Effects of prone position on lung function of patients undergoing mechanical ventilation under total intravenous anesthesia

Lung function of patients is one of the most important issues for anesthesiologists during the perioperative period. This study aimed to evaluate the effects of prone position on lung function of patients undergoing mechanical ventilation under total intravenous anesthesia. Sixty patients undergoing elective surgery were randomly divided into 2 groups: supine group (receiving operation in supine position requiring mechanical ventilation under total intravenous anesthesia) and prone group (receiving operation in prone position requiring mechanical ventilation under total intravenous anesthesia). Arterial partial pressure of oxygen (PaO2), alveolar-arterial oxygen difference (A-aDO2), peak airway pressure and peak mean pressure were measured at the same time. The results showed that there were no significant difference in peak airway pressure and peak mean pressure between two groups at the different time points (95% CI: 6.3-6.9 cmH2O VS. 6.4-7.2 cmH2O, P=0.57; 17.0-18.1 cmH2O VS. 16.117.7 cmH2O, P=0.49). Compared with supine group, PaO2 was significantly increased, and A-aDO2 was significantly decreased in prone position (95% CI: 301.2-493.0 mmHg VS. 244.1-272.6 mmHg, P<0.004; 186.1-265.0 mmHg VS. 396.1-422.4 mmHg, P<0.001). In conclusion this article suggests that mechanical ventilation under total intravenous anesthesia do not negatively affect the lung function when patients are in either prone or supine position, and the pulmonary ventilation function is better than that in supine position.