In vivo comparison of the effects of bupivacaine and levobupivacaine on the pregnant rat myometrium using electrohysterogram.

BACKGROUND AND AIMS: The effect of local anesthetics on myometrial contractility during labor analgesia is debatable. We aimed to compare the effects of bupivacaine and levobupivacaine on rat uterine contractility in an in vivo setting. METHODS: Electrical activities of 40 pregnant rat uteruses were recorded on electrohysterogram after dividing the rats into bupivacaine and levobupivacaine groups. Uterine contraction frequencies were recorded at each 5-min interval. The first 5-min recording was considered the control, which was immediately followed by intramyometrial administration of either bupivacaine or levobupivacaine. The recordings were continued for 30 min. The changes in frequencies at each time interval of the groups were compared with each other and the control recording. RESULTS: The frequencies from both groups at each interval were lower than the control values, but not different between the groups. The frequencies of the bupivacaine group during the 5-10 min and 10-15 min intervals were lower than the control time interval, but no significant differences were present between the control and the other time intervals. However, no significant differences were found at any time interval for the levobupivacaine group. CONCLUSION: Levobupivacaine led to less muscle relaxation compared to bupivacaine and may be a better option for labor analgesia and anesthesia considering uterine contractility.

Randomized comparison of efficacy of paracetamol, lornoxicam, and tramadol representing three different groups of analgesics for pain control in extracorporeal shockwave lithotripsy.

PURPOSE: Extracorporeal shockwave lithotripsy (SWL) is the mainstay treatment modality for upper urinary tract stones. However, it is a relatively painful procedure and so an efficient analgesia is required for better clinical success. The ideal method of anesthesia has not been standardized. The objective of this randomized study, for the first time in the literature, was to compare the efficacy of three common analgesics, each belonging to a different group, in pain control during SWL. PATIENTS AND METHODS: In this randomized controlled study, 90 patients with upper urinary tract stones undergoing SWL were randomly divided into three groups. Group I (n = 30) received 1 g of paracetamol, group II (n = 30) received 8 mg of lornoxicam, and group III (n = 30) had 1 mg/kg of tramadol. No premedication was applied in all groups. Pain scores by visual analog scale (VAS), blood pressure, heart rate, respiratory rate, and peripheral oxygen saturation were noted before procedure and at 1 minute and every 5 minutes during the SWL. Supplementary analgesic consumption was recorded. Moreover, all adverse effects and both patient and urologist satisfaction were documented. RESULTS: Demographic parameters of the three groups were similar. All monitored parameters were also not different among the groups. The mean VAS scores at all measured times during SWL were below 4 except for two occasions, indicating a relatively efficient overall pain control provided by these three medications. Moreover, the mean VAS scores were similar among these three groups at all measured times during SWL except for those at 5 and 20 minutes at which groups III and II showed lesser pain control, respectively. No difference was observed in the amount of supplementary analgesia, which was required at higher voltages in a majority of patients. There was no significant difference in side effects. CONCLUSION: This study suggests that paracetamol, lornoxicam, and tramadol can be safely and efficiently preferred in pain control during SWL.