HEMIDIAPHRAGMATIC PARALYSIS AS A RESULT OF INTERSCALENE BRACHIAL PLEXUS NERVE BLOCK FOR POSTOPERATIVE PAIN

Abstract

SESSION TITLE: Wednesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: Hemidiaphragmatic paralysis (HDP) is an uncommon complication of an interscalene brachial plexus block (ISBPB) and normally resolves within the first few days to months. In rare occurrences HDP can be permanent. CASE PRESENTATION: A 71-year-old female presented for a three-month history of worsening shortness of breath and developed fever, productive cough, and myalgias in the preceding days. A chest x-ray showed right-sided lower lobe consolidation. The patient was diagnosed with community-acquired pneumonia and placed on antibiotics. Six-weeks after diagnosis the patient had resolution of the cough, fever, and myalgia, without improvement in her shortness of breath. A CT scan of the chest demonstrated complete resolution of her pneumonia. However, she was noted to have elevation of her right hemidiphragm to the level of the carina. Her only prior imaging was a CT of the abdomen obtained approximately one-year prior that showed a normal diaphragm. As her only recent medical history was a right rotator cuff repair, the operative report was reviewed. The report revealed that she had a right ISBPB for pain control, a procedure that has been associated with HDP (3). A sniff test showed complete paralysis of the right hemidiaphragm. EMG testing confirmed right phrenic nerve palsy and no cervical radiculopathy. The patient has had regular follow up over the past three years with repeat sniff testing continues to show paralysis of the right hemidiaphragm. DISCUSSION: ISBPB is an effective method for controlling pain after shoulder surgery and is regular practice in orthopedic surgery. While most complications of ISBPB are benign, this procedure has been associated with serious complications such as motor weakness, pneumothorax, and HDP (1). While cases of HDP usually resolve within the first 6 months, paralysis can be permanent (2). HDP as a complication of ISBPB occurs due to needle trauma, intraneuronal injection, or local toxicity of the anesthetic (2). Technique of the interscalene block has changed since the institution of routine ultrasound in anesthetic procedures. Changing from landmark-guided to ultrasound-guided technique has resulted in a significant decline in phrenic nerve paralysis (3). Phrenic nerve and resultant diaphragmatic paralysis can lead to difficulty clearing secretions, bronchiatatic changes in the lungs, and an increased risk for infection. The above case illustrates a patient who may have developed pneumonia due to HDP. CONCLUSIONS: HDP is an uncommon but potentially serious complication of ISBPB. Although the paralysis is usually short-lived, it can be permanent with long-term implications for development of subsequent pulmonary disease. The use of intraprocedural ultrasound has significantly reduced the occurrence of HDP. Practitioners performing these nerve blocks should consider using ultrasound to reduce the risk of unintended complications. Reference #1: Bowens, C., & Sripada, R. (2012). Regional Blockade of the Shoulder: Approaches and Outcomes. Anesthesiology Research and Practice, 2012, 1-12. https://doi.org/10.1155/2012/971963 Reference #2: Borgeat, A., Ekatodramis, G., Kalberer, F., & Benz, C. (2001). Acute and Nonacute Complications Associated with Interscalene Block and Shoulder Surgery. Anesthesiology, 95(4), 875-880. https://doi.org/10.1097/00000542-200110000-00015 Reference #3: Borgeat, A., Blumenthal, S., & Hadžić, A. (2007). Mechanisms of Neurologic Complications with Peripheral Nerve Blocks. Complications of Regional Anesthesia, 74-86. https://doi.org/10.1007/978-0-387-68904-3_5 DISCLOSURES: No relevant relationships by Eric Micallef, source=Web Response No relevant relationships by Ellen Mooney, source=Web Response