Respiratory effects of sufentanil and remifentanil in spontaneously ventilated patients after major abdominal surgery

Introduction

Opioids as analgosedative agents are commonly used in intensive care units but they are not performed in spontaneously breathing patients because of the potential risks of adverse respiratory events. The aim of this study was to assess the respiratory effects of sufentanil and remifentanil in postsurgical critically ill patients during spontaneous ventilation since the drugs show pharmacokinetic and pharmacodynamic properties which make them attractive for intensive care use.

Patients and methods

Twenty-seven patients requiring mechanical ventilatory support were admitted in the general Intensive Care Unit of the San Giacomo Hospital after major abdominal surgery. They were randomised to receive either sufentanil (group S = 13 patients) or remifentanil (group R = 14 patients) variable continuous infusion in order to obtain pain control and to maintain a Ramsay Sedation Score of 2-3 as the target point. Rescue sedation was provided, when needed, with Midazolam boluses. Respiratory rate (RR), V_E, TV, EtCO₂, pH, PaO₂, PaCO₂ and SpO₂ were measured in the two groups of patients during the continuous infusion of the opioids before and 1 hour after the beginning of spontaneous ventilation (Pressure Support Ventilation) and then every 6 hours, even after extubation. Statistical differences were scored using the Mann-Whitney U test and ANOVA test for repeated measures.

Results

Adequate analgesia and sedation were achieved with sufentanil and remifentanil administration. Midazolam mean dosage was significantly higher in the remifentanil group. There were no statistically significant differences between the two groups for RR, TV, T_E, EtCO₂, pH, PaO₂, PaCO₂, SpO₂ at the different times. No adverse respiratory events were seen during the study.

Discussion

The present results show that sufentanil and remifentanil continuous infusion at the appropriate dosage appear to have no important adverse effects on respiratory drive and gas exchange in spontaneously breathing critically ill patients after surgery.