Aim to elucidate the factors influencing length of stay (LOS) in patients with hyponatraemia admitted to an acute medical unit (AMU).
Methodology: a prospective study of patients admitted to AMU at West Middlesex University Hospital from November 2009 to June 2011. A proforma was completed for each patient by the registrar on his duty days.
Results: 70 patients were identified with a mean age of 69.2 years. 41 (59%) were female. 20 (29%) patients were symptomatic; confusion was the commonest symptom in 45%. Of the 51 (73%) patients with LOS > 72 hours, 8 (16%) had severe (sodium level of <120 mmol/l), 26 (51%) had moderate (120129 mmol/l), and 17 (33%) had mild (130135 mmol/l) hyponatraemia. Of the 16 (23%) patients with LOS of between 24 and 72 hours, 1 (6%) had severe, 10 (63%) had moderate, and 5 (31%) had mild hyponatraemia. 3 patients with LOS < 24 hours had mild hyponatraemia. LOS and level of hyponatraemia on admission were independent of each other (P=>0.05). LOS was also independent of the treatment received or the presence of co-morbidities. 48 (69%) patients were discharged, while 11 (16%) patients passed away. Of the 59 patients who survived, 6 (10%) were readmitted within 2 weeks, and 6 (10%) were readmitted more than 2 weeks after discharge. Level of hyponatraemia on admission did not influence readmission rates (P=>0.05).
Conclusion: The majority of patients had moderate hyponatraemia, with confusion and multiple co-morbidities. Most patients stayed in hospital >72 hours, and were discharged without readmission. LOS and readmission rates were not influenced by the level of hyponatraemia on admission.
Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.
Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.