Elevated lactate level and shock index in nontraumatic hypotensive patients presenting to the emergency department

BACKGROUND: The aim of our study was to evaluate the effect of lactate level (LL) and shock index (SI) on the outcome in nontraumatic hypotensive patients in the emergency department, and also to show the significance of the combined usage of these two parameters.

METHODS: This is a prospective, observational study. Elevated and normal LL (ELL and NLL), elevated and normal SI (ESI and NSI), and a combination of these two parameters (lactate-SI group 1: ELL and ESI, lactate-SI group 2: ELL or ESI, and lactate-SI group 3: NLL and NSI) were evaluated for primary (mortality) and secondary outcome measures.

RESULTS: A total of 131 patients who fulfilled the inclusion criteria were analysed. Of the patients with ELL, 34.78% were mechanically ventilated (P<0.001), 31.88% received vasoactive drugs (P<0.001), and 68.1% were hospitalized (P<0.01). The mortality rate among patients with ELL was 50.72% (P<0.001). Of the patients with ESI, 39.42% died (P<0.01). Use of mechanical ventilation in the emergency department was higher in lactate-SI group 1 [36.1%, P<0.0001, sensitivity: 100.0%, negative predictive value (NPV): 100.0%]. Vasoactive drug use was higher in lactate-SI group 1 (32.8%, P<0.0001, sensitivity: 100.0%, NPV: 100.0%). Lactate-SI group 1 showed a higher hospitalization rate (67.8%, P>0.05). In-hospital mortality in lactate-SI group 1 was higher (54.1%, P<0.0001, sensitivity: 100.0%, NPV: 100.0%).

CONCLUSION: The combination of both parameters is effective in predicting these outcome measures with higher sensitivities and NPVs. Further studies on the subject are required.