Prediction of fatal outcome in patients with pneumonia caused by carbapenem-resistant Klebsiella pneumoniae

Pneumonia caused by carbapenem-resistant K. pneumoniae often has a severe course and a significant risk of unfavorable outcome. Various scales and indices have been proposed for timely assessment of the patient's condition and detection of a high risk of unfavorable outcome. For the attending physician, the ease of use and prognostic accuracy of the index used in the assessment are important. The aim of the study was to evaluate the diagnostic significance of clinical and laboratory parameters for predicting a fatal outcome in patients with pneumonia caused by carbapenem-resistant K. pneumoniae. A total of 71 cases of pneumonia caused by K. pneumoniae with multiple and extreme drug resistance were retrospectively analyzed. Two groups of patients were formed depending on the outcome: group 1 – 41 patients discharged from the hospital upon completion of treatment; group 2 – 30 patients with a fatal outcome. The structure of concomitant diseases, body mass index (BMI), blood saturation (SpO 2 ), hemogram parameters, C-reactive protein (CRP) were analyzed. It was found that patients with a fatal outcome were characterized by higher leukocyte counts, neutrophils in the hemogram, neutrophil/lymphocyte ratio (NLR), CRP, BMI; lower lymphocyte counts, SpO2. The most significant prognostic indicators of an unfavorable outcome are lymphocytes, neutrophils, NLR, BMI. To predict the risk of death, we proposed the index (BMI*NLR)/SpO 2 . ROC analysis was performed: the AUC was 0,99 (0,93–1,00), test sensitivity 100,0 %, specificity 97,6 % at a cutoff point of > 1,53, Youden index 0,98. Diagnostic value of the index (BMI*NLR)/SpO 2 (at a threshold value > 1,53): test sensitivity is 100,0 %, specificity is 95,1 %, positive predictive value is 93,8 %, negative predictive value is 100,0 %, accuracy is 97,2 %. The proposed index (BMI*NLR)/SpO 2 (at a level > 1,53) may be preferable for predicting a fatal outcome of pneumonia caused by carbapenem-resistant K. pneumoniae, due to its high sensitivity (100 %) and specificity (97,6 %), as well as ease of use.