Effects on respiration of nonintubated anesthesia in thoracoscopic surgery under spontaneous ventilation

Thoracoscopic surgery without tracheal intubation [nonintubated video-assisted thoracoscopic surgery (VATS)] is an emerging treatment modality for a wide variety of thoracic procedures. By surgically induced open pneumothorax, the operated lung collapse progressively while the dependent lung is responsible for sufficiency of respiratory function, including oxygenation and ventilation. Encouraging results showed that ventilatory changes and oxygenation could be adequately maintained in major lung resection surgery and in patients with impaired respiratory function. In spite of a relative hypoventilation, mild hypercapnia is inevitable but clinically well tolerated. An understanding the respiratory physiology during surgical pneumothorax, either in awake or sedative status, and an established protocol for conversion into tracheal intubation are essential for patient safety during nonintubated VATS.