Twitch Monitoring FAQ
The first time the patient’s train-of-four (TOF) count drops to zero, the user is prompted to add post-tetanic count (PTC). PTC enables the user to quantify a deep block. Each PTC sequence is preceded by a TOF to validate the necessity. If the TOF count is zero, a five-second, 50 Hz tetanus is delivered followed by a 3-second pause. Single twitch stimuli are then delivered each second and the total responses counted. The total number of single twitches that elicit a response is reported as the PTC. The max PTC is 15 with higher numbers indicating that the TOF count will reemerge. PTC stimulation is delivered once every five minutes, and TwitchView will automatically switch between TOF and PTC depending on the patient’s level of the block (see video).