Evaluation of the effect of perioperative administration of S(+)-ketamine hydrochloride injection for postoperative acute pain in children: study protocol for a prospective, multicenter, randomized, open-label, parallel-group, pragmatic clinical trial

Table 1 The sample sizes under different effect sizes

Control group (N)	S(+)-ketamine hydrochloride group (N)	Total subjects (N)	Effect sizes
58	116	174	0.500
130	260	390	0.333
229	458	687	0.250
357	714	1071	0.200
514	1028	1542	0.167
699	1398	2097	0.143
913	1826	2739	0.125
1155	2310	3465	0.111
1426	2852	4278	0.100

Sample size under different effect sizes assuming power is 80%, two-sided significant level of 0.025, and the ratio of S(+)-ketamine hydrochloride group to conventional group is 2:1

ISSN: 1745-6215