PROLONGED, PROFOUND UNTREATED HYPOXIA IN COVID-19 ARDS WITH REFUSAL OF TREATMENT

Abstract

TOPIC: Critical Care TYPE: Medical Student/Resident Case Reports INTRODUCTION: The drastic contrast between relatively mild dyspnea and severe hypoxemia seen in some Covid-19 ARDS patients, dubbed "happy" or "silent" hypoxia, has been brought into the spotlight by the current pandemic. The pathophysiology behind this phenomenon is not well understood, though appears to be associated with worse outcomes.1 However, the relative lack of respiratory discomfort may embolden some patients to forego medical therapies, as is seen in this case. CASE PRESENTATION: A 66-year-old man with hypertension, diabetes type 2, chronic kidney disease, hyperlipidemia, and coronary artery disease was admitted to the ICU for acute hypoxic respiratory failure secondary to Covid-19 ARDS in October. He was treated with alternating high flow nasal cannula (HFNC) and Bi-level Positive Airway Pressure (BiPAP), 5 days of Remdesivir, and 10 days of dexamethasone. His hospital course was uneventful until day 12, when patient decided to leave the hospital against medical advice. His vitals showed hemodynamic stability with 92% saturation on HFNC 40 L/min, 65% FiO2. Following a thorough evaluation, the patient was deemed to have medical decision-making capacity. Following the patient's removal of HFNC oxygen saturations declined to 67% on room air, heart rate increased from 106 to 130, and he became visibly tachypneic. The patient denied dyspnea, declined home oxygen therapy, and left the hospital. Fifty-three hours after discharge, he returned with a primary complaint of dyspnea. Vitals showed pulse 105, respiratory rate 35, and oxygen saturation 61% on room air. Venous blood gas showed pH 7.40 and pCO2 37. HFNC was resumed at 60 L/min, 100% FiO2, and patient achieved adequate saturation. The patient was readmitted, a workup revealed no additional etiologies, and supportive care was resumed. Despite supportive care he experienced progressive respiratory failure and nine days following readmission died. DISCUSSION: Given the vitals noted on initial discharge and readmission, it can be inferred that our patient had profound hypoxia throughout the 53 hours that were spent at home. Hypoxia as profound and prolonged as this is poorly described in current literature. Comparisons can be drawn with high-altitude illnesses, even then, literature is limited. A group of mountain climbers was found to have a mean oxygen saturation of 66% when they reached 6,865 meters.2 Ascent to high altitudes triggers pulmonary vasoconstriction, which leads to increased pulmonary pressures and pulmonary edema.3 Similar pathophysiology may have been experienced by this patient and may have contributed to his decline. CONCLUSIONS: This patient suffered severe hypoxia as a result of untreated Covid-19 ARDS. Examples of similar circumstances in the current literature are rare. It remains unclear how the patient survived without treatment or what triggered his decline, though comparisons can be made with high altitude illness. REFERENCE #1: Brouqui P, Amrane S, Million M, et al. Asymptomatic hypoxia in COVID-19 is associated with poor outcome [published online ahead of print, 2020 Oct 31]. Int J Infect Dis. 2020;102:233-238. doi:10.1016/j.ijid.2020.10.067 REFERENCE #2: Bosch MM, Merz TM, Barthelmes D, Petrig BL, Truffer F, Bloch KE, Turk A, Maggiorini M, Hess T, Schoch OD, Hefti U, Sutter FK, Pichler J, Huber A, Landau K. New insights into ocular blood flow at very high altitudes. J Appl Physiol (1985). 2009 Feb;106(2):454-60. doi: 10.1152/japplphysiol.90904.2008. Epub 2008 Dec 4. PMID: 19057000. REFERENCE #3: Schoene RB. Illnesses at high altitude. Chest. 2008 Aug;134(2):402-416. doi: 10.1378/chest.07-0561. PMID: 18682459. DISCLOSURES: No relevant relationships by Dustin Krutsinger, source=Web Response No relevant relationships by Kaleb Thomas, source=Web Response