Effect of cooled hyperbaric bupivacaine on unilateral spinal anesthesia success rate and hemodynamic complications in inguinal hernia surgery.

PURPOSE: We hypothesized that cooling hyperbaric bupivacaine from 23 to 5 °C may limit the intrathecal spread of bupivacaine and therefore increase the success rate of unilateral spinal anesthesia and decrease the rate of hemodynamic complications. METHODS: A hundred patients scheduled for elective unilateral inguinal hernia surgery were randomly allocated to receive 1.8 ml of 0.5 % hyperbaric bupivacaine intrathecally at either 5 °C (group I, n = 50) or at 23 °C (group II, n = 50). Following spinal block at the L2-3 interspace, the lateral decubitus position was maintained for 15 min. Unilateral spinal anesthesia was assessed and confirmed at 15 and 30 min. The levels of sensory and motor block on the operative side were evaluated until complete resolution. RESULTS: The rate of unilateral spinal anesthesia at 15 and 30 min was significantly higher in group I (p = 0.015 and 0.028, respectively). Hypotensive events and bradycardia were significantly rarer in group I (p = 0.014 and 0.037, respectively). The density and viscosity of the solution at 5 °C was significantly higher than at 23 °C (p < 0.0001). Compared with group II, sensory block peaked later in group I (17.4 vs 12.6 min) and at a lower level (T9 vs T7), and two-segment regression of sensory block (76.4 vs 84.3 min) and motor block recovery was shorter (157.6 vs 193.4 min) (p < 0.0001). CONCLUSIONS: Cooling of hyperbaric bupivacaine to 5 °C increased the density and viscosity of the solution and the success rate of unilateral spinal anesthesia, and decreased the hemodynamic complication rate.

A comparison of dexmedetomidine versus midazolam for sedation, pain and hemodynamic control, during colonoscopy under conscious sedation.

OBJECTIVE: The intent of our study was to compare the effects of dexmedetomidine versus midazolam on perioperative hemodynamics, sedation, pain, satisfaction and recovery scores during colonoscopy. MATERIAL AND METHODS: A total of 60 ASA I-II patients, between 20 and 80 years of age were included in the study. Patients were randomly assigned to two groups. Midazolam 0.05 mg kg(-1) and fentanyl citrate 1 microg kg(-1) were administered intravenously to cases in Group I (n = 30). An initial loading dose of 1 microg kg(-1) dexmedetomidine was administered intravenously in 10 min to cases in Group II (n = 30) before the procedure and as a continuous infusion dose of 0.5 microg kg(-1) h(-1) just before the procedure started. Also 1 microg kg(-1) fentanyl citrate was administered intravenously immediately before the procedure. Peripheral oxygen saturation (S(pO2)), mean arterial pressure (MAP), heart rate (HR), Ramsay Sedation Scale (RSS), Numeric Rating Scale (NRS) scores and colonoscopist satisfaction scores of the cases were recorded. RESULTS: Although statistically significant values were not detected between the two groups with regard to mean arterial pressure, in Group I heart rates were higher and S(pO2) scores were lower in a statistically significant manner. When the groups were compared with regard to RSS, the RSS scores of Group I at the 10th and 15th minutes were significantly lower than Group II. There was no statistically significant difference between the two groups when compared with regard to NRS scores. Satisfaction scores were significantly lower in Group II. CONCLUSION: Dexmedetomidine provides more efficient hemodynamic stability, higher Ramsay sedation scale scores, higher satisfaction scores and lower NRS scores in colonoscopies. According to our results we believe that dexmedetomidine can be used safely as a sedoanalgesic agent in colonoscopies.