OBJECTIVE The aim of this study was to create prediction models for outcome parameters by decision tree analysis based on clinical and laboratory data in patients with aneurysmal subarachnoid hemorrhage (aSAH). METHODS The database consisted of clinical and laboratory parameters of 548 patients with aSAH who were admitted to the Neurocritical Care Unit, University Hospital Zurich. To examine the model performance, the cohort was randomly divided into a derivation cohort (60% [n = 329]; training data set) and a validation cohort (40% [n = 219]; test data set). The classification and regression tree prediction algorithm was applied to predict death, functional outcome, and ventriculoperitoneal (VP) shunt dependency. Chi-square automatic interaction detection was applied to predict delayed cerebral infarction on days 1, 3, and 7. RESULTS The overall mortality was 18.4%. The accuracy of the decision tree models was good for survival on day 1 and favorable functional outcome at all time points, with a difference between the training and test data sets of < 5%. Prediction accuracy for survival on day 1 was 75.2%. The most important differentiating factor was the interleukin-6 (IL-6) level on day 1. Favorable functional outcome, defined as Glasgow Outcome Scale scores of 4 and 5, was observed in 68.6% of patients. Favorable functional outcome at all time points had a prediction accuracy of 71.1% in the training data set, with procalcitonin on day 1 being the most important differentiating factor at all time points. A total of 148 patients (27%) developed VP shunt dependency. The most important differentiating factor was hyperglycemia on admission. CONCLUSIONS The multiple variable analysis capability of decision trees enables exploration of dependent variables in the context of multiple changing influences over the course of an illness. The decision tree currently generated increases awareness of the early systemic stress response, which is seemingly pertinent for prognostication.

BackgroundTo assess whether circadian patterns of temperature correlate with further values of intracranial pressure (ICP) in severe brain injury treated with hypothermia.MethodsWe retrospectively analyzed temperature values in subarachnoid hemorrhage patients treated with hypothermia by endovascular cooling. The circadian patterns of temperature were correlated with the mean ICP across the following day (ICP24).ResultsWe analyzed data from 17 days of monitoring of three subarachnoid hemorrhage patients that underwent aneurysm coiling, sedation and hypothermia due to refractory intracranial hypertension and/or cerebral vasospasm. ICP24 ranged from 11.5 ± 3.1 to 24.2 ± 6.2 mmHg. The ratio between the coefficient of variation of temperature during the nocturnal period (18:00–6:00) and the preceding diurnal period (6:00–18:00) [temperature variability (TV)] ranged from 0.274 to 1.97. Regression analysis showed that TV correlated with ICP24 (Pearson correlation = −0.861, adjusted R square = 0.725, p < 0.001), and that ICP24 = 6 (4–TV) mmHg or, for 80% prediction interval,  mmHg. The results indicate that the occurrence of ICP24 higher than 20 mmHg is unlikely after a day with TV ≥1.0.ConclusionsTV correlates with further ICP during hypothermia regardless the strict range that temperature is maintained. Further studies with larger series could clarify whether intracranial hypertension in severe brain injury can be predicted by analysis of oscillation patterns of autonomic parameters across a period of 24 h or its harmonics.Electronic supplementary materialThe online version of this article (doi:10.1186/s12967-017-1272-y) contains supplementary material, which is available to authorized users.

No abstract

OBJECTIVEWomen taking combined hormonal contraceptives (CHCs) are generally considered to be at low risk for cerebral venous thrombosis (CVT). When it does occur, however, intensive care and neurosurgical management may, in rare cases, be needed for the control of elevated intracranial pressure (ICP). The use of nonsurgical strategies such as barbiturate coma and induced hypothermia has never been reported in this context. The objective of this study is to determine predictive factors for invasive or surgical ICP treatment and the potential complications of nonsurgical strategies in this population.METHODSThe authors conducted a 2-center, retrospective chart review of 168 cases of CVT in women between 2000 and 2012. Eligible patients were classified as having had a mild or a severe clinical course, the latter category including all patients who underwent invasive or surgical ICP treatment and all who had an unfavorable outcome (modified Rankin Scale score ≥ 3 or Glasgow Outcome Scale score ≤ 3). The Mann-Whitney U-test was used for continuous parameters and Fisher’s exact test for categorical parameters, and odds ratios were calculated with statistical significance set at p ≤ 0.05.RESULTSOf the 168 patients, 57 (age range 16–49 years) were determined to be eligible for the study. Six patients (10.5%) required invasive or surgical ICP treatment. Three patients (5.3%) developed refractory ICP > 30 mm Hg despite early surgical decompression; 2 of them (3.5%) were treated with barbiturate coma and induced hypothermia, with documented infectious, thromboembolic, and hemorrhagic complications. Coma on admission, thrombosis of the deep venous system with consecutive hydrocephalus, intraventricular hemorrhage, and hemorrhagic venous infarction were associated with a higher frequency of surgical intervention. Coma, quadriparesis on admission, and hydrocephalus were more commonly seen among women with unfavorable outcomes. Thrombosis of the transverse sinus was less common in patients with an unfavorable outcome, with similar distribution in patients needing invasive or surgical ICP treatment.CONCLUSIONSThe need for invasive or surgical ICP treatment in women taking CHCs who have CVT is partly predictable on the basis of the clinical and radiological findings on admission. The use of nonsurgical treatments for refractory ICP, such as barbiturate coma and induced hypothermia, is associated with systemic infectious and hematological complications and may worsen morbidity in this patient population. The significance of these factors should be studied in larger multicenter cohorts.