Understanding the disease: aneurysmal subarachnoid hemorrhage

Increased blood coagulation is associated with poor neurological outcome in aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Patients with aneurysmal subarachnoid hemorrhage (aSAH) have demonstrated increased blood coagulation which is thought to contribute to delayed cerebral ischemia (DCI) and to a worse outcome. Therefore, we sought to determine whether this increased blood coagulation, detectable with rotational thromboelastometry (ROTEM), was associated with DCI and neurological outcome.

METHODS

We conducted a prospective observational study of 60 consecutive adult aSAH patients. ROTEM's EXTEM and FIBTEM assays and D-dimer were analyzed at admission and post-bleed days (PBDs) 2-3, 4-5, 7-8, and 11-12. ROTEM's clot formation time (CFT) represents the stabilization of the clot, and the maximum clot firmness (MCF) the maximum clot strength. Glasgow Outcome Scale extended (GOSe) at three months determined the neurological outcome.

RESULTS

DCI incidence was 41.7%. EXTEM-CFT was significantly shorter in patients with unfavorable neurological outcome (GOSe 1-4) on PBDs 4-5 and 7-8, p < 0.05, respectively. FIBTEM-MCF was significantly higher in patients with unfavorable neurological outcomes on PBD 4-5 (p < 0.05), PBD 7-8 (p < 0.05), and PBD 11-12 (p < 0.05). EXTEM-CFT decreased, and FIBTEM-MCF rose during the study period in all patients. Patients with unfavorable neurological outcome had a higher D-dimer at all studied time points, p < 0.05. No difference was found in the ROTEM parameters or D-dimer when assessing patients with and without DCI.

CONCLUSIONS

Patients were in a state of increased blood coagulation after aSAH, with those with unfavorable neurological outcome being more coagulable than those with favorable outcome. However, increased blood coagulation was not associated with DCI.

CLINICALTRIALS

gov, NCT03985176.

Melatonin alleviates early brain injury by inhibiting the NRF2-mediated ferroptosis pathway after subarachnoid hemorrhage

Ferroptosis is a novel form of cell death that plays a critical role in the pathological and physiological processes of early brain injury following subarachnoid hemorrhage. Melatonin, as the most potent endogenous antioxidant, has shown strong protective effects against pathological changes following subarachnoid hemorrhage, but its impact on ferroptosis induced by subarachnoid hemorrhage remains unexplored. In our study, we established a subarachnoid hemorrhage model in male SD rats. We found that subarachnoid hemorrhage induced changes in ferroptosis-related indicators such as lipid peroxidation and iron metabolism, while intraperitoneal injection of melatonin (40 mg/kg) effectively ameliorated these changes to a certain degree. Moreover, in a subset of rats with subarachnoid hemorrhage who received pre-treatment via intravenous injection of the melatonin receptor antagonist Luzindole (1 mg/kg) and 4P-PDOT (1 mg/kg), we found that the protective effect of melatonin against subarachnoid hemorrhage includes inhibition of lipid peroxidation and reduction of iron accumulation depended on melatonin receptor 1B (MT2). Furthermore, our study demonstrated that melatonin inhibited neuronal ferroptosis by activating the NRF2 signaling pathway, as evidenced by in vivo inhibition of NRF2. In summary, melatonin acts through MT2 and activates NRF2 and downstream genes such as HO-1/NQO1 to inhibit ferroptosis in subarachnoid hemorrhage-induced neuronal injury, thereby improving neurological function in rats. These results suggest that melatonin is a promising therapeutic target for subarachnoid hemorrhage.

Impact of pre-hospital handling and initial time to cranial computed tomography on outcome in aneurysmal subarachnoid hemorrhage patients with out-of-hospital sudden cardiac arrest-a retrospective bi-centric study

Background

Aneurysmal subarachnoid hemorrhage (SAH) presents occasionally with cardiac arrest (CA). The impact of pre-hospital and emergency room (ER) treatment on outcome remains unclear. Therefore, we investigated the impact of pre-hospital treatment, focusing on lay cardiopulmonary resuscitation (CPR), and ER handling on the outcome of SAH patients with out-of-hospital CA (OHCA).

