Cerebrospinal Fluid Glucose and Lactate Levels After Subarachnoid Hemorrhage: A Multicenter Retrospective Study

Stress hyperglycemia ratio is associated with delayed cerebrovascular ischemia and poor prognosis in patients with aneurysmal subarachnoid hemorrhage undergoing neurointerventional therapy

OBJECTIVE

Previous research has established a correlation between hyperglycemia following aneurysmal subarachnoid hemorrhage (aSAH) and the onset of delayed cerebrovascular ischemia (DCI), and influencing patient prognosis. The objective of this study was to evaluate the potential association between stress hyperglycemia ratio (SHR) and both the occurrence of DCI and prognosis in patients with aSAH undergoing neurointervention.

METHODS

We retrospectively analyzed 214 patients with aSAH undergoing neurointervention. The outcomes evaluated were DCI and 90-days poor prognosis (Modified Rankin Scale, mRS >2). The association between SHR level and both DCI and prognosis was analyzed. Stress hyperglycemia was assessed using SHR, calculated as: SHR = admission fasting plasma glucose (FPG, mmol/L) / [1.59 * hemoglobin A1c (HbA1c%) - 2.59].

RESULTS

Among the 214 patients, 59 (27.6 %) experienced DCI, and 60 (28 %) had a poor prognosis. Following adjustments for confounding factors, SHR emerged as an independent risk factor of both DCI (p = 0.006) and poor prognosis (p = 0.020), individuals in the T3 tertile of SHR had a higher risk of DCI than those in the T1 tertile [odds ratio (OR) 2.68; 95 % CI (1.19-6.06); p = 0.018], and individuals in the T3 tertile of SHR had a higher risk of poor 90-day prognosis than those in the T1 tertile [OR 2.47; 95 % CI (1.08-5.63); p = 0.032].

CONCLUSION

SHR was found to be a significant and independent risk factor for DCI and 90-days poor prognosis in patients with aSAH who underwent neurointerventional therapy.

Triglyceride Glucose Index and Prognosis of Patients with Subarachnoid Hemorrhage

OBJECTIVE

The triglyceride glucose (TyG) index is regarded as a reliable alternative indicator for measuring insulin resistance. We investigated the association between the prognosis of patients with subarachnoid hemorrhage (SAH)and the TyG index, explored the potential of the TyG index as a new biomarker for forecasting the outcomes of SAH patients, and explored independent risk factors for predicting the condition of SAH patients.

METHODS

A retrospective analysis was performed of patients who were admitted to a single center due to SAH. Differences in clinical data and correlation between laboratory indexes, disease severity score on admission, and prognosis score were compared between the 2 groups. The study employed multivariate logistic regression analysis to examine the independent influencing aspects of Glasgow Outcome Scale score. The receiver operating characteristic curve was drawn and the area under the curve (AUC) calculated to predict the best cutoff value of the degree of neurological impairment in patients with SAH.

RESULTS

Univariate analysis showed that Glasgow Coma Scale score (86.3% vs. 12.0%, P < 0.001), Hunt-Hess grade (88.2% vs. 15.7%, P < 0.001), white blood cell count (11.20 [7.9, 15.2] vs. 9.1 [7.0, 12.2], P = 0.027), and TyG index (1.49 [1.40, 1.59] vs. 1.16 [1.06, 1.27], P < 0.001) were statistically significantly different. Multivariate analysis showed that TyG index, Hunt-Hess grade, and GCS score were independent risk factors for poor prognosis.

CONCLUSIONS

Patients with SAH may benefit from using the TyG index as a predictive method. In our clinical practice, the TyG index is beneficial for managing diseases and making decisions. More research is required to determine if improved TyG index control would lead to better clinical results in the future.

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.

Association between Peripheral Arterial Lactate Levels and Malignant Brain Edema Following Endovascular Treatment for Ischemic Stroke

AIMS

To investigate the factors of postoperative malignant brain edema (MBE) in patients with acute ischemic stroke (AIS) treated with endovascular treatment (EVT).

