Depth of anaesthesia monitoring during procedural sedation and analgesia: A systematic review and meta-analysis

Objectives: Processed electroencephalogram-based depth of anaesthesia monitoring devices provide an additional method to monitor level of consciousness during procedural sedation and analgesia. The objective of this systematic review was to determine whether using a depth of anaesthesia monitoring device improves the safety and efficacy of sedation.

Design: Systematic review and meta-analysis.

Data sources: Electronic databases (CENTRAL; Medline; CINAHL) were searched up to May 2015.

Review methods: Randomised controlled trials that compared use of a depth of anaesthesia monitoring device to a control group who received standard monitoring during procedural sedation and analgesia were included. Study selection, data extraction and risk of bias assessment (Cochrane risk of bias tool) were performed by two reviewers. Safety outcomes were hypoxaemia, hypotension and adverse events. Efficacy outcomes were amount of sedation used, duration of sedation recovery and rate of incomplete procedures.

Results: A total of 16 trials (2138 participants) were included. Evidence ratings were downgraded to either low or moderate quality due to study limitations and imprecision. Meta-analysis of 8 trials (766 participants) found no difference in hypoxaemia (RR 0.87; 95% CI=0.67-1.12). No statistically significant difference in hypotension was observed in meta-analysis of 8 trials (RR 0.96; 95% CI=0.54-1.7; 942 participants). Mean dose of propofol was 51mg lower for participants randomised to depth of anaesthesia monitoring (95% CI=-88.7 to -13.3mg) in meta-analysis of results from four trials conducted with 434 participants who underwent interventional endoscopy procedures with propofol infusions to maintain sedation. The difference in recovery time between depth of anaesthesia and standard monitoring groups was not clinically significant (standardised mean difference -0.41; 95% CI=-0.8 to -0.02; I²=86%; 8 trials; 809 participants).

Conclusions: Depth of anaesthesia monitoring did impact sedation titration during interventional procedures with propofol infusions. For this reason, it seems reasonable for anaesthetists to utilise a depth of anaesthesia monitoring device for select populations of patients if it is decided that limiting the amount of sedation would be beneficial for the individual patient. However, there is no need to invest in purchasing extra equipment or training staff who are not familiar with this technology (e.g. nurses who do not routinely use a depth of anaesthesia monitoring device during general anaesthesia) because there is no high quality evidence suggestive of clear clinical benefits for patient safety or sedation efficacy.