[Evaluation of upper limb intravenous block: ketamine with lidocaine versus lidocaine]

ABSTRACT

The most important side effect of venous [Bier] block is systemic toxicity induced by local anesthetics. This is occurred by accidental tourniquet release after drugs' injection. Effects of sensory and motor block of lidocaine increase by use of subanesthetic dose of ketamine with lidocaine simultaneously and its toxicity reduces. To evaluate the sensory and motor block via venous block in patients under upper extremity, surgeries induced by lidocaine compared to lidocaine and ketamine. Forty ASA physical status I-II patients, undergoing elective surgery of the hand or the forearm, were studied in Shahid Rajaee University Hospital. Patients divided in two groups randomly [n= 20]. The affected extremity was exsanguinated by elevating it and wrapping it with an esmarsh bandage. The proximal double- cuffed tourniquet was inflated on the arm of affected extremity and local anesthetics administered [each patient in control group received with 40 ml of lidocaine 0.5% and each patient in intervention group received 40 ml of lidocaine 0.25% plus ketamine 0.1% [40 mg]]. Sensory blocking was assessed by using a blunt pin every 1 minute after local anesthetic injection. Motor block also assessed based on patient's ability to move the operative hand fingers. Data were analyzed using t- test. The mean time of sensory and motor blocks were 4.25 +/- 0.63 and 7.65 +/- 0.24 minutes in control group and 4.35 +/- 0.62 and 8.35 +/- 0.67 minutes in intervention group resoectively. Time of motor block was significantly longer in lidocaine and ketamine group compared to lidocaine group [p= 0/003]. Using lidocaine combined with ketamine is safe method for the intravenous regional anesthesia especially in surgeries on hand or forearm. In this method lidocaine doses for blocking is lessen and reach to nontoxic level