Anesthesia for awake video-assisted thoracic surgery

Awake video-assisted thoracic surgery (VATS) has been increasingly employed in a variety of procedures involving pleura, lungs, and mediastinum. Adequate anesthesia and analgesia obtained from thoracic epidural anesthetic (TEA) allow VATS to be performed in awake patients. The potential general anesthesia-related adverse effects, such as intubation-related trauma, pneumonia, ventilator-associated lung injury, effects of neuromuscular blocking agents, and postoperative nausea and vomiting, can thus be avoided. Moreover, TEA holds the benefits of reducing pulmonary and cardiac morbidities and mortalities after noncardiac surgery. Patients who undergo awake VATS may also benefit from the efficient contraction of the dependent hemidiaphragm and preserved hypoxic pulmonary vasoconstriction during surgically-induced pneumothorax. Preliminary results from early case series have indicated certain benefits, including greater patient satisfaction, less nursing care, less sore throat, earlier resumption of oral intake, lower rate of morbidity, reduced perioperative pain, reduced cost, and shorter hospital stay. However, anesthesia for awake VATS presents a particular challenge to anesthesiologists and requires extra vigilance. Potential hazards include paradoxical respiration and mediastinum shift after surgery induced pneumothorax, which may cause progressive hypoxia, hypercapnia and hypotension. Anesthesiologists should be acquainted with the procedure to be performed, be knowledgeable on the physiological changes, be aware of the potential problems, and have good judgment on suitable timing for conversion of regional anesthesia to intubation general anesthesia in enforced circumstance.