Efficacy of preoperative white blood cell count and lymphocyte/monocyte ratio in predicting post-lobectomy pneumonia

BACKGROUND: This study aims to examine preoperative white blood cell count and lymphocyte/monocyte ratio and to investigate foreknown risk factors for pneumonia following lobectomy. METHODS: Between January 2005 and May 2018, a total of 152 patients (135 males, 17 females; mean age: 61.9±7.5 years; range, 45 to 73 years) who underwent right lower lobectomy for non-small cell lung cancer were retrospectively analyzed. Data including age, sex, preoperative white blood cell count and lymphocyte/monocyte ratio, smoking, preexisting chronic diseases, body mass index, stage of lung cancer, the use of neoadjuvant chemotherapy, type of surgery, operation duration, blood transfusion, and postoperative intensive care unit admission were recorded. RESULTS: Twenty-five (16.4%) patients developed postoperative pneumonia. Older patients presenting with elevated levels of preoperative white blood cell count and lymphocyte/monocyte ratio, excessive tobacco consumption, prolonged operation duration, history of a chronic disease, a body mass index over 30 kg/m2, advanced lung cancer, neoadjuvant chemotherapy, and intensive care unit admission after surgery were at high risk for postoperative pneumonia. There was no significant difference in sex, type of surgery (thoracotomy versus thoracoscopy), and the use of blood products. In predicting the development of postoperative pneumonia, lymphocyte/monocyte ratio had 85.% sensitivity and 87.5% specificity, while white blood cell count had 72.5% sensitivity and 77.5% specificity. CONCLUSION: Preoperative white blood cell count and lymphocyte/ monocyte ratio provide supporting evidence in predicting pneumonia following lobectomy contributing to the existing risk identification criteria.