Table 3.

Comparison of POST severity between three groups by pair at different times

Times¦	Mann-Whitney Test (P)
	Group C* & K†	Group C & G‡	Group K & G
Time 1	<0.001	<0.001	0.301
Time 2	0.007	0.001	0.323
Time 3	0.003	<0.001	0.307
Time 4	0.601	0.014	0.039
Time 5	0.016	<0.001	0.092

*Group C gargled normal saline, ^†Group K gargled 50 mg ketamine mixed in normal saline, ^‡Group G gargled 100 mg ketamine mixed in normal saline, ^¦Time 1: immediately after the entrance to the recovery room, time 2: 2 h post-operation, time 3: 4 h post-operation, time 4:8 h post-operation, and time 5: 24 h after operation