Time course of CSF lactate level in subarachnoid haemorrhage. Correlation with clinical grading and prognosis

Cerebrospinal Fluid Lactate and Glucose Levels as Predictors of Symptomatic Delayed Cerebral Ischemia in Patients with Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Aneurysmal subarachnoid hemorrhage (aSAH) is a complex neurovascular syndrome with profound systemic effects associated with high rates of disability and mortality. Delayed cerebral ischemia (DCI), which encompasses all neurobiological events occurring in the subacute-late stage after aSAH, has a complex pathogenesis and can occur in the absence of instrumental vasospasm. Our aim was to assess the correlation between cerebrospinal fluid (CSF) lactate and glucose levels measured on the second or third day after aSAH with clinical deterioration caused by DCI and with 3-month functional outcome.

METHODS

This prospective study included all aSAH patients admitted between January 2020 and December 2021 who underwent external ventricular drain placement and CSF lactate and glucose measurement.

RESULTS

Among 133 aSAH patients, 48 had an external ventricular drain placed and early CSF lactate and glucose assessment. Independent predictors of symptomatic DCI were World Federation of Neurosurgical Societies grade IV-V (adjusted odds ratio [aOR] 25.8, 95% confidence interval [CI] 2.9-649.2, P = 0.012), elevated CSF glucose (aOR 28.8, 95% CI 3.3-775.2, P = 0.010), and elevated CSF lactate (aOR 14.7, 95% CI 1.9-205.7, P = 0.018). The only independent predictor of 3-month functional outcome was occurrence of symptomatic DCI (aOR 0.02, 95% CI 0.0-0.2, P = 0.01).

CONCLUSIONS

Elevated CSF lactate and glucose levels in the first 3 days following aSAH were independent predictors of subsequent DCI-related neurological impairment; the presence of instrumental vasospasm was not significantly correlated with DCI after multivariate adjustment. CSF lactate and glucose monitoring may represent a point-of-care test, which could potentially improve prediction of subacute neurological worsening and guide therapeutic choices. Further research with larger prospective cohorts is warranted.

Spatial and temporal variation of routine parameters: pitfalls in the cerebrospinal fluid analysis in central nervous system infections

The cerebrospinal fluid (CSF) space is convoluted. CSF flow oscillates with a net flow from the ventricles towards the cerebral and spinal subarachnoid space. This flow is influenced by heartbeats, breath, head or body movements as well as the activity of the ciliated epithelium of the plexus and ventricular ependyma. The shape of the CSF space and the CSF flow preclude rapid equilibration of cells, proteins and smaller compounds between the different parts of the compartment. In this review including reinterpretation of previously published data we illustrate, how anatomical and (patho)physiological conditions can influence routine CSF analysis. Equilibration of the components of the CSF depends on the size of the molecule or particle, e.g., lactate is distributed in the CSF more homogeneously than proteins or cells. The concentrations of blood-derived compounds usually increase from the ventricles to the lumbar CSF space, whereas the concentrations of brain-derived compounds usually decrease. Under special conditions, in particular when distribution is impaired, the rostro-caudal gradient of blood-derived compounds can be reversed. In the last century, several researchers attempted to define typical CSF findings for the diagnosis of several inflammatory diseases based on routine parameters. Because of the high spatial and temporal variations, findings considered typical of certain CNS diseases often are absent in parts of or even in the entire CSF compartment. In CNS infections, identification of the pathogen by culture, antigen detection or molecular methods is essential for diagnosis.

Cerebrospinal Fluid and Arterial Acid-Base Equilibrium of Spontaneously Breathing Patients with Aneurismal Subarachnoid Hemorrhage

BACKGROUND

Hyperventilation resulting in hypocapnic alkalosis (HA) is frequently encountered in spontaneously breathing patients with acute cerebrovascular conditions. The underlying mechanisms of this respiratory response have not been fully elucidated. The present study describes, applying the physical-chemical approach, the acid-base characteristics of cerebrospinal fluid (CSF) and arterial plasma of spontaneously breathing patients with aneurismal subarachnoid hemorrhage (SAH) and compares these results with those of control patients. Moreover, it investigates the pathophysiologic mechanisms leading to HA in SAH.

