Naslov
Comparison of minimum effective volume of local anesthetic for ultrasound guided supraclavicular block (MEAV95) in elderly and middle aged patients

Autori
PAVIČIĆ ŠARIĆ, JADRANKA ; VIDJAK, VINKO ; ZENKO, JELENA ; BOGDANOVIĆ DVORŠČAK, MATEA ; VONČINA, VANJA ; PAKLAR, NATAŠA

Izvornik
Periodicum biologorum (0031-5362) 117 (2015), 2; 273-276

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, ostalo

Ključne riječi
Supraclavicular brachial plexus block ; Local anaesthetic

Sažetak
The aim of this study was to determine the minimum effective volume of local anesthetic (LA) required to produce an efficient supraclavicular block in 95% of patients (MEAV95) using an ultrasound (US)- guided technique in an elderly (>65 y) and a middle aged group (<45 y) of patients. Furthermore, we aimed to calculate potency ratio of LA between the groups. We assumed a reduced MEAV95 in elderly group. Fourty-four patients (N=22 per group) undergoing upper limb surgery received a US- guided supraclavicular block. The study method is a previously validated step-up/step-down sequential model where the volume of LA for each following patient is determined according to the outcome of the previous block. The starting volume was 30 mL ; in the case of block failure, the volume was increased by 5 ml. After successful block, the volume was reduced by 5 mL. MEAV95 was calculated using probit transformation and logistic regression. Potency ratio of LA is calculated using Fieller’s method. The calculated minimum effective anesthetic volume in 95% of patients was 16.49 mL (95% CI, 12.23–20.75 mL) in elderly and 44.52 mL (95% CI, 19.05– 69.99 mL) in middle aged group (95% CI, 0.7–55.3 mL, P=0.044). A potency ratio of LA between middle aged and elderly is 2.69 (95% CI 2.13 to 3.44). The minimum volume requirement for effective US-guided supraclavicular block in 95% of elderly patients was significantly reduced. A potency ratio of 2.69 indicates almost three times stronger LA potency in the elderly.

Izvorni jezik
Engleski

POVEZANOST RADA