Methods

In this bi-centric retrospective analysis, we reviewed SAH databases for OHCA and CPR from January 2011 to June 2021. Patients were analyzed for general clinical and epidemiological parameters. CPR data were obtained from ambulance reports and information on ER handling from the medical records. Data were correlated with patient survival at hospital discharge as a predefined outcome parameter.

Results

Of 1,120 patients with SAH, 45 (4.0%) were identified with OHCA and CPR, 38 of whom provided all required information and were included in this study. Time to resuscitation was significantly shorter with lay resuscitation (5.3 ± 5.2 min vs. 0.3 ± 1.2 min, p = 0.003). Nineteen patients were not initially scheduled for cranial computed tomography (CCT), resulting in a significantly longer time interval to first CCT (mean ± SD: 154 ± 217 min vs. 40 ± 23 min; p < 0.001). Overall survival to discharge was 31.6%. Pre-hospital lay CPR was not associated with higher survival (p = 0.632). However, we observed a shorter time to first CCT in surviving patients (p = 0.065).

Conclusions

OHCA in SAH patients is not uncommon. Besides high-quality CPR, time to diagnosis of SAH appears to play an important role. We therefore recommend considering CCT diagnostics as part of the diagnostic algorithm in patients with OHCA.

Brain alarm by self-extracellular nucleic acids: from neuroinflammation to neurodegeneration

Neurological disorders such as stroke, multiple sclerosis, as well as the neurodegenerative diseases Parkinson's or Alzheimer's disease are accompanied or even powered by danger associated molecular patterns (DAMPs), defined as endogenous molecules released from stressed or damaged tissue. Besides protein-related DAMPs or "alarmins", numerous nucleic acid DAMPs exist in body fluids, such as cell-free nuclear and mitochondrial DNA as well as different species of extracellular RNA, collectively termed as self-extracellular nucleic acids (SENAs). Among these, microRNA, long non-coding RNAs, circular RNAs and extracellular ribosomal RNA constitute the majority of RNA-based DAMPs. Upon tissue injury, necrosis or apoptosis, such SENAs are released from neuronal, immune and other cells predominantly in association with extracellular vesicles and may be translocated to target cells where they can induce intracellular regulatory pathways in gene transcription and translation. The majority of SENA-induced signaling reactions in the brain appear to be related to neuroinflammatory processes, often causally associated with the onset or progression of the respective disease. In this review, the impact of the diverse types of SENAs on neuroinflammatory and neurodegenerative diseases will be discussed. Based on the accumulating knowledge in this field, several specific antagonistic approaches are presented that could serve as therapeutic interventions to lower the pathological outcome of the indicated brain disorders.

Intracranial Pressure Monitoring and Management in Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage is a medical condition that can lead to intracranial hypertension, negatively impacting patients' outcomes. This review article explores the underlying pathophysiology that causes increased intracranial pressure (ICP) during hospitalization. Hydrocephalus, brain swelling, and intracranial hematoma could produce an ICP rise. Although cerebrospinal fluid withdrawal via an external ventricular drain is commonly used, ICP monitoring is not always consistently practiced. Indications for ICP monitoring include neurological deterioration, hydrocephalus, brain swelling, intracranial masses, and the need for cerebrospinal fluid drainage. This review emphasizes the importance of ICP monitoring and presents findings from the Synapse-ICU study, which supports a correlation between ICP monitoring and treatment with better patient outcomes. The review also discusses various therapeutic strategies for managing increased ICP and identifies potential areas for future research.

