Abstract
Neuroleptanalgesia (NLA) without endtracheal intubation is recommended as one of the anesthesia for endoscopic microsurgery of larynx that stands presently an important situation in phonosurgery. The indications are as follows: (1) cases in which phonatory function should be examined during surgery, and (2) cases in which operation is done at the cartilagenous portion of the glottis. The administration of oxygen from one to two l/min prior to the operation should be recommended, because NLA is apt to cause respiratory acidosis and hypoxic influences to the cardiovascular system.
Two types of influences upon cardiovascular function can occur when a laryngoscope is inserted: a suppresive and accelerative effects to the heart. In the former case an increase in pulse rate, mean arterial pressure and left ventricular ejection index are presumably caused by pain and pressure of epiglottis. In the latter case a decrease in pulse rate, left ventricular ejection index, a transient drop of mean arterial pressure and an increase in central venous pressure chiefly result from vago-vagal reflex. It seems that anesthesia which we have done is very desirable to both surgeons and patients, because no seriously anesthetic complications were experienced and 75% of the cases were operated with facility by surgeons, in addition 94% of the patients were satisfied with our anesthesia. Therefore, NLA without intubation is considered to be a safe and appropriate modality of anesthesia for endoscopic microsurgery of larynx if it is carefully performed.
