Table 3.

Summary of significance of outcome measures for Doppler ultrasound guidance compared with landmark method for catheterisation

	Internal jugular vein				Subclavian vein				Femoral vein
	No of placements				No of placements				No of placements
Variable	Doppler ultrasound guidance	Landmark method	Effect size (95% CI)	P value	Doppler ultrasound guidance	Landmark method	Effect size (95% CI)	P value	Doppler ultrasound guidance	Landmark method	Effect size (95% CI)	P value
Adults
Relative risk:
Failed catheter placement	86	99	0.39 (0.17 to 0.92)	0.03	310	314	1.48 (1.03 to 2.14)*	0.03*	—	—	NA	NA
Complication with placement	89	89	0.43 (0.17 to 1.05)	0.06	262	264	0.57 (0.11 to 2.88)	0.5	—	—	NA	NA
Failure on first attempt	52	64	0.57 (0.37 to 0.88)	0.01	143	143	1.04 (0.76 to 1.43)*	0.8*	—	—	NA	NA
Mean No:
Attempts to successful catheterisation	34	35	−0.59 (−1.82 to 0.65)	0.4	48	50	−0.4 (−0.61 to −0.19)	0.0002	—	—	NA	NA
Seconds to successful catheterisation	86	99	34.86 (−54.49 to 124.21)*	0.4*	48	50	209.00 (175.48 to 242.52)*	<0.0001*	—	—	NA	NA
Infants
No of failed catheter placements	13	16	1.23 (0.30 to 5.11)*	0.8*	—	—	NA	NA	—	—	NA	NA
No of complications from placement	13	16	0.82 (0.16 to 4.20)	0.8	—	—	NA	NA	—	—	NA	NA
Risk of failure on first attempt	—	—	NA	NA	—	—	NA	NA	—	—	NA	NA
Mean No of attempts to successful catheterisation	—	—	NA	NA	—	—	NA	NA	—	—	NA	NA
Mean No of seconds to successful catheterisation	13	16	138.00 (−114.72 to 390.72)*	0.3*	—	—	NA	NA	—	—	NA	NA

NA=not available. Relative risks <1 favour Doppler ultrasound guidance.

^*Outcome favours landmark method.