Anesthesia for laser surgery

Abstract

Laser surgery offers several advantages to the surgeon and patient: microscopic precision, a bloodless operative field, and complete sterility. While the majority of procedures pose few problems beyond protection of the eyes of operating room personnel and patients, microlaryngeal surgery with the CO2 laser requires very careful anesthetic management. A preoperative visit to determine the degree of existing airway obstruction is mandatory in deciding the safest anesthetic technique. Continued communication and cooperation between the surgeon and anesthesiologist throughout the procedure will help minimize the conflicting needs for airway access and ventilation. We feel the best approach to the anesthetic management of patients undergoing laser airway surgery is to have several alternatives available at the time of induction of anesthesia. For adult patients wrapped tubes, metal tubes, and a jet injector should be on hand. The options are more limited in children. The smallest metal tubes available have external diameters of 6 mm (Norton tube) or 7 mm (Porch tube), which are too large to use in these younger patients. Small wrapped, uncuffed tubes or Venturi ventilation through a small-gauge needle are most often used. Regardless of the technique, constant vigilance throughout the procedure is required to detect complications early. Wrapped tubes, metal tubes, insufflation using no tube, and jet ventilation using a needle or metal tube reduce the fire hazard but each method substitutes its own set of problems. Before adopting any approach, we strongly recommend that the equipment selected be tested for flammability with the laser before its use in patients. If, in spite of precautions, ignition of equipment does occur, immediately interrupt the flow of oxygen and nitrous oxide as most materials do not burn readily in air. Then remove the offending material. We have reviewed selected aspects of the management of the patient undergoing laser surgery, outlined the principles of laser technology, and listed the many surgical procedures employing lasers. Also, recommendations on anesthetic management of microlaryngeal surgery with the CO2 laser with emphasis on currently available measures to prevent problems were reviewed in light of our own experience with this technique along with a summary of the literature on laser surgery. An understanding of the fundamental principles and applications of lasers will hopefully lead to safer patient care.