Air embolism during anesthesia for shoulder arthroscopy.

Venous gas embolism is a rare complication during arthroscopy, occurring when air or another gas is used to distend the joint. The case reported here appears to be only the second in which venous air embolism occurred during shoulder arthroscopy. The patient, a 28-yr-old man, was scheduled for elective arthroscopy of the left shoulder. There was no history of trauma to the joint, and MRI scans had not revealed any abnormalities. Arthroscopy was performed with the patient placed in the beach chair position. A syringe with air to the inflow portal was attached on the arthroscope and 50 mL of air was injected into the joint. Within 1 min after the injection, the patient experienced a marked decrease in endtidal carbon dioxide (from 4.0 to 1.5 kPa). Heart rate increased from 60 to 90 beats/min. An air embolism was suspected and the patient was placed horizontal. Nitrous oxide was discontinued. After 4 mm, the end tidal carbon dioxide concentration returned to 4.0 kPa. The surgical procedure continued and the patient subsequently made a full recovery from the anesthetic. Venous air embolism is very rare in shoulder arthroscopy, even though air is commonly used as the joint distending agent. In the present case, the authors believe that a vein was accidentally punctured during the stab incision or by introduction of the arthroscope into the joint. The increased intraarticular pressure resulted in air entering an open vein. An awareness of the possibility of air embolism, together with a high index of suspicion and vigilance, are important in arthroscopy. The precordial Doppler probe is an inexpensive, noninvasive, sensitive, and easy-to-use monitor. Carbon dioxide or normal saline are safer than IV air for distension of joints during arthroscopy.