Aneurysmal subarachnoid hemorrhage outcome

Aneurysmal subarachnoid hemorrhage outcome

Several studies have investigated the changes in CSF metabolomics that occur after aSAH. These studies have identified alterations in various metabolites and metabolic pathways, including those involved in energy metabolism, amino acid metabolism, and lipid metabolism.

One study found that levels of lactate, a marker of anaerobic metabolism, were significantly increased in the CSF of aSAH patients compared to controls. This suggests that there is a shift towards anaerobic metabolism in the brain following aSAH, possibly due to decreased oxygen delivery and increased metabolic demand.

Other studies have reported alterations in amino acid metabolism, particularly involving glutamate and gamma-aminobutyric acid (GABA). Glutamate is an excitatory neurotransmitter that can lead to neuronal damage when present in excess, while GABA is an inhibitory neurotransmitter that can protect against excitotoxicity. Studies have shown that CSF levels of glutamate are increased and GABA levels are decreased in aSAH patients, which may contribute to the pathophysiology of the disease.

Alterations in lipid metabolism have also been reported in aSAH patients, with decreased levels of sphingomyelins and phosphatidylcholines in the CSF. These lipids play important roles in cellular membrane structure and function, and their depletion may contribute to neuronal damage and inflammation.

Overall, the findings of metabolomics studies suggest that aSAH leads to widespread metabolic alterations in the brain, involving multiple metabolic pathways. These alterations may contribute to the pathophysiology of the disease and represent potential targets for therapeutic intervention.

There is increasing evidence suggesting that biomarkers can give insight into the aneurysmal subarachnoid hemorrhage pathogenesis and can serve as an outcome predictor 1)

NFE2L2 SNP, rs10183914, is significantly associated with aneurysmal subarachnoid hemorrhage outcome. This is consistent with a clinically relevant pathophysiological role for oxidative and inflammatory brain injury due to blood and its breakdown products in aSAH. Furthermore, the findings support NRF2 as a potential therapeutic target following aSAH and other forms of intracranial hemorrhage 2)

In a study by Hammer et al. from the Paracelsus Medical University, complications like pneumonia (β = 5.11; 95% CI = 1.75-8.46; p = 0.0031), sepsis (β = 9.54; 95% CI = 3.27-15.82; p = 0.0031), hydrocephalus (β = 4.63; 95% CI = 1.82-7.45; p = 0.0014), and delayed cerebral ischemia (DCI) (β = 3.38; 95% CI = 0.19-6.56; p = 0.038) were critical factors depending on the LOS in intensive care as well as decompressive craniectomy (β = 5.02; 95% CI = 1.35-8.70; p = 0.0077). All analyzed comorbidities such as hypertensiondiabeteshypothyroidismcholesterolemia, and smoking history had no significant impact on the LOS in intensive care. LOS in intensive care (OR = 1.09; 95% CI = 1.03-1.15; p = 0.0023), as well as World Federation of Neurosurgical Societies grading for subarachnoid hemorrhage (OR = 3.72; 95% CI = 2.23-6.21; p < 0.0001) and age (OR = 1.06; 95% CI = 1.02-1.10; p = 0.0061), were significant factors that had an impact on the outcome after 1 year. Complications in intensive care but not comorbidities are associated with higher LOS in intensive care. LOS in intensive care is a modest but significant predictor of outcomes after subarachnoid hemorrhage 3).

Aneurysmal subarachnoid hemorrhage (aSAH) occurs in about 5% of all strokes and has still a mortality of 50% and a significant morbidity in survivors 4).

The second cause of disability after the initial hemorrhage is cerebral vasospasm and the delayed cerebral ischemia which occurs in 50–70% of patients 5).

These two pathological entities seem to have different pathophysiological etiologies and cannot be detected by the same techniques. Vasospasms of the vessels of the circle of Willis can be detected by transcranial Doppler ultrasonography (TCD), whereas microcirculation disturbances can be detected by perfusion imaging techniques. Digital subtraction angiography (DSA) remains until now the gold standard of imaging vasospasms, but it is invasive, and it is proven to be associated with the risk of mild neurological deficit as well as ischemic insults 6).

As angiographic vasospasm is strongly associated with delayed cerebral ischemia (DCI) and clinical outcome, clinical trials in the last few decades focused on prevention of these angiographic spasms. Despite all efforts, no new pharmacological agents have shown to improve patient outcome. As such, it has become clear that our understanding of the pathophysiology of SAH is incomplete and we need to reevaluate our concepts on the complex pathophysiological process following SAH. Angiographic vasospasm is probably important.

The case fatality in aneurysmal subarachnoid hemorrhage (aSAH) is 50% due to the initial hemorrhage or subsequent complications like aneurysm rebleeding or delayed cerebral ischemia (DCI).

One factor that might influence the initial brain damage or subsequent complications is the use of antiplatelet medication before the initial hemorrhage.

