Risk factors for mortality after subarachnoid hemorrhage: a retrospective observational study

Regulatory T Cell- and Natural Killer Cell-Mediated Inflammation, Cerebral Vasospasm, and Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage-A Systematic Review and Meta-Analysis Approach

Aneurysmal subarachnoid hemorrhage (SAH) involves a significant influx of blood into the cerebrospinal fluid, representing a severe form of stroke. Despite advancements in aneurysm closure and neuro-intensive care, outcomes remain impaired due to cerebral vasospasm and delayed cerebral ischemia (DCI). Previous pharmacological therapies have not successfully reduced DCI while improving overall outcomes. As a result, significant efforts are underway to better understand the cellular and molecular mechanisms involved. This review focuses on the activation and effects of immune cells after SAH and their interactions with neurotoxic and vasoactive substances as well as inflammatory mediators. Particular attention is given to clinical studies highlighting the roles of natural killer (NK) cells and regulatory T cells (Treg) cells. Alongside microglia, astrocytes, and oligodendrocytes, NK cells and Treg cells are key contributors to the inflammatory cascade following SAH. Their involvement in modulating the neuro-inflammatory response, vasospasm, and DCI underscores their potential as therapeutic targets and prognostic markers in the post-SAH recovery process. We conducted a systematic review on T cell- and natural killer cell-mediated inflammation and their roles in cerebral vasospasm and delayed cerebral ischemia. We conducted a meta-analysis to evaluate outcomes and mortality in studies focused on NK cell- and T cell-mediated mechanisms.

Development of a predictive nomogram for 28-day mortality risk in non-traumatic or post-traumatic subarachnoid hemorrhage patients

OBJECTIVE

Subarachnoid hemorrhage (SAH) is associated with high rates of mortality and permanent disability. At present, there are few definite clinical tools to predict prognosis in SAH patients. The current study aims to develop and assess a predictive nomogram model for estimating the 28-day mortality risk in both non-traumatic or post-traumatic SAH patients.

METHODS

The MIMIC-III database was searched to select patients with SAH based on ICD-9 codes. Patients were separated into non-traumatic and post-traumatic SAH groups. Using LASSO regression analysis, we identified independent risk factors associated with 28-day mortality and incorporated them into nomogram models. The performance of each nomogram was assessed by calculating various metrics, including the area under the curve (AUC), net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA).

RESULTS

The study included 999 patients with SAH, with 631 in the non-traumatic group and 368 in the post-traumatic group. Logistic regression analysis revealed critical independent risk factors for 28-day mortality in non-traumatic SAH patients, including gender, age, glucose, platelet, sodium, BUN, WBC, PTT, urine output, SpO2, and heart rate and age, glucose, PTT, urine output, and body temperature for post-traumatic SAH patients. The prognostic nomograms outperformed the commonly used SAPSII and APSIII systems, as evidenced by superior AUC, NRI, IDI, and DCA results.

CONCLUSION

The study identified independent risk factors associated with the 28-day mortality risk and developed predictive nomogram models for both non-traumatic and post-traumatic SAH patients. The nomogram holds promise in guiding prognosis improvement strategies for patients with SAH.

Detecting Sepsis in Patients with Severe Subarachnoid Hemorrhage during Critical Care

Introduction: Sepsis and septic shock continue to have a very high mortality rate. Therefore, the last consensus-based sepsis guideline introduced the sepsis related organ failure assessment (SOFA) score to ensure a rapid diagnosis and treatment of sepsis. In neurosurgical patients, especially those patients with subarachnoid hemorrhage (SAH), there are considerable difficulties in interpreting the SOFA score. Therefore, our study was designed to evaluate the applicability of the SOFA for critical care patients with subarachnoid hemorrhage. Methods: Our retrospective monocentric study was registered (NCT05246969) and approved by the local ethics committee (# 211/18). Patients admitted to the Department of Neurosurgery at the Frankfurt University Hospital were enrolled during the study period. Results: We included 57 patients with 85 sepsis episodes of which 141 patients had SOFA score-positive results and 243 SIRS positive detections. We failed to detect a correlation between the clinical diagnosis of sepsis and positive SOFA or SIRS scores. Moreover, a significant proportion of sepsis that was incorrectly detected via the SOFA score could be attributed to cerebral vasospasms (p < 0.01) or a decrease in Glasgow Coma Scale (p < 0.01). Similarly, a positive SIRS score was often not attributed to a septic episode (49.0%). Discussion: Regardless of the fact that SAH is a rare disease, the relevance of sepsis detection should be given special attention in light of the long duration of therapy and sepsis prevalence. Among the six modules represented by the SOFA score, two highly modules were practically eliminated. However, to enable early diagnosis of sepsis, the investigator’s clinical views and synopsis of various scores and laboratory parameters should be highlighted. Conclusions: In special patient populations, such as in critically ill SAH patients, the SOFA score can be limited regarding its applicability. In particular, it is very important to differentiate between CVS and sepsis.