The train-of-four response is used to assess a patient's level of paralysis during high-frequency oscillatory ventilation, and the patient's foot twitches four times. The most appropriate evaluation of this circumstance is which of the following?

a. Nothing need be done; paralysis is ade-quate.
b. The paralyzing agent is moderately effec-tive.
c. The paralyzing agent needs to be readmin-istered.
d. Propofol needs to be added to enhance the effect.

ANS: C
For the train-of-four assessment, an electrical current consisting of four impulses is applied to the peripheral nerve over 2 seconds; the muscle contractions (twitches) produced provide information about the level of paralysis. With four twitches, the paralyzing agent needs to be readministered if continued paralysis is required.