BACKGROUND

MBE is a severe complication following EVT for AIS, and it is essential to identify risk factors early. Peripheral arterial lactate (PAL) levels may serve as a potential predictive marker for MBE.

OBJECTIVE

To determine whether immediate postoperative PAL levels and the highest PAL level within 24 hours of EVT are independently associated with MBE development in AIS patients.

METHODS

We retrospectively analyzed patients with AIS who underwent EVT from October 2019 to October 2022. Arterial blood was collected every 8 h after EVT to measure PAL, and record the immediate postoperative PAL and the highest PAL level within 24 h. Brain edema was evaluated using brain computed tomography scans within 7 days of EVT.

RESULTS

The study included 227 patients with a median age of 71 years, of whom 59.5% were male and MBE developed in 25.6% of patients (58/227). Multivariate logistic regression analysis showed that the immediate postoperative PAL (odds ratio, 1.809 [95% confidence interval (CI), 1.215-2.693]; p = 0.004) and the highest PAL level within 24 h of EVT (odds ratio, 2.259 [95% CI, 1.407-3.629]; p = 0.001) were independently associated with MBE. The area under the curve for predicting MBE based on the highest PAL level within 24 hours of EVT was 0.780 (95% CI, 0.711-0.849).

CONCLUSION

Early increase in PAL levels is an independent predictor of MBE after EVT in AIS patients.

Cerebrospinal fluid analysis of metabolites is not correlated to microdialysis measurements in acute brain injured patients

BACKGROUND

Cerebral microdialysis (CMD) has become an established bedside monitoring modality but its implementation remains complex and costly and is therefore performed only in a few well-trained academic centers. This study investigated the relationship between cerebrospinal fluid (CSF) and CMD glucose and lactate concentrations.

METHODS

Two centers retrospective study of prospectively collected data. Consecutive adult (>18 years) acutely brain injured patients admitted to the Intensive Care Unit between 2010 and 2021 were eligible if CSF and CMD glucose and lactate concentrations were concomitantly measured at least once.

RESULTS

Of 113 patients being monitored with an external ventricular drainage and CMD, 49 patients (25 from Innsbruck and 24 from Brussels) were eligible for the final analysis, including a total of 96 measurements. Median CMD glucose and lactate concentrations were 1.15 (0.51-1.57) mmol/L and 3.44 (2.24-5.37) mmol/L, respectively; median CSF glucose and lactate concentrations were 4.67 (4.03-5.34) mmol/L and 3.40 (2.85-4.10) mmol/L, respectively. For the first measurements, no correlation between CSF and CMD glucose concentrations (R2 <0.01; p = 0.95) and CSF and CMD lactate concentrations (R2 =0.16; p = 0.09) was found. Considering all measurements, the repeated measure correlation analysis also showed no correlation for glucose (rrm = -0.01; 95% Confidence Intervals -0.306 to 0.281; p = 0.93) and lactate (rrm = -0.11; 95% Confidence Intervals -0.424 to 0.236; p = 0.55).

CONCLUSIONS

In this study including acute brain injured patients, no correlation between CSF and brain tissue measurements of glucose and lactate was observed. As such, CSF measurements of such metabolites cannot replace CMD findings.

The Role of Early Serum Biomarkers and Clinical Rating Scales in the Prediction of Delayed Cerebral Ischaemia and Short-Term Outcome after Aneurysmal Subarachnoid Haemorrhage: Single Centre Experience

