Severe Postural Respiratory Insufficiency Following Interscalene Brachial Plexus Block: A Case Report

摘要

Background: Phrenic nerve block leading to ipsilateral diaphragmatic paralysis is common following the performance of an interscalene brachial plexus block. The diaphragmatic paralysis is generally well tolerated by most patients. Here, we present a case of severe postural respiratory insufficiency following the performance of an interscalene block, in a patient with unrecognized contralateral diaphragmatic eventration.Case presentation: A 53-year-old male with a history of a laparotomy following a motor vehicle accident some years previously, was scheduled to undergo arthroscopic repair of his right rotator cuff. The patient was administered an ultrasound-guided interscalene brachial plexus block for post-operative pain control. The patient remained asymptomatic following the placement of the block while he was in the sitting up position. When he was laid supine for the induction of general anesthesia, he developed severe respiratory insufficiency. The surgery was cancelled. Subsequent chest x-ray and CT scan imaging revealed diaphragmatic eventration on the contralateral side.Conclusion: Unrecognized pathology of the contralateral lung can lead to severe respiratory insufficiency following the placement of an interscalene block. Background The interscalene brachial plexus block (ISBPB) is frequently performed either as a primary anesthetic or for the provision of post-operative pain relief in patients undergoing shoulder surgical procedures.(1) Although the ISBPB is easy to perform and has few complications, concomitant occurrence of phrenic nerve block is universal.(2,3) The phrenic nerve blockade leads to diaphragmatic paralysis with accompanying decrease in pulmonary function. This decrease in pulmonary function is well tolerated by most patients.(4) For those patients in whom the diaphragmatic paralysis may not be well tolerated, the ISBPB is generally avoided. Due to the risk of diaphragmatic paralysis, it is recommended that the ISBPB not be performed in patients who have severe respiratory disease, contralateral pneumonectomy or contralateral diaphragmatic paralysis.(4) Despite these caveats, the ISBPB occasionally results in respiratory insufficiency. In most reported cases of respiratory insufficiency following the ISBPB, there are preoperatively identifiable risk factors.(5,6,7) Here, we present a case of severe postural respiratory insufficiency following an ISBPB in a patient in whom the contralateral diaphragmatic pathology was not preoperatively identified. The patient that is the subject of this report has consented to the publication of this report. Case Report A 53-year-old Hispanic male was scheduled to undergo arthroscopic repair of his right rotator cuff. His medical history was significant for hypertension treated with lisinopril 10 mg and amlodipine 5 mg, PO daily. He also had a 25-pack-year history of smoking. He was obese with a body mass index (BMI) of 31 Kg/m2. He had no symptoms related to his cardiac or respiratory systems. Ten years prior, the patient had undergone laparotomy following a motor vehicle accident that had caused blunt abdominal trauma. He did not have any symptoms related to this laparotomy and was unaware of the actual operative procedure performed. Preoperatively, his vital signs were: non-invasive blood pressure (NBP) 170/102 mm Hg, heart rate (HR) 94/min, respiratory rate (RR) 16 b/min. His pulse oximetric saturation was 98% while breathing room air. Bilaterally, his lung sounds were clear with no adventitious sounds.Following discussion of his anesthetic options, the patient agreed to undergo his surgical procedure under a general anesthetic and elected to have an ISBPB for postoperative pain relief. An ultrasound guided ISBPB was performed following intravenous administration of 2 mg of midazolam. ISBPB was performed using real time ultrasound guidance. The nerve roots were visualized at the level of the cricoid cartilage and a 22 g short bevel needle was directed using an in-