title: Elevated PEEP without effect upon gas embolism frequency or severity in experimental laparoscopic liver resection.
abstract: BACKGROUND
  Carbon dioxide (CO(2)) embolism is a potential complication in laparoscopic liver surgery. Gas embolism (GE) is thought to occur when central venous pressure (CVP) is lower than the intra-abdominal pressure (IAP). This study aimed to investigate whether an increased CVP due to induction of PEEP could influence the frequency and severity of GE during laparoscopic liver resection.
  
  
  METHODS
  Twenty anaesthetized piglets underwent laparoscopic left liver lobe resection and were randomly assigned to either 5 or 15 cm H(2)O PEEP (n=10 per group). During resection, a standardized injury to the left hepatic vein [venous cut (VC)] was created to increase the risk of GE. Haemodynamic and respiratory variables were monitored, and online arterial blood gas monitoring and transoesophageal echocardiography (TOE) were used. The occurrence and severity of embolism was graded as 0 (none), 1 (minor), or 2 (major), depending on the TOE results.
  
  
  RESULTS
  No differences were found between the two groups regarding the frequency or severity of GE, during either the VC (P=0.65) or the rest of the surgery (P=0.24). GE occurred irrespective of the CVP-IAP gradient.
  
  
  CONCLUSIONS
  Mechanisms other than the CVP-IAP gradient seemed during laparoscopic liver surgery to contribute to the formation of CO(2) embolism. This is of clinical importance to the anaesthetists.
authors.affiliation: Department of Surgical Sciences/Anaesthesiology and Intensive Care, Uppsala University, SE-75185 Uppsala, Sweden. diddi.fors@akademiska.se
authors.forename: D
authors.initials: D
authors.lastname: Fors
authors.forename: K
authors.initials: K
authors.lastname: Eiriksson
authors.forename: D
authors.initials: D
authors.lastname: Arvidsson
authors.forename: S
authors.initials: S
authors.lastname: Rubertsson
mesh_terms: D000818:Animals; D002245:Carbon Dioxide; D002496:Central Venous Pressure; D004618:Embolism, Air / Q000209:etiology*; D005260:Female; D006498:Hepatectomy / Q000009:adverse effects* / Q000379:methods; D006503:Hepatic Veins / Q000293:injuries; D010535:Laparoscopy / Q000009:adverse effects* / Q000379:methods; D008297:Male; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects; D011175:Positive-Pressure Respiration / Q000009:adverse effects* / Q000379:methods; D034421:Sus scrofa
chemical_list: D002245:Carbon Dioxide