Effects of positioning and ventilation strategy on the parameters of respiratory mechanics and blood gases during video-assisted thoracoscopic esophagectomy

Background: In this study, the effects of positioning and ventilation strategy on respiratory mechanics and blood gases throughout video-assisted thoracoscopic (VAT) esophagectomy were evaluated. Methods: After obtaining approval from the ethics committee, nine patients (2 females, 7 males; mean age 60 years; range 39 to 74 years) who underwent a VAT-esophagectomy for esophageal cancer with ASA I (Society of Anesthesiologists I) or II physical classification were included in the study. Standard general anesthesia was performed. Dynamic respiratory compliance, airway resistance, and peak inspiratory pressure were monitored. Measurements were recorded in five periods; 10 minutes after intubation (Intubation: T1, control), 10 minutes after left lateral decubitus position (Left lateral: T2), 10 minutes after single lung ventilation with left lateral decubitus position (Single lung-initiation: T3), 10 minutes before single lung ventilation ends (Single lung-end: T4), and 10 minutes after supine position (Supine: T5). Samples of arterial blood gases were obtained at the same periods. Results: Dynamic respiratory compliance records were 66+/-12 ml. cm. H2O(-1), 53+/-8 ml. cm. H2O(-1), 49+/-8 ml. cm. H2O(-1), 48+/-8 ml. cm. H2O(-1) and 52+-11 ml. cm. H2O(-1), in T1, T2, T3, T4 and T5, respectively. The changes were significant in T2, T3, T4 and T5 (p<0.05). Conclusion: According to our results, respiratory mechanics, oxygenation and partial oxygen pressures were negatively affected during VAT-esophagectomy compared to the control group, especially during the single lung ventilation period.