title: Incidence of venous air embolism during myomectomy: the effect of patient position.
abstract: OBJECTIVE
  Venous 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.
  
  
  METHODS
  In 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.
  
  
  RESULTS
  In 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).
  
  
  CONCLUSIONS
  The incidence and grade of VAE in the head-up tilt group were significantly lower than those in the supine group during abdominal myomectomy.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Korea.
authors.forename: Jiwon
authors.initials: J
authors.lastname: An
authors.forename: Seo Kyung
authors.initials: SK
authors.lastname: Shin
authors.forename: Ja-Young
authors.initials: JY
authors.lastname: Kwon
authors.forename: Ki Jun
authors.initials: KJ
authors.lastname: Kim
mesh_terms: D000005:Abdomen / Q000473:pathology; D000328:Adult; D017548:Echocardiography, Transesophageal; D004618:Embolism, Air / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D009214:Myoma / Q000473:pathology / Q000601:surgery*; D011187:Posture; D016683:Supine Position; D063186:Uterine Myomectomy / Q000009:adverse effects / Q000379:methods*; D014599:Uterus / Q000000981:diagnostic imaging / Q000473:pathology; D014680:Veins / Q000000981:diagnostic imaging*