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.

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

BACKGROUND: Hyponatraemia is a common complication of aneurysmal subarachnoid haemorrhage (SAH). We aimed to determine current neurosurgical practice for the identification, investigation and management of hyponatraemia after SAH. METHODS: An online questionnaire was completed by UK and Irish neurosurgical trainees and consultant collaborators in the Sodium after Subarachnoid Haemorrhage (SaSH) audit. RESULTS: Between August 2019 and June 2020, 43 responses were received from 31 of 32 UK and Ireland adult neurosurgical units (NSUs). All units reported routine measurement of serum sodium either daily or every other day. Most NSUs reported routine investigation of hyponatraemia after SAH with paired serum and urinary osmolalities (94%), urinary sodium (84%), daily fluid balance (84%), but few measured glucose (19%), morning cortisol (13%), or performed a short Synacthen test (3%). Management of hyponatraemia was variable, with units reporting use of oral sodium supplementation (77%), fluid restriction (58%), hypertonic saline (55%), and fludrocortisone (19%). CONCLUSIONS: Reported assessment of serum sodium after SAH was consistent between units, whereas management of hyponatraemia varied. This may reflect the lack of a specific evidence-base to inform practice.

A national survey of clinical practice of surveillance for post-traumatic brain injury hypopituitarism in the United Kingdom and Ireland.

Background: Traumatic brain injury (TBI) is the most common cause of death and disability in young adults in industrialised countries. Post-TBI hypopituitarism (PTHP) is thought to occur in one-third of patients, however the natural history and predictive factors are not fully understood and as such guidelines for surveillance vary. The aim of this study was to assess the variations in current surveillance practices across the Neurosurgery Centres within the United Kingdom.Methods: A questionnaire was developed following discussions with an expert panel and distributed to members of the Society of British Neurosurgeons (SBNS), by email and printed copy, to survey surveillance practices for PTHP. The questionnaire primarily aimed to determine how commonly screening was performed and the clinical parameters used to guide these surveillance practices.Results: There were 45 responders representing Neurosurgery units in regions of England, Scotland and Ireland. The majority of participants (86.7%) considered PTHP to be a problem but only 25% (11/45) routinely screened for PTHP. There was wide variation in the criteria used to determine which patients were screened.Conclusions: Our survey suggests that few Neurosurgeons routinely screen for PTHP and those that do use a wide variation of clinical parameters to guide surveillance practice. A UK-wide prospective cohort study may help identify patients at risk of developing PTHP.

Medically induced hypertension, hypervolaemia and haemodilution for the treatment and prophylaxis of vasospasm following aneurysmal subarachnoid haemorrhage: systematic review.

PURPOSE: Arterial vasospasm is a major cause of death and long-term disability following subarachnoid haemorrhage (SAH). The use of medically induced hypertension, hypervolaemia and/or haemodilution is widely practiced for prophylaxis and treatment of vasospasm following SAH. We aimed to determine if the quality of available research is adequate to inform use of haemodynamic management strategies to prevent or treat vasospasm following SAH. METHODS: Individual searches of the following databases were conducted: The Cochrane Database of Systematic Reviews, The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE and OpenSIGLE. Pertinent randomised clinical trials and cohort studies comparing any element or combination thereof: medically induced hypertension, hypervolaemia, and haemodilution were included. Data were extracted using standardised proformas and risk of bias assessed using a domain-based risk of bias assessment tool. RESULTS: 348 study reports were identified by our literature search. Eight studies were included, three of which examined both volume expansion and medically induced hypertension. Three randomised clinical trials and two cohort studies examining prophylactic volume expansion were included. Two trials of prophylactic medically induced hypertension and two cohort studies were included. One trial and one cohort study of medically induced hypertension for treatment of established vasospasm was included. These trials demonstrated no significant difference in any of the clinical outcome measures studied. No trials of blood transfusion were included. CONCLUSIONS: There is currently insufficient evidence to determine the efficacy or non-efficacy of intravenous volume expansion, medically induced hypertension or blood transfusion for the treatment or prophylaxis of vasospasm following SAH. All of these approaches have been associated with adverse events, of unclear incidence. The current evidence base therefore cannot be used to reliably inform clinical practice. This is a priority for further research.