Hyponatraemia tied to worse outcome, acute chest syndrome in sickle cell disease patients

Hyponatraemia at admission for an acute painful episode appears to be a robust and independent predictor of worse outcome and acute chest syndrome in patients with sickle cell disease, suggests a recent study.

The investigators carried out this retrospective study between 2010 and 2015 in a French referral centre for sickle cell disease. They sought to examine the value of low plasma sodium concentration at admission in predicting a complication in adult patients with sickle cell disease hospitalized for an initially uncomplicated acute painful episode.

The primary outcome was a composite criterion including acute chest syndrome, intensive care unit (ICU) transfer, red blood cell transfusion, or inpatient death. Analyses were also adjusted for age, sex, haemoglobin genotype and concentration, lactate dehydrogenase concentration, and white blood cell count.

Four hundred six patients with a total of 1,218 hospital stays were included. No inpatient death occurred during the study period.

Hyponatraemia (plasma sodium ≤135 mmol/L) at admission correlated with the primary outcome (adjusted odds ratio [OR], 195, 95 percent confidence interval [CI], 1.3–2.91; p=0.001), acute chest syndrome (OR, 1.95, 95 percent CI, 1.2–3.17; p=0.008), and red blood cell transfusion (OR, 2.71, 95 percent CI, 1.58–4.65; p<0.001), but not significantly with ICU transfer (OR, 1.83, 95 percent CI, 0.94–3.79; p=0.074).

In addition, patients with hyponatraemia at admission had longer adjusted mean length of stay by 1.1 days (95 percent CI, 0.5–1.6; p<0.001).

These findings could help in identifying patients who might benefit from closer monitoring, according to the investigators.