Pre-emptive analgesia using intravenous fentanyl plus low-dose ketamine for radical prostatectomy under general anesthesia does not produce short-term or long-term reductions in pain or analgesic use.
The aim of the study was to evaluate post-operative pain and analgesic use after pre-operative or post-incisional i.v. fentanyl plus low dose i.v. ketamine vs. a standard treatment receiving i.v. fentanyl but not ketamine. Men undergoing radical prostatectomy under general anesthesia were randomly assigned in a double-blinded manner to one of three groups. Patients received i.v. fentanyl before incision followed by an i.v. bolus dose (0.2 ml kg(-1)) and an i.v. infusion (0.0025 ml kg(-1)min(-1)) of 1 mg ml(-1) ketamine (group 1) or normal saline (groups 2 and 3). Seventy minutes after incision, patients received i.v. fentanyl followed by an i.v. bolus dose (0.2 ml kg(-1)) and an i.v. infusion (0.0025 ml kg(-1)min(-1)) of saline (groups 1 and 3) or ketamine (group 2). Pain, von Frey pain thresholds, and cumulative morphine consumption using patient-controlled analgesia (PCA) were assessed up to 72 h after surgery. 143 patients completed the study (group 1, n = 47, group 2, n = 50, group 3, n = 46). Cumulative PCA morphine (mean+/-SD) did not differ significantly among groups (group 1, 92.3+/-45.9 mg; group 2, 107.2+/-58.4 mg; group 3, 103.6+/-50.4 mg; P = 0.08 for groups 1 vs. 2, and groups 1 vs. 3). On day 3, the hourly rate (mean+/-SEM) of morphine consumption was significantly lower (p < 0.0009) in group 1 (0.61+/-0.013 mg h(-1)) than group 2 (0.86+/-0.011 mg h(-1)) and group 3 (0.89+/-0.008 mg h(-1)). Pain scores and von Frey pain thresholds did not differ significantly among groups. Two-week and 6-month follow-ups did not reveal significant group differences in pain incidence, intensity, disability or mental health. Pre-operative, low-dose administration of i.v. ketamine did not result in a clinically meaningful reduction in pain or morphine consumption when compared with post-incisional administration of ketamine or a saline control condition.
Department of Psychology and School of Kinesiology and Health Science, York University, Toronto, Ont., Canada Department of Anesthesia and Pain Management, University Health Network and Mount Sinai Hospital, Toronto, Ont., Canada Department of Anesthesia, University of Toronto, Toronto, Ont., Canada Department of Anesthesiology/Pain Centre, University Medical Centre Nijmegen, Nijmegen, The Netherlands Departments of Anesthesia, Neurology and Neurosurgery and Psychology, McGill University; McGill University Health Centre Research Institute and McGill Centre for Research on Pain, Montreal, Que., Canada.
Joel
J
Katz
Roger
R
Schmid
Dirk G
DG
Snijdelaar
Terence J
TJ
Coderre
Colin J L
CJL
McCartney
Adarose
A
Wowk
D000368:Aged; D000698:Analgesia / Q000379:methods*; D000704:Analysis of Variance; D000768:Anesthesia, General / Q000379:methods; D016009:Chi-Square Distribution; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D005283:Fentanyl / Q000008:administration & dosage*; D006801:Humans; D007262:Infusions, Intravenous; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods; D010149:Postoperative Pain / Q000188:drug therapy* / Q000503:physiopathology; D011468:Prostatectomy / Q000379:methods*; D013997:Time Factors
D007649:Ketamine; D005283:Fentanyl