PurposeWe aimed to determine the feasibility of targeting low-normal or high-normal mean arterial pressure (MAP) after out-of-hospital cardiac arrest (OHCA) and its effect on markers of neurological injury. MethodsIn the Carbon dioxide, Oxygen and Mean arterial pressure After Cardiac Arrest and REsuscitation (COMACARE) trial, we used a 23 factorial design to randomly assign patients after OHCA and resuscitation to low-normal or high-normal levels of arterial carbon dioxide tension, to normoxia or moderate hyperoxia, and to low-normal or high-normal MAP. In this paper we report the results of the low-normal (65–75 mmHg) vs. high-normal (80–100 mmHg) MAP comparison. The primary outcome was the serum concentration of neuron-specific enolase (NSE) at 48 h after cardiac arrest. The feasibility outcome was the difference in MAP between the groups. Secondary outcomes included S100B protein and cardiac troponin (TnT) concentrations, electroencephalography (EEG) findings, cerebral oxygenation and neurological outcome at 6 months after cardiac arrest.ResultsWe recruited 123 patients and included 120 in the final analysis. We found a clear separation in MAP between the groups (p < 0.001). The median (interquartile range) NSE concentration at 48 h was 20.6 µg/L (15.2–34.9 µg/L) in the low-normal MAP group and 22.0 µg/L (13.6–30.9 µg/L) in the high-normal MAP group, p = 0.522. We found no differences in the secondary outcomes.ConclusionsTargeting a specific range of MAP was feasible during post-resuscitation intensive care. However, the blood pressure level did not affect the NSE concentration at 48 h after cardiac arrest, nor any secondary outcomes.Electronic supplementary materialThe online version of this article (10.1007/s00134-018-5446-8) contains supplementary material, which is available to authorized users.

PurposeWe assessed the effects of targeting low-normal or high-normal arterial carbon dioxide tension (PaCO2) and normoxia or moderate hyperoxia after out-of-hospital cardiac arrest (OHCA) on markers of cerebral and cardiac injury.MethodsUsing a 23 factorial design, we randomly assigned 123 patients resuscitated from OHCA to low-normal (4.5–4.7 kPa) or high-normal (5.8–6.0 kPa) PaCO2 and to normoxia (arterial oxygen tension [PaO2] 10–15 kPa) or moderate hyperoxia (PaO2 20–25 kPa) and to low-normal or high-normal mean arterial pressure during the first 36 h in the intensive care unit. Here we report the results of the low-normal vs. high-normal PaCO2 and normoxia vs. moderate hyperoxia comparisons. The primary endpoint was the serum concentration of neuron-specific enolase (NSE) 48 h after cardiac arrest. Secondary endpoints included S100B protein and cardiac troponin concentrations, continuous electroencephalography (EEG) and near-infrared spectroscopy (NIRS) results and neurologic outcome at 6 months.ResultsIn total 120 patients were included in the analyses. There was a clear separation in PaCO2 (p < 0.001) and PaO2 (p < 0.001) between the groups. The median (interquartile range) NSE concentration at 48 h was 18.8 µg/l (13.9–28.3 µg/l) in the low-normal PaCO2 group and 22.5 µg/l (14.2–34.9 µg/l) in the high-normal PaCO2 group, p = 0.400; and 22.3 µg/l (14.8–27.8 µg/l) in the normoxia group and 20.6 µg/l (14.2–34.9 µg/l) in the moderate hyperoxia group, p = 0.594). High-normal PaCO2 and moderate hyperoxia increased NIRS values. There were no differences in other secondary outcomes.ConclusionsBoth high-normal PaCO2 and moderate hyperoxia increased NIRS values, but the NSE concentration was unaffected.RegistrationClinicalTrials.gov, NCT02698917. Registered on January 26, 2016.Electronic supplementary materialThe online version of this article (10.1007/s00134-018-5453-9) contains supplementary material, which is available to authorized users.

Purpose: Neurofilament light (NfL) is a biomarker reflecting neurodegeneration and acute neuronal injury, and an increase is found following hypoxic brain damage. We assessed the ability of plasma NfL to predict outcome in comatose patients after out-of-hospital cardiac arrest (OHCA). We also compared plasma NfL concentrations between patients treated with two different targets of arterial carbon dioxide tension (PaCO 2), arterial oxygen tension (PaO 2), and mean arterial pressure (MAP). Methods: We measured NfL concentrations in plasma obtained at intensive care unit admission and at 24, 48, and 72 h after OHCA. We assessed neurological outcome at 6 months and defined a good outcome as Cerebral Performance Category (CPC) 1-2 and poor outcome as CPC 3-5. Results: Six-month outcome was good in 73/112 (65%) patients. Forty-eight hours after OHCA, the median NfL concentration was 19 (interquartile range [IQR] 11-31) pg/ml in patients with good outcome and 2343 (587-5829) pg/ml in those with poor outcome, p < 0.001. NfL predicted poor outcome with an area under the receiver operating characteristic curve (AUROC) of 0.98 (95% confidence interval [CI] 0.97-1.00) at 24 h, 0.98 (0.97-1.00) at 48 h, and 0.98 (0.95-1.00) at 72 h. NfL concentrations were lower in the higher MAP (80-100 mmHg) group than in the lower MAP (65-75 mmHg) group at 48 h (median, 23 vs. 43 pg/ml, p = 0.04). PaCO 2 and PaO 2 targets did not associate with NfL levels. Conclusions: NfL demonstrated excellent prognostic accuracy after OHCA. Higher MAP was associated with lower NfL concentrations.