Aims: To ascertain the incidence of hypo- and hyper-natraemia in patients admitted to a tertiary neurosurgical centre with confirmed spontaneous aneurysmal subarachnoid haemorrhage (SAH), and to determine their impact on length of hospital stay and mortality.
Methods: Retrospective case note review of patients admitted between January 2008 and April 2011.
Results: 402 patients with SAH were identified [mean (±sd) age 56±12 years, range 2084, 70% female]. 376 patients were treated with endovascular coiling ± stent, 19 underwent craniotomy surgical clipping and 7 patients were managed conservatively. Mean length of hospital stay was 19.5 days (range 1161 days). Normal Sodium: 26% (104/402) of patients maintained their serum sodium within the normal range (135145 mmol/l) throughout their hospital stay. Hyponatraemia: 62% (248/402) developed hyponatraemia (Na <135 mmol/l) at some stage of their hospital admission: mild (Na 130134) in 44.5% (179/402), moderate (Na 125129) in 13% (51/402), and severe hyponatraemia (Na ≤124) in 4.5% (18/402). The lowest serum sodium was documented a mean of 8.4 (±6.4) days into their hospital admission. Hypernatraemia: 26% (106/402) of patients developed hypernatraemia (Na ≥146 mmol/l) at some stage of their admission. Impact on length of stay: In survivors of SAH (n=352), hospital stay was more prolonged in those who had developed any serum sodium abnormality (hypo- or hyper-natraemia) at some stage of their hospitalisation [20.6 days (±20) vs 17 (±11), P=0.04] compared with those who remained normonatraemic throughout their admission. Impact on mortality: 50 deaths (mean age 60±12.6 years) were recorded. Serum sodium had ranged from 118170 mmol/l but 26% (13/50) had remained normonatraemic during their hospital stay which was similar to those who survived.
Conclusions: Hypo-and hypernatraemia are common in hospitalised patients post-SAH, and impact negatively on length of hospital stay. The incidence of severe hyponatraemia is relatively low.
Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.
Funding: Declaration of Funding: This work was supported by an unrestricted research grant by Otsuka pharmaceuticals.