Investigation and management of serum sodium after subarachnoid haemorrhage (SaSH): a survey of practice in the United Kingdom and Republic of Ireland

Usage of mineralocorticoids and isotonic crystalloids in subarachnoid hemorrhage patients in the United States

BACKGROUND

The usage rates of mineralocorticoids (fludrocortisone) to treat hyponatremia and isotonic crystalloids (saline and balanced crystalloids) to maintain intravascular volume in patients with aneurysmal subarachnoid hemorrhage (aSAH) patients across the United States are unknown.

METHODS

We surveyed National Institute of Neurologic Disorders and Stroke (NINDS) StrokeNet sites in 2023, which are mostly large, tertiary, academic centers, and analyzed subarachnoid hemorrhage encounters from 2010 to 2020 in the Premier Healthcare Database that is representative of all types of hospitals and captures about 20 % of all acute inpatient care in the United States.

RESULTS

Although mineralocorticoids are used by 70 % of the NINDS StrokeNet sites, it is used in less than 20 % of the aSAH encounters in the Premier Database. Although saline is ubiquitously used, balanced crystalloids are increasingly used for fluid therapy in aSAH patients. Its use in the NINDS StrokeNet sites and the Premier Healthcare Database is 41 and 45 %, respectively.

CONCLUSIONS

The use of mineralocorticoids remains low, and balanced crystalloids are increasingly used as fluid therapy in aSAH patients. The effectiveness of mineralocorticoids and balanced crystalloids in improving outcomes for aSAH patients must be rigorously tested in randomized clinical trials.

Usage of Mineralocorticoids and Isotonic Crystalloids in Subarachnoid Hemorrhage Patients in the United States

Background

The usage rates of mineralocorticoids (fludrocortisone) to treat hyponatremia and isotonic crystalloids (saline and balanced crystalloids) to maintain intravascular volume in patients with aneurysmal subarachnoid hemorrhage (aSAH) patients across the United States are unknown.

Methods

We surveyed National Institute of Neurologic Disorders and Stroke (NINDS) StrokeNet sites, which are mostly large, tertiary, academic centers, and analyzed subarachnoid hemorrhage encounters in the Premier Healthcare Database that is representative of all types of hospitals and captures about 20% of all acute inpatient care in the United States.

Results

Although mineralocorticoids are used by 70% of the NINDS StrokeNet sites in aSAH patients, it is used in less than 25% of the aSAH encounters in the Premier Database. Although saline is ubiquitously used, balanced crystalloids are increasingly used for fluid therapy in aSAH patients. Its use in the NINDS StrokeNet sites and the Premier Healthcare Database is 41% and 45%, respectively.

Conclusions

The use of mineralocorticoids remains low, and balanced crystalloids are increasingly used as fluid therapy in aSAH patients. The effectiveness of mineralocorticoids and balanced crystalloids in improving outcomes for aSAH patients must be rigorously tested in randomized clinical trials.

Prevention and Correction of Dysnatremia After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Dysnatremia occurs commonly in patients with aneurysmal subarachnoid hemorrhage (aSAH). The mechanisms for development of sodium dyshomeostasis are complex, including the cerebral salt-wasting syndrome, the syndrome of inappropriate secretion of antidiuretic hormone, diabetes insipidus. Iatrogenic occurrence of altered sodium levels plays a role, as sodium homeostasis is tightly linked to fluid and volume management.

METHODS

Narrative review of the literature.

RESULTS

Many studies have aimed to identify factors predictive of the development of dysnatremia, but data on associations between dysnatremia and demographic and clinical variables are variable. Furthermore, although a clear relationship between serum sodium serum concentrations and outcomes has not been established-poor outcomes have been associated with both hyponatremia and hypernatremia in the immediate period following aSAH and set the basis for seeking interventions to correct dysnatremia. While sodium supplementation and mineralocorticoids are frequently administered to prevent or counter natriuresis and hyponatremia, evidence to date is insufficient to gauge the effect of such treatment on outcomes.

CONCLUSIONS

In this article, we reviewed available data and provide a practical interpretation of these data as a complement to the newly issued guidelines for management of aSAH. Gaps in knowledge and future directions are discussed.