METHODS

Patients with SAH admitted to the neurological intensive care unit and patients (American Society of Anesthesiologists physical status of 1 and 2) undergoing elective surgery under spinal anesthesia were enrolled. CSF and arterial samples were collected simultaneously. Electrolytes, strong ion difference (SID), partial pressure of carbon dioxide (PCO₂), weak noncarbonic acids (A_TOT), and pH were measured in CSF and arterial blood samples.

RESULTS

Twenty spontaneously breathing patients with SAH and 25 controls were enrolled. The CSF of patients with SAH, as compared with controls, was characterized by a lower SID (23.1 ± 2.3 vs. 26.5 ± 1.4 mmol/L, p < 0.001) and PCO₂ (40 ± 4 vs. 46 ± 3 mm Hg, p < 0.001), whereas no differences in A_TOT (1.2 ± 0.5 vs. 1.2 ± 0.2 mmol/L, p = 0.95) and pH (7.34 ± 0.06 vs. 7.35 ± 0.02, p = 0.69) were observed. The reduced CSF SID was mainly caused by a higher lactate concentration (3.3 ± 1.3 vs. 1.4 ± 0.2 mmol/L, p < 0.001). A linear association (r = 0.71, p < 0.001) was found between CSF SID and arterial PCO₂. A higher proportion of patients with SAH were characterized by arterial HA, as compared with controls (40 vs. 4%, p = 0.003). A reduced CSF-to-plasma difference in PCO₂ was observed in nonhyperventilating patients with SAH (0.4 ± 3.8 vs. 7.8 ± 3.7 mm Hg, p < 0.001).

CONCLUSIONS

Patients with SAH have a reduction of CSF SID due to an increased lactate concentration. The resulting localized acidifying effect is compensated by CSF hypocapnia, yielding normal CSF pH values and resulting in a higher incidence of arterial HA.

Utility of cerebrospinal fluid lactate in aneurysmal subarachnoid hemorrhage

Background:

An external ventricular drain (EVD) treats hydrocephalus in patients with aneurysmal subarachnoid hemorrhage (aSAH). This study examines the utility of cerebrospinal fluid (CSF) lactate collected from an EVD as a proposed biomarker to predict patient outcome and vasospasm/delayed cerebral ischemia.

Methods:

Consecutive adults admitted to Wake Forest Baptist Medical Center from 2010 to 2015 with aSAH were identified through the electronic medical record, and clinical variables were collected and analyzed for correlation with incidence of vasospasm and discharge outcome.

Results:

In all, 51 patients with aSAH and an EVD had CSF lactate measured which ranged from 1.9 to 6.2 mmol/L, with a median value of 3.2 mmol/L. Vasospasm based on transcranial Doppler assessment occurred in 29 patients (57%), of which 20 (45%) were clinically symptomatic. Good outcome (discharge to home/acute rehab) occurred in 35 patients (69%). Sixteen patients (31%) had an unfavorable outcome (died/discharged to nursing homes/long-term acute care facility). In multivariate regression analysis, unfavorable outcome at discharge (P = 0.02), elevated CSF protein (P = 0.04), and admission Hunt and Hess score 3–5 (P = 0.05) were significantly associated with higher CSF lactate. The risk of symptomatic vasospasm increased with lactate in univariate analysis, but did not reach statistical significance (P = 0.077).

Conclusion:

The measurement of the CSF biochemical markers using an EVD is feasible and safe. We found that elevated CSF lactate correlates with patient outcome. Larger prospective studies are needed to test the validity of this finding and for understanding the underlying pathophysiologic mechanisms.

Prolonged Intracisternal Papaverine Toxicity: Index Case Description and Proposed Mechanism of Action

BACKGROUND

Intracisternal papaverine (iPPV) is a vasodilator used for prophylaxis of intraoperative vasospasm during aneurysmal clipping. Postoperative side effects of iPPV include transient cranial nerve palsies, most commonly mydriasis owing to oculomotor nerve involvement, with rapid resolution.