Regional Variability in the Care and Outcomes of Subarachnoid Hemorrhage Patients in the United States

Background and Objectives

Regional variability in subarachnoid hemorrhage (SAH) care is reported in physician surveys. We aimed to describe variability in SAH care using patient-level data and identify factors impacting hospital outcomes and regional variability in outcomes.

Methods

A retrospective multi-center cross-sectional cohort study of consecutive non-traumatic SAH patients in the Vizient Clinical Data Base, between January 1st, 2009 and December 30th, 2018 was performed. Participating hospitals were divided into US regions: Northeast, Midwest, South, West. Regional demographics, co-morbidities, severity-of-illness, complications, interventions and discharge outcomes were compared. Multivariable logistic regression was performed to identify factors independently associated with primary outcomes: hospital mortality and poor discharge outcome. Poor discharge outcome was defined by the Nationwide Inpatient Sample-SAH Outcome Measure, an externally-validated outcome measure combining death, discharge disposition, tracheostomy and/or gastrostomy. Regional variability in the associations between care and outcomes were assessed by introducing an interaction term for US region into the models.

Results

Of 109,034 patients included, 24.3% were from Northeast, 24.9% Midwest, 34.9% South, 15.9% West. Mean (SD) age was 58.6 (15.6) years and 64,245 (58.9%) were female. In-hospital mortality occurred in 21,991 (20.2%) and 44,159 (40.5%) had poor discharge outcome. There was significant variability in severity-of-illness, co-morbidities, complications and interventions across US regions. Notable findings were higher prevalence of surgical clipping (18.8 vs. 11.6%), delayed cerebral ischemia (4.3 vs. 3.1%), seizures (16.5 vs. 14.8%), infections (18 vs. 14.7%), length of stay (mean [SD] days; 15.7 [19.2] vs. 14.1 [16.7]) and health-care direct costs (mean [SD] USD; 80,379 [98,999]. vs. 58,264 [74,430]) in the West when compared to other regions (all p < 0.0001). Variability in care was also associated with modest variability in hospital mortality and discharge outcome. Aneurysm repair, nimodipine use, later admission-year, endovascular rescue therapies reduced the odds for poor outcome. Age, severity-of-illness, co-morbidities, hospital complications, and vasopressor use increased those odds (c-statistic; mortality: 0.77; discharge outcome: 0.81). Regional interaction effect was significant for admission severity-of-illness, aneurysm-repair and nimodipine-use.

Discussion

Multiple hospital-care factors impact SAH outcomes and significant variability in hospital-care and modest variability in discharge-outcomes exists across the US. Variability in SAH-severity, nimodipine-use and aneurysm-repair may drive variability in outcomes.

Hemodynamic Monitoring in Patients With Subarachnoid Hemorrhage: A Systematic Review and Meta-Analysis

Aneurysmal subarachnoid hemorrhage (aSAH) often causes cardiopulmonary dysfunction. Therapeutic strategies can be guided by standard (invasive arterial/central venous pressure measurements, fluid balance assessment), and/or advanced (pulse index continuous cardiac output, pulse dye densitometry, pulmonary artery catheterization) hemodynamic monitoring. We conducted a systematic review and meta-analysis of the literature to determine whether standard compared with advanced hemodynamic monitoring can improve patient management and clinical outcomes after aSAH. A literature search was performed for articles published between January 1, 2000 and January 1, 2019. Studies involving aSAH patients admitted to the intensive care unit and subjected to any type of hemodynamic monitoring were included. A total of 14 studies were selected for the qualitative synthesis and 3 randomized controlled trials, comparing standard versus advanced hemodynamic monitoring, for meta-analysis. The incidence of delayed cerebral ischemia was lower in the advanced compared with standard hemodynamic monitoring group (relative risk [RR]=0.71, 95% confidence interval [CI]=0.52-0.99; P=0.044), but there were no differences in neurological outcome (RR=0.83, 95% CI=0.64-1.06; P=0.14), pulmonary edema onset (RR=0.44, 95% CI=0.05-3.92; P=0.46), or fluid intake (mean difference=-169 mL; 95% CI=-1463 to 1126 mL; P=0.8) between the 2 groups. In summary, this systematic review and meta-analysis found only low-quality evidence to support the use of advanced hemodynamic monitoring in selected aSAH patients. Because of the small number and low quality of studies available for inclusion in the review, further studies are required to investigate the impact of standard and advanced hemodynamic monitoring-guided management on aSAH outcomes.

