Effect of extradural Ketamine on onset time and sensory block in extradural bupivacaine-induced anesthesia

Epidural anesthesia is an appropriate approach for surgical operations on lower limbs, abdominal region and painless delivery. Since the application of epidural anesthesia is time-consuming and the onset of the effects of injected anesthetic drugs in epidural space is slow [about 20 minutes], therefore, the time of occupying the operating room is prolonged and this results in wasting of time of the surgeon and staff in the operating room. This study was conducted to assess the effect of bupivacaine while used with ketamine on shortening the onset time. This double blind study was done on 40 patients. All the patients were physically ASA I, II and they underwent orthopedic and urologic surgical operations. The patients were randomly divided into two groups of 20 individuals, receiving the drugs as follows: study group: bupivacaine 0.5% - 20 ml + ketamine 25mg [0.5ml] + adrnaline 1/200000, control group: bupivacaine 0.5%, 20ml + ketamine 25mg [0.5ml] + saline 0.9%, 0.5ml + adrenaline 1/200000. After injecting the drug in epidural space in L3-L4 or L4-L5 regions, blood pressure, heartbeat, onset of anesthesia and the level of anesthesia were evaluated in all patients. Patients in both groups were compared with regard to their height, weight, sex, age and systolic blood pressure before the injection of the drugs and no significant difference was noted among them. The systolic blood pressure and heartbeat of patients in both groups were checked in 2[nd], 5[th], 10[th], 15[th], 20[th], 25[th] and 30[th] minutes after drug injection and no significant differences were found in both groups compared to pre-anesthesia status. However, the onset and level of anesthesia was statistically significant in the two groups. The onset of anesthesia in study group was 3.5 to 4 minutes faster and the anesthesia level was two segments higher than that of the control group. Results of this study demonstrated that the addition of 25mg of ketamine to bupivacaine resulted in the acceleration of the onset as well as increase the level of anesthesia in extradural bupivacaine-induced anesthesia and this might be a useful approach in emergency surgical procedures

[Extent of hyperbaric spinal anesthetic with lidocaine 5% influences the duration of spinal block]

Introduction and Objective: elimination of local anesthetic from subarachnoid space is probably depends on rate of local diffusional surface of anesthetic and its vascular absorption. This study was designed to evaluate the relationship between the spread of hyperbaric spinal anesthesia and duration of spinal block

Materials and Methods: to determine the effects of hyperbaric local anesthetic extension on duration of spinal block we studied 40 ASA Class I, II patients whom were candidate for elective surgery [Inguinal hernia]. We randomly divided them into 2 equal groups. After performing spinal block with 2cc hyperbaric lidocaine 5% the first group was left in horizontal position and the second group in 30 torso elevated position. The patients was monitored for pulse oximetry, ECG and noninvasive BP. BP and HR were checked 5 minutes for 30 minutes and then every 15 minute until the end of study

Results: the decrease in MAP was significantly more obvious in horizontal group than 30degree toros elevated group. Duration of block existing is less in horizontal group than 30degree toros elevated group

Conclusion: placing patients in 30degree elevation of torso, after spinal injection, prolonged the duration of spinal block and lessen the hemodynamic changes of spinal anesthesia