Sedative, hemodynamic, and respiratory effects of dexmedetomidine, propofol, and ketamine for intraoperative sedation during spinal anesthesia

This prospective, randomized study was performed to investigate and compare the effect of ultra operative sedatives dexmedetomidine, propofol, and ketamine, in patients undergoing urological procedures under spinal anesthesia with respect to sedation, hemodynamics, respiration, and side effects. The study included 60 adult male patients undergoing urological procedures [e.g. stone ureter and uretroscopy] under spinal anesthesia. Patients were randomized into 3 groups [n=20 in each group], all patients received spinal anesthesia followed by i.v. sedation with dexmedetomidine [bolus dose of 1 micro g/kg over 10 mm followed by iv. infusion of 0.2-0.5 micro g/kgm.], propofol [bolus dose of 0.5mg/kg followed by an intravenous infusion of 1-3mg/kg/h], or ketamine, after iv. administration of 0.01mg/kg midazolam, a continuous infusion of ketamine [0.5mg/kg/h] was started till the end of surgery. Hemodynamic data, oxygen saturation, and respiratory rate were monitored continuously and recorded at the beginning of the procedure and every 10min till the end of surgery and at 1 and 2h post operative. The sedation levels of the patients were assessed by the Ramsay sedation score and measured at 10-minute intervals; a score of 4 was targeted. Serum cortisol level was assessed before surgery [baseline], at 30 mm after skin incision, and 2h post operative. After surgery, the patients were observed in the recovery room until the motor block resolved. Time to the first analgesic demand [VAS 4-5] was recorded. The onset of sedation, and recovery time were also recorded. Side effects such as respiratory depression, hypotension, bradycardia, increased secretions, nausea, vomiting, and visual disturbances were recorded. Demographic and clinical data were comparable in all groups as regards age, sex, ASA physical status, body weight, and operative time. Hemodynamic parameters [SBP, DBP and HR] were comparable in the three groups at baseline. Significant reduction in SBP and DBP was recorded in the three groups after spinal anesthesia which responded well to fluid resuscitation. After 10min of starting sedative infusion SBP and DBP significantly reduced in dexmedetomidine and propofol groups [compared to group III] till the end of the study. HR mean values also showed significant reduction in the three study groups after spinal anesthesia [as compared to baseline]. HR was significantly lower in dexmedetomidine group after starting sedative infusion till end of the study. Serum cortisol level was significantly increased in the three groups compared to baseline reading at 30min and 2h of the study. Serum cortisol at 30min after skin incision in the three groups respectively [19.64 +/- 1.4 micro g/dL] - [23.31 +/- 2.4 micro g/dL] - [23.20 +/- 2.6 micro g/dL]. Serum cortisol at 2h post operative [19.90 +/- 1.3 micro g/dL] - [25.92 +/- 2.7 micro g/dL] - [24.14 +/- 3.1 micro g/dl] in the three groups respectively. Significant lower cortisol level was recorded in dexmedetomidine group compared to group II and III at 30min and 2h post operative. Respiratory rate was decreased significantly from baseline in all groups during sedation [p<0.05] with insignificant difference between groups before or during sedation. Spo2 did not fall below 93% in any patient in dexmedetomidine and ketamine groups during the study, but Spo2<93% was observed in two patients in propofol group. As regards complications, 2 patients in propofol group had respiratory depression. 2 patients in dexmedetomidine group had bradycardia [HR<50 beat/min]. Hypotension was recorded in 1 patient in dexmedetomidine group. Increased secretion was observed in 2 patients in ketamine group. There was no nausea, vomiting, visual disturbances, or hallucinations in the three groups in the postoperative period. In adult patients undergoing urological procedures under spinal anesthesia dexmedetomidine can be used safely. It can provide easily controllable analgesia and sedation without respiratory depression and good attenuating effect on stress response

Pre-emptive analgesia for laparoscopic surgery. a randomized, double-blind, placebo-controlled comparison between parecoxib sodium and tramadol

This study was performed to compare the preemptive effect of intravenous parecoxib vs intravenous tramadol as regards control of stress response to intubation and efficacy of analgesia, in adult patients undergoing laparoscopic surgery. Forty five adult patients ASA physical status I-II scheduled to undergo abdominal laparoscopic surgery were included in this study. Patients were randomly divided into three equal groups. Group I [n = 15] received parecoxib [40 mg iv]. Group II [n = 15] received tramadol [100 mg iv]. Group III [n = 15] received placebo [10 ml normal saline iv]. Anesthesia was induced 10 minutes later using propofol [2 mg/kg] and fentanyl [1-2 micro g/kg]. Tracheal intubation was facilitated using succinyl choline [1.5 mg/kg]. Maintenance of anesthesia was achieved using isoflurane [0.6% - 1.5% according to blood pressure] in a mixture of 50% N[2]O in oxygen. Intraoperative muscle relaxation was maintained using atracurium [0.5 mg/kg followed by 0.1 mg/kg every 20 min]. Mechanical ventilation parameters were adjusted to maintain end-tidal CO[2] [ETCO[2]] at normal levels. Surgery was performed using standard techniques. Catecholamine levels [adrenaline and noradrenaline] were measured 1 minute before and 1 minute after intubation. Heart rate [HR], systolic [SBP] and mean arterial blood pressures [MBP] were recorded 1 minute before, and then every 1 minute after intubation, for 5 minutes. Postoperatively, patients received a continuous infusion of iv morphine at a rate of 0.03 mg/kg/hr. When requested, an additional [rescue] dose of morphine was administered at a dose of 0.05 mg/ kg, to a maximum of one rescue dose per 6 hours. The time till request of the first rescue dose, the number of rescue doses given, and the total rescue morphine dose given were recorded. Patients were observed for the first 24 hrs after surgery for occurrence of nausea and/or vomiting, and pruritis. Data was recorded at 8 hour intervals [8, 16 and 24 hrs after surgery]. There were no intergroup differences as regards age, gender, height or weight. Time to intubation, duration of surgery, doses of propofol and fentanyl used were also similar in-between the groups. Catecholamine levels increased significantly from baseline after intubation in all groups [P < 0.05], but the increase was significantly less in group II [tramadol] than in group I [parecoxib], and both study groups showed a lesser increase compared to placebo [P < 0.05]. Relative to baseline, HR, SBP and MBP increased significantly after intubation in all groups. This increase was significantly greater in group III [P < 0.05]. The tramadol group showed a slightly lesser increase in HR, SBP and MBP compared to the parecoxib group [P < 0.05], but these differences were not clinically significant. Patients in the parecoxib group showed a longer time [median] to first request of rescue analgesia [11.6 hrs] as compared to the tramadol group [7.2 hrs]. Both groups were superior to placebo [3.9 hrs to rescue dose, P < 0.05]. A similar trend was shown in the number, and total dose of rescue morphine, in-between the groups. Nausea and/or vomiting was greatest in the tramadol group [P < 0.05], and more pronounced in all groups in the first 8 hours after surgery. Pruritis was an isolated finding in the tramadol, group; none of the patients in the other two groups complained of pruritis. Both parecoxib and tramadol are effective agents as preemptive analgesics for laparoscopic surgery. While tramadol can have a more stable hemodynamic profile, parecoxib provides a more intense analgesic effect, with a hemodynamic profile that is not clinically inferior to tramadol. The use of tramadol, however, can be associated with more side effects, such as nausea, vomiting, and pruritis