Lower vs Higher Oxygenation Target and Days Alive Without Life Support in COVID-19: The HOT-COVID Randomized Clinical Trial.

Importance: Supplemental oxygen is ubiquitously used in patients with COVID-19 and severe hypoxemia, but a lower dose may be beneficial. Objective: To assess the effects of targeting a Pao2 of 60 mm Hg vs 90 mm Hg in patients with COVID-19 and severe hypoxemia in the intensive care unit (ICU). Design, Setting, and Participants: Multicenter randomized clinical trial including 726 adults with COVID-19 receiving at least 10 L/min of oxygen or mechanical ventilation in 11 ICUs in Europe from August 2020 to March 2023. The trial was prematurely stopped prior to outcome assessment due to slow enrollment. End of 90-day follow-up was June 1, 2023. Interventions: Patients were randomized 1:1 to a Pao2 of 60 mm Hg (lower oxygenation group; n = 365) or 90 mm Hg (higher oxygenation group; n = 361) for up to 90 days in the ICU. Main Outcomes and Measures: The primary outcome was the number of days alive without life support (mechanical ventilation, circulatory support, or kidney replacement therapy) at 90 days. Secondary outcomes included mortality, proportion of patients with serious adverse events, and number of days alive and out of hospital, all at 90 days. Results: Of 726 randomized patients, primary outcome data were available for 697 (351 in the lower oxygenation group and 346 in the higher oxygenation group). Median age was 66 years, and 495 patients (68%) were male. At 90 days, the median number of days alive without life support was 80.0 days (IQR, 9.0-89.0 days) in the lower oxygenation group and 72.0 days (IQR, 2.0-88.0 days) in the higher oxygenation group (P = .009 by van Elteren test; supplemental bootstrapped adjusted mean difference, 5.8 days [95% CI, 0.2-11.5 days]; P = .04). Mortality at 90 days was 30.2% in the lower oxygenation group and 34.7% in the higher oxygenation group (risk ratio, 0.86 [98.6% CI, 0.66-1.13]; P = .18). There were no statistically significant differences in proportion of patients with serious adverse events or in number of days alive and out of hospital. Conclusion and Relevance: In adult ICU patients with COVID-19 and severe hypoxemia, targeting a Pao2 of 60 mm Hg resulted in more days alive without life support in 90 days than targeting a Pao2 of 90 mm Hg. Trial Registration: ClinicalTrials.gov Identifier: NCT04425031.

Restriction of Intravenous Fluid in ICU Patients with Septic Shock.

BACKGROUND: Intravenous fluids are recommended for the treatment of patients who are in septic shock, but higher fluid volumes have been associated with harm in patients who are in the intensive care unit (ICU). METHODS: In this international, randomized trial, we assigned patients with septic shock in the ICU who had received at least 1 liter of intravenous fluid to receive restricted intravenous fluid or standard intravenous fluid therapy; patients were included if the onset of shock had been within 12 hours before screening. The primary outcome was death from any cause within 90 days after randomization. RESULTS: We enrolled 1554 patients; 770 were assigned to the restrictive-fluid group and 784 to the standard-fluid group. Primary outcome data were available for 1545 patients (99.4%). In the ICU, the restrictive-fluid group received a median of 1798 ml of intravenous fluid (interquartile range, 500 to 4366); the standard-fluid group received a median of 3811 ml (interquartile range, 1861 to 6762). At 90 days, death had occurred in 323 of 764 patients (42.3%) in the restrictive-fluid group, as compared with 329 of 781 patients (42.1%) in the standard-fluid group (adjusted absolute difference, 0.1 percentage points; 95% confidence interval [CI], -4.7 to 4.9; P = 0.96). In the ICU, serious adverse events occurred at least once in 221 of 751 patients (29.4%) in the restrictive-fluid group and in 238 of 772 patients (30.8%) in the standard-fluid group (adjusted absolute difference, -1.7 percentage points; 99% CI, -7.7 to 4.3). At 90 days after randomization, the numbers of days alive without life support and days alive and out of the hospital were similar in the two groups. CONCLUSIONS: Among adult patients with septic shock in the ICU, intravenous fluid restriction did not result in fewer deaths at 90 days than standard intravenous fluid therapy. (Funded by the Novo Nordisk Foundation and others; CLASSIC ClinicalTrials.gov number, NCT03668236.).

Oxygenation targets in ICU patients with COVID-19: A post hoc subgroup analysis of the HOT-ICU trial.

BACKGROUND: Supplemental oxygen is the key intervention for severe and critical COVID-19 patients. With the unstable supplies of oxygen in many countries, it is important to define the lowest safe dosage. METHODS: In spring 2020, 110 COVID-19 patients were enrolled as part of the Handling Oxygenation Targets in the ICU trial (HOT-ICU). Patients were allocated within 12 h of ICU admission. Oxygen therapy was titrated to a partial pressure of arterial oxygen (PaO2 ) of 8 kPa (lower oxygenation group) or a PaO2 of 12 kPa (higher oxygenation group) during ICU stay up to 90 days. We report key outcomes at 90 days for the subgroup of COVID-19 patients. RESULTS: At 90 days, 22 of 54 patients (40.7%) in the lower oxygenation group and 23 of 55 patients (41.8%) in the higher oxygenation group had died (adjusted risk ratio: 0.87; 95% confidence interval, 0.58-1.32). The percentage of days alive without life support was significantly higher in the lower oxygenation group (p = 0.03). The numbers of severe ischemic events were low with no difference between the two groups. Proning and inhaled vasodilators were used more frequently, and the positive end-expiratory pressure was higher in the higher oxygenation group. Tests for interactions with the results of the remaining HOT-ICU population were insignificant. CONCLUSIONS: Targeting a PaO2 of 8 kPa may be beneficial in ICU patients with COVID-19. These results come with uncertainty due to the low number of patients in this unplanned subgroup analysis, and insignificant tests for interaction with the main HOT-ICU trial. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov number, NCT03174002. Date of registration: June 2, 2017.

