Title : Incidence of hyponatraemia and impact on morbidity and mortality after subarachnoid haemorrhage: A systematic review and meta-analysis
Abstract:
Introduction:
Hyponatraemia after subarachnoid haemorrhage (SAH) is common, however the incidence, and association of hyponatraemia with vasospasm, morbidity, and mortality, has yet to be defined. We aimed to identify incidence of hyponatraemia after SAH, and association with measurable outcomes.
Methods:
A PRISMA-compliant systematic review and meta-analysis was conducted (PROSPERO ID CRD42022363472). Articles published in MEDLINE, EMBASE, and Cochrane Library between January 2000-September 2022 were included. Hyponatraemia definitions, Incidence at diagnosis, and association between vasospasm, length of hospital stay, and poor outcome (Glasgow Outcome Scale 3 or less) were identified. Pooled incidence rates and binary outcomes were calculated using random effects meta-analysis models.
Results:
In total, 51 studies (17,230 patients) were included. Most studies included patients admitted to tertiary neuroscience centres (78.4%, N=40), or critical care units (21.6%, N=11). Less than 135 mmol was the most commonly utilised hyponatraemia definition (82.4%, N=42). The pooled incidence of hyponatraemia was 35.4% (95% CI 31.0-39.4%). Hyponatraemia increased the risk of vasospasm (16 studies, OR 2.41, 95% CI 1.76-3.30), mean length of hospital stay (6 studies, 20.0 days vs 14.0 days, p<0.001), and risk of poor outcome (9 studies, OR 3.07, 95% CI 1.83-5.17).
Conclusions:
Hyponatraemia is common after people admitted to hospital for SAH, and increases the likelihood of vasospasm, hospital stay, and poor outcome. Managing hyponatraemia effectively should be a priority for treating clinicians.
