Changes in Blood Gases and Hemodynamic Parameters in Patients Undergoing Lung Resection Surgery and Its Clinical Implications

Introduction: Lung resection surgery is a challenge to thoracic surgeons. The outcome of this surgery depends on patients’ tolerance for reduced lung volume and hemodynamic alterations. The present study aimed to investigate the changes in blood gases and hemodynamic parameters in patients undergoing lung resection surgery and the associated clinical implications. Material and Methods: This study included 25 candidates for lung resection surgery. After thoracotomy, the isolation of pulmonary artery (PA) and veins was performed as usual. Blood samples were taken from the PA and radial artery simultaneously before PA clamping, as well as 5 and 20 min after clamping the PA. The systemic and PA pressure was also measured. All patients were followed up, and arterial blood gas and pulmonary function tests were performed 3-6 months after the surgery. Results: Cough (56%) and hemoptysis (56%) were the most common symptoms. Squamous cell carcinoma (56%) was identified as the most prevalent pathology. Lobectomy was the most common procedure performed on the patients. No change was observed in blood gases before and after the clamping of the PA. There was a significant increase in the mean PA pressure (P<0.001), while the mean arterial pressure showed no significant change (P=0.457). The pulmonary function tests showed a significant decrease in vital capacity, forced vital capacity, and forced expiratory volume in 1 sec at the postoperative follow-up. The patients with a pre-operative partial pressure of carbon dioxide (PCO2) of > 45 mmHg had more postoperative complications than those with a PCO2 of ≤ 45 mmHg (P=0.047). Conclusion: Given the lack of any significant changes in the PCO2 and oxygen saturation following the lung resection surgery, it seems that this parameter is not a limiting factor for deciding on operability in patients with lung lesions having an acceptable preoperative partial pressure of oxygen. However, the patients with a PCO2 of > 45 mmHg should be categorized as a high-risk group since they have significantly higher postoperative complications/morbidity.