The level of PEEP that is most appropriate for a patient with the ...

[evelyn o bentley]

The level of PEEP that is most appropriate for a patient with the information shown below is which of the following?
 
  Time 0725 0730 0742 0748 0755 0800
  PEEP (cm H2O) 5 8 10 12 15 18
  Cs (mL/cm H2O) 27 28 34 29 29 25
  P(a-et)CO2 (mm Hg) 8.8 6.2 4.8 4.9 6.5 10
  PaO2/FIO2 159 190 237 237 221 204
 
  a. 8 cm H2O
  b. 10 cm H2O
  c. 12 cm H2O
  d. 15 cm H2O

Question 2

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 thera-pist increases the PEEP to 18 cm H2O, maintaining the FIO2 at 0.4. The patient's static compli-ance changes from 28 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 in-crease the FIO2 to 0.6.
  b. Decrease PEEP to 15 cm H2O and meas-ure 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.

[ecox1012]

Answer to Question 1

ANS: B
At a PEEP of 10 cm H2O, the static compliance is at its highest level (34 mL/cm H2O), and the arterial to end-tidal CO2 tension gradient is at its lowest (4.8 mm Hg). This means that at a PEEP of 10 cm H2O, this patient's FRC has been restored and the effectiveness of ventilation has been optimized. With PEEP higher than 10 cm H2O, these values show that the alveoli are being over-stretched. The PaO2/FIO2 is also at its highest level of 237.

Answer to Question 2

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 in-creased in increments of 3-5 cm H2O at a time. Therefore, the respiratory therapist should step the PEEP back to 13-15 cm H2O and check the static compliance.

[evelyn o bentley]

Gracias!

[cdmart10]

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