Early Metabolic Disruption and Predictive Biomarkers of Delayed-Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage.

Delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH) is a major cause of complications and death. Here, we set out to identify high-performance predictive biomarkers of DCI and its underlying metabolic disruptions using metabolomics and lipidomics approaches. This single-center prospective observational study enrolled 61 consecutive patients with severe aSAH; among them, 22 experienced a DCI. Nine patients without aSAH were included as validation controls. Blood and cerebrospinal fluid (CSF) were sampled within the first 24 h after admission. We identified a panel of 20 metabolites that, together, showed high predictive performance for DCI. This panel of metabolites included lactate, cotinine, salicylate, 6 phosphatidylcholines, and 4 sphingomyelins. The interplay of the metabolome and the lipidome found between CSF and plasma in our patients underscores that aSAH and its associated DCI complications can extend beyond cerebral implications, with a peripheral dimension as well. As an illustration, early biological disruptions that might explain the subsequent DCI found systemic hypoxia driven mainly by higher blood lactate, arginine, and proline metabolism likely associated with vascular NO and disrupted ceramide/sphingolipid metabolism. We conclude that targeting early peripheral hypoxia preceding DCI could provide an interesting strategy for the prevention of vascular dysfunction.

Early matrix metalloproteinase-9 concentration in the first 48 h after aneurysmal subarachnoid haemorrhage predicts delayed cerebral ischaemia: An observational study.

BACKGROUND: Delayed cerebral ischaemia from vasospasm is an important cause of complications and death after aneurysmal subarachnoid haemorrhage. There is currently no established biomarker for identifying patients at high risk of delayed cerebral ischaemia. OBJECTIVE: Considering the important role of inflammation in the pathogenesis of delayed cerebral ischaemia, we investigated whether matrix metalloproteinase-9 (MMP-9) may be an efficient biomarker for predicting elayed cerebral ischaemia after subarachnoid haemorrhage. DESIGN: Single-centre prospective observational study. SETTING: Neuroscience Critical Care Unit of a teaching hospital. PARTICIPANTS: Thirty consecutive patients with severe subarachnoid haemorrhage requiring external ventricular drainage were enrolled during 2013 and 2014. INTERVENTIONS: Blood and cerebrospinal fluid (CSF) were sampled within the first 24 h and between 48 and 72 h after admission. We evaluated the activity and concentrations of MMP-9 and endothelin-1 with zymography and ELISA. Patients were allocated to groups with delayed cerebral ischaemia (n = 16) or without delayed cerebral ischaemia (n = 14). RESULTS: Within 24 h, median [interquartile range] MMP-9 concentrations in CSF were significantly higher in patients with delayed cerebral ischaemia (47 [21 to 102] ng ml) than in those without delayed cerebral ischaemia (4 [2 to 13] ng ml, P = 0.001). CSF MMP-9 activity and endothelin-1 concentrations were correlated (r = 0.6, P = 0.02). The areas under the receiver operating characteristic curves were 0.73 (95% confidence interval [0.53 to 0.87]) and 0.91 (95% confidence interval [0.75 to 0.98]) for MMP-9 concentrations in plasma and CSF, respectively, at 24 h to predict delayed cerebral ischaemia CSF MMP-9 concentrations more than 14.3 ng ml at 24 h predicted the occurrence of delayed cerebral ischaemia with a sensitivity and specificity of 88 and 86%, respectively. After multivariate logistic analysis, only CSF MMP-9 concentrations at 24 h predicted the occurrence of delayed cerebral ischaemia (P = 0.01). CONCLUSION: MMP-9 concentrations in both plasma and CSF, measured within 48 h after subarachnoid haemorrhage, were highly predictive of the occurrence of delayed cerebral ischaemia within the first 2 weeks. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02397759.

Reliability of standard pupillometry practice in neurocritical care: an observational, double-blinded study.

