Does the " Curare Cleft " on the Capnogram always mean that the Patient is in Need of Relaxant ? / 대한마취과학회지

A fifty-eight years old male patient was given general anesthesia for the clipping of aneurysm on the posterior communicating artery. The respiration of the patient was controlled with Ohmeda 7000 anesthesia ventilator. During the surgery there appeared curare cleft on the capnogram which did not disappear after the administration of neuromuscular blocker, but disappeared after the change of the anesthesia ventilator with another one. After that another curare cleft was made by the transient obstruction of the outlet of the excess patient circuit gas of the new anesthesia ventilator. It may be said that inappropriately functioning pop-off valve of the anesthesia ventilator can be one of the causes of curare cleft on the capnogram.