Acute renal impairment after immersion and near-drowning.

Acute renal impairment (ARI) secondary to immersion and near-drowning is rarely described and poorly understood. A retrospective case-control study was performed: (1) to determine the incidence of ARI associated with near-drowning or immersion and (2) to define the clinical syndrome and to assess clinical predictors of ARI. Of 30 patients presenting after immersion or near-drowning, 50% were identified with ARI, with a mean admission serum creatinine of 0.24 +/- 0.33 mmol/L (2.7 +/- 3.7 mg/dl). These patients were a heterogeneous group: Eight had mild reversible ARI, three had ARI related to shock and multisystem failure, two had rhabdomyolysis-related ARI, and two had severe isolated ARI. Two patients required supportive hemodialysis and two died. Patients with ARI experienced more marked acidosis than control patients, as measured by serum bicarbonate (P < 0.001), pH (P < 0.001), and base excess (P < 0.001). There was also a higher admission lymphocyte count in the ARI group (P = 0.056). Dipstick hematuria on admission was significantly more common in patients with ARI (P = 0.016), and patients with 2 to 3+ of admission dipstick proteinuria had a higher peak serum creatinine than patients with less proteinuria (P < 0.05). Admission predictors of ARI by univariate logistic regression analysis included reduced serum bicarbonate (P = 0.002), pH (P = 0.001), and base excess (P < 0.001). The best predictor of ARI on multivariate analysis was a negative base excess (P = 0.01). In summary, acute renal impairment commonly occurs after immersion and near-drowning and is a heterogeneous condition. Although mild reversible renal impairment (serum creatinine < 0.30 mmol/L) (3.4 mg/dl) is usual, severe acute renal failure requiring dialysis can occur. It is recommended that any patient who presents after near-drowning or immersion should be assessed for potential ARI by serial estimations of serum creatinine, particularly when there is an increase in the initial serum creatinine, marked metabolic acidosis, an abnormal urinalysis, or a significant lymphocytosis.