Considering the variety of complications that arise after aneurysmal subarachnoid haemorrhage (aSAH) and the complex pathomechanism of delayed cerebral ischaemia (DCI), the task of predicting the outcome assumes a profound complexity. Therefore, there is a need to develop early predictive and decision-making models. This study explores the effect of serum biomarkers and clinical scales on patients' outcomes and their interrelationship with DCI and systemic complications in aSAH. This was a retrospective analysis including aSAH patients admitted to the Wroclaw University Hospital (Wrocław, Poland) from 2011 to 2020. A good outcome was defined as a modified Rankin Scale (mRS) score of 0-2. The prediction of the development of DCI and poor outcome was conducted using logistic regression as a standard model (SM) and random forest as a machine learning method (ML). A cohort of 174 aSAH patients were included in the analysis. DCI was diagnosed in 79 (45%) patients. Significant differences between patients with poor vs. good outcome were determined from their levels of albumin (31 ± 7 vs. 35 ± 5 (g/L); p < 0.001), D-dimer (3.0 ± 4.5 vs. 1.5 ± 2.8 (ng/mL); p < 0.001), procalcitonin (0.2 ± 0.4 vs. 0.1 ± 0.1 (ng/mL); p < 0.001), and glucose (169 ± 69 vs. 137 ± 48 (nmol/L); p < 0.001). SM for DCI prediction included the Apache II scale (odds ratio [OD] 1.05; 95% confidence interval [CI] 1.00-1.09) and albumin level (OD 0.88; CI 0.82-0.95). ML demonstrated that low albumin level, high Apache II scale, increased D-dimer and procalcitonin levels had the highest predictive values for DCI. The integration of clinical parameters and scales with a panel of biomarkers may effectively facilitate the stratification of aSAH patients, identifying those at high risk of secondary complications and poor outcome.

Posthemorrhagic Hydrocephalus in Patients with Subarachnoid Hemorrhage Occurs Independently of CSF Osmolality

The molecular mechanisms underlying the development of posthemorrhagic hydrocephalus (PHH) remain incompletely understood. As the disease pathogenesis often cannot be attributed to visible cerebrospinal fluid (CSF) drainage obstructions, we here aimed to elucidate whether elevated CSF osmolality following subarachnoid hemorrhage (SAH) could potentiate the formation of ventricular fluid, and thereby contribute to the pathological CSF accumulation observed in PHH. The CSF osmolality was determined in 32 patients with acute SAH after external ventricular drainage (EVD) placement and again upon EVD removal and compared with the CSF osmolality from 14 healthy control subjects undergoing vascular clipping of an unruptured aneurism. However, we found no evidence of elevated CSF osmolality or electrolyte concentration in patients with SAH when compared to that of healthy control subjects. We detected no difference in CSF osmolality and electrolyte content in patients with successful EVD weaning versus those that were shunted due to PHH. Taken together, elevated CSF osmolality does not appear to underlie the development of PHH following SAH. The pathological CSF accumulation observed in this patient group must thus instead be attributed to other pathological alterations associated with the abnormal presence of blood within the CSF compartments following SAH.

Cerebro-spinal fluid glucose and lactate concentrations changes in response to therapies in patIents with primary brain injury: the START-TRIP study

INTRODUCTION

Altered levels of cerebrospinal fluid (CSF) glucose and lactate concentrations are associated with poor outcomes in acute brain injury patients. However, no data on changes in such metabolites consequently to therapeutic interventions are available. The aim of the study was to assess CSF glucose-to-lactate ratio (CGLR) changes related to therapies aimed at reducing intracranial pressure (ICP).

METHODS

A multicentric prospective cohort study was conducted in 12 intensive care units (ICUs) from September 2017 to March 2022. Adult (> 18 years) patients admitted after an acute brain injury were included if an external ventricular drain (EVD) for intracranial pressure (ICP) monitoring was inserted within 24 h of admission. During the first 48-72 h from admission, CGLR was measured before and 2 h after any intervention aiming to reduce ICP ("intervention"). Patients with normal ICP were also sampled at the same time points and served as the "control" group.

RESULTS

A total of 219 patients were included. In the intervention group (n = 115, 53%), ICP significantly decreased and CPP increased. After 2 h from the intervention, CGLR rose in both the intervention and control groups, although the magnitude was higher in the intervention than in the control group (20.2% vs 1.6%; p = 0.001). In a linear regression model adjusted for several confounders, therapies to manage ICP were independently associated with changes in CGLR. There was a weak inverse correlation between changes in ICP and CGRL in the intervention group.