BACKGROUND: In critical care units, pupil examination is an important clinical parameter for patient monitoring. Current practice is to use a penlight to observe the pupillary light reflex. The result seems to be a subjective measurement, with low precision and reproducibility. Several quantitative pupillometer devices are now available, although their use is primarily restricted to the research setting. To assess whether adoption of these technologies would benefit the clinic, we compared automated quantitative pupillometry with the standard clinical pupillary examination currently used for brain-injured patients. METHODS: In order to determine inter-observer agreement of the device, we performed repetitive measurements in 200 healthy volunteers ranging in age from 21 to 58 years, providing a total of 400 paired (alternative right eye, left eye) measurements under a wide variety of ambient light condition with NeuroLight Algiscan pupillometer. During another period, we conducted a prospective, observational, double-blinded study in two neurocritical care units. Patients admitted to these units after an acute brain injury were included. Initially, nursing staff measured pupil size, anisocoria and pupillary light reflex. A blinded physician subsequently performed measurement using an automated pupillometer. RESULTS: In 200 healthy volunteers, intra-class correlation coefficient for maximum resting pupil size was 0.95 (IC: 0.93-0.97) and for minimum pupil size after light stimulation 0.87 (0.83-0.89). We found only 3-pupil asymmetry (≥ 1 mm) in these volunteers (1.5% of the population) with a clear pupil asymmetry during clinical inspection. The mean pupil light reactivity was 40 ± 7%. In 59 patients, 406 pupillary measurements were prospectively performed. Concordance between measurements for pupil size collected using the pupillometer, versus subjective assessment, was poor (Spearmen's rho = 0.75, IC: 0.70-0.79; P < 0.001). Nursing staff failed to diagnose half of the cases (15/30) of anisocoria detected using the pupillometer device. A global rate of discordance of 18% (72/406) was found between the two techniques when assessing the pupillary light reflex. For measurements with small pupils (diameters <2 mm) the error rate was 39% (24/61). CONCLUSION: Standard practice in pupillary monitoring yields inaccurate data. Automated quantitative pupillometry is a more reliable method with which to collect pupillary measurements at the bedside.

Effect of sedative premedication on patient experience after general anesthesia: a randomized clinical trial.

IMPORTANCE: Sedative premedication is widely administered before surgery, but little clinical evidence supports its use. OBJECTIVE: To assess the efficacy of sedative premedication on perioperative patient experience. DESIGN, SETTING, AND PARTICIPANTS: A randomized clinical trial, the PremedX study, enrolled 1062 adult patients who were younger than 70 years and had been scheduled for various elective surgeries under general anesthesia at 5 French teaching hospitals (in Marseille, Montpellier, Nimes, and Nice) between January 2013 and June 2014. Neurosurgery, obstetrical, cardiac, and outpatient surgery were excluded. INTERVENTIONS: Patients were randomized to 3 groups of 354 participants each to receive 2.5 mg of lorazepam, no premedication, or placebo. MAIN OUTCOMES AND MEASURES: The primary outcome was perioperative patient experience assessed 24 hours after surgery with a validated questionnaire (Evaluation du Vécu de l'Anesthésie Generale; EVAN-G) describing 6 domains of satisfaction and a global index (score range, 0-100; high scores represent high satisfaction); secondary outcomes included time to extubation and early cognitive recovery. A subgroup analysis was planned a priori in patients with a high level of preoperative anxiety. RESULTS: Premedication with lorazepam did not improve the EVAN-G mean global index for overall level of patient satisfaction (72 [95% CI, 70-73]; n = 330) compared with no premedication (73 [95% CI, 71-74]; n = 319) or placebo (71 [95% CI, 70-73]; n = 322) (P = .38). Among patients with heightened preoperative anxiety, there were no significant differences found in the EVAN-G mean global index between the lorazepam group (68 [95% CI, 65-72]; n = 87) and the no premedication group (73 [95% CI, 69-77]; n = 57) or the placebo group (70 [95% CI, 67-72]; n = 87) (P = .18). Time to extubation was 17 minutes (95% CI, 14-20 minutes) in the lorazepam group, 12 minutes (95% CI, 11-13 minutes) for the no premedication group, and 13 minutes (95% CI, 12-14 minutes) for the placebo group (P < .001) and the rate of early cognitive recovery was 51% (95% CI, 45%-56%), 71% (95% CI, 66%-76%), and 64% (95% CI, 59%-69%), respectively (P < .001). CONCLUSIONS AND RELEVANCE: Among patients undergoing elective surgery under general anesthesia, sedative premedication with lorazepam compared with placebo or no premedication did not improve the self-reported patient experience the day after surgery, but was associated with modestly prolonged time to extubation and a lower rate of early cognitive recovery. The findings suggest a lack of benefit with routine use of lorazepam as sedative premedication in patients undergoing general anesthesia. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01901003.