Improvements in multidisciciplinary neurocritical care and advancements in medical and surgical treatment have contributed to a decline in the case fatality rate of aneurysmal subarachnoid hemorrhage 7).

A greater proportion of patients, therefore, are surviving their initial hemorrhagic event but remain at increased risk of a number of complications.

see Aneurysmal subarachnoid hemorrhage complications.

The case fatality after aneurysmal haemorrhage is 50%; one in eight patients with subarachnoid haemorrhage dies outside hospital. Rebleeding is the most imminent danger; a first aim is therefore occlusion of the aneurysm 8).

Prothrombotic states of early brain injury (EBI) and delayed cerebral ischemia (DCI) after aSAH determine morbidity and mortality.

The outcome depends on their condition on arrival at the hospital. However, a small number of patients recover from an initially poor condition.

Associated with intracerebral hematoma (ICH) typically has a poor outcome. SAH with ICH tends to have a worse prognosis than SAH alone.

It has a high socioeconomic impact as it tends to affect younger patients. The NCEPOD study looking into management of aSAH has recommended that neurovascular units in the United Kingdom should aim to secure cerebral aneurysms within 48 h and that delays because of weekend admissions can increase the mortality and morbidity attributed to aSAH.

A study provides important data showing excess in-Hospital mortality of patients with SAH on weekend admissions served by the United Kingdom’s National Health Service.; However, there were no effects of weekend admission on long-term outcomes 9).

Prediction models

Clinical prediction models were developed with individual patient data from 10 936 patients and validated with data from 3355 patients after development of the model. In the validation cohort, a core model including patient age, premorbid hypertension, and neurological grade on admission to predict risk of functional outcome had good discrimination, with an area under the receiver operator characteristics curve (AUC) of 0.80 (95% confidence interval 0.78 to 0.82). When the core model was extended to a “neuroimaging model,” with inclusion of clot volume, aneurysm size, and location, the AUC improved to 0.81 (0.79 to 0.84). A full model that extended the neuroimaging model by including treatment modality had AUC of 0.81 (0.79 to 0.83). Discrimination was lower for a similar set of models to predict risk of mortality (AUC for full model 0.76, 0.69 to 0.82). All models showed satisfactory calibration in the validation cohort.

The prediction models reliably estimate the outcome of patients who were managed in various settings for ruptured intracranial aneurysms that caused subarachnoid haemorrhage. The predictor items are readily derived at hospital admission. The web based SAHIT prognostic calculator ( and the related app could be adjunctive tools to support management of patients 10).

National Institute of Health Stroke Scale

Barthel Index

Extended Glasgow Outcome Scale.

Modified Rankin Scale

Systematic reviews for clinical prognostic factors and clinical prediction tools in aneurysmal subarachnoid hemorrhage (aSAH) face a number of methodological challenges. These include within and between study patient heterogeneity, regional variations in treatment protocols, patient referral biases, and differences in treatment, and prognosis viewpoints across different cultures 11).

It is critical to determine the neural basis for executive deficits in aSAH, in order to better understand and improve patient outcomes.

In a tertiary care center in India, despite recent advances in the treatment of patients with aSAH, the morbidity and mortality rates have failed to improve significantly in unselected patients and natural cohorts. This may be attributed to the natural history of aSAH, and calls for new strategies to diagnose and treat such patients before the catastrophe 12).

In the series of Nieuwkamp et al., despite an increase in the mean age of patients with SAH, case-fatality rates have decreased by 17% between 1973 and 2002 and show potentially important regional differences. This decrease coincides with the introduction of improved management strategies 13).

The case fatality after aneurysmal haemorrhage is 50%; one in eight patients with subarachnoid haemorrhage dies outside hospital.

Mortality is 10% within first few days

30-day mortality rate was 46% in one series, and in others over half the patients died within 2 weeks of their SAH.

overall mortality is 45% (range: 32—67%)

causes of mortality

neurogenic stunned myocardium

about 8% die from progressive deterioration from the initial hemorrhage

of those reaching neurosurgical care, vasospasm kills 7%, and causes severe deficit in another 7%.

about 30% of survivors have moderate to severe disability.

about 66 % of those who hove successful aneurysm clipping never return to the same quality of life as before the SAH.

With the limitation of an explorative cohort study the results indicate that routine transcranial doppler (TCD) studies do not improve the overall outcome of patients after aSAH 14).

Quantitative imaging indicators of ventricular hemorrhage (standard deviation of third ventricular hemorrhage density, minimum density of fourth ventricular hemorrhage, and left ventricular sphericity) are helpful to predict the poor prognosis of patients with aSAH with ventricular hemorrhage. The dimensional fusion model has greater value in predicting the poor prognosis of patients 15)

Quantitative estimation of the hemorrhage volume associated with aneurysm rupture is a tool of assessing prognosis.

