[Experience with remifentanil in the ICU]

Abstract

Background: Analgesia and sedation are indispensable in patients admitted to intensive care for the following, principal reasons: to control their state of anxiety, induce amnesia, improve their adaptation to mechanical ventilation, make invasive manoeuvres tolerable. The purpose of the present retrospective analysis is to assess the effectiveness of remifentanil in a total of 1085 patients admitted to our Resuscitation and Intensive Care Department in 1997-2001.

Methods: A sample of 60 adults was taken from these patients. The group was homogeneous in terms of age (67.3+/-10.2 kg), weight (66.7+/-10.2 kg), duration of sedation (6.8+/-1.6 days) and index of gravity (SAPS 30.1+/-4.4). The patients were suffering from chronic obstructive bronchopneumopathy, subjected to mechanical ventilation and sedated with remifentanil. The sample was then compared with another 2 groups (homogeneous with the first) of 20 patients each, treated with propofol and midazolam as the only drug. Following an initial bolus of 2 mg/kg (+/-0.04) for propofol and 0.15 mg/kg (+/-0.03) for midazolam (no bolus for remifentanil), the doses of subsequent continuous infusion (initial doses in the case of remifentanil) were: 0.05 mcg/kg/m (+/-0.01) for remifentanil; 1 mg/kg/h (+/-0.04) for propofol; 0.03 mg/kg/h (+/-0.006) for midazolam. In order to assess the level and quality of sedation, 2 subjective evaluation scales (Ramsey score and the Sedation-Agitation Score: SAS) and one system of objective evaluation (Bispectral Index; BIS) were employed. The BIS is a direct measure of the effects of anaesthetics on the brain. It is represented by a single digit (between 100, state of arousal, and zero, EEG flat), derived statistically and empirically from the EEG.

Results: No significant differences were encountered as regards quality of sedation among the 3 groups but there was a significant difference in negative cardiovascular activity in patients treated with propofol (12% reduction in Cl, 13.8% reduction in SVR). A significant accumulation of the drug was observed in cases treated with midazolam, whereas there was no accumulation for remifentanil and propofol in relation to the duration of the infusion.

Conclusions: Of the various sedation modalities employed, we prefer the one which uses remifentanil as the sole drug because a good level of sedation is obtained, there is no accumulation, little interference with cardiovascular parameters and lower costs in comparison with the others.