Critical Care Medicine-Neurologic Disorders>>>>>Other Parenchymal Disease and pulmonary edema
Question 5#

A 5-year-old female patient has fallen from the balcony of her apartment located on a third floor. Impact on various branches of a tree before hitting the soil has dampened the velocity of the impact. Trauma burden includes two broken ribs on the right hemithorax, lung contusion, and a suspicion of spinal cord injury at the level of T1. She has to be sedated for a magnetic resonance imaging session.

Which strategy could BETTER diminish the incidence of postprocedure atelectasis?

a. Intubation, sedation with sevoflurane, PEEP of 5 cm H2O, a tidal volume of 10 mL/kg, and a FiO2 of 1.0
b. Spontaneous breathing, sedation with propofol, and 15 L/min of oxygen on a non-rebreathing O2 mask
c. Noninvasive ventilation, sedation with midazolam, and a FiO2 of 1.0
d. Any strategy with the lowest possible FiO2

Correct Answer is D

Comment:

Correct Answer: D

Breathing an unnecessarily high FiO2 leads to alveolar collapse (hyperoxic atelectasis) and, in addition, increases alveolar permeability, decreases surfactant production, and induces inflammatory mediators (thereby ventilation-induced lung injury). There is not an easy predictable PEEP value that protects all patients from atelectasis, although any value has been shown to be more protective than a PEEP of 0 cm H2O. It has been shown that patients who are sedated and spontaneously breathing without invasive ventilation or PEEP have a lower risk for atelectasis when compared to those who were sedated and mechanically ventilated. Available physiological evidence suggests that breathing a lower FiO2 was protective against atelectasis. 

References:

  1. Tusman G, Bohm SH, Warner DO, Sprung J. Atelectasis and perioperative pulmonary complications in high-risk patients. Curr Opin Anaesthesiol. 2012;25(1):1-10.
  2. Duggan M, Kavanagh BP. Pulmonary atelectasis: a pathogenic perioperative entity. Anesthesiology. 2005;102(4):838-854.
  3. Lutterbey G, Wattjes MP, Doerr D, Fischer NJ, Gieseke J Jr, Schild HH. Atelectasis in children undergoing either propofol infusion or positive pressure ventilation anesthesia for magnetic resonance imaging. Pediatr Anesth. 2007;17(2):121-125.
  4. Kallet RH, Branson RD. Should oxygen therapy be tightly regulated to minimize hyperoxia in critically ill patients? Respir Care. 2016;61(6):801- 817.