Ch. 13 Test, PEEP and ARDS Flashcards
PEEP therapy is indicated for patients with which of the following?
a. PaO2 of 95 mm Hg while receiving an FIO2 of 0.3
b. PaO2 of 100 mm Hg while receiving an FIO2 of 0.8
c. Returned VT of 600 mL with a Pplateau of 12 cm H2O
d. Returned VT of 800 mL with a Pplateau of 15 cm H2O
ANS: B
The PaO2/FIO2 for answer A is 317, which shows no ALI or ARDS. The PaO2/FIO2 for answer B is 125; this is an indication for PEEP therapy (PaO2/FIO2
Patients with which of the following clinical disorders may benefit from PEEP?
a. COPD
b. Asthma
c. ARDS
d. Cystic fibrosis
ANS: C
ARDS is a clinical disorder that benefits from the use of PEEP. The other three choices are obstructive lung diseases and will not benefit from the use of PEEP therapy.
DIF: 1 REF: p. 275
How long after PEEP is increased should all ventilatory and available hemodynamic parameters be measured and calculated?
a. 5 minutes
b. 15 minutes
c. 25 minutes
d. 40 minutes
ANS: B
Approximately 15 minutes after an increase in PEEP, all ventilatory and available hemodynamic parameters are measured and calculated.
DIF: 1 REF: p. 267
Assessing the outcome of PEEP at levels set above 15 to 20 cm H2O is best done using which of the following?
a. Static compliance measurements
b. Pressure-volume loop graphics
c. Pulmonary artery occlusion pressure
d. Central venous pressure measurements
ANS: C
At pressures above 15 to 20 cm H2O, the compliance measurement is not a good indicator of cardiovascular function, and monitoring of the pulmonary artery pressure may be indicated.
DIF: 1 REF: p. 270
An absolute contraindication to PEEP is which of the following?
a. Emphysema
b. Bronchopleural fistula
c. Untreated tension pneumothorax
d. Elevated intracranial pressures
ANS: C
An absolute contraindication to PEEP is a tension pneumothorax. PEEP must be used with care in patients with bronchopleural fistulas and elevated intracranial pressures. PEEP also must be used with care in patients with emphysema, because it may increase hyperinflation, which can lead to compression of adjacent capillaries.
DIF: 1 REF: p. 270
The level of applied PEEP should be set at what point on the pressure-volume curve?
a. At the upper inflection point of the inflation curve.
b. Above the lower inflection point of the deflation curve.
c. At the peak inspiration point of the inflation curve.
d. Above the upper inflection point of the deflation curve
ANS: D
The level of applied PEEP should be set 3 to 4 cm H2O above the upper inflection point of the deflation limb of the P-V curve to help maintain an open lung.
DIF: 1 REF: p. 281
A patient is being ventilated with a PEEP of 10 cm H2O and an FIO2 of 0.4. The arterial blood gas results show that the patient remains hypoxemic, and the respiratory therapist increases the PEEP to 18 cm H2O, maintaining the FIO2 at 0.4. The patient’s static compliance changes from 28 mL/cm H2O to 22 mL/cm H2O just after this change. The respiratory therapist should do which of the following?
a. Decrease PEEP to 10 cm H2O and increase the FIO2 to 0.6.
b. Decrease PEEP to 15 cm H2O and measure static compliance.
c. Keep PEEP at 18 cm H2O and increase the FIO2 to 0.6.
d. Increase PEEP to 20 cm H2O and measure static compliance.
ANS: B
The increase in PEEP from 10 to 18 cm H2O caused overdistention of the gas exchange units. This is evidenced by the decrease in compliance from 28 to 22 mL/cm H2O. PEEP should be increased in increments of 3 to 5 cm H2O at a time. Therefore, the respiratory therapist should step the PEEP back to 13 to 15 cm H2O and check the static compliance.
