Between April and July in 2019, 342 pregnant women at two centers were evaluated for study participation. Of these, eighteen women did not meet the inclusion criteria, twenty women refused to participate, and four women were excluded for other reasons (Figure 1). Finally, three hundred patients were randomly 1:1:1 divided into group B (n=100), group FB (n=100) and group DB (n=100). All patients were well-blocked and no one needed additional analgesia during the surgery. In addition, all patients completed the assessment and received postoperative follow-up for 30 days.
The three groups were comparable with regard to baseline variables include age, height, weight, BMI, ASA physical status, gestational age. There were also no significant differences in perioperative variables including peak sensory level, duration of surgery, intraoperative fluid volume and blood loss (Table 1).
Table 1 Baseline and perioperative characteristics of parturients.
|
Group B (n=100)
|
Group FB (n=100)
|
Group DB (n=100)
|
P-Value
|
Age (yr.)
|
27 (26-29)
|
27 (25-30)
|
27 (25-29)
|
0.244
|
Height (cm)
|
161.5 (159.0-164.0)
|
162.0 (159.0-165.0)
|
160 (159.0-164.0)
|
0.284
|
Weight (kg)
|
72.3±6.2
|
72.8±5.3
|
72.6±5.3
|
0.771
|
BMI (kg/m2)
|
27.6±2.5
|
27.6±2.2
|
27.8±2.3
|
0.865
|
ASA physical status, n (%)
|
|
|
|
0.394
|
II
|
78 (78)
|
74 (74)
|
82 (82)
|
III
|
22 (22)
|
26 (26)
|
18 (18)
|
Gestational week (Wk.)
|
39 (38-39)
|
39 (38-39)
|
39 (38-39)
|
0.379
|
Peak sensory level
|
|
|
|
0.846
|
T2
|
2 (2)
|
1 (1)
|
1 (1)
|
T4
|
37 (37)
|
36 (36)
|
42 (42)
|
T6
|
61 (61)
|
63 (63)
|
57 (57)
|
Surgery duration (min)
|
41.0 (38.0-44.0)
|
41.0 (39.0-44.0)
|
41.0 (39.0-44.0)
|
0.746
|
Intraoperative fluid volume (ml)
|
1351.1±115.4
|
1361.6±97.8
|
1356.5±98.7
|
0.775
|
Intraoperative blood loss (ml)
|
421.2±36.0
|
424.5±30.5
|
423.1±30.7
|
0.773
|
Notes: Data are presented as n (%) or mean±SD or median (range); There were no significant differences among the three groups (P>0.05). Group B = bupivacaine group; Group FB = bupivacaine and fentanyl group; Group DB = bupivacaine and dexmedetomidine group.
Abbreviations: ASA= American Society of Anesthesiologists; BMI= Body Mass Index.
Compared with group B, the duration of sensory block in group FB and group DB were prolonged (108.4 min [95% Confidence Interval (CI)=104.6-112.3] in group B, and 122.0 min [95% CI=116.8-127.3] in group FB, 148.2 min [95% CI=145.3-151.1] in group DB) with statistical significance (P< 0.001) (Figure 2a). The duration of sensory block was significantly longer in group DB as compared with group FB (P< 0.001). Compared with group B, the onset time of sensory block (Figure 2b) in group DB was significantly shorter (12.2 s [95% CI=12.0-12.4]) in group DB, 14.5 s [95% CI=14.0-15.1] in group B, P< 0.001). Besides, compared with group B and group FB (Figure 2c), the onset time of motor block in group DB was statistically shorter (2.9 min [95% CI=2.7-3.0] in group DB, 3.1 min [95% CI=3.0-3.3] in group FB, 3.4 min [95% CI=3.2-3.6], in group B, P< 0.001). However, compared with group B (147.5 min [95% CI=143.7-151.3]), the duration of motor block (Figure 2d) in group DB (190.3 min [95% CI=186.9-193.8]) was prolonged by 43 min (P< 0.001), while that in group FB (154.9 min [95% CI=150.0-160.0]) was prolonged by 7 min (P= 0.038).