Handling oxygenation targets in ICU patients with COVID-19-Protocol and statistical analysis plan in the HOT-COVID trial.

BACKGROUND: Coronavirus disease (COVID-19) primarily affects the lungs and lower airways and may present as hypoxaemic respiratory failure requiring admission to an intensive care unit (ICU) for supportive treatment. Here, supplemental oxygen remains essential for COVID-19 patient management, but the optimal dosage is not defined. We hypothesize that targeting an arterial partial pressure of oxygen of 8 kPa throughout ICU admission is superior to targeting 12 kPa. METHODS: The Handling Oxygenation Targets in ICU patients with COVID-19 (HOT-COVID) trial, is an investigator-initiated, pragmatic, multicentre, randomized, parallel-group trial comparing a lower oxygenation target versus a higher oxygenation target in adult ICU patients with COVID-19. The primary outcome is days alive without life-support (use of mechanical ventilation, renal replacement therapy or vasoactive therapy) at day 90. Secondary outcomes are 90-day and 1-year mortality, serious adverse events in the ICU and days alive and out of hospital in the 90-day period, health-related quality-of-life at 1 year, and health economic analyses. One-year follow-up of cognitive and pulmonary function is planned in a subgroup of Danish patients. We will include 780 patients to detect or reject an absolute increase in days alive without life-support of 7 days with an α of 5% and a ß of 20%. An interim analysis is planned after 90-day follow-up of 390 patients. CONCLUSIONS: The HOT-COVID trial will provide patient-important data on the effect of two oxygenation targets in ICU patients with COVID-19 and hypoxia. This protocol paper describes the background, design and statistical analysis plan for the trial.

Lower or Higher Oxygenation Targets for Acute Hypoxemic Respiratory Failure.

BACKGROUND: Patients with acute hypoxemic respiratory failure in the intensive care unit (ICU) are treated with supplemental oxygen, but the benefits and harms of different oxygenation targets are unclear. We hypothesized that using a lower target for partial pressure of arterial oxygen (Pao2) would result in lower mortality than using a higher target. METHODS: In this multicenter trial, we randomly assigned 2928 adult patients who had recently been admitted to the ICU (≤12 hours before randomization) and who were receiving at least 10 liters of oxygen per minute in an open system or had a fraction of inspired oxygen of at least 0.50 in a closed system to receive oxygen therapy targeting a Pao2 of either 60 mm Hg (lower-oxygenation group) or 90 mm Hg (higher-oxygenation group) for a maximum of 90 days. The primary outcome was death within 90 days. RESULTS: At 90 days, 618 of 1441 patients (42.9%) in the lower-oxygenation group and 613 of 1447 patients (42.4%) in the higher-oxygenation group had died (adjusted risk ratio, 1.02; 95% confidence interval, 0.94 to 1.11; P = 0.64). At 90 days, there was no significant between-group difference in the percentage of days that patients were alive without life support or in the percentage of days they were alive after hospital discharge. The percentages of patients who had new episodes of shock, myocardial ischemia, ischemic stroke, or intestinal ischemia were similar in the two groups (P = 0.24). CONCLUSIONS: Among adult patients with acute hypoxemic respiratory failure in the ICU, a lower oxygenation target did not result in lower mortality than a higher target at 90 days. (Funded by the Innovation Fund Denmark and others; HOT-ICU ClinicalTrials.gov number, NCT03174002.).

Depletion of myocardial glucose is observed during endotoxemic but not hemorrhagic shock in a porcine model.

INTRODUCTION: Metabolic dysfunction is one of the hallmarks of sepsis yet little is known about local changes in key organs such as the heart. The aim of this study was to compare myocardial metabolic changes by direct measurements of substrates, such as glucose, lactate and pyruvate, using microdialysis (MD) in in-vivo porcine endotoxemic and hemorrhagic shock. To assess whether these changes were specific to the heart, we simultaneously investigated substrate levels in skeletal muscle. METHODS: Twenty-six female pigs were randomized to three groups: control (C) n = 8, endotoxemic shock (E) n = 9 and hemorrhagic shock (H) n = 9. Interstitial myocardial pyruvate, lactate and glucose were measured using MD. Skeletal muscle MD was also performed in all three groups. RESULTS: Marked decreases in myocardial glucose were observed in the E group but not in the H group compared to controls (mean difference (CI) in mmol/L: C versus E -1.5(-2.2 to -0.8), P <0.001; H versus E -1.1(-1.8 to -0.4), P = 0.004; C versus H -0.4(-1.1 to 0.3), P = 0.282). Up to four-fold increases in myocardial pyruvate and three-fold increases in lactate were seen in both shock groups with no differences between the two types of shock. There was no evidence of myocardial anaerobic metabolism, with normal lactate:pyruvate (L:P) ratios seen in all animals regardless of the type of shock. CONCLUSIONS: Endotoxemia, but not hemorrhage, induces a rapid decrease of myocardial glucose levels. Despite the decrease in glucose, myocardial lactate and pyruvate concentrations were elevated and not different than in hemorrhagic shock. In skeletal muscle, substrate patterns during endotoxemic shock mimicked those seen in myocardium. During hemorrhagic shock the skeletal muscle response was characterized by a lack of increase in pyruvate and higher L:P ratios. Hence, metabolic patterns in the myocardium during endotoxemic shock are different than those seen during hemorrhagic shock. Skeletal muscle and myocardium displayed similar substrate patterns during endotoxemic shock but differed during hemorrhagic shock.