using PEEP is _______ in respect to alveoli & at the same time avoiding __________________ to open alveoli.
The goal of peep is to recruit collapsed alveoli while avoiding overdistension to open alveoli
Indications for use of PEEP include: A. Bilateral infiltrates on chest x-ray B. Reduced lung compliance C. Atelectasis with low FRC D. All of the above
D. all of the above
Expiratory pressure that are kept above ambient pressure with PEEP use a variety of devices that are either _____ or _______ resistors
Flow or threshold resistors
This type of resistor is flow dependent?
Flow resistors; the higher the expired gas the higher the expiratory pressure generated
This type of resistor provides a constant pressure throughout expiration irregardless of rate of gas flow.
Threshold resistor
Conditions which may benefit from the use of higher PEEPS include? A. Ali B. Ards C. Cardiogenic pulmonary edema D. Unilateral pneumonia E. All of the above F. A, B, & C G. A, B, & D
Answer: F: A, B, C
Only bilateral pneumonia would benefit from PEEP therapy
In normal oxygen transport you would want to see your pulmonary shunt fraction less than?
15%
If you have a patient that has perfusion but no ventilation what would you suspect was going on?
Shunt is present, use of peep would be beneficial
When PEEP is used and you see a restoral of FRC what else should improve?
Compliance
T or F: When using Peep you would expect an increase of Ve
False
T or F: TWhen monitoring patients with chest wall injuries or hypovolemia the measurement of Compliance would serve as a good indicator of optimum PEEP or cardiovascular changes.
False
In a hypovolemic patient what should be used to judge if you have a good level of peep without cardiovascular decline?
Invasive technique such as balloon tipped pulmonary artery catheter
What is a normal value for your arterial to venous oxygen difference?
5vol% at rest
When Peep is applied successfully what would you expect to happen to your alveolar to O2 tension gradient?
The gradient difference of P(A-a)O2 should decrease to reflect improving V/Q.
Oxygen delivery depends on what 3 factors?
Oxygen delivery depends on FIO2, CaO2
and CMO
FIO2 change of 10% = ____ torr
50 torr
Your goal of oxygenation is to keep FIO2 at _________
to prevent oxygen toxicity
60% or less
A patient with myasthenia gravis is started on mechanical ventilation. THE chest x-ray is normal. Breath sounds are clear. Initial ABG’s on 0.25 are pH 7.31, PaCO2 62, PaO2 58 and HCO3 31 mEq/L A. increase FIO2 to improve oxygenation B. improve ventilation C. Make no change at this time and monitor patient until prognosis worsens
B improve ventilation; patient in respiratory acidosis
T or F: It would be acceptable to treat a patient that has cardiac tamponade (heart leaking fluid) post- heart surgery with PEEP
True
Conditions that will not respond to O2 and cause shunt include: A. Pneumothorax B. Atelectasis C. Pneumonia D. all of the above E. none of the above
D. all of the above cause shunting that will not respond to O2
What affect does PEEP have on Mean airway pressure?
It will increase mean airway pressure
What is a normal therapeutic range for PEEP?
above 5
All of these patients would be poor candidates for PEEP except:
A. Emphysema patient
B. Patient with highly compliant lungs
C. A patient with a head injury
D. A patient with bilateral lung disorder
D. bilateral lung disorder
Hazards of Peep include? A. Increased CMO B. Increased Venous return C. Increased Right ventricle afterload D. all of the above E. A & B only F. B & C only
Right ventricle afterload
When you experience right ventricle afterload what is the effect felt to the patient?
Stiffness
T or F: Volutrauma and barotrauma are known to be a hazard of PEEP
True
Other Hazards of Peep include? A. Decreased CMO B. Decreased Venous return C. decreased left ventricular distension D. Decreased liver and renal function E. All of the above
E. All of the above
T or F: PVR is another hazard associated with use of peep which means increased ventricular resistance
true
T or F: When using the recruitment maneuvers, patients suffering from direct lung injury such as those conditions affecting lung tissue will be less successful than those suffering indirectly injuries
True
T or F: It is impossible for lungs to hyper-inflate without overstretching?
False
________ is defined as a higher than normal ratio of gas to tissue.
Hyperinflation
Increases to alveolar wall tension or distending pressure causes? A. Over-distention/overstretch B. Hyperinflation C. increased levels of inflammatory mediators D. A & B E. A & C F. ABC G. B & C
D: overdistention and increased levels of inflammatory mediators results from too much pressure on alveolar walls
T or F: Use of PEEP in patients with head injuries is not recommended as it may cause an increase in CVP.
True
T or F: Peep can be effective in treating either overdistention or already existing hyperinflation.
False; Peep is not effective in treating hyperinflation in patients like emphsyema
An example of a condition that causes overdistention is ______ while another condition of _________ causes hyperinflation.
- Ards
2. Emphysema
T or F: When a patient presents with fluid consolidation, pink frothy secretions, and crackles this is indicative of development of ARDS and use of PEPP would be indicated
False: Pink, frothy secretions with fluid buildup is a symptom of CHF and cardiogenic pulmonary edema which is different from edema of ARDS; They will benefit from PPV that reduces venous return and the amount of blood the heart must pump which reduces the work of the heart
Why is oxygen therapy less effective in
absolute shunt than in V/Q mismatch?
With V/Q mismatch there is still contact with the alveoli but in absolute shunt no contact is made which is why O2 not effective
Name an absolute contraindication for Peep
Untreated Tension Pneumothorax
Name 4 relative contraindications of Peep.
Hypovolemia
Increased ICP
Increased FRC due to emphysema or over compliance
Unilateral lung diseases
In the case of Hypovolemia it is still possible to use PEEP but what must first be done?
Vasopressors must first be given to increase volumes
The best Peep will provide what important outcomes? Name 4
Improved O2 transport at best FRC Improved FRC Improved Compliance Opening of alveoli Avoids unmanageable cardiovascular side effects
How do you find your O2 transport from cardiac output?
CO x CaO2 = O2 transport
What is a normal value for alveolar-arterial O2 tension gradients?
5-10 mmHg on room air;
When you measure your O2 delivery you look at what is getting to the tissues; what is a better indicator of O2
A. DO2
B. C(a-v)O2
B. O2 utilization is better illustrated to show us what the tissue is taking
A normal CvO2 is
15 vol%
Normal DO2 is?
1000 ml/min
Normal O2 consumption is?
250 ml/min
You can determine O2 consumption with which formula?
VO2=CO x (CaO2 - CvO2)
In a normal lung the greatest amount of perfusion occurs in which zone?
A. Zone 1
B. Zone 2
C. Zone 3
C. Zone 3
