Severe stridor and marked respiratory difficulty after right-sided supraclavicular brachial plexus block

Brachial plexus block is commonly used for upper limb surgery. Although the procedure is safe, it may be associated with some life-threatening complications. We performed right-sided supraclavicular brachial plexus block for below-elbow amputation in a 45-year-old female. At completion of the block the patient developed marked respiratory difficulty with audible inspiratory stridor. Although SpO(2) decreased to 82% initially, it was increased to 100% by continuous positive airway pressure with a face mask. On conventional direct laryngoscopy, the left vocal cord was found to be in the midline position and the right vocal cord was in the paramedian position. The trachea was intubated and surgery proceeded without any other complication. Postoperative indirect laryngoscopy revealed that the left vocal cord was fixed, whereas the right vocal cord was mobile, and diagnosis of pre-existing incomplete left vocal cord paralysis was made. This clinical report is to emphasize the importance of thorough pre-operative evaluation of the vocal cord in patients who have undergone any surgical procedure or radiation treatment of the neck before planning for brachial plexus block. If such an evaluation cannot be obtained, an alternative technique, for example axillary approach, should be preferred.