Elevated PEEP without effect upon gas embolism frequency or severity in experimental laparoscopic liver resection

Abstract

Background Carbon dioxide (CO2) 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.MethodsTwenty anaesthetized piglets underwent laparoscopic left liver lobe resection and were randomly assigned to either 5 or 15 cm H2O PEEP (n10 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.ResultsNo differences were found between the two groups regarding the frequency or severity of GE, during either the VC (P0.65) or the rest of the surgery (P0.24). GE occurred irrespective of the CVPIAP gradient.ConclusionsMechanisms other than the CVPIAP gradient seemed during laparoscopic liver surgery to contribute to the formation of CO2 embolism. This is of clinical importance to the anaesthetists. © The Author [2012]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissionsoup.com2012 © © The Author [2012]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved.