Prospective determination of the incidence and severity of hyponatraemia in older hospitalised patients with acute urinary tract obstruction

Abstract

Introduction acute urinary tract obstruction (aUTO) is a common finding in older hospitalised patients. Anecdotal reports described hyponatraemia in patients with aUTO, which subsides rapidly with relief of the obstruction. The aim of this study was to determine the incidence, severity and subsequent correction of hyponatraemia in patients with aUTO. Methods this is a prospective, single-centre, observational study including inpatients in the internal medicine and geriatric wards. A total of 204 patients were investigated, 104 with aUTO and 100 controls. The prevalence, severity and associations of hyponatraemia between aUTO and control patients were compared. Results the incidence of hyponatraemia was similar in aUTO and control groups 28% versus 22%, respectively (P = 0.42). However, the incidence of severe hyponatraemia was significantly higher in the study group 7% versus 1% (P = 0.04). Mean sodium level was lower in hyponatremic patients with aUTO 127.7 ± 5.9 mEq/l versus 130.8 ± 3 mEq/l (P = 0.013). Serum sodium remained largely unchanged in the control group (∆Na 1.5 ± 2.3 mEq/l) but increased significantly within 48 hours following catheter insertion in patients with urinary retention (∆Na 5.3 ± 4.2 mEq/l overall in the aUTO group and 9.6 ± 3 mEq/l in those with urinary retention and severe hyponatraemia (P = 0.002)).

Syndrome of Inappropriate Antidiuresis Due to Chronic Perforated Diverticulitis With Colovesical Fistula

“…The underlying pathophysiological mechanism in this case is not clear, although it is possible that it is similar to other inflammatory processes that stimulate the non-osmotic secretion of ADH. SIAD is also described in the context of acute urinary retention, probably due to stimulation of ADH secretion by bladder distension [3,4]. It is possible that in our case, infiltration of the bladder wall by the inflammatory mass stimulated ADH by a similar mechanism.…”