title: Severe Venous Air Embolism Related to Positioning in Posterior Cranial Fossa Surgery in Siriraj Hospital.
abstract: BACKGROUND
  Posterior cranial fossa surgery is commonly performed under sitting and horizontal position in our institution. Venous air embolism is a potentially serious complication of neurosurgery especially in the sitting position.
  
  
  OBJECTIVE
  We aim to compare the incidence of severe venous air embolism and other complications of both positions.
  
  
  METHODS
  A retrospective analysis of medical record was performed in 192 patients undergoing posterior cranial fossa craniotomy from January 2010 to December 2013. Data collected from the records included demographic profile, patient position, hemodynamic changes, venous air embolism (VAE), blood loss/transfusion, duration of surgery, postoperative complications, duration of ICU stay, and postoperative discharge status. The definition of severe air embolism was identified as suspected VAE with decreased systolic blood pressure greater than 20%.
  
  
  RESULTS
  There were 92 patients in sitting position (SP) group and 100 patients in horizontal position (HP) group. The incidence of severe venous air embolism was signficantly higher in SP group compared with HP group (41.3% vs. 11.0%, p<0. 001). SP group had more complications than HP group in both central nervous system (71% vs. 34.0%, p = 0.001), and cardiovascular system (17% vs. 6%, p = 0.001). Although postoperative ventilator time in SP group was less than HP group (1.24 vs. 1.60 days, p = 0.029), ICU and hospital stay were not different in either group.
  
  
  CONCLUSIONS
  The incidence of severe venous air embolism detected by end tidal CO₂ was significantly higher in SP group. However, 11% of HP group were suspected of severe air embolism.
authors: Pranee
authors: P
authors: Rushatamukayanunt
authors: Patchanon
authors: P
authors: Seanho
authors: Saipin
authors: S
authors: Muangman
authors: Manee
authors: M
authors: Raksakietisak
mesh_terms: D000328:Adult; D000368:Aged; D003388:Cranial Fossa, Posterior / Q000601:surgery*; D003399:Craniotomy / Q000009:adverse effects; D004618:Embolism, Air / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D056888:Patient Positioning; D012189:Retrospective Studies