Effect of pharmacological preconditioning with sevoflurane during hepatectomy with intermittent portal triad clamping.

BACKGROUND: During hepatectomy, intermittent portal triad clamping (IPC) reduces ischemia-reperfusion injuries. Pharmacological preconditioning with sevoflurane revealed similar properties. The aim of the study was to evaluate the combination of a sevoflurane preconditioning regimen with IPC on ischemia-reperfusion injuries. METHODS: Three regimens of anesthesia were applied: group SEV with continuous application of sevoflurane, group PRO with continuous propofol infusion and group PC where continuous propofol was substituted by sevoflurane (adjusted to reach MAC∗1.5) for 15 min before IPC. Endpoints were the values of AST and ALT, factor V, prothrombin time, bilirubinemia over the 5-postoperative days (POD), morbidity and mortality at POD30 and POD90. RESULTS: The ALT values at POD5 were lower in the PC group (n = 27) 74 (48 -98) IU/L compared to PRO (n = 26) and SEV (n = 67) respectively 110 (75 -152) and 100 (64 -168) IU/L (p = 0.038). The variation of factor V compared to preoperative values was less important in the PC and SEV groups respectively -14% and -16% vs -30% (PRO) (p = 0.047). CONCLUSION: Our study suggests that sevoflurane attenuates ischemia-reperfusion injuries on liver function, compared to propofol, without benefit for a specific regimen of pharmacological preconditioning when IPC is applied.

[Why is the morbidly obese patient at high risk of anesthetic complications?] / Pourquoi le patient obèse morbide est-il un patient à risque anesthésique élevé ?

Obesity is often associated with obstructive sleep apnea (OSA), which increases the risk of intraoperative and postoperative complications. The role of preoperative screening of OSA is crucial, with adequate management based on continuous positive pressure before, during and after surgery. The obese patient is at risk of postoperative complications: difficult airway management, acute respiratory failure following extubation due to atelectasis and airway obstruction, added to morphine overdosing. Optimal management of difficult mask ventilation and intubation, protective ventilation, combined to the reduction of sedatives and analgesics and the sitting position as soon as possible with a postoperative monitoring should decrease the occurrence of complications. Cardiovascular risk is also increased in the obese patient. Preoperative screening of cardiovascular complications with appropriate therapy, combined to per- and postoperative hemodynamic optimization with a close monitoring allow to limit the cardiovascular risk. Drug dosing titration is fundamental due to unknown pharmacokinetic and pharmacodynamics properties in obese patients. Neuromuscular monitoring should always be used whenever neuromuscular blocking drugs are used, as depth of anaesthesia monitoring, especially when total intravenous anaesthesia is used in conjunction with neuromuscular blocking drugs. Appropriate prophylaxis against venous thromboembolism (VTE) after assessment of risk benefit ratio and early mobilisation are recommended since the incidence of venous thromboembolism is increased in the obese.