Impact of non-invasive oxygen reserve index versus standard SpO2 monitoring on peripheral oxygen saturation during endotracheal intubation in the intensive care unit: Protocol for the randomized controlled trial NESOI2.

In critically ill patients, endotracheal intubation (ETI) is lifesaving but carries a high risk of adverse events, notably hypoxemia. Preoxygenation is performed before introducing the tube to increase the safe apnea time. Oxygenation is monitored by pulse oximeter measurement of peripheral oxygen saturation (SpO2). However, SpO2 is unreliable at the high oxygenation levels produced by preoxygenation and, in the event of desaturation, may not decrease sufficiently early to allow preventive measures. The oxygen reserve index (ORI) is a dimensionless parameter that can also be measured continuously by a fingertip monitor and reflects oxygenation in the moderate hyperoxia range. The ORI ranges from 0 to 1 when arterial oxygen saturation (PaO2) varies between 100 to 200 mmHg, as occurs during preoxygenation. No trial has assessed the potential effects of ORI monitoring to guide preoxygenation for ETI in unstable patients. We designed a multicenter, two-arm, parallel-group, randomized, superiority, open trial in 950 critically ill adults requiring ETI. The intervention consists in monitoring ORI values and using an ORI target for preoxygenation of at least 0.6 for at least 1 minute. In the control group, preoxygenation is guided by SpO2 values recorded by a standard pulse oximeter, according to the standard of care, the goal being to obtain 100% SpO2 during preoxygenation, which lasts at least 3 minutes. The standard-of-care ETI technique is used in both arms. Baseline parameters, rapid-sequence induction medications, ETI devices, and physiological data are recorded. The primary outcome is the lowest SpO2 value from laryngoscopy to 2 minutes after successful ETI. Secondary outcomes include cognitive function on day 28. Assuming a 10% standard deviation for the lowest SpO2 value in the control group, no missing data, and crossover of 5% of patients, with the bilateral alpha risk set at 0.05, including 950 patients will provide 85% power for detecting a 2% between-group absolute difference in the lowest SpO2 value. Should ORI monitoring with a target of ≥0.6 be found to increase the lowest SpO2 value during ETI, then this trial may change current practice regarding preoxygenation for ETI. Trial registration: Registered on ClinicalTrials.gov (NCT05867875) on April 27, 2023.

Effect of sodium bicarbonate on functional outcome in patients with out-of-hospital cardiac arrest: a post-hoc analysis of a French and North-American dataset.

BACKGROUND AND IMPORTANCE: No large randomised controlled trial has assessed the potential benefits on neurologic outcomes of prehospital sodium bicarbonate administration in patients with nontraumatic out-of-hospital cardiac arrest (OHCA). OBJECTIVE: To obtain information of assistance in designing a randomised controlled trial of bicarbonate therapy after OHCA in specific patient subgroups. DESIGN: We conducted two, separate, simultaneous, retrospective studies of two distinct, unlinked datasets. SETTING AND PARTICIPANTS: One dataset was a French nationwide population-based registry (RéAC Registry, French dataset) and the other was a randomised controlled trial comparing continuous to interrupted chest compressions in North America (ROC-CCC trial, North-American dataset). INTERVENTION: We investigated whether prehospital bicarbonate administration was associated with better neurologic outcomes. OUTCOME MEASURES AND ANALYSES: The main outcome measure was the functional outcome at hospital discharge. To adjust for potential confounders, we conducted a nested propensity-score-matched analysis with inverse probability-of-treatment weighting. MAIN RESULTS: In the French dataset, of the 54 807 patients, 1234 (2.2%) received sodium bicarbonate and 450 were matched. After propensity-score matching, sodium bicarbonate was not associated with a higher likelihood of favourable functional outcomes on day 30 [adjusted odds ratio (aOR), 0.912; 95% confidence interval (95%CI), 0.501-1.655]. In the North-American dataset, of the 23 711 included patients, 4902 (20.6%) received sodium bicarbonate and 1238 were matched. After propensity-score matching, sodium bicarbonate was associated with a lower likelihood of favourable functional outcomes at hospital discharge (aOR, 0.45; 95% CI, 0.34-0.58). CONCLUSION: In patients with OHCA, prehospital sodium bicarbonate administration was not associated with neurologic outcomes in a French dataset and was associated with worse neurologic outcomes in a North-American dataset. Given the considerable variability in sodium bicarbonate use by different prehospital care systems and the potential resuscitation-time bias in the present study, a large randomised clinical trial targeting specific patient subgroups may be needed to determine whether sodium bicarbonate has a role in the prehospital management of prolonged OHCA.