A DIVER WITH SWIMMING-INDUCED PULMONARY EDEMA AND CARDIAC ARREST

Abstract

TOPIC: Occupational and Environmental Lung Diseases TYPE: Medical Student/Resident Case Reports INTRODUCTION: Swimming-induced pulmonary edema (SIPE) is classically considered to be a self-resolving, non-fatal condition that occurs in high exertion surface swimmers and divers. We report an unusual case of a scuba diver who had both SIPE and presumed cardiac arrest. CASE PRESENTATION: A 71-year old man with atrial fibrillation on apixaban, diabetes mellitus, and hypertension developed shortness of breath during a scuba dive at 50 feet of seawater. The maximum dive depth was 70 feet with an average water temperature of 67° Fahrenheit. He ascended per protocol. After being pulled onto the boat, the patient syncopized. Chest compressions and rescue breaths were initiated, and he regained consciousness 2-3 minutes later. Upon EMS arrival, the patient had oxygen saturation by pulse oximetry in the mid-70s. He was placed on 15 L/min of supplemental oxygen and transported to the hospital by helicopter. EKG and telemetry showed atrial fibrillation with a normal rate. Chest radiograph showed pulmonary edema, and CTA chest showed pulmonary edema with no pulmonary embolism. Transthoracic echocardiogram showed an ejection fraction of 55-60%, mild valvular disease, and no evidence of hypertrophy or shunting. Coronary angiogram showed mild non-obstructive coronary artery disease. The patient's hypoxia resolved within 24 hours of presentation, with resolution of the pulmonary edema on repeat chest radiograph. DISCUSSION: Swimming-induced pulmonary edema is primarily thought to be self-resolving and non-fatal. However, this case prompts the question of an association between SIPE and cardiac arrest that has not been described to our knowledge. The patient was presumed to have cardiac arrest, as opposed to non-cardiogenic syncope, given continued loss of consciousness during chest compressions. Coronary angiogram was pursued because the arrest was indistinguishable between sudden cardiac arrest (SCA) and provoked cardiac arrest, for example from hypoxia. SIPE is hypothesized to be a hydrostatic pulmonary edema that occurs due to elevated pulmonary artery pressures from increased peripheral vascular resistance and central redistribution of blood flow. Meanwhile, SCA is typically due to coronary disease, structural disease, or congenital arrhythmias. The absence of these pathologies in this patient suggest that SIPE may have played a distinct role in his SCA. Water immersion has been proposed to cause SCA through "autonomic conflict," whereby simultaneous sympathetic activation from exertion and parasympathetic activation from immersion increases likelihood of arrhythmia. However, the precise impact of SIPE on cardiac activity is not clear. CONCLUSIONS: Swimming induced pulmonary edema may have contributed to this patient's cardiac arrest. The possibility for life-threatening secondary complications of SIPE such as cardiac arrest warrants further investigation. REFERENCE #1: Spencer S, Dickinson J, Forbes L. Occurrence, Risk Factors, Prognosis and Prevention of Swimming-Induced Pulmonary Oedema: a Systematic Review [Internet]. Sport. Med. - Open. 2018 [cited 2021 Apr 28];4(1):43. REFERENCE #2: Moon RE, Martina SD, Peacher DF, et al. Swimming-induced pulmonary edema - Pathophysiology and Risk Reduction with Sildanefil. Circulation [Internet] 2016 [cited 2021 Apr 28];133(10):988–996. REFERENCE #3: Shattock MJ, Tipton MJ. 'Autonomic conflict': a different way to die during cold water immersion? J Physiol [Internet] 2012 [cited 2021 Apr 28];590(14):3219–3230. DISCLOSURES: No relevant relationships by Christopher Androski, source=Web Response Advisory Committee Member relationship with Actelion Please note: $5001 - $20000 by Richard Channick, source=Web Response, value=Consulting fee Consultant relationship with Actelion Please note: $5001 - $20000 by Richard Channick, source=Web Response, value=Consulting fee Advisory Committee Member relationship with Arena Please note: $5001 - $20000 by Richard Channick, source=Web Response, value=Consulting fee Advisory Committee Member relationship with Bayer Please note: $5001 - $20000 by Richard Channick, source=Web Response, value=Consulting fee Advisory Committee Member relationship with United Therapeutics Please note: $5001 - $20000 by Richard Channick, source=Web Response, value=Consulting fee No relevant relationships by Estebes Hernandez, source=Web Response No relevant relationships by Laura Santoso, source=Web Response No relevant relationships by Michael Tripp, source=Web Response