No abstract

BACKGROUNDThe appropriate oxygenation target for mechanical ventilation in comatose survivors of out-of-hospital cardiac arrest is unknown. METHODSIn this randomized trial with a 2-by-2 factorial design, we randomly assigned comatose adults with out-of-hospital cardiac arrest in a 1:1 ratio to either a restrictive oxygen target of a partial pressure of arterial oxygen (Pao 2 ) of 9 to 10 kPa (68 to 75 mm Hg) or a liberal oxygen target of a Pao 2 of 13 to 14 kPa (98 to 105 mm Hg); patients were also assigned to one of two blood-pressure targets (reported separately). The primary outcome was a composite of death from any cause or hospital discharge with severe disability or coma (Cerebral Performance Category [CPC] of 3 or 4; categories range from 1 to 5, with higher values indicating more severe disability), whichever occurred first within 90 days after randomization. Secondary outcomes were neuron-specific enolase levels at 48 hours, death from any cause, the score on the Montreal Cognitive Assessment (ranging from 0 to 30, with higher scores indicating better cognitive ability), the score on the modified Rankin scale (ranging from 0 to 6, with higher scores indicating greater disability), and the CPC at 90 days. RESULTSA total of 789 patients underwent randomization. A primary-outcome event occurred in 126 of 394 patients (32.0%) in the restrictive-target group and in 134 of 395 patients (33.9%) in the liberal-target group (hazard ratio, 0.95; 95% confidence interval, 0.75 to 1.21; P = 0.69). At 90 days, death had occurred in 113 patients (28.7%) in the restrictive-target group and in 123 (31.1%) in the liberal-target group. On the CPC, the median category was 1 in the two groups; on the modified Rankin scale, the median score was 2 in the restrictive-target group and 1 in the liberaltarget group; and on the Montreal Cognitive Assessment, the median score was 27 in the two groups. At 48 hours, the median neuron-specific enolase level was 17 μg per liter in the restrictive-target group and 18 μg per liter in the liberaltarget group. The incidence of adverse events was similar in the two groups. CONCLUSIONSTargeting of a restrictive or liberal oxygenation strategy in comatose patients after resuscitation for cardiac arrest resulted in a similar incidence of death or severe disability or coma. (Funded by the Novo Nordisk Foundation; BOX ClinicalTrials .gov number, NCT03141099.

These results support the thickening of the soft palate as a component of severe brachycephalic airway syndrome. Further studies are required to confirm the association between this anatomical characteristic and functional impairment.

Background: After resuscitation from out-of-hospital cardiac arrest, mean arterial pressure below 65 mm Hg is avoided with vasopressors. A higher blood-pressure target could potentially improve outcome. The aim of this pilot trial was to investigate the effect of a higher mean arterial pressure target on biomarkers of organ injury. Methods: This was a single-centre, double-blind trial of 50 consecutive, comatose out-of-hospital cardiac arrest patients randomly assigned in a 1:1 ratio to a mean arterial pressure target of 65 mm Hg (MAP65) or 72 mm Hg (MAP72). Modified blood pressure modules with a –10% offset were used, enabling a double-blind study design. End-points were biomarkers of organ injury including markers of endothelial integrity (soluble trombomodulin) brain damage (neuron-specific enolase) and renal function (estimated glomerular filtration rate). Results: Mean arterial pressure was significantly higher in MAP72 with a mean difference of 5 mm Hg ( pgroup=0.03). After 48 h, soluble trombomodulin (median (interquartile range)) was 8.2 (6.7–12.9) ng/ml and 8.3 (6.0–10.8) ng/ml ( p=0.29), neuron-specific enolase was 20 (13–31 μg/l) and 18 (13–44 μg/l) p=0.79) and estimated glomerular filtration rate (mean (±standard deviation)) was 61±19 ml/min/1.73m2 and 48±22 ml/min/1.73 m2 ( p=0.08) for the MAP72 and MAP65 groups, respectively. Renal replacement therapy was needed in eight patients (31%) in MAP65 and three patients (13%) in MAP72 ( p=0.14). Conclusions: Double-blind allocation to different mean arterial pressure targets is feasible in comatose out-of-hospital cardiac arrest patients. A mean arterial pressure target of 72 mm Hg compared to 65 mm Hg did not result in improved biomarkers of organ injury. We observed a trend towards preserved renal function in the MAP72 group.