Hemidiaphragmatic Paresis During Interscalene Brachial Plexus Block

Abstract

We studied the effects of unilateral hemidiaphragmatic paresis caused by interscalene brachial plexus block on routine pulmonary function in eight patients. In an additional four patients, we studied changes in chest wall motion during interscalene block anesthesia by chest wall magnetometry. Ipsilateral hemidiaphragmatic paresis, as diagnosed by ultrasonography, developed in all patients within 5 min of interscalene injection of 45 mL of 1.5% mepivacaine with added epinephrine and bicarbonate. Large decreases in all pulmonary function variables were measured in every patient. Forced vital capacity and forced expiratory volume at 1 s decreased 27% +/- 4.3% and 26.4% +/- 6.8%, respectively (P = 0.0001). Peak expiratory and maximum midexpiratory flow rates were also significantly reduced. Interscalene block caused changes in pulmonary function and chest wall mechanical motion that were similar to those published in previous studies on patients with hemidiaphragmatic paresis of pathological or surgical etiology. Interscalene block probably should not be performed in patients who are dependent on intact diaphragmatic function and in those patients unable to tolerate a 25% reduction in pulmonary function.

Eficácia analgésica pós-operatória de diferentes volumes e massas de ropivacaína no bloqueio de plexo braquial pela via posterior

“…Ipsilateral diaphragmatic paralysis is a common complication expected after brachial plexus block both by the interscalene and the paravertebral cervical approach, due to the block of phrenic nerve (C3-C5 roots), it may occur in 100% of cases when habitual doses of local anesthetics are used 29,30 . However, paresis, and even total hemidiaphragmatic paralysis, does not lead to respiratory failure in healthy people 29 .…”

Bloqueio do plexo braquial por via axilar com neuroestimulador: verificação da latência e da eficácia

“…A via interescalênica, embora muito usada para cirurgias acima do cotovelo, além de, com freqüência, promover anestesia incompleta do nervo ulnar, não é recomendada para pacientes que não tolerem 25% de redução na função pulmonar, já que a paralisia do frênico ocorre em todos os casos 11 . A via supraclavicular, embora seja considerada a mais eficaz 13 e confiável, apresenta riscos de paralisia do frênico (até 50% dos casos) e pneumotórax (0,5 a 6%), que pode ocorrer até 12 horas após o bloqueio.…”

“…The interscalenic route, although widely used for surgeries above the elbow very often promotes incomplete anesthesia of the ulnar nerve and is not recommended for patients sensitive to 25% reduction in pulmonary function, since phrenic nerve paralysis is present in all cases 11 . The supraclavicular route, although being considered the most efffective 13 and reliable technique, poses a risk for phrenic nerve paralysis (up to 50% of cases) and pneumothorax (0.5% to 6%), which may occur up to 12 hours after the blockade.…”

Anesthesia for Shoulder Surgery: A Review of the Interscalene Block and a Discussion of Regional vs. General Anesthesia

“…However, patients whose ability to ventilate is dependent on bilateral diaphragmatic function may not tolerate interscalene block anesthesia since the incidence of ipsilateral hemidiaphragmatic paralysis has been reported to be 100% following interscalene block [9][10][11].…”

“…This is because the positions usually assumed for shoulder surgery confer physiologic advantages to pulmonary mechanics [9,[71][72][73][74]. Gravity influences pulmonary blood flow to help offset changes in ventilation/perfusion mismatching.…”