DIF: 3 REF: p. 268
Regardless of the procedure used to establish an appropriate PEEP level, ventilating pressures should not be allowed to exceed which of the following?
a. Upper inflation point on the inspiratory limb (UIPi)
b. 2 to 3 cm H2O above the UIPi
c. 30 cm H2O
d. Lower inflection point on the inspiratory limb
ANS: A
Regardless of the procedure used to establish an appropriate PEEP level, ventilating pressures should not be allowed to exceed the UIP on the UIPi, because injury to lungs can occur if the lungs become overstretched. The appearance of the UIP on the graphic display may be influenced by the type of recruitment procedure used. For example, in one study, when the VT was set low (5 to 6 mL/kg), the UIP was 26 cm H2O.
DIF: 1 REF: p. 281
Despite the risk, it is still important to use PEEP, because it can prevent alveolar collapse during exhalation and reopening, even when a low VT is used. It now is theorized that it is important to use the pressure-volume loop to set PEEP _____________________.
a. at the upper inflection point detected during inflation of the lung
b. above the upper inflection point detected during deflation of the lung
c. at the lower inflection point detected during inflation of the lung
d. at the peak inspiration point detected during inflation of the lung
ANS: B
Regardless of the procedure used to establish an appropriate PEEP level, ventilating pressures should not be allowed to exceed the UIP on the UIPi, because injury to lungs can occur if the lungs become overstretched. The appearance of the UIP on the graphic display may be influenced by the type of recruitment procedure used.
During a patient case study, increasing increments of PEEP showed no significant effects until 15 cm H2O was used, at which time the PaO2 improved markedly. This represents the point at which _______________.
a. cardiac output decreased
b. airway resistance decreased
c. hemoglobin saturation improved
d. alveolar recruitment probably occurred
ANS: D
Recruitment maneuvers can produce varying results among patients. In patients who respond to an RM, PaO2 increases, PaCO2 decreases, and the change in pressure (ΔP) required to cause an acceptable VT decreases.
DIF: 2 REF: p. 272
In which ventilator mode should a patient receiving a sustained inflation technique be placed?
a. VC-CMV
b. APRV
c. PC-IMV
d. CPAP/spontaneous
ANS: D
To perform the sustained inflation technique, the ventilator needs to be set in the CPAP/spontaneous mode, because no mechanical breaths should be given during the procedure. The patient also requires sedation and short-term paralysis during this procedure.
DIF: 1 REF: p. 285
To perform a slow-flow (quasi-static) technique for determining the appropriate PEEP level, the most appropriate ventilator flow setting is which of the following?
a. 2 L/min
b. 6 L/min
c. 10 L/min
d. 14 L/min
ANS: A
Although flow rates up to 9 L/min can be used, the higher flow rates cause a slight shift to the right of the resulting P-V curve. The single breath slow-flow should be 2 L/min.
DIF: 1 REF: p. 280
The highest pressure attained during the slow-flow (quasi-static) technique should be ______ cm H2O.
a. 25
b. 35
c. 45
d. 55
ANS: C
The slow-flow for static P-V measurement uses a single breath delivered at 2 L/min until the pressure reaches 45 cm H2O.
DIF: 1 REF: p. 280
The point on a static pressure-volume curve (SPV) where the alveoli begin to open is referred to as which of the following?
a. Lower inflection point on the inflation limb
b. Upper inflection point on the inflation limb
c. Upper inflection point on the deflation limb
d. Lower inflection point on the deflation limb
ANS: A
At the lower inflection point on the inflation limb, the slope of the line changes significantly. It originally was believed that this point represents the opening of most of the collapsed alveoli. However, it is the point at which the alveoli begin to open. Even at the upper inflection point on the inflation limb, the alveoli are still being recruited in some parts of the lungs.
DIF: 1 REF: p. 281
The “sigmoid” shape of the static pressure-volume lung recruitment maneuver indicates which of the following?
a. All parts of the lungs open with the same pressure.
b. Independent portions of the lungs open with the same pressure.
c. Dependent portions of the lungs open with different pressures.
d. Lung units open at different times with different pressures
ANS: D
The shape of the pressure-volume curve suggests that different areas of the lung open at different pressures during the recruitment maneuver. As pressure is exerted every few seconds, different areas of the lungs are recruited. This occurs between the lower inflection point on the inspiratory limb up to the upper inflection point on the inspiratory limb.
DIF: 1 REF: p. 283
