Efficacy of intravenous patient-controlled analgesia after supratentorial intracranial surgery: a prospective randomized controlled trial

Abstract

Opioid administration following major intracranial surgery is often limited by a presumed lack of need and a concern that opioids will adversely affect postoperative outcome and interfere with the neurological examination. Nevertheless, evidence is accumulating that these patients suffer moderate to severe postoperative pain and that this pain is often undertreated. The authors hypothesized that intravenous patient-controlled analgesia (PCA) would safely and more effectively treat postoperative supratentorial craniotomy pain than conventional as needed (PRN) therapy. Following a standardized course of general anesthesia, adult patients who underwent elective supratentorial intracranial surgery were randomized in the neurosciences intensive care unit to receive either PRN intravenous fentanyl 25-50 microg every 30 minutes or PCA intravenous fentanyl 0.5 microg/kg every 15 minutes (maximum 4 doses/hour). The authors measured pain (self-reported scale score [0-10]), sedation (Ramsay Sedation Scale score), Glasgow Coma Scale score, fentanyl use, and major adverse events (excessive sedation, respiratory depression, pruritus, nausea, or vomiting) hourly. Sixty-four patients with a mean age of 48 years (range 22-77 years) were randomized to intravenous PCA (29 patients) or PRN fentanyl (35 patients) groups. There were no statistically significant demographic differences between the 2 groups. Patients receiving intravenous PCA had significantly lower pain scores than those receiving intravenous PRN fentanyl (2.53 +/- 1.96 vs 3.62 +/- 2.11 [p = 0.039]) and received significantly more fentanyl than the PRN group (44.1 +/- 34.5 vs 23.6 +/- 23.7 microg/hour [p = 0.007]). There were no differences between the 2 groups regarding the number of patients with adverse events. Intravenous PCA more effectively treats the pain of supratentorial intracranial surgery than PRN fentanyl, and patients in the former group did not experience any untoward events related to the self-administration of opioids.