Elevated K/iCa ratio is an ancillary predictor for mortality in patients with severe hemorrhage: A decision tree analysis.

ABSTRACT

INTRODUCTION: Trauma patients receiving massive transfusion protocol (MTP) are at risk of citrate-induced hypocalcemia and hyperkalemia. Here we evaluate potassium (K), ionized calcium (iCa), and K/iCa ratio as predictors of mortality. METHODS: This retrospective study includes all adult trauma patients who received MTP within 1 h at our level I trauma center between 2014 and 2019. Receiver operating characteristic curve analysis assessed predictive accuracy of K/iCa ratio at admission on 120-day mortality. RESULTS: Of 614 patients, 146 received MTP within 1 h and 38 expired. Patients who expired had higher K/iCa ratio than survivors (median [IQR] = 5.7 [3.8-7.2] vs 3.7 [3.1-4.9], p < 0.001). Area under the curve of K/iCa was 0.72 (95%CI = 0.62-0.82, p < 0.001) with sensitivity = 63.2% and specificity = 77.6%. At the optimum K/iCa cutoff (5.07), patients with high ratios had 4 times higher mortality risk (HR = 3.97, 95%CI = 1.89-8.32, p < 0.001). CONCLUSION: Elevated K/iCa ratio was an independent predictor of mortality in trauma patients managed with MTP.