ABSTRACT
Local anesthesia techniques are suitable for upper limb surgery but the effects of anesthetic agent's concentration, volume and total dose on motor and sensory block success rate is controversial. The aim of the present study was to investigate the effect of anesthetic agent's concentration and volume on the sensory and motor nerve block onset time and its quality in upper limb orthopedic surgeries. In this double blind clinical trial 60 patients ASA class I, II who were candidate for upper limb surgeries were enrolled to the study and were randomly divided into two groups; lidocaine 2% [7ml] and lidocaine 1.3% [10ml]. Vertical infra-clavicular technique using ultrasound guide was applied. Onset time and quality of sensory and motor block of Radial, Median, Ulnar and MSN nerves were recorded and compared every 5 minutes for 20 minutes. Onset time of sensory and motor block in the lidocaine 1.3% was significantly shorter than lidocaine 2% [p>0.05]. The success rate of sensory and motor block in group of lidocaine 1.3% was higher than lidocaine 2% but there was no significant difference between the two groups [82.8% and 78.6% respectively, p>0.05]. The quality of motor block of Radial nerve and sensory block of MSN were significantly better in the group of lidocaine 1.3%. The volume of anesthetic agents can affect the onset time of sensory and motor block of brachial plexus but there was no statistically significant effect on success rate of blockade
ABSTRACT
Neonatal respiratory depression due to narcotics usage during cesarean section under general anesthesia is an important challenge for anesthesiologists. Remifentanil, due to its pharmacokinetic properties, may be a solution for this challenge. This study was designed to evaluate the effect of this drug on maternal hemodynamics and Apgar scores of their neonates during cesarean section under general anesthesia. In this double blind randomized controlled clinical trial, 84 women who were candidates for elective cesarean section under general anesthesia were randomly allocated into three groups. In the first group remifentanil was infused at a rate of 0.5micro g/kg/min and the second group received an IV bolus of 0.7 micro g/kg of the drug. Control group received an equivalent volume of normal saline. Maternal heart rate and blood pressure were measured and recorded before induction of anesthesia and one minute after tracheal intubation. Neonatal Apgar scores in the first and fifth minutes postnatal were also recorded and compared. Mean maternal HR changes before and after tracheal intubation were not significant between groups [P= 0.33]. Mean arterial pressure [MAP] changes between groups were significantly different [P= 0.001]. MAP changes were smallest in the bolus group and largest in the control group. These changes were not significantly different between infusion and control groups [P= 0.994]. This difference was significant between the bolus group with the infusion and control groups [P=0.001 and 0.002 respectively]. The mean first minute Apgar scores in neonates were significantly different in three groups [p=0.006]. This parameter was not significantly different between bolus and infusion groups [p=0.603]. Mean first minute Apgar scores in the bolus [8.46] and infusion [8.31] groups were significantly less than the control [8.93] group [p= 0.005 and 0.002 respectively]. The mean fifth minute Apgar scores were not significantly different between three groups. None of the neonates in the remifentanil groups needed resuscitation. The results indicated that bolus administration of remifentanil [compared with infusion and control groups] produces more stability in maternal blood pressure during cesarean section under general anesthesia. The decrease in first minute Apgar score in remifentanil groups were clinically negligible [none of these neonates needed resuscitation]. Despite these results, multicenter studies more samples are needed to confirm using remifentanil in elective cesarean section