ABSTRACT
BACKGROUND: Video-assisted thoracic surgical procedure via thoracoscopy has recently gained popularity, as it avoids a thoracotomy, reducing intraoperative blood loss, postoperative pain, respiratory dysfunction and hospital stay. However, to visualize adequately the intrathoracic structures, creation of artificial pneumothorax by carbon dioxide insufflation during thoracoscopy would cause significant hemodynamic compromise. The aim of this study was to evaluate the effect of CO2 insufflation into the pleural cavity on the hemodynamics and the arterial blood gas tension under general anesthesia. METHODS: Twenty-five patients, after intubation with single lumen endotracheal tube, underwent enflurane (1~2%) and N2O-O2 (1:1) general anesthesia. Before placement of a thoracoscope, the baseline mean arterial pressure and heart rate were obtained. Measurements were taken at 5, 10, and 20 min. after the beginning of carbon dioxide insufflation (3~5 mmHg) and 10 min. after gas evacuation. Blood gas analyses were done before, during CO2 insufflation and after CO2 evacuation. Data were analyzed using Student t-test. RESULTS: Positive-pressure CO2 insufflation (3~5 mmHg) caused a decrease of mean arterial pressure (5~7%) and an increase of airway pressure (1.5 times) and heart rate (13~20%) throughout the gas insufflation period (p<0.05). Blood gas analyses revealed no significant change. CONCLUSIONS: These results suggest that low CO2 insufflation pressures (3~5 mmHg) may cause cardiovascular depression during thoracoscopy. Therefore careful monitorings should be done during this procedure.