METHODS

We critically reviewed current literature on the adverse effects of iPPV in aneurysmal surgery with a focus on oculomotor nerve involvement. We also present the index case of prolonged bilateral mydriasis secondary to iPPV irrigation toxicity and its putative underlying mechanism.

RESULTS

Papaverine toxicity occurs in the setting of its antimuscarinic action and blood-cerebrospinal fluid and blood-brain barrier compromise owing to acute subarachnoid hemorrhage and direct effect of papaverine. Our patient also experienced severe vasospasm and a minor stroke, both contributing to further blood-brain barrier disruption, and relatively acidic pH of the subarachnoid hemorrhage milieu.

CONCLUSIONS

We propose that these factors perpetuate phase dynamics of papaverine crystals and facilitate a sustained slow release of papaverine within the cisternal system. Were it indicated, 0.3% iPPV would reasonably diminish the risk for neurotoxicity.

Frequency and Outcomes of Hyperlactatemia After Neurosurgery

Objectives. The aim of this study was to evaluate the incidence and significance of elevated serum lactate and its impact on outcome in postoperative neurosurgical patients admitted to neurosurgical intensive care unit (NSICU). Design. This study’s design is a retrospective analysis in a 13-bed NSICU in a tertiary care hospital. A total of 673 patients were screened and 328 patients were included in the study. Methods. Patients were divided into neurosurgery versus nonneurosurgical admissions. Neurosurgical patients were further grouped as brain surgery, spinal surgery, or intracranial vascular surgery. Reason for admission, length of stay, serum lactate levels, and survival were analyzed. Results. The incidence of hyperlactatemia (lactate level ≥2.0 mmol/L) ranged from 67% in the brain tumor group to 33% in the nonneurosurgery group. Mean serum lactates were significantly higher in the brain tumor (3.17 ± 1.99) and spinal surgery groups (2.79 ± 1.51) than in the nonneurosurgery group (1.86 ± 1.10), P < .05, but not in the intracranial vascular surgery group (2.28 ± 1.71), P > .05. The serum lactate level was not significantly associated with survival. Conclusion. Postoperative hyperlactatemia occurs frequently in neurosurgery patients but appears benign.

Cerebrospinal fluid lactate concentration after withdrawal of metabolic suppressive therapy in subarachnoid hemorrhage

Hyperglycolysis is a known phenomenon after severe subarachnoid hemorrhage (SAH) and after brain injury. It is characterized by decreased oxidative metabolism and relatively increased anaerobic glycolysis. Metabolic suppressive therapy reduces the cerebral metabolic rate of oxygen (CMRO(2)) and the cerebral metabolic rate of glucose (CMRGluc). If CMRO(2) is suppressed after SAH, withdrawal of metabolic suppressive therapy could lead to the accumulation of lactate. In this project, we assessed the relationship between the withdrawal of metabolic suppressive therapy and cerebrospinal fluid (CSF) lactate concentration. A prospective observational database containing 262 patients with SAH was retrospectively analyzed. CSF lactate levels were compared with the daily dose of metabolic suppressive therapy. Outcome was assessed with the Glasgow Outcome Scale (GOS). In 56% of patients an increase in CSF lactate (mean: 3.2 ± 0.9 mmol/L) after withdrawal of metabolic suppressive therapy was observed. Mean Glasgow Outcome Score (GOS) was lower in patients with an increase in CSF lactate concentration (>0.5 mmol/L) after withdrawal of metabolic suppressive therapy (p = 0.095). In 88% of patients who died during the first 30 days after SAH, a CSF lactate elevation of more than 0.5 mmol/L after withdrawal of metabolic suppressive therapy was found (p = 0.071).

