(964.15) Oxygen therapy limiting peripheral oxygen saturation to 89-93% is associated with a better survival prognosis for critically ill COVID-19 patients at high altitudes

Poster Board Number: E667

Christian Arias-Reyes (Centre de Recherche de l’Institute Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval), Antonio Viruez-Soto (Clínica Los Andes del Grupo Embriovid, Clínica Los Andes del Grupo Embriovid, Clínica Los Andes del Grupo Embriovid, Clínica Los Andes del Grupo Embriovid), Samuel Arias (High Altitude Intensive Care Medicine International Group, GIMIA), Ronnie Casas-Mamani (Hospital del Norte), Gabriel Rada-Barrera (Hospital Agramont), Alfredo Merino-Luna (High Altitude Intensive Care Medicine International Group), Daniel Molano-Franco (High Altitude Intensive Care Medicine International Group, GIMIA), Amilcar Tinoco-Solorzano (High Altitude Intensive Care Medicine International Group, GIMIA), Danuzia Marques (Centre de Recherche de l’Institute Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval), Natalia Zubieta-DeUrioste (High Altitude Pulmonary and Pathology Institute (HAPPI-IPPA)), Gustavo Zubieta-Calleja (High Altitude Pulmonary and Pathology Institute (HAPPI-IPPA)), Jorge Soliz (Université Laval, Faculté de Médecine, Centre de Recherche de l’Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Faculté de Médecine, Centre de Recherche de l’Institut Universitaire de Cardiologie et de Pneumologie de Québec)

Patients admitted to the Intensive Care Unit (ICU) with acute hypoxemic respiratory failure automatically receive oxygen therapy to improve inspiratory oxygen fraction (FiO2). Supplemental oxygen is the most prescribed drug for critically ill patients regardless of altitude of residence. In high altitude dwellers (i.e. in La Paz [»3,400 m] and El Alto [»4,150 m] in Bolivia), a peripheral oxygen saturation (SatpO2) of 89-95% and an arterial partial pressure of oxygen (PaO2) of 50-67mmHg (lower as altitude rises), are considered normal values for arterial blood. Consequently, it has been suggested that limiting oxygen therapy to maintain SatpO2 around normoxia may help avoid episodes of hypoxemia, hyperoxemia, intermittent hypoxemia, and ultimately, mortality. In this study, we evaluated the impact of oxygen therapy on the mortality of critically ill COVID-19 patients who permanently live at high altitudes. A multicenter cross-sectional descriptive observational study was performed on 100 patients admitted to the ICU at the “Clinica Los Andes” (in La Paz city) and “Agramont” and “Del Norte” Hospitals (in El Alto city). Our results show that: 1) as expected, fatal cases were detected only in patients who required intubation and connection to invasive mechanical ventilation as a last resort to overcome their life-threatening desaturation; 2) among intubated patients, prolonged periods in normoxia are associated with survival, prolonged periods in hypoxemia are associated with death, and time spent in hyperoxemia shows no association with survival or mortality; 3) the oxygenation limits required to effectively support the intubated patients’ survival in the ICU are between 89% and 93%; 4) among intubated patients with similar periods of normoxemic oxygenation, those with better SOFA scores survive; and 5) a lower frequency of observable reoxygenation events is not associated with survival. In conclusion, our findings indicate that high-altitude patients entering an ICU at altitudes of 3,400 – 4,150 m should undergo oxygen therapy to maintain oxygenation levels between 89 and 93 %.