[Massive water infusion into the patient's trachea during the use of cascade type heated humidifier]

A case of an inadvertent massive infusion of water via the humidifier module into the trachea during the use of cascade type heated humidifier is described. A Fisher and Paykel anesthetic humidifier was employed in the exhalation side of Jackson Rees type breathing circuit between the anesthesia machine and patient's endotracheal tube. During anesthesia for inguinal hernia, fresh gas flow was 6 liters per minute in the breathing circuit. Humidifier module was inadvertently upside down, and the water in the module was abruptly injected into the patient's trachea and we could not ventilate for a short period of time. This water infusion into the trachea was caused by a large supply of fresh gas flow into the breathing circuit and by narrowing of tube diameter. It is essential, when using heated humidifier, to examine it carefully before anesthesia.