Purpose: The aim was to evaluate the predictive value of serial serum sodium determination for mortality in enteric fistula (EF) patients complicated with sepsis.
Methods: Between January 1(st), 2012 to January 13(th), 2013, we performed a prospective observational study enrolling 162 patients. Patients were divided into survivors group (n = 119) and nonsurvivors group (n = 43) according to 28-day outcomes. Laboratory variables on day 0, day 3, and day 7 after admission were recorded. [Na(+)]0 was defined as serum [Na(+)] value on admission. [Na(+)]3 was defined as serum [Na(+)] value on day 3. Δ [Na(+)]3 was defined as changes from [Na(+)]3 to [Na(+)]0. The definition applied to other parameters. The results were validated in an independent cohort of 116 patients.
Results: ROC analysis showed that [Na(+)]7>147.5 mmol/L and ΔNa7>5.2 mmol/L were reliable predictors ([Na(+)]7: 81.2% sensitivity, 87.7% specificity, (area under the curve(AUC):0.872, p < .001; Δ[Na(+)]7: 81.3% sensitivity, 83.6% specificity, AUC:0.836, p < .001) for mortality. The combination form ([Na(+)]7>147.5 mmol/L+ Δ[Na]7>5.2 mmol/L+ ΔPCT7<5.3 ng/ml) had greatest predictive value (AUC:0.899, p < .001). Their predictive values were confirmed in the validation cohort.
Conclusions: Serum sodium was a reliable predictor for mortality in abdominal septic patients, which should be paid close attention in the critical care.
Keywords: abdominal sepsis; biomarker; enteric fistula; hypernatremia; predictor.