Role of Adaptor Protein Myeloid Differentiation 88 (MyD88) in Post-Subarachnoid Hemorrhage Inflammation: A Systematic Review

Myeloid differentiation 88 (MyD88) is a well-established inflammatory adaptor protein. It is one of the essential downstream proteins of the toll-like receptor 4 (TLR4) signaling pathway. TLRs are pattern recognition receptors that are usually activated by the damage-associated molecular pattern molecules (DAMPs). Sterile inflammation is triggered by the endogenous DAMPs released in response to global cerebral ischemia and from extravasated blood after subarachnoid hemorrhage (SAH). In this review, we highlight the importance of the neuroinflammatory role of the MyD88 in the SAH. We also explore a few possible pharmacological agents that can be used to decrease SAH-associated neuroinflammation by modulating the MyD88 dependent functions. Pharmacological agents such as flavonoids, melatonin, fluoxetine, pentoxifylline and progesterone have been investigated experimentally to reduce the SAH-associated inflammation. Inhibition of the MyD88 not only reduces the expression of pro-inflammatory cytokines, but also potentially inhibits other processes that can augment the SAH associated inflammation. Further investigations are required to translate these findings in the clinical setting.

Association of Dose of Intracranial Hypertension with Outcome in Subarachnoid Hemorrhage

BACKGROUND

In patients with aneurysmal subarachnoid hemorrhage (aSAH) the burden of intracranial pressure (ICP) and its contribution to outcomes remains unclear. In this multicenter study, the independent association between intensity and duration, or "dose," of episodes of intracranial hypertension and 12-month neurological outcomes was investigated.

METHODS

This was a retrospective analysis of multicenter prospectively collected data of 98 adult patients with aSAH amendable to treatment. Patients were admitted to the intensive care unit of two European centers (Medical University of Innsbruck [Austria] and San Gerardo University Hospital of Monza [Italy]) from 2009 to 2013. The dose of intracranial hypertension was visualized. The obtained visualizations allowed us to investigate the association between intensity and duration of episodes of intracranial hypertension and the 12-month neurological outcomes of the patients, assessed with the Glasgow Outcome Score. The independent association between the cumulative dose of intracranial hypertension and outcome for each patient was investigated by using multivariable logistic regression models corrected for age, occurrence of delayed cerebral ischemia, and the Glasgow Coma Scale score at admission.

RESULTS

The combination of duration and intensity defined the tolerance to intracranial hypertension for the two cohorts of patients. A semiexponential transition divided ICP doses that were associated with better outcomes (in blue) with ICP doses associated with worse outcomes (in red). In addition, in both cohorts, an independent association was found between the cumulative time that the patient experienced ICP doses in the red area and long-term neurological outcomes. The ICP pressure-time burden was a stronger predictor of outcomes than the cumulative time spent by the patients with an ICP greater than 20 mmHg.

CONCLUSIONS

In two cohorts of patients with aSAH, an association between duration and intensity of episodes of elevated ICP and 12-month neurological outcomes could be demonstrated and was visualized in a color-coded plot.

Prognostic value of the 2010 consensus definition of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Delayed cerebral ischemia (DCI) complicates the recovery of approximately 30% of patients with aneurysmal subarachnoid hemorrhage (aSAH). The definition of DCI widely varies, even though a consensus definition has been recommended since 2010. This study aimed to evaluate the prognostic value of the 2010 consensus definition of DCI in a cohort of patients with aSAH.

