engleski

Effects of age on onset time and duration of sensory blockade in ultrasound guided supraclavicular block Abstract

Involutive changes of brachial plexus occur with aging. The aim of this study was to determine if these changes would effect onset time and duration of sensory blockade in all four distal nerves of brachial plexus in middle aged (<50 years) and elderly patients (>65 years). Middle aged (N=22) and elderly patients (N=22) undergoing upper limb surgery received an ultrasound guided supraclavicular block with a mixture of local anesthetics (50 : 50, 0.5% levobupivacaine, 2% lidocaine). The prospective, observer-blinded study method is a previously validated step-up/step-down sequential model where the local anesthetic volume for each following patient is determined by the outcome of the previous block. The starting volume was 30 ml. Only the blocks with complete sensory blockade in all four regions of distal nerves were analyzed for the onset time and duration of sensory blockade. The mean (SD) block onset time was 25.8±0.6 min and the mean (SD) block duration was 151.5±8.9 min in the entire middle aged group. In the entire elderly group, the mean (SD) block onset time was 21±0.82 min and the mean (SD) block duration was 195.75±14.99 min. The difference in both, onset time and duration was significant (P=0.0002, 95%CI 3.352–6.248 ; P=0.0023, 95% CI 65.63– 22.95, respectively). In conclusion, local anesthetics have a faster onset time and longer duration of sensory blockade in elderly due to alterations of peripheral nerves and increased sensitivity to local anesthetic

Supraclavicular brachial plexus block ; Local anaesthetic

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