(Kiosk 1) Pulmonary Embolism Despite Heparin Prophylaxis in a Patient with Acute Motor-sensory Axonal Neuropathy: A Case Report

Case Diagnosis: 64-year-old male with acute motor-sensory axonal neuropathy (AMSAN) subtype of Guillain-Barré syndrome (GBS) who developed acute pulmonary embolism (PE) while on thromboembolic prophylaxis with unfractionated heparin.

Case Description or Program Description: Patient with atrial fibrillation on rivaroxaban presented to the emergency room after a fall 3 weeks prior followed by progressive bilateral lower extremity weakness. On exam, he additionally had distal bilateral upper extremity weakness, diminished reflexes, and decreased sensation in bilateral lower extremities. Lumbar puncture was notable for albuminocytologic dissociation, and EMG showed symmetric axonal sensory-motor polyneuropathy. He was treated empirically for GBS with a 5-day course of intravenous immunoglobulin without improvement or progression in symptoms. Full body MRI and both sural nerve and vastus lateralis muscle biopsies were inconclusive. Prior to biopsy, rivaroxaban was discontinued in favor of subcutaneous unfractionated heparin dosed 5000 units BID.

Setting: Tertiary care hospital and standalone rehabilitation center

Assessment/Results: Patient was admitted to inpatient rehabilitation on day 4 of heparin prophylaxis. He participated in therapy sessions until day 10 of prophylaxis, when he resumed rivaroxaban. That evening he developed pleuritic chest pain, and CT imaging showed extensive bilateral PE with evidence of right heart strain. He was transferred to the emergency department and initiated on heparin infusion.

Discussion (relevance): Several options for pharmacologic thromboprophylaxis are available yet there is limited evidence on the comparative efficacy and safety of these agents. Given the nature of GBS in causing ascending flaccid paralysis, these patients are at exceedingly high risk of thromboembolism. We present a rare case of extensive PE in a patient with AMSAN variant of GBS in which unfractionated heparin BID was not sufficient despite being a commonly accepted prophylaxis regimen.

Conclusions: Clinicians weigh treatment efficacy with risk of bleeding when selecting a prophylactic anticoagulant regimen. The use of heparin in this patient with AMSAN GBS was not effective to prevent thrombosis.