Efficacy of two-lung ventilation with different tidal volume assisted by CO 2 pneumothorax for airway management in patients undergoing radical resection of esophageal cancer using combined laparoscopic and thoracoscopic approach

Abstract

Objective: To evaluate the efficacy of two-lung ventilation with different tidal volume assisted by CO2 pneumothorax for airway management in patients undergoing radical esophagectomy using combined thoracoscopic and laparoscopic approach. Methods: One hundred and eighty patients undergoing radical esophagectomy using combined thoracoscopy and laparoscopy under general anesthesia from the Affiliated Cancer Hospital of Zhengzhou University between February and September 2019 were randomly divided into three groups (group V1, V2, V3, n=60) according to the tidal volume (TV) used. The TVs of group V1-V3 were 4, 5, 7 ml/kg during thoracoscopic surgery, respectively. All the patients were intubated with a single-lumen endotracheal tube and underwent two-lung ventilation assisted by continuous positive pressure CO2 pneumothorax in group V1, V2 and V3, with the CO2 pressure of 10 mmHg (1 mmHg=0.133 kPa) and the frequency of 20 times/min. Mean arterial pressure (MAP) and heart rate (HR) were recorded before thoracoscopic surgery (T1), 30 minutes after thoracoscopic surgery (T2), at the end of thoracoscopic surgery (T3), after thoracoscopic surgery and 30 minutes after two-lung intermittent positive pressure ventilation, respectively. The results of arterial blood gas were collected at T1, T2, T3 and T4. Recovery time from anesthesia, consciousness recovery time, and lung collapse condition were recorded. Results: At T2, the value of MAP in group V1 was (81±10) mmHg, which was higher than those of group V2 [(69±7) mmHg] and group V3 [(71±8) mmHg], with a statistically significant difference (F=9.270, P<0.05). Meanwhile, at T2, the value of HR in group V1 was (83±7) times/min, which was higher than those of group V2 [(68±6) times/min] and group V3 [(71±7) times/min], and there was a statistically significant difference (F=23.460, P<0.05). However, at T2, the values of arterial partial pressure of oxygen (PaO2) in three groups were (262±16), (249±16) and (241±20) mmHg, respectively, with no statistically significant difference (F=1.929, P>0.05). At T3, the value of arterial partial pressure of carbon dioxide (PaCO2) in group V3 was (46±5) mmHg, which was lower than those of group V1 [(63±9) mmHg] and V2 [(62±10) mmHg], with a statistically significant difference (F=20.890, P<0.05). Moreover, at T3, the value of pH in group V3 was (7.35±0.04), which was higher than those of group V1 (7.28±0.04) and V2 (7.32±0.04), and there was a statistically significant difference (F=9.309, P<0.05). Additionally, the satisfaction rates of lung collapse in group V3 was 57.1%, which was lower than those of group V1 (94.7%) and group V2 (96.3%), with a statistically significant difference (χ²=7.601, P<0.05). There was no statistical significance in the time of awakening and consciousness recovery among three groups (F=1.020 and 1.110, both P>0.05). Conclusion: The two-lung ventilation with 5 ml/kg tidal volume assisted by CO2 pneumothorax has advantages in terms of hemodynamics and surgical field exposure, and is more suitable as the appropriate dose for respiratory management in patients undergoing radical resection of esophageal cancer using combined thoracoscopic and laparoscopic approach.