Comparison of pulmonary function during interscalene block vs. supraclavicular block: a single-center, double-blind, randomized trial

Backround The supraclavicular plexus block (SCB) and interscalene plexus block (ISB) have the potential to pulmonary function, the duration of the potential remains uncertain. So, we compared the effect of SCB and ISB on pulmonary function, especially the duration time. Methods Ninety-six patients were finally allocated to group I and group S. The ISB and the SCB procedures were performed with ultrasound guidance before anesthesia induction. An investigator recorded the diaphragm mobility and respiratory function test indicators before the block (T-0) and at 30 min (T-30 min), 4 h (T-4), 8 h (T-8), and 12 h (T-12) after the block. The diaphragmatic paralysis rate was calculated for above timepoint. The VAS, the recovery time for the sensory and motor block, and adverse reactions within 24 h of administering the block were also recorded. Results The recovery times of diaphragm mobility in group I were longer than those in group S. Compared with group I, group S had a significantly lower diaphragmatic paralysis rate during eupnea breathing at T-30 min and T-8 after the block. Similarly, group S had a significantly lower diaphragmatic paralysis rate at deep breathing at T-30 min, T-8,T- and T-12 after the block. The recovery times of FEV1 and FVC in group I were longer than those in group S. The other results were not statistically significant. Conclusions Ultrasound-guided ISB resulted in a longer periods with a suppressive effect on pulmonary function than SCB.