Addition of ketamine to propofol for initiation of procedural anesthesia in children reduces propofol consumption and preserves hemodynamic stability.

BACKGROUND: There is no ideal anesthesia protocol to perform short invasive procedures in pediatric oncology. The combination of propofol and ketamine may offer advantages over propofol alone. METHODS: In a prospective, randomized, double-blind study, we analyzed 63 consecutive procedures performed in 47 oncology children. All patients received 1 mug/kg fentanyl, followed by propofol 1 mg/kg in group P (n=33) or propofol 0.5 mg/kg and ketamine 0.5 mg/kg in group PK (n=30) for the initiation of anesthesia. The need for supplementation with propofol and/or fentanyl to maintain an adequate level of anesthesia was recorded. The hemodynamic and respiratory profile, recovery time and the occurrence of side effects were compared. RESULTS: Significantly more children required propofol (100% vs. 83.3%) and fentanyl (75.5% vs. 43.3%) rescue doses, and developed hypotension (63.6% vs. 23.4%) and bradycardia (48.5 vs. 23.4%) in group P compared with group PK, with a comparable incidence of respiratory adverse events and recovery times. However, 40% of children in group PK were agitated following recovery compared with 6% in group P. CONCLUSIONS: The combination of propofol and ketamine for invasive procedures in pediatric oncology resulted in reduced propofol and fentanyl consumption and preserved hemodynamic stability, but more children in the combination group recovered with agitation.

Effect of low-dose dexmedetomidine or clonidine on the characteristics of bupivacaine spinal block.

BACKGROUND: The purpose of this study was to compare the onset and duration of sensory and motor block, as well as the hemodynamic changes and level of sedation, following intrathecal bupivacaine supplemented with either dexmedetomidine or clonidine. METHODS: In a prospective, double-blind study, 60 patients undergoing transurethral resection of prostate or bladder tumor under spinal anesthesia were randomly allocated to one of three groups. Group B received 12 mg of hyperbaric bupivacaine, group D received 12 mg of bupivacaine supplemented with 3 microg of dexmedetomidine and group C received 12 mg of bupivacaine supplemented with 30 microg of clonidine. The onset times to reach peak sensory and motor levels, and the sensory and motor regression times, were recorded. Hemodynamic changes and the level of sedation were also recorded. RESULTS: Patients in groups D and C had a significantly shorter onset time of motor block and significantly longer sensory and motor regression times than patients in group B. The mean time of sensory regression to the S1 segment was 303 +/- 75 min in group D, 272 +/- 38 min in group C and 190 +/- 48 min in group B (B vs. D and B vs. C, P < 0.001). The regression of motor block to Bromage 0 was 250 +/- 76 min in group D, 216 +/- 35 min in group C and 163 +/- 47 min in group B (B vs. D and B vs. C, P < 0.001). The onset and regression times were not significantly different between groups D and C. The mean arterial pressure, heart rate and level of sedation were similar in the three groups intra-operatively and post-operatively. CONCLUSIONS: Dexmedetomidine (3 microg) or clonidine (30 microg), when added to intrathecal bupivacaine, produces a similar prolongation in the duration of the motor and sensory block with preserved hemodynamic stability and lack of sedation.