Effect of Body Repositioning after Venous Air Embolism

Abstract

In dogs, body repositioning after VAE provided no benefit in hemodynamic performance or cardiac dimension changes, although relocation of intracardiac air was demonstrated. Right ventricular air did not appear to result in significant RV outflow obstruction, as pulmonary artery pressure increased uniformly in all groups and was not influenced by the relocation of intracardiac air. The combination of increased RV afterload and arterial hypotension, possibly with subsequent RV ischemia rather than RV outflow obstruction by an airlock appeared to be the primary mechanism for cardiac dysfunction after VAE.

Update to “Anesthesia advanced circulatory life support”

“…The authors quote an article by Mirski 3 which identifies the animal studies by Geissler 4 and Mehlhorn 5 that clearly refute the benefit of positioning change.…”

Venous Air Embolism

“…This may present as pulseless electrical activity as a result of obstruction to right ventricular ejection while cardiac electrical activity is preserved. 64 A study on dogs 82 to evaluate the effect of repositioning on VAE found no evidence of this air lock mechanism in "massive" VAE. However, the intravenous infusions of air were relatively slow (boluses over an average of 14 s) and in amounts that were less than previous studies.…”

“…These investigators showed that, in dogs, repositioning to partial left lateral decubitus (Durant's position) after VAE resulted in no improvement of hemodynamics as measured by echocardiography. 82 They also introduced an important concept: that subacute circulatory collapse and death after VAE may also result from the vicious cycle established by pulmonary hypertension, subsequent elevation of CVP, systemic hypotension, and RV ischemia. 82 As such, smaller bubbles associated with slow continuous VGE will not cause an air lock in the right ventricular outflow tract, but rather distribute further downstream in the pulmonary arterial tree based on gas buoyancy and preexisting pulmonary flow characteristics.…”

Venous Air Embolism during Total Laparoscopic Hysterectomy

“…Animal studies have found no benefit from the left lateral position in improving hemodynamic performance, 6,7 and human data are lacking. Conversely, in the case of a major event, such as cerebral gas embolism, the authors did not mention hyperbaric oxygen therapy.…”