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Introduction

The incidence of haemodynamic disturbance and myocardial ischaemia in the ICU can be reduced if sedation is continued over the peri-extubation period [1]. Dexmedetomidine has been shown to cause only minimal ventilatory depression in human volunteers [2] and also possesses analgesic and sympatholytic properties and so may be a useful agent for this peri-extubation period.

Methods

Twenty-five patients involved in a randomised, placebo-controlled, double-blind study were ventilated for at least 6 h postoperatively and were sedated with dexmedetomidine or placebo infusions. They were then extubated whilst receiving these respective infusions. Following extubation, infusions (Dexmedetomidine 0.2-0.7 µg/kg/h) were continued for six hours to maintain a Ramsay sedation score = 2. Rescue sedation and analgesia was provided by midazolam and morphine respectively, if clinically required. Arterial blood gas estimation, oxygen saturation, respiratory rate and analgesic requirements were recorded for the peri-extubation period. Results are reported as mean (SD) and analysed using Mann-Whitney-U and ANOVA for repeated measures where appropriate.

Results

Patient demographics and degree of sedation and analgesia was equivalent in the two groups but the placebo group required three times more morphine (P=0.04). The average dexmedetomidine infusion rate was 0.15 µg.kg-1h-1 following extubation. No adverse respiratory events were seen in either group.

Summary

Dexmedetomidine is safe to use in extubated spontaneous breathing intensive care patients and does not cause clinically significant respiratory depression.

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