METHODS

We conducted a single-center, retrospective, observational study that included consecutive adult patients with aSAH who were admitted to the intensive care unit from January 2010 to December 2014. DCI was evaluated 48 h to 14 days after onset of aSAH symptoms using the 2010 consensus criteria and outcome was assessed by the Glasgow Outcome Scale (GOS) at discharge from hospital.

RESULTS

A total of 340 patients were analyzed and the incidence of DCI was 37.1%. The median time from primary hemorrhage to the occurrence of DCI was 97 h. Neurological deterioration was observed in most (89.7%) of the patients who fulfilled the DCI criteria. The occurrence of DCI was strongly associated with an unfavorable outcome (GOS 1-3) at hospital discharge (OR 2.65, 95% CI 1.69-4.22, p < 0.001).

CONCLUSIONS

The incidence of DCI after aSAH is high and its occurrence is strongly associated with an unfavorable neurological outcome. This finding adds to the previous literature, which has shown that DCI appears to be a major contributor affecting the functional ability of survivors of aSAH. To further advance reliable knowledge of DCI, future studies should adhere to the consensus definition of DCI.

Anemia After Aneurysmal Subarachnoid Hemorrhage Is Associated With Poor Outcome and Death

Background and Purpose- Anemia after aneurysmal subarachnoid hemorrhage is common and potentially modifiable. Here, we first evaluate the effect of anemia on neurological outcome and death and second, study the effects of packed red blood cell transfusion on outcome. Methods- A secondary analysis on 413 subjects in the CONSCIOUS-1 study (Clazosentan to Overcome Neurological Ischemia and Infarction Occurring After Subarachnoid Hemorrhage). Multivariable logistic regression identified independent risk factors for anemia and determined the effect of anemia on neurological outcome and death, while adjusting for selected covariates. Optimal predictive thresholds for hemoglobin levels were determined using receiver operating characteristic curve analysis. Finally, patients were pseudorandomized to transfusion using propensity score matching to study the effect of transfusions on outcome. Results- Anemia, defined as hemoglobin <10 g/dL, was present in 5% of patients at presentation, in 29% of patients after aneurysm securing (days 1-3), and in 32% of patients during the peak delayed cerebral ischemia risk period (days 5-9). Anemia after aneurysm securing (odds ratio, 1.96; 95% confidence interval, 1.07-3.59; P=0.03) and during the delayed cerebral ischemia window (odds ratio, 2.63; 95% confidence interval, 1.46-4.76; P=0.0014) was independently associated with poor neurological outcome. Anemia postaneurysm securing (odds ratio, 3.50; 95% confidence interval, 1.15-10.62; P=0.027) but not during the delayed cerebral ischemia window was associated with death. Using propensity score-matched cohorts, we found that transfusion of anemic patients did not improve long-term outcome (P=0.8) or mortality rates (P=0.9). Transfusion of patients with a hemoglobin concentration >10 g/dL was associated with improved neurological outcomes (odds ratio, 0.09; 95% confidence interval, 0.002-0.72; P=0.015), with no differences in mortality. Conclusions- Anemia after aneurysmal subarachnoid hemorrhage is associated with poor long-term neurological outcome and death. Transfusion of packed red blood cells is beneficial for patients who are not considerably anemic beforehand, suggesting further work needs to define the threshold but also the time period of anemia that is sufficient and necessary to contribute to poor outcomes. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT00111085.

S100B, NSE and MMP-9 fail to predict neurologic outcome while elevated S100B associates with milder initial clinical presentation after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Despite advances in the treatment of aneurysmal subarachnoid hemorrhage (aSAH) one-year mortality remains approximately 50%. Making an accurate prognosis at the early phase of the disease is notoriously difficult. A clinically reliable biomarker that could be used for better prediction of prognosis and/or as a surrogate for developing complications after aSAH is still lacking. In this study, we evaluated the prognostic values of three promising biomarkers, i.e. S100B, NSE, and MMP-9 in aSAH.

