311 Retrospective Analysis of Patients Receiving Immune Checkpoint Inhibitors Presenting to the Emergency Department

Abstract

The use of immune checkpoint inhibitors (ICIs) in the treatment of cancer is rapidly expanding. ICIs may cause a wide range of autoimmune toxicities referred to as immune-related adverse effects (irAEs). There is sparse literature regarding why patients on ICI go to the emergency department (ED). In this study, we aim to describe why patients on ICIs go to the ED, whether or not ED providers consider an irAE in the differential diagnoses, and the subsequent management of the irAEs. We performed a retrospective review of all patients receiving an ICI who presented to a tertiary care ED between May 1, 2017 and April 30, 2018. Data including ED chief complaint, diagnosis, treatment, and disposition were collected along with baseline characteristics and diagnosis at the time of outpatient oncology follow-up. We report descriptive statistics summarizing the characteristics of the cohort. There were 97 ED visits identified among 66 unique patients identified. IrAE was diagnosed in 16 (16.3%) cases. The most common ED chief complaint within this group was gastrointestinal symptoms (abdominal pain, diarrhea, or nausea and vomiting) which accounted for 10 cases (62.5%). Other chief complaints included 2 cases (12.5%) of dyspnea, 2 cases (12.5%) of hyperglycemia, 1 case (6.25%) of chest tightness/pressure, and 1 case (6.25%) of dizziness. Among the 16 confirmed irAE cases, the most common irAE diagnosed was colitis, identified in 9 cases (56.3%). Other irAEs diagnosed included 2 cases (12.5%) of new onset type 1 diabetes mellitus, 2 cases (12.5%) of pancreatitis, 1 case (6.25%) of pneumonitis, 1 case (6.25%) of myasthenia gravis, and 1 case (6.25%) of adrenal insufficiency. ED providers documented consideration of an irAE in the differential diagnoses in 14.4% of total ED visits. Among cases with confirmed irAE, ED providers considered an irAE in the differential diagnoses in 43.8% of visits. Two patients with irAEs (12.5%) received corticosteroids during their stay in the ED, and 10 patients (62.5%) required hospital admission. Among patients on ICIs presenting for emergency care, irAEs were infrequently considered and were ultimately diagnosed at a rate of 16%. Gastrointestinal symptoms were the most common chief complaint for these patients. Colitis was the most common irAE diagnosed. Patients with irAE were rarely treated with corticosteroids during their ED visit. Large, multi-center prospective studies are needed to better understand the presentation and subsequent management of patients on ICIs who seek emergency care.