Prognostic value of plasma lactate levels in pulmonary emboli̇sm patients

Background and Purpose: An early risk assessment tool is used to determine prognosis and treatment protocol in patients with PTE diagnosis. The prognosis of normotensive PTE patients depends on the efficiency of the treatment and clinical follow-up. Elevated lactate levels are correlated with 30-day mortality in PTE patients. Our purpose is to evaluate the relation between plasma lactate levels and 30 day mortality in patients diagnosed in the emergency service and to evaluate the availability of application of these risk factors for early risk classification. Materials and Method: This study that was designed as a prospective cross sectional research and held in Ege University Medicine Faculty Emergency Service between 01 February 2014 and 01 August 2014. Patients complaining of shortness of breath, chest pains, etc. and who have done thorax CT angiography scanning for PE differential diagnosis were included in the study. The Risk factors, vital findings, blood lactate levels (admittance, 6th and 12th hours), cardiac markers, thorax CT angiography images, echocardiographic screenings of the patients were examined. Lower extremities venous doppler USG examination was used for deep vein thrombosis diagnosis. The patients were monitored after discharge and 30 day follow up was used to report mortality. Findings: 236 patients had thorax CT angiography scanning for PE differential diagnosis and 88 patients with pulmonary embolisim diagnosis were included in the study. 45 (51.1%) patients were female and average age was 68.1± 1.12 (between ages 21-100). 64 patients had lactate levels below 2 mmol/L and 15 of them died (23.4%). 24 cases had blood lactate levels higher than 2 mmol/L and 12 of them died (50%). When the 'cut-off' blood lactate level is selected as 2 mmol/L, sensitivity was 44.4% and specificity was 80.3%. However, the positive predictive value was found %50 and the negative predictive value was %76. It was observed that plasma lactate levels were correlated with 30 day mortality. Blood lactate levels at 0th, 6th and 12th hour showed that, mortality increased if the lactate level was showing progression. Discussion and Conclusion: Among patients diagnosed with PE at emergency department, the high lactate levels were correlated with short term mortality. Blood troponin levels showed high sensitivity for short term prognosis in PE diagnosed patients and could have more prognostic value with blood lactate level measurement. Keywords: pulmonary embolism, plasma lactate level, mortality