METHODS

In this prospective population-based study, S100B, NSE, and MMP-9 levels were measured in 47 aSAH patients for up to five days. Blood samples were taken at 0, 12 and 24 h after the admission to the intensive care unit (ICU) and daily after that until the patient was transferred from the ICU. The patients' neurological outcome was evaluated with the modified Rankin Scale (mRS) at six months after aSAH.

RESULTS

Biomarker-levels measured during the first 24 h were not associated with neurological outcome. S100B levels during the first 24 h were elevated in patients with a non-severe initial clinical presentation. Otherwise, there was no association between selected clinical variables and the early biomarker levels. In 22 patients, whose ICU follow-up lasted for up to five days, the total release of biomarkers was not associated with the neurological outcome.

CONCLUSIONS

None of the measured biomarkers were associated with the neurological outcome evaluated at six months after aSAH. Elevated levels of S100B in patients with non-severe initial presentation suggest an adaptive role of this biomarker in aSAH. Based on our findings it is not advisable to use these biomarkers to guide clinical decision-making in patients with aSAH.

A Comparison of Pathophysiology in Humans and Rodent Models of Subarachnoid Hemorrhage

Non-traumatic subarachnoid hemorrhage (SAH) affects an estimated 30,000 people each year in the United States, with an overall mortality of ~30%. Most cases of SAH result from a ruptured intracranial aneurysm, require long hospital stays, and result in significant disability and high fatality. Early brain injury (EBI) and delayed cerebral vasospasm (CV) have been implicated as leading causes of morbidity and mortality in these patients, necessitating intense focus on developing preclinical animal models that replicate clinical SAH complete with delayed CV. Despite the variety of animal models currently available, translation of findings from rodent models to clinical trials has proven especially difficult. While the explanation for this lack of translation is unclear, possibilities include the lack of standardized practices and poor replication of human pathophysiology, such as delayed cerebral vasospasm and ischemia, in rodent models of SAH. In this review, we summarize the different approaches to simulating SAH in rodents, in particular elucidating the key pathophysiology of the various methods and models. Ultimately, we suggest the development of standardized model of rodent SAH that better replicates human pathophysiology for moving forward with translational research.

Speckle tracking analysis allows sensitive detection of stress cardiomyopathy in severe aneurysmal subarachnoid hemorrhage patients

PURPOSE

Stress cardiomyopathy is a common life-threatening complication after aneurysmal subarachnoid hemorrhage (SAH). We hypothesized that left ventricular (LV) longitudinal strain alterations assessed with speckle tracking could identify early systolic function impairment.

METHODS

This was an observational single-center prospective pilot controlled study conducted in a neuro-intensive care unit. Forty-six patients with severe SAH with a World Federation of Neurological Surgeons grade (WFNS) ≥ III were included. Transthoracic echocardiography (TTE) was performed on day 1, day 3, and day 7 after the patient's admission. A cardiologist blinded to the patient's management analyzed the LV global longitudinal strain (GLS). The control group comprised normal subjects matched according to gender and age.

RESULTS

On day 1 median (25th-75th percentile) GLS was clearly impaired in SAH patients compared to controls [-16.7 (-18.7/-13.7) % versus -20 (-22/-19) %, p < 0.0001], whereas LVEF was preserved [65 (59-70) %]. GLS was severely impaired in patients with a WFNS score of V versus III-IV [-15.6 (-16.9/-12.3) % versus -17.8 (-20.6/-15.8) %, p = 0.008]. Seventeen (37 %) patients had a severe GLS alteration (>- 16 %). In these patients, GLS improved from day 1 [-12.4 (-14.8/-10.9) %] to last evaluation [-16.2 (-19/-14.6) %, p = 0.0007] in agreement with the natural evolution of stress cardiomyopathy.

