Preprocedure ultrasound imaging combined with palpation technique in epidural labor analgesia

Table 1 Patient baseline characteristics

All parturient	Combined group (n = 36)	Palpation group (n = 36)	P value
Age (yr)	29.25 ± 3.05	29.39 ± 2.72	0.248
Height (cm)	162.06 ± 4.65	162.08 ± 5.04	0.507
Weight (kg)	72.56 ± 10.2	69.33 ± 7.96	0.645
BMI (kg/m2)	27.61 ± 3.59	26.37 ± 2.67	0.213
ASA classification	2.0 ± 0.61	2.0 ± 0.53	0.985

All values are expressed as the mean ± SD. No significant differences between the two groups. ASA: American Society of Anesthesiologists; BMI: Body mass index.

Table 2 Duration of the procedure

All parturients	Combined group (n = 36)	Palpation group (n = 36)	P value
Total duration of the epidural procedure(s)	406.5 ± 92.15	380.0 ± 128.2	0.318
Time to perform epidural puncture and catheterization procedure (s)	320.62 ± 87.33	380.0 ± 128.2	0.0011
Time to perform ultrasound procedure (s)	85.83 ± 3.92	NA	NA

¹Significant statistical analyses. All values expressed as the mean ± SD. There was no significant difference in duration of the total epidural procedure between the two groups.

Table 3 Characteristics of the epidural procedure

All parturient	Combined group (n = 36)	Palpation group (n = 36)	P value
Number of needle passes	1.14 ± 0.42	1.72 ± 0.94	0.0011
Number of skin punctures	1.20 ± 0.12	1.25 ± 0.20	0.398
Success rate at the first needle pass	32 (88.89)	24 (66.67)	0.0451
Depth from skin to epidural space	4.40 ± 0.45	4.41 ± 0.52	0.965

¹Significant statistical analyses. Data are presented as the mean ± SD or n (%).

Table 4 Complications of the procedure

No. of patients with side effects	Combined group (n = 36)	Palpation group (n = 36)	P value
Vascular puncture	1	6	0.107
Dural puncture	1	1	0.754
Nerve irritation during the procedure	1	4	0.201
Backache during the procedure	1	2	0.555
Unilateral or patchy block	1	1	0.754
Failed block	1	2	0.555

Data are presented as a number. No significant difference between the two groups.