PEEP in venous air embolism

Q: During the management of venous air embolism (VAE), with an intubated patient, positive end-expiratory pressure (PEEP) should be (select one)

A) increased
B) optimized by running pressure-volume (PV) loop on ventilator
C) discontinued
D) May keep PEEP at 5 cm H2O
E) C and D


Answer: E

Increasing the PEEP increases the chance of an intracardiac right-to-left shunt, which may convert a VAE into a paradoxical air embolism (PAE), a life-threatening complication (choice A). During VAE there is no luxury of time to run PV loop (choice B).

There is a lot of debate between choices C and D but evidence is very weak to recommend to discontinue the PEEP (choice C) though it can be done if danger of hypoxemia is not anticipated. Ans, some studies have suggested a benefit of (regular) PEEP in prevention of VAE.

Objective of the above question is to highlight the controversy of PEEP in the management of VAE


#ventilators
#cardiology


References:

1. Meyer, PG Cuttaree, H Charron, B Jarreau, MM Peri, AC Sainte-Rose, C Perkins NA, Bedford RF: Hemodynamic consequences of PEEP in seated neurological patients: Implications for paradoxical air embolism. Anesth Analg 1984; 63:429–32

2. Perkins, NA Bedford, RF Zasslow MA, Pearl RG, Larson CP, Silverberg G, Shuer LF: PEEP does not affect left atrial-right atrial pressure difference in neurosurgical patients. Anesthesiology 1988; 68:760–3

3. Zasslow, MA Pearl, RG Larson, CP Silverberg, G Shuer, LF Schmitt HJ, Hemmerling TM: Venous air emboli occur during release of positive end-expiratory pressure and repositioning after sitting position surgery. Anesth Analg 2002; 94:400–3

4. Schmitt, HJ Hemmerling, TM Giebler R, Scherer R, Erhard J: Effect of positive end-expiratory pressure on the incidence of venous air embolism and on the cardiovascular response to the sitting position during neurosurgery. Br J Anaesth 1998; 80:30–5Giebler, R Scherer, R Erhard, J