Question

A patient receiving volume-controlled ventilation shows a sudden decrease in cardiac output in response to an increase in PEEP from 25 cm H2O to 28 cm H2O. FIO2 is 0.60. After reverting to a PEEP of 25 cmH2O, the physician asks the respiratory therapist what should be done next to address the persistent hypoxemia. The therapist would recommend

A. reducing PEEP to 15 cm H2O
B. switching to pressure-controlled ventilation
C. increasing FIO2
D. utilizing an inverse I:E ratio breathing pattern

Answer 1

To address persistent hypoxemia after decreasing PEEP from 28 to 25 cm H2O, without causing additional cardiovascular compromise, the recommended action would be increasing FIO2 to raise the available oxygen for gas exchange.

Step-by-step explanation:

A patient who experiences a sudden decrease in cardiac output in response to an increase in PEEP from 25 cm H2O to 28 cm H2O likely had the decrease as a result of the increased intrathoracic pressure reducing venous return to the heart. While reverting to a PEEP of 25 cm H2O might have been a good initial step, addressing persistent hypoxemia will require additional interventions. To avoid further cardiovascular compromise, the respiratory therapist would most likely recommend increasing FIO2. This would enhance the amount of oxygen available for gas exchange in the lungs without further increasing intrathoracic pressure. It's also crucial to monitor the patient's oxygen saturation and often their acid-base balance to ensure that increasing the FIO2 does not result in oxygen toxicity or alter their ventilation/perfusion status significantly.