CONCLUSIONS

On the basis of LV GLS assessment, we demonstrated for the first time that myocardial alteration compatible with a stress cardiomyopathy is detectable in up to 37 % of patients with severe SAH while LVEF is preserved. GLS could be used for sensitive detection of stress cardiomyopathy. This is critical because cardiac impairment remains a major cause of morbidity and mortality after SAH.

Diagnosis and Management of Subarachnoid Hemorrhage

PURPOSE OF REVIEW

The purpose of this article is to present the epidemiology, clinical presentation, and management of patients with subarachnoid hemorrhage (SAH). SAH is a neurologic emergency that carries high morbidity and mortality. Patients with SAH are at risk for several significant neurologic complications, including hydrocephalus, cerebral edema, delayed cerebral ischemia, rebleeding, seizures, and neuroendocrine abnormalities that lead to impaired body regulation of sodium, water, and glucose.

RECENT FINDINGS

The incidence of SAH has remained stable, but mortality of hospitalized patients has significantly declined over the past 3 decades. Many common therapies for SAH have created controversy, and various recent neuroprotective clinical trials have produced negative results. However, the publication of two consensus guidelines by the American Heart Association/American Stroke Association and the Neurocritical Care Society have provided a clarification for what should constitute best practice for patients with SAH. The most important of those recommendations include the following: admission of patients to high-volume centers (defined as more than 35 patients with SAH per year) under the management of a specialized and multidisciplinary team; early identification and management of the bleeding source; evaluation and treatment decision for unsecured aneurysms by a multidisciplinary team made up of cerebrovascular neurosurgeons, endovascular practitioners, and neurointensivists; management of patients in the neurocritical care unit with oral nimodipine, blood pressure control, euvolemia, and frequent monitoring for neurologic and systemic complications; and delayed cerebral ischemia secondary to cerebral vasospasm should be treated with induced hypertension and endovascular therapies once confirmed.

SUMMARY

SAH is a devastating neurologic disease. Management of patients with SAH should adhere to currently available treatment guidelines. Several aspects of SAH management remain controversial and need further studies to clarify their role in improving patient outcome.

High-Resolution Intracranial Pressure Burden and Outcome in Subarachnoid Hemorrhage

Background and Purpose—

Intracranial pressure (ICP) control is a therapeutic target in patients with aneurysmal subarachnoid hemorrhage, although only a limited number of studies assessed its course and effect on outcome. Pressure–time dose (PTD ICP ) is a method to quantify the burden and the time spent above a defined threshold of ICP. PTD ICP or its relationship with outcome has never been evaluated in aneurysmal subarachnoid hemorrhage.

Methods—

Analysis of data prospectively collected from aneurysmal subarachnoid hemorrhage patients admitted to Neurointensive Care Unit. Monitored data, including intraparenchymal ICP, were digitally recorded minute-by-minute in the first 7 days. PTD ICP (mm Hg h) was computed using 4 predefined thresholds (15, 20, 25, and 30 mm Hg). Outcome was assessed through Extended Glasgow Outcome Scale at hospital discharge and at 6 months.

Results—

Fifty-five patients were enrolled. Forty-two patients (76%) presented with a poor clinical grade. Overall, mortality was 17% at hospital discharge and 34% at 6 months. Half of patients required extensive therapy to control high ICP during day 1. Median ICP was 10 mm Hg (4–75), whereas median PTD ICP15 , PTD ICP20 , PTD ICP25 , PTD ICP30 were, respectively, 13, 4, 2, and 1 mm Hg h. We observed an association between mortality at hospital discharge and higher level of PTD ICP using 20, 25, and 30 mm Hg as thresholds and between exposure to a moderate-level PTD ICP30 and unfavorable long-term outcome.

Conclusions—

PTD ICP may better define one of the insults that the brain suffers after aneurysmal rupture, and exposure to moderate PTD ICP30 was significant prognostic factor of 6-month unfavorable outcome.