Lymphocyte to neutrophil ratio and procalcitonin as prognostic factors in children with lower respiratory tract infection

Background Illnesses that impact the respiratory system below the throat are known as lower respiratory infections.Aim: to assess how blood biomarkers (leucocyte, PCT, and CRP levels), clinical symptoms, and their interaction help differentiate pediatric pneumonia from lower respiratory tract infections (LRTIs).Patients and Methods.This prospective study was performed on 100 cases with LRTI who were admitted to pediatric ICU of Mallawi specialized hospital from May 2023 to Nov 2023.The studied patients were divided into two subgroups: 21 Patients who need admission to PICU and 79 patients who didn't need admission to PICU.The two groups were sub divided into another 2 subgroups which were (pneumonia and other LRTI.)53% male and 47% female.The other LRTI were bronchitis, bronchiolitis, lung abscess, tuberculosis, bronchial asthma.Lab.Evaluations including CBC, ABG, CRP, procalcitonin results were recorded.Absolute lymphocyte count divided on absolute neutrophil count to calculate LNR.In our study we used RISC (respiratory index of severity in children score) which is a six-predictor standardized means for assessment of severity of respiratory illness among children.Variables in RISC score (hypoxia, chest indrawing, feed refusal, wheeze, malnutrition, age) represent known risk factors for severe outcomes of pneumonia in children with a maximum score of 6 points.Results: There was significant increase in patients who needed PICU than who didn't need PICU regarding lymphocyte to neutrophil ratio, CRP, and Procalcitonin, while there was significant decrease in patients who needed PICU than who didn't need regarding Lymphocyte, while there was no statistically significant distinction among two groups regarding HB, neutrophil, Platelets, pH, PCO2, and HCO3.54% of the patients was diagnosed as pneumonia and 46% was diagnosed as other LRTI (viral bronchitis 25%,10% recurrent wheezy chest,11% complicated asthma).Patients who needed PICU admission were 21 (20 diagnosed as pneumonia and 1 other LRTI), and those who didn't need PICU were 79 (34 diagnosed as pneumonia and 45 other LRTI.Conclusion Procalcitonin, CRP increase in patient admitted to PICU more than those who didn't need.neutrophil-lymphocyte ratio (NLR) increases in patient who admitted to PICU more than those who didn't need.RISC score was higher in patient who admitted to PICU.Duration of hospital stay increases when patient need PICU admission.Mortality rate increases when patients admitted to PICU.PCT, CRP, NLR higher in pneumonia rather than other LRTI.