Metabolomic investigation of CLN6 neuronal ceroid lipofuscinosis in affected South Hampshire sheep

The neuronal ceroid lipofuscinoses (NCLs; Batten disease) are a group of fatal inherited neurodegenerative diseases in humans and animals distinguished by a common clinical pathology, characteristic storage body accumulation in cells, and gross brain atrophy. An (1)H NMR spectroscopy- and GC-MS-based metabolomic investigation of changes in the cerebellum, frontal and occipital lobes, and cerebrospinal fluid (CSF) of CLN6 NCL affected South Hampshire sheep charted changes from the preclinical state to advanced disease. Glutamine and succinate concentrations increased in all brain regions in affected sheep relative to controls, whereas concentrations of aspartate, acetate, glutamate, N-acetyl aspartate (NAA), and gamma-aminobutyric acid (GABA) decreased. Changes in the concentrations of inositols, NAA, and GABA were consistent with glial cell activation and neurodegeneration beginning in the frontal and occipital lobes, in agreement with previous histopathological data. Further metabolic deficits were defined in all regions at earlier time points, including the cerebellum, where very little neurological degeneration has been reported. Biochemical abnormalities in the CSF of affected sheep at 18-31 months include relative increases in lactate, acetate, tyrosine, and creatine/creatinine concentrations and decreases in myo- and scyllo-inositol and citrate concentrations. The changes detected in the CSF and brain tissue mirrored those previously apparent in NCL mouse models, suggesting that they are common to all NCLs. However, the changes in glutamate and glutamine concentrations in CSF occurred after clinical disease, indicating that any changes in glutamate/glutamine cycling occur as a consequence of the primary deficits associated with the NCLs.

Lactate Contents From Cerebrospinal Fluid in Experimental Subarachnoid Hemorrhage, Well Correlate With Vasospasm

The role of lactate composition of cerebrospinal fluid (CSF) with vasospasm severity and rabbit neurologic status in subarachnoid hemorrhage was determined. The neurologic status of 20 New Zealand rabbits were graded initially and then, anesthetized and basal angiograms were performed. Then 1.0 mL of CSF was withdrawn through cisterna magna and then 1 mL autologous arterial blood was injected in all rabbits over 1 minute. After 5 days, neurologic severity score (NSS) and vertebrobasilar angiograms of all rabbits were repeated. Rabbits without radiologic vasospasm or spasm under 50% (n=7) were termed as group 1. Rabbits whose cerebral vasospasm were 50% or over 50% (n=7) and NSS is lesser than 3 were termed as groups 2, and rabbits whose cerebral vasospasm were 50% or above 50% (n=7) and NSS is greater than 3 were termed groups 3. On day 7, the CSF lactate values of each group were significantly different (P<0.05) with each other. But when compared with only CSF baseline lactate values groups 2 and 3 were significantly different (P<0.05). However, the NSSs were similar in groups 1 and 2, but group 3 significantly differed from groups 1 and 2 (P<0.05). All groups significantly differed from baseline NSSs (P<0.05). The data showed clearly that the degree of vasospasm correlates not only with neurologic status but also with CSF lactate levels. We suggest that CSF lactate level may be useful as a surrogate marker of cerebral vasospasm degree after subarachnoid hemorrhage in clinics where invasive cerebral angiography could not be assessed for whatever reasons.

Prediction of Cerebral Vasospasm in Patients Presenting with Aneurysmal Subarachnoid Hemorrhage: A Review

OBJECTIVE:

Cerebral vasospasm is a devastating medical complication of aneurysmal subarachnoid hemorrhage (SAH). It is associated with high morbidity and mortality rates, even after the aneurysm has been treated. A substantial amount of experimental and clinical research has been conducted in an effort to predict and prevent its occurrence. This research has contributed to significant advances in the understanding of the mechanisms leading to cerebral vasospasm. The ability to accurately and consistently predict the onset of cerebral vasospasm, however, has been challenging. This topic review describes the various methodologies and approaches that have been studied in an effort to predict the occurrence of cerebral vasospasm in patients presenting with SAH.