CONCLUSIONS

In this study, CGLR significantly changed over time, regardless of the study group. However, these effects were more significant in those patients receiving interventions to reduce ICP.

Serum lactate monitoring may help to predict neurological function impairment caused by acute metabolism crisis

To investigate the predictive value of serum lactate on neurological function impairment and the possible etiology. In this retrospective study, all the adult patients admitted to ICU more than 24 h after general anesthesia elective neurosurgery from January 2018 to January 2019 were recruited. The data of the serum lactate every 8 h during the 24 h of ICU admission were acquired and analyzed. 169 patients were included in the outcomes analysis. The average serum lactate after ICU admission was 3.7(3.4-4.1) mmol/L, higher than normal, and serum lactate elevated commonly after neurosurgery. The serum lactate at ICU admission (lactate_serum0h) was not correlated with the outcomes, whereas the predictive value increased as the monitoring time was extended. The result indicated that lactate_serum8h, the lactate_serum16h, and the lactate_serum24h were correlated with the primary outcome (difference of GCS scores before the surgery and after 24 h of ICU admission (ΔGCS_24h) (p < 0.05). The lactate_serum16h and the lactate_serum 24 h were correlated with all the outcomes except for the hospital LOS. The ROC curve suggested that the lactate_serum24h achieved the best predictive value. Patients with serum lactate non-recovered trend after 24 h of ICU stay had decreased GCS scores and vice versa, as indicated by the graph of the dynamic changes in the serum lactate. The predictive value of the serum glucose/serum lactate ratio at ICU admission (G/L_serum) was analyzed, and the result indicated that it was correlated with the ΔGCS_24h (p < 0.05), the G/L_serum can predict neurological impairment earlier. Dynamic serum lactate monitoring and the G/L_serum at ICU admission have predict value on neurological function impairment after neurosurgery which might be attributed to ACMC.

Alpha-Ketoglutarate Alleviates Neuronal Apoptosis Induced by Central Insulin Resistance through Inhibiting S6K1 Phosphorylation after Subarachnoid Hemorrhage

Neuronal apoptosis after subarachnoid hemorrhage (SAH) is believed to play an important role in early brain injury after SAH. The energy metabolism of neuron is closely related to its survival. The transient hyperglycemia caused by insulin resistance (IR) after SAH seriously affects the prognosis of patients. However, the specific mechanisms of IR after SAH are still not clear. Studies have shown that α-KG takes part in the regulation of IR and cell apoptosis. In this study, we aim to investigate whether α-KG can reduce IR after SAH, improve the disorder of neuronal glucose metabolism, alleviate neuronal apoptosis, and ultimately play a neuroprotective role in SAH-induced EBI. We first measured α-KG levels in the cerebrospinal fluid (CSF) of patients with SAH. Then, we established a SAH model through hemoglobin (Hb) stimulation with HT22 cells for further mechanism research. Furthermore, an in vivo SAH model in mice was established by endovascular perforation. Our results showed that α-KG levels in CSF significantly increased in SAH patients and could be used as a potential prognostic biomarker. In in vitro model of SAH, we found that α-KG not only inhibited IR-induced reduction of glucose uptake in neurons after SAH but also alleviated SAH-induced neuronal apoptosis. Mechanistically, we found that α-KG inhibits neuronal IR by inhibiting S6K1 activation after SAH. Moreover, neuronal apoptosis significantly increased when glucose uptake was reduced. Furthermore, our results demonstrated that α-KG could also alleviate neuronal apoptosis in vivo SAH model. In conclusion, our study suggests that α-KG alleviates apoptosis by inhibiting IR induced by S6K1 activation after SAH.

