[Interest of entropy monitoring during low-grade cerebral aneurysm embolisation]

Abstract

Objective: Evaluate the use of entropy monitoring on anaesthetic drugs consumption, haemodynamic stability, and recovery time in patients undergoing embolisation of cerebral artery aneurysm (asymptomatic or low Hunt and Hess grades).

Methods: Two groups, G1 without entropy monitoring (Datex-Ohmeda S/5), G2 with entropy monitoring (16 patients in each group). Each group had similar anaesthetic protocol (propofol target control infusion and continuous intravenous infusion remifentanil). For G2, the state entropy (SE) values were kept between 35 and 45. We studied anaesthetic drug consumption, arterial pressure parameters, extubation delay and feasibility. Statistical analysis used Mann and Whitney test, Fisher test. Significativity was p<0.05.

Results: No intraoperative incident. Propofol consumption was lower in G2 (7.49+/-2.28 mg/kg per hour versus 9.46+/-2.50mg/kg per hour; p<0.05). A tendency to reduction was observed for remifentanil consumption (6.65+/-2.04 microg/kg per hour versus 7.94+/-2.92 microg/kg per hour; p=0.056), and extubation delay (14.1+/-8.6 min versus 26.5+/-22.0 min; p=0.056), in G2. The entropy monitoring had no repercussion on haemodynamic stability, but the arterial pressure values were significantly higher in G2 (73.60+/-8.49 mmHg versus 67.10+/-5.58 mmHg). Entropy captor does not disrupt embolisation procedure. Coils liberation alter temporarily RE and SE values.