A prospective cohort of 206 patients consecutively admitted with the diagnosis of aneurysmal subarachnoid hemorrhage to Hospital 12 de Octubre were included in the study. Subarachnoid, intraventricular, intracerebral, and total bleeding volumes were calculated using analytic software. For assessing factors related to prognosis, univariate and multivariate analysis (logistic regression) were performed. The relative importance of factors in determining prognosis was established by calculating their proportion of explained variation. Maximum Youden index was calculated to determine the optimal cut point for subarachnoid and total bleeding volume.

Variables independently related to prognosis were clinical grade at admission, age, and the different bleeding volumes. The proportion of variance explained is higher for subarachnoid bleeding. The optimal cut point related to poor prognosis is a volume of 20 mL both for subarachnoid and total bleeding.

Volumetric measurement of subarachnoid or total bleeding volume are both independent prognostic factors in patients with aneurysmal subarachnoid hemorrhage. A volume of more than 20 mL of blood in the initial noncontrast computed tomography is related to a clear increase in poor outcome risk 16).

Acute lung injury or acute respiratory distress syndrome (ALI/ARDS) is a common complication after aneurysmal subarachnoid hemorrhage (aSAH), and is associated with worse neurologic outcomes and longer hospitalization. However, the effect of ALI/ARDS in SAH has not been well elucidated. The purpose of this study was to determine the incidence of ALI/ARDS in a cohort of patients with SAH and to determine the risk factors for ALI/ARDS and their impact on patient prognosis. We performed a retrospective analysis of 167 consecutive patients with aSAH enrolled. ALI/ARDS patients were rigorously adjudicated using North American-European Consensus Conference definition. Regression analyses were used to test the risk factors for ALI/ARDS in patients with SAH. A total of 167 patients fulfilled the inclusion criteria, and 27% patients (45 of 167) developed ALI. Among all 45 ALI patients, 33 (20%, 33 of 167) patients met criteria for ARDS. On multivariate analysis, elderly patients, lower glasgow coma scale (GCS), higher Hunt-Hess grade, higher simplified acute physiology score (SAPS) II score, pre-existing pneumonia, gastric aspiration, hypoxemia, and tachypnea were the strongest risk factor for ALI/ARDS. Patients with ALI/ARDS showed worse clinical outcomes measured at 30 days. Development of ALI/ARDS was associated with a statistically significant increasing the odds of tracheostomy and hospital complications, and increasing duration of mechanical ventilation, intensive care unit (ICU) length and hospitalization stay. Development of ALI/ARDS is a severe complication of SAH and is associated with a poor clinical outcome, and further studies should focus on both prevention and management strategies specific to SAH-associated ALI/ARDS 17).

Higher early IL6 serum levels after aSAH are associated with poor outcome at discharge. In addition, involvement of leukemia inhibitory factor (LIF) in the early inflammatory reaction after aSAH has been demonstrated 18).

The APOΕε4 polymorphism was analysed in 147 patients with aSAH. Allele and genotype frequencies were compared to those found in a gender- and area-matched control group of healthy individuals (n = 211). Early cerebral vasospasm (CVS) was identified and treated according to neurointensive care unit (NICU) guidelines. Neurological deficit(s) at admittance and at 1-year follow-up visit was recorded. Neurological outcome was assessed by the National Institute of Health Stroke ScaleBarthel Index and the Extended Glasgow Outcome Scale.

APOEε4 and non-APOEε4 allele frequencies were similar in aSAH patients and healthy individuals. The presence of APOEε4 was not associated with the development of early CVS. We could not find an influence of the APOE polymorphism on 1-year neurological outcome between groups. Subgroup analyses of patients treated with surgical clipping vs endovascular coiling did not reveal any associations.

For Csajbok et al. APOEε4 polymorphism has no major influence on risk of aSAH, the occurrence of CVS or long-term neurological outcome after aSAH 19).

For Cheng et al., Apolipoprotein E (APOEε4) may induce cerebral perfusion impairment in the early phase, contributing to early brain injury (EBI) following aneurysmal subarachnoid hemorrhage (aSAH), and assessment of APOE genotypes could serve as a useful tool in the prognostic evaluation and therapeutic management of aSAH 20).

Iatrogenic coagulopathy caused by Direct oral anticoagulants or vitamin K antagonists was not associated with more severe radiological or clinical subarachnoid hemorrhage or worse clinical outcomes in hospitalized SAH patients 21).

Brain edema in aneurysmal subarachnoid hemorrhage

Myosteatosis was found to be associated with poor physical condition directly after the onset of aSAH. Skeletal muscle atrophy and myosteatosis were however irrelevant to outcome in the Western-European aSAH patient. Future studies are needed to validate these finding 22).

A low PbtO2 value is associated with a worse prognosis, and an increase in the PbtO2 value in response to treatment is a marker of a good outcome 23).

The inverse correlation between mean arterial pressure and mean transit time (MTT) in early perfusion computed tomography, increasing with the severity of aSAH, suggests an increasing disturbance of cerebral autoregulation with the severity of early brain injury. The results emphasize the importance of maintaining physiological blood pressure values in the early phase of aSAH and preventing hypotension, especially in patients with poor-grade aSAH 24)


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