A Prospective Observational Feasibility Study of Jugular Bulb Microdialysis in Subarachnoid Hemorrhage

BACKGROUND

Cerebral metabolic perturbations are common in aneurysmal subarachnoid hemorrhage (aSAH). Monitoring cerebral metabolism with intracerebral microdialysis (CMD) allows early detection of secondary injury and may guide decisions on neurocritical care interventions, affecting outcome. However, CMD is a regional measuring technique that is influenced by proximity to focal lesions. Continuous microdialysis of the cerebral venous drainage may provide information on global cerebral metabolism relevant for the care of aSAH patients. This observational study aimed to explore the feasibility of jugular bulb microdialysis (JBMD) in aSAH and describe the output characteristics in relation to conventional multimodal monitoring.

METHODS

Patients with severe aSAH were included at admission or after in-house deterioration when local clinical guidelines prompted extended multimodal monitoring. Non-dominant frontal CMD, intracranial pressure (ICP), partial brain tissue oxygenation pressure (PbtO₂), and cerebral perfusion pressure (CPP) were recorded every hour. The dominant jugular vein was accessed by retrograde insertion of a microdialysis catheter with the tip placed in the jugular bulb under ultrasound guidance. Glucose, lactate, pyruvate, lactate/pyruvate ratio, glycerol, and glutamate were studied for correlation to intracranial measurements. Modified Rankin scale was assessed at 6 months.

RESULTS

Twelve adult aSAH patients were monitored during a mean 4.2 ± 2.6 days yielding 22,041 data points for analysis. No complications related to JBMD were observed. Moderate or strong significant monotonic CMD-to-JBMD correlations were observed most often for glucose (7 patients), followed by lactate (5 patients), and pyruvate, glycerol, and glutamate (3 patients). Moderate correlation for lactate/pyruvate ratio was only seen in one patient. Analysis of critical periods defined by ICP > 20, CPP < 65, or PbtO₂ < 15 revealed a tendency toward stronger CMD-to-JBMD associations in patients with many or long critical periods. Possible time lags between CMD and JBMD measurements were only identified in 6 out of 60 patient variables. With the exception of pyruvate, a dichotomized outcome was associated with similar metabolite patterns in JBMD and CMD. A nonsignificant tendency toward greater differences between outcome groups was seen in JBMD.

CONCLUSIONS

Continuous microdialysis monitoring of the cerebral drainage in the jugular bulb is feasible and safe. JBMD-to-CMD correlation is influenced by the type of metabolite measured, with glucose and lactate displaying the strongest associations. JBMD lactate correlated more often than CMD lactate to CPP, implying utility for detection of global cerebral metabolic perturbations. Studies comparing JBMD to other global measures of cerebral metabolism, e.g., PET CT or Xenon CT, are warranted.

Fluid metabolic pathways after subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating cerebrovascular disease with high mortality and morbidity. In recent years, a large number of studies have focused on the mechanism of early brain injury (EBI) and delayed cerebral ischemia (DCI), including vasospasm, neurotoxicity of hematoma and neuroinflammatory storm, after aSAH. Despite considerable efforts, no novel drugs have significantly improved the prognosis of patients in phase III clinical trials, indicating the need to further re-examine the multifactorial pathophysiological process that occurs after aSAH. The complex pathogenesis is reflected by the destruction of the dynamic balance of the energy metabolism in the nervous system after aSAH, which prevents the maintenance of normal neural function. This review focuses on the fluid metabolic pathways of the central nervous system (CNS), starting with ruptured aneurysms, and discusses the dysfunction of blood circulation, cerebrospinal fluid (CSF) circulation and the glymphatic system during disease progression. It also proposes a hypothesis on the metabolic disorder mechanism and potential therapeutic targets for aSAH patients.

Neuroanesthesiology Update

This review summarizes the literature published in 2020 that is relevant to the perioperative care of neurosurgical patients and patients with neurological diseases as well as critically ill patients with neurological diseases. Broad topics include general perioperative neuroscientific considerations, stroke, traumatic brain injury, monitoring, anesthetic neurotoxicity, and perioperative disorders of cognitive function.