METHODS:

The English-language literature on the prediction of cerebral vasospasm after aneurysmal SAH was reviewed using the MEDLINE PubMed (1966–present) database.

RESULTS:

The risk factors, diagnostic imaging, bedside monitoring approaches, and pathological markers that have been evaluated to predict the occurrence of cerebral vasospasm after SAH are presented.

CONCLUSION:

To date, a large blood burden is the only consistently demonstrated risk factor for the prediction of cerebral vasospasm after SAH. Because vasospasm is such a multifactorial problem, attempts to predict its occurrence will probably require several different approaches and methodologies, as is done at present. Future improvements in the prevention of cerebral vasospasm from aneurysmal SAH will most likely require advances in our understanding of its pathophysiology and our ability to predict its onset.

Metabolites from cerebrospinal fluid in aneurysmal subarachnoid haemorrhage correlate with vasospasm and clinical outcome: a pattern-recognition 1H NMR study

Following subarachnoid haemorrhage the most significant complication is sustained cerebral vascular contraction (vasospasm), which may result in terminal brain damage from cerebral infarction. Despite this, the biochemical cause of vasospasm remains poorly understood. In this study, the global high-concentration metabolite composition of CSF has been correlated with patient outcome after subarachnoid haemorrhage using multivariate statistics and 1H NMR spectroscopy. In total, 16 patients with aneurysmal subarachnoid haemorrhage (aSAH) were compared with 16 control patients who required a procedure where CSF was obtained but did not have aSAH. Multivariate statistics readily distinguished the aSAH group from the heterogeneous control group, even when only those controls with blood contamination in the CSF were used. Using principal components analysis and orthogonal signal correction, vasospasm was correlated to the concentrations of lactate, glucose and glutamine. These pattern recognition models of the NMR data also predicted Glasgow Coma Score (54% within +/- 1 of the actual score on a scale of 1-15 for the whole patient group), Hunt and Hess SAH severity score (88% within +/- 1 of the actual score on a scale of 1-5 for the aSAH group) and cognitive outcome scores (78% within +/- 3 of the actual score on a 100% scale for the whole patient group). Thus, the approach allowed the prediction of outcome as well as confirming the presence of aSAH.

Cerebral blood flow and glucose metabolism in the squirrel monkey during the late phase of cerebral vasospasm

A double-isotope autoradiography technique was used to evaluate cerebral blood flow (CBF) and cerebral glucose metabolism (CMRglu) during the late phase of vasospasm in a squirrel monkey subarachnoid haemorrhage (SAH) model. Cisternal blood injections induced both global and focal changes in CBF and CMRglu six days following SAH, the timepoint of maximal late spasm in this model. There was a global decrease in CBF of about 30% accompanied by an increase in deoxyglucose uptake of about 50%. Four of seven animals also had foci with flow decreased to 40% of control and deoxyglucose uptake increased to 300% of control. There was an altered but still present interdependence between flow and metabolism post SAH.

Long-term monitoring of CSF lactate levels and lactate/pyruvate ratios following subarachnoid haemorrhage

Ventricular cerebrospinal fluid (CSF) lactate concentrations and lactate/pyruvate (L/P) ratios were measured daily in 20 patients from day 1 to day 12 after subarachnoid haemorrhage due to ruptured aneurysms. Patients without symptomatic vasospasm were classified in Group 1, patients with symptomatic vasospasm were classified in Group 2, and patients who were Hunt and Kosnik grade 4 on admission clinically were classified in Group 3. Patients in all three groups had high CSF lactate concentrations on day 1, and, especially in Group 3, the high lactate was accompanied by an increased L/P ratio and a decreased CSF bicarbonate. Lactate concentrations in Group 1 decreased throughout the observation period. Lactate concentrations in Group 2 also decreased but then began to increase again on days 5 to 7, correlating well with the onset of cerebral vasospasm. The delayed increase of CSF lactate in Group 2 was also accompanied by increases in the CSF pyruvate level and the CSF L/P ratio. Daily monitoring of CSF lactate may thus serve as a chemical marker for cerebral vasospasm.