ABSTRACT
Dexmedetomidine is an alpha2-adrenergic agonist with sedative and analgesic properties. This study aimed to investigate if the use of a continuous dexmedetomidine infusion with i.v. morphine patient-controlled analgesia [PCA] could improve postoperative analgesia while reducing opioid consumption and opioid-related side effects. In this prospective randomized, double-blinded, controlled study, 39 patients with obstructive sleep apnea syndrome undergoing uvulopalatopharyngoplasty were assigned to two groups. Group D [dexmedetomidine group] received a loading dose of dexmedetomidine 1 microg.kg[-1] i.v., 30 minutes before the anticipated end of surgery, followed by infusion at 0.6 microg.kg[-1] h[-1] for 24 hours. Group P [placebo group] received a bolus and infusion of placebo. In both groups, postoperative pain was initially controlled by i.v. morphine titration and then PCA with morphine. Cumulative PCA morphine consumption, pain intensities, sedation scores, cardiovascular and respiratory variables and opioid-related adverse effects were recorded for 48 hours after operation. Compared with placebo group, patients in the dexmedetomidine group required 52.7% less PCA morphine during the first 24 hours postoperatively, with significantly better visual analogue scale scores, less incidence of respiratory obstruction [5 vs. 12 patients, respectively; P = .037] and longer time to first analgesic request [21 [11] vs. 9 [4] minutes; P = .002]. Fewer patients in group D experienced nausea and vomiting than those in group P [7 vs. 24 patients, respectively; P < .05]. Continuous dexmedetomidine infusion may be a useful analgesic adjuvant for patients susceptible to opioid-induced respiratory depression
ABSTRACT
To compare the effects of intramuscular ketamine with pethidine and placebo on post operative shivering in children undergoing tonsillectomy. A prospective randomized double-blind study was conducted at King Abdulaziz Naval Base Hospital, Jubail, Kingdom of Saudi Arabia, from November 2006 to October 2007. One hundred and twenty children [American Society of Anesthesiologists Grade 1, aged 5-12 years] were enrolled. Children were randomly allocated to receive ketamine 1 mg/kg [group K, n=40], or pethidine 0.5 mg/kg [group P, n=40], or normal saline [group S, n=40] intramuscularly just after induction of general anesthesia. Hemodynamic parameters, oxygen saturation and tympanic temperature were measured and recorded before induction of anesthesia and at regular intervals thereafter. An investigator blinded to the treatment group, graded postoperative shivering using a 5 point scale. The number of patients shivering on arrival to the recovery room and at 10 and 20 minutes after operation were significantly less in groups K [1,1,1] than in group S [19,12,17]. No patient that received pethidine shivered. The time to first analgesic requirement in group S was shorter than groups K and P [p=0.001]. The study indicates that the use of a prophylactic low dose ketamine was found to be effective in preventing post anesthesia shivering in children undergoing tonsillectomy. Ketamine may have at least theoretical advantages over pethidine as regard respiratory depression, nausea, and vomiting