Different Learning Curves for Axillary Brachial Plexus Block: Ultrasound Guidance versus Nerve Stimulation

Table 3

Different success rates for both ultrasound and nerve stimulation groups for the cumulated first 10, 20, 30, and 40 attempts with the according confidence intervals. Chi-square test with Bonferroni correction, 𝑃<.01.

		Number of attempts and success rate (SR) per group
Attempts			Ultrasound		Stimulator	𝑃-value
	Number of residents	𝑁	(SR%) (CI ± 95%)	𝑁	(SR%) (CI ± 95%)
10	20	100	(86) (78–92)	100	(68) (58–76)	.002
20	16	179	(88) (82–92)	199	(76) (70–82)	.004
30	13	235	(89) (85–93)	289	(79) (74–83)	.001
40	4	259	(89) (85–92)	343	(80) (75.0–84)	.002