Conservative versus liberal oxygenation targets in critically ill children (Oxy-PICU): a UK multicentre, open, parallel-group, randomised clinical trial

Breath Markers of Oxidative Stress in Children with Severe Viral Lower Respiratory Tract Infection

Severe viral lower respiratory tract infection (LRTI), resulting in both acute and long-term pulmonary disease, constitutes a substantial burden among young children. Viral LRTI triggers local oxidative stress pathways by infection and inflammation, and supportive care in the pediatric intensive care unit may further aggravate oxidative injury. The main goal of this exploratory study was to identify and monitor breath markers linked to oxidative stress in children over the disease course of severe viral LRTI. Exhaled breath was sampled during invasive ventilation, and volatile organic compounds (VOCs) were analyzed using gas chromatography and mass spectrometry. VOCs were selected in an untargeted principal component analysis and assessed for change over time. In addition, identified VOCs were correlated with clinical parameters. Seventy breath samples from 21 patients were analyzed. A total of 15 VOCs were identified that contributed the most to the explained variance of breath markers. Of these 15 VOCs, 10 were previously linked to pathways of oxidative stress. Eight VOCs, including seven alkanes and methyl alkanes, significantly decreased from the initial phase of ventilation to the day of extubation. No correlation was observed with the administered oxygen dose, whereas six VOCs showed a poor to strong positive correlation with driving pressure. In this prospective study of children with severe viral LRTI, the majority of VOCs that were most important for the explained variance mirrored clinical improvement. These breath markers could potentially help monitor the pulmonary oxidative status in these patients, but further research with other objective measures of pulmonary injury is required.

High-Flow Nasal Cannula Versus Nasal Prong Bubble Continuous Positive Airway Pressure in Children With Moderate to Severe Acute Bronchiolitis: A Randomized Controlled Trial

OBJECTIVES

To compare high-flow nasal cannula (HFNC) versus nasal prong bubble continuous positive airway pressure (b-CPAP) in children with moderate to severe acute bronchiolitis.

DESIGN

A randomized controlled trial was carried out from August 2019 to February 2022. (Clinical Trials Registry of India number CTRI/2019/07/020402).

SETTING

Pediatric emergency ward and ICU within a tertiary care center in India.

PATIENTS

Children 1-23 months old with moderate to severe acute bronchiolitis.

INTERVENTION

Comparison of HFNC with b-CPAP, using a primary outcome of treatment failure within 24 hours of randomization, as defined by any of: 1) a 1-point increase in modified Wood's clinical asthma score (m-WCAS) above baseline, 2) a rise in respiratory rate (RR) greater than 10 per minute from baseline, and 3) escalation in respiratory support. The secondary outcomes were success rate after crossover, if any, need for mechanical ventilation (invasive/noninvasive), local skin lesions, length of hospital stay, and complications.

RESULTS

In 118 children analyzed by intention-to-treat, HFNC (n = 59) versus b-CPAP (n = 59) was associated with a lower failure rate (23.7% vs. 42.4%; relative risk [95% CI], RR 0.56 [95% CI, 0.32-0.97], p = 0.031). The Cox proportion model confirmed a lower hazard of treatment failure in the HFNC group (adjusted hazard ratio 0.48 [95% CI, 0.25-0.94], p = 0.032). No crossover was noted. A lower proportion escalated to noninvasive ventilation in the HFNC group (15.3%) versus the b-CPAP group (15.3% vs. 39% [RR 0.39 (95% CI, 0.20-0.77)], p = 0.004). The HFNC group had a longer median (interquartile range) duration of oxygen therapy (4 [3-6] vs. 3 [3-5] d; p = 0.012) and hospital stay (6 [5-8.5] vs. 5 [4-7] d, p = 0.021). No significant difference was noted in other secondary outcomes.

CONCLUSION

In children aged one to 23 months with moderate to severe acute bronchiolitis, the use of HFNC therapy as opposed to b-CPAP for early respiratory support is associated with a lower failure rate and, secondarily, a lower risk of escalation to mechanical ventilation.

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.