Aim: The aim of the study was the evaluation of postoperative short term analgesia-based sedation provided by a continuous i.v. morphine vs morphine+remifentanil infusion in the ICU.
Methods: A prospective, randomized, controlled study was carried out.
Inclusion criteria: patients aged > 18 years undergoing major surgery (abdominal, vascular, thoracic). A total of 100 patients undergoing balanced anaesthesia, were enrolled; at the end of surgery an i.v. loading morphine dose (0.1 mg/kg) was administered and a continuous ground i.v. infusion (0.24 microg/kg/min) was started. When the patient was admitted to the ICU, a second i.v. continuous infusion was started and patients were allocated into 2 groups with regard to the second opioid: MM = morphine + morphine, MR = morphine + remifentanil. The second continuous infusion (boluses allowed) was titrated to obtain a numerical rate score (NRS) < 3 and Ramsay Scale =or>2. If Ramsay =or< 2 rescue sedation was administered (diazepam).
Results: The groups were homogeneous with regard to gender, age, weight, duration of surgery, intraoperative opioids, SAPS II. The second infusion rate in the first 24 postoperative hours was 0.73+/-0.55 microg/kg/min morphine in MM and 0.06+/-0.05 microg/kg/min remifentanil in RM. Hemodynamic parameters and SpO(2) were similar. Hypnotic consumption and NRS were significantly lower in RM, while Ramsay Scale was higher. Postextubation respiratory rate and minute volume were lower in group MM, while PaCO(2), postoperative nausea and vomiting (PONV) incidence and frequency of diazepam administration were higher. In both groups more than 70% of the patients were very satisfied.
Conclusion: The combination of morphine + remifentanil provided better analgesia and sedation than morphine alone, with a lower incidence of side effects and a similar hemodynamic profile and patient satisfaction. The adherence to a clear analgesia based sedation protocol probably represents the most important issue carrying out analgosedation; however, the continuous infusion of a short acting drug, although more expensive, allows better titration and adjustment of the desired level of analgesia and sedation, avoiding the risk of undersedation as well as oversedation with a potential reduction of otherwise unnecessary ICU stays and, consequently, a decrease in comprehensive costs.