Handling Oxygenation Targets in COVID-19

Patients with COVID-19 and hypoxaemic respiratory failure and admitted to the intensive care unit (ICU) are treated with supplementary oxygen as a standard. However, quality of quantity evidence regarding this practise is low. The aim of the HOT-COVID trial is to evaluate the benefits and harms of two targets of partial pressure of oxygen in arterial blood (PaO2) in guiding the oxygen therapy in acutely ill adult COVID-19 patients with hypoxaemic respiratory failure at ICU admission.

Acutely ill adult COVID-19 patients with hypoxaemic respiratory failure admitted to the intensive care unit (ICU) are at risk of life-threatening hypoxia, and are provided supplementary oxygen. Liberal use of supplementary oxygen may increase the number of serious adverse events including death. However, the use of supplementary oxygen therapy, and the optimal oxygenation target in COVID-19 patients have not yet been studied. The World Health Organisation (WHO) recommends an oxygen therapy during resuscitation of COVID-19 patients to achieve an SpO2 of 94% or more, and 90% or more when stable (non-pregnant patients). The Surviving Sepsis Campaing (SSC) recommends a conservative oxygenation strategy for COVID-19 patients targeting an SpO2 no higher than 96%. Both are based on a systematic review and metanalysis from 2018, investigating the association with mortality and higher versus lower oxygenation strategies in critically ill patients in general. COVID-19 patients admitted to the ICU and treated with positive pressure ventilation fulfil the 2012 Berlin criteria for acute respiratory distress syndrome (ARDS). Current practice regarding supplementary oxygen therapy in patients with ARDS follows the regimen used in an randomised clinical trial (RCT) from 2000 comparing lower versus higher tidal volumes; i.e. a partial pressure of arterial oxygen (PaO2) of 55-80 mmHg (7.3-10.7 kPa) or a peripheral oxygen saturation (SpO2) of 88-95%. Of note, a recent published RCT demonstrated a lowered all-cause mortality when targeting a higher oxygenation target (PaO2: 12-14 kPa \[90-105 mmHg\]) compared to a lower oxygenation target (PaO2: 7.3-9.3 \[55-70 mmHg\]) in ARDS patients. The quality and quantity of the current body of evidence regarding oxygenation targets in ARDS is still low. The aim of the HOT-COVID trial is to evaluate the benefits and harms of two targets of partial pressure of oxygen in arterial blood (PaO2) in guiding the oxygen therapy in acutely ill adults COVID-19 patients with hypoxaemic respiratory failure at ICU admission. The HOT-COVID trial is an amendment to the HOT-ICU trial (NCT03174002)