Monitoring bispectral index of the EEG and management of hypertension during laparoscopic surgery.

Objective: Assessment of the usefulness of Bispectral Index of the EEG (BIS(TM)) for the management of hypertension during laparoscopic surgery. Study design: Preliminary, non-randomized study. Patients: 15 patients undergoing laparoscopic surgery. Methods: Anaesthesia by TCl of propofol and boluses of fentanyl in order to maintain fentanyl effect site concentration above 2 ng.mL(-1) according to Scott kinetics model. Mean arterial pressure (MAP), heart rate (HR) and BIS(TM) were recorded. BIS(TM) values between 40 and 60 and MAP between 80 to 120% of preinduction values were maintained using a Gurman like decision matrix. Results: MAP rose significantly after insufflation while variations of HR and BIS(TM) were not significant. Discussion: During laparoscopy, factors other than pain can be responsible for hypertension. Nevertheless in clinical practice, inadequate anaesthesia should be ruled out before considering other mechanisms for hypertension. In this study, hypnosis remained adequate with a BIS(TM) under 60, and analgesia was considered sufficient as demonstrated by a good stability of the BIS(TM) despite nociceptive stimuli. This suggests that more specific haemodynamic factors were responsible for the observed rise in arterial pressure. Conclusion: Associating BIS(TM) monitoring and MAP in a modified Gurman decision matrix may allow more judicious therapeutic choices for hypertension during laparoscopic surgery. (C) 2000 Editions scientifiques et medicales Elsevier SAS.