Incidence of Venous Air Embolism during Myomectomy: The Effect of Patient Position

Abstract

PurposeVenous air embolism (VAE) is characterized by the entrainment of air or exogenous gases from broken venous vasculature into the central venous system. No study exists regarding the effect of patient positioning on the incidence of VAE during abdominal myomectomy. The purpose of this study was to assess the incidence and grade of VAE during abdominal myomectomy in the supine position in comparison to those in the head-up tilt position using transesophageal echocardiography.Materials and MethodsIn this study, 84 female patients of American Society of Anesthesiologist physical status I or II who were scheduled for myomectomy under general anesthesia were included. Patients were randomly divided into two groups: supine group and head-up tilt group. Transesophageal echocardiography images were videotaped throughout the surgery. The tapes were then reviewed for VAE grading.ResultsIn the supine group, 10% of the patients showed no VAE. Moreover, 10% of the patients were classified as grade I VAE, while 50% were categorized as grade II, 22.5% as grade III, and 7.5% as grade IV. In the head-up tilt group, no VAE was detected in 43.2% of the patients. In addition, 18.2% of the patients were classified as grade I VAE, 31.8% as grade II, and 6.8% as grade III; no patients showed grade IV. VAE grade in the head-up tilt group was significantly lower than that in the supine group (p<0.001).ConclusionThe incidence and grade of VAE in the head-up tilt group were significantly lower than those in the supine group during abdominal myomectomy.

Effects of different fractions of inspired oxygen on gas embolization during hysteroscopic surgery: A double‐blind, randomized, controlled trial

“…Previous studies on GE during hysteroscopic surgery have mainly focused on the incidence of GE; the influence of surgical location, surgical instruments, and anesthetics; and the monitoring of GE 5,7–10 . Intriguingly, in our clinical observation, we found that GE did not occur when patients were administered 100% oxygen, but different degrees of GE occurred when 50% oxygen was inhaled with the same surgical instruments and surgical personnel.…”

“…Previous studies on GE during hysteroscopic surgery have mainly focused on the incidence of GE; the influence of surgical location, surgical instruments, and anesthetics; and the monitoring of GE. 5,[7][8][9][10] Intriguingly, in our clinical observation, we found that GE did not occur when patients were administered 100% oxygen, but different degrees of GE occurred when 50% oxygen was inhaled with the same surgical instruments and surgical personnel. A study comparing the effects of 100% oxygen, 50% oxygen in nitrogen, and 50% oxygen in nitrous oxide controlled ventilation on venous air embolization responses in pigs indicated a small hemodynamic change after venous air embolism in the 100% oxygen group, which suggested that 100% inspiratory oxygen is preferable to oxygen in air for surgeries with a high risk of venous air embolism.…”