Hypotension following pre-hospital rapid sequence induction of anaesthesia: a retrospective database analysis

IntroductionRecent trends in Pre-Hospital Emergency Medicine (PHEM) have demonstrated the potential benefit of using fentanyl, ketamine and rocuronium for pre-hospital rapid sequence induction of anaesthesia (RSI). Isolated cases of potentially significant hypotension have been reported. This study aimed to establish a potential link between the incidence of hypotension and the dose and combination of anaesthetic induction agents used.MethodsA retrospective database review was undertaken of all cases attended by the Great North Air Ambulance Service requiring RSI during a 25-month period. The blood pressure (BP) before and after RSI and doses of drugs were recorded. Cases were divided into three groups based on changes in BP: group 1 (increase in BP post induction >20% or more), group 2 (between 20% increase and 20% fall in BP) and group 3 (fall in BP of 20% or more).Results105 cases were included in the analysis. Group 1 included 11 cases (range 23% to 106% increase in BP), group 2 included 57 cases (19% increase to 18% decrease) and group 3 included 37 cases (20% fall to 63% fall in BP).There was no statistically significant link to rocuronium (p=0.46) or ketamine (p=0.054) but the dose of fentanyl administered was highly significant (p<0.001).DiscussionThis review showed a potential link between fentanyl dose and the degree of hypotension during RSI. Although this is a small study with some limitations it gives an indication that dose ratios in RSI may need to be reviewed.