'Train of four' is characteristically used in concern with: (A) Malignant hypehermia, (B) Non-depolarizing neuromuscular blockers, (C) Mechanical ventilation, (D) To check hemodynamic parameters
Answer is B. Train-of-four stimulation devotes four successive 200 - ms stimuli in 2 s (2 Hz). The twitches in a train-of-four pattern progressively fade as relaxation increases. The ratio of the responses to the first and fouh twitches is a sensitive indicator of nondepolarizing muscle paralysis. Disappearance of the fouh twitch represents a 75% block, the third twitch an 80% block, and the second twitch a 90% block. Clinical relaxation usually requires 75-95% neuromuscular blockade. Ref: KD Tripathi 8th ed.