Prospective, multicentre study of screening, investigation and management of hyponatraemia after subarachnoid haemorrhage in the UK and Ireland

BACKGROUND

Hyponatraemia often occurs after subarachnoid haemorrhage (SAH). However, its clinical significance and optimal management are uncertain. We audited the screening, investigation and management of hyponatraemia after SAH.

METHODS

We prospectively identified consecutive patients with spontaneous SAH admitted to neurosurgical units in the United Kingdom or Ireland. We reviewed medical records daily from admission to discharge, 21 days or death and extracted all measurements of serum sodium to identify hyponatraemia (<135 mmol/L). Main outcomes were death/dependency at discharge or 21 days and admission duration >10 days. Associations of hyponatraemia with outcome were assessed using logistic regression with adjustment for predictors of outcome after SAH and admission duration. We assessed hyponatraemia-free survival using multivariable Cox regression.

RESULTS

175/407 (43%) patients admitted to 24 neurosurgical units developed hyponatraemia. 5976 serum sodium measurements were made. Serum osmolality, urine osmolality and urine sodium were measured in 30/166 (18%) hyponatraemic patients with complete data. The most frequently target daily fluid intake was >3 L and this did not differ during hyponatraemic or non-hyponatraemic episodes. 26% (n/N=42/164) patients with hyponatraemia received sodium supplementation. 133 (35%) patients were dead or dependent within the study period and 240 (68%) patients had hospital admission for over 10 days. In the multivariable analyses, hyponatraemia was associated with less dependency (adjusted OR (aOR)=0.35 (95% CI 0.17 to 0.69)) but longer admissions (aOR=3.2 (1.8 to 5.7)). World Federation of Neurosurgical Societies grade I-III, modified Fisher 2-4 and posterior circulation aneurysms were associated with greater hazards of hyponatraemia.

CONCLUSIONS

In this comprehensive multicentre prospective-adjusted analysis of patients with SAH, hyponatraemia was investigated inconsistently and, for most patients, was not associated with changes in management or clinical outcome. This work establishes a basis for the development of evidence-based SAH-specific guidance for targeted screening, investigation and management of high-risk patients to minimise the impact of hyponatraemia on admission duration and to improve consistency of patient care.

Dysnatremia and 6-Month Functional Outcomes in Critically Ill Patients With Aneurysmal Subarachnoid Hemorrhage: A Prospective Cohort Study

OBJECTIVES

To investigate the association between plasma sodium concentrations and 6-month neurologic outcome in critically ill patients with aneurysmal subarachnoid hemorrhage.

DESIGN

Prospective cohort study.

SETTING

Eleven ICUs in Australia and New Zealand.

PARTICIPANTS

Three-hundred fifty-six aneurysmal subarachnoid hemorrhage patients admitted to ICU between March 2016 and June 2018. The exposure variable was daily measured plasma sodium.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Six-month neurologic outcome as measured by the modified Rankin Scale. A poor outcome was defined as a modified Rankin Scale greater than or equal to 4. The mean age was 57 years (± 12.6 yr), 68% were female, and 32% (n = 113) had a poor outcome. In multivariable analysis, including age, illness severity, and process of care measures as covariates, higher mean sodium concentrations (odds ratio, 1.17; 95% CI, 1.05-1.29), and greater overall variability-as measured by the sd (odds ratio, 1.53; 95% CI, 1.17-1.99)-were associated with a greater likelihood of a poor outcome. Multivariable generalized additive modeling demonstrated, specifically, that a high initial sodium concentration, followed by a gradual decline from day 3 onwards, was also associated with a poor outcome. Finally, greater variability in sodium concentrations was associated with a longer ICU and hospital length of stay: mean ICU length of stay ratio (1.13; 95% CI, 1.07-1.20) and mean hospital length of stay ratio (1.08; 95% CI, 1.01-1.15).

CONCLUSIONS

In critically ill aneurysmal subarachnoid hemorrhage patients, higher mean sodium concentrations and greater variability were associated with worse neurologic outcomes at 6 months, despite adjustment for known confounders. Interventional studies would be required to demonstrate a causal relationship.