Sedation in the critically ill patient

Comparison of selected sedation scales for reporting opioid-induced sedation assessment

A descriptive survey-based study was undertaken to test the validity and reliability of three scales that are used to assess sedation during opioid administration for pain management: the Inova Health System Sedation Scale (ISS), the Richmond Agitation and Sedation Scale (RASS), and the Pasero Opioid-Induced Sedation Scale (POSS). The study was conducted in a large (830 beds) suburban level I trauma hospital with a random convenience sample of 96 medical-surgical nurses. The study reports: measures of reliability and validity of each scale and significant findings related to correct nursing score and selected actions; nurses' ratings of each scale in terms of combined ease of use; information provided by the scale to inform clinical decisions; and nursing confidence measures. Both the RASS and the POSS demonstrated adequate measures of reliability and validity for measurement of sedation during opioid administration for pain management. However, the POSS scored higher in combined measures of ease of use, nursing confidence, and usefulness of information provided to make clinical decisions. The POSS also yielded the highest percentage agreement with the correct score and correct nursing actions chosen by the nurse among the three scales tested. Study results have clinical significance for accuracy of clinical assessments and subsequent actions on behalf of patients experiencing advancing sedation during opioid analgesia. The POSS can be recommended as a superior sedation scale for the measurement of sedation during opioid administration for pain management.

Remifentanil versus fentanyl for analgesia based sedation to provide patient comfort in the intensive care unit: a randomized, double-blind controlled trial [ISRCTN43755713]

INTRODUCTION

This double-blind, randomized, multicentre study was conducted to compare the efficacy and safety of remifentanil and fentanyl for intensive care unit (ICU) sedation and analgesia.

METHODS

Intubated cardiac, general postsurgical or medical patients (aged >/= 18 years), who were mechanically ventilated for 12-72 hours, received remifentanil (9 microgram/kg per hour; n = 77) or fentanyl (1.5 microgram/kg per hour; n = 75). Initial opioid titration was supplemented with propofol (0.5 mg/kg per hour), if required, to achieve optimal sedation (i.e. a Sedation-Agitation Scale score of 4).

RESULTS

The mean percentages of time in optimal sedation were 88.3% for remifentanil and 89.3% for fentanyl (not significant). Patients with a Sedation-Agitation Scale score of 4 exhibited significantly less between-patient variability in optimal sedation on remifentanil (variance ratio of fentanyl to remifentanil 1.84; P = 0.009). Of patients who received fentanyl 40% required propofol, as compared with 35% of those who received remifentanil (median total doses 683 mg and 378 mg, respectively; P = 0.065). Recovery was rapid (median time to extubation: 1.1 hours for remifentanil and 1.3 hours for fentanyl; not significant). Remifentanil patients who experienced pain did so for significantly longer during extubation (6.5% of the time versus 1.4%; P = 0.013), postextubation (10.2% versus 3.6%; P = 0.001) and post-treatment (13.5% versus 5.1%; P = 0.001), but they exhibited similar haemodynamic stability with no significant differences in adverse event incidence.

CONCLUSION

Analgesia based sedation with remifentanil titrated to response provided effective sedation and rapid extubation without the need for propofol in most patients. Fentanyl was similar, probably because the dosing algorithm demanded frequent monitoring and adjustment, thereby preventing over-sedation. Rapid offset of analgesia with remifentanil resulted in a greater incidence of pain, highlighting the need for proactive pain management when transitioning to longer acting analgesics, which is difficult within a double-blind study but would be quite possible under normal circumstances.