There were 11 items in ObsQoR-11 score Table (Table 2) to reflect the quality of postoperative recovery. The overall score of group DB (71.6 [95% CI=71.0-72.2]) was higher than that of group FB (61.5 [95% CI=60.8-62.2], P< 0.001) and group B (61.7 [95% CI=61.0-62.4], P< 0.001). All items showed recovery quality of group DB was significantly better than that of group B, except in terms of feeling dizzy (P> 0.05). Moreover, there was no statistical difference between group B and group FB about the ObsQoR-11 score.
Table 2 ObsQoR-11 of parturients.
|
Group B (n=100)
|
Group FB (n=100)
|
Group DB (n=100)
|
P-Value
|
Moderate pain
|
3.6±1.1
|
5.6±0.9*
|
7.3±1.2*#
|
<0.001
|
Severe pain
|
4.4±1.2
|
5.0±2.1*
|
7.5±1.6*#
|
<0.001
|
Nausea or vomiting
|
5.2±1.0
|
6.0±0.9*
|
7.3±1.2*#
|
<0.001
|
Feeling dizzy
|
6.3±1.2
|
5.0±0.8*
|
6.3±1.1#
|
<0.001
|
Shivering
|
3.7±0.8
|
5.3±0.7*
|
7.2±1.0*#
|
<0.001
|
Have been
comfortable
|
6.4±1.0
|
6.4±0.6
|
7.4±1.8*#
|
<0.001
|
Able to mobilize
independently
|
6.0±1.9
|
6.9±1.5*
|
6.9±1.1*
|
<0.001
|
Can hold baby
without assistance
|
6.9±0.8
|
8.2±0.7*
|
8.1±0.8*
|
<0.001
|
Can feed/nurse baby without assistance
|
6.6±0.7
|
7.0±1.0*
|
7.1±0.7*
|
<0.001
|
Can look after personal hygiene/toilet
|
5.6±0.9
|
6.3±0.6*
|
6.5±0.9*
|
<0.001
|
Feeling in control
|
7.0±0.8
|
7.3±1.0*
|
8.0±0.8*#
|
<0.001
|
Total
|
61.7±3.3
|
61.5±3.6
|
71.6±3.1*#
|
<0.001
|
Notes: Data are presented as mean±SD; Group B= bupivacaine group; Group FB= bupivacaine and fentanyl group; Group DB= bupivacaine and dexmedetomidine group; ObsQoR-11= obstetric quality of recovery-11 score, 0-10 in each term, where 0 = strongly agree and 10 = strongly disagree.
* P<0.017 Group DB or Group FB vs Group B; # P<0.017 Group DB vs Group FB.
Kaplan-Meier curve (Figure 3) showed that time to first analgesic request in group DB was longer than that in group FB and group B (log-rank P< 0.017). However, the sufentanil dosage within postoperative 24 h was not statistically different among three groups (P= 0.681).
The maternal hemodynamic characteristics including HR and mean arterial pressure (MAP) were found significantly higher in group DB than that in group B (Figure 4). The incidence of shivering (Table 3) was statistically lowered in group DB (3%) compared with group FB (18%) and group B (35%). The incidence of hypotension in group DB (33%) was higher than that in group FB (25%) and group B (28%) but with no statistical difference. There was no statistical difference for the dosage of ephedrine and atropine, intra-operative or post-operative nausea and vomiting among three groups.
Table 3 Maternal outcomes
|
Group B (n=100)
|
Group FB (n=100)
|
Group DB (n=100)
|
P-Value
|
Shivering, n (%)
|
35 (35)
|
18 (82) *
|
3 (97) *#
|
<0.001
|
Hypotension, n (%)
|
28 (28)
|
25 (25)
|
33 (33)
|
0.450
|
Dose of ephedrine (mg)
|
2.8±3.9
|
2.1±3.6
|
1.5±3.0
|
0.029
|
Nausea and/or vomiting, n (%)
|
11 (11)
|
17 (17)
|
14 (14)
|
0.474
|
Sufentanil consumption (μg)
|
106.0±9.2
|
105.5±7.7
|
105.0±7.8
|
0.681
|
Notes: Data are presented as n (%) or mean±SD; Group B = bupivacaine group; Group FB = bupivacaine and fentanyl group; Group DB = bupivacaine and dexmedetomidine group.
* P<0.017 Group DB or Group FB vs Group B; # P<0.017 Group DB vs Group FB.
For PH, PaO2, and PaCO2 in the umbilical artery and umbilical vein blood of newborn (Table 4), there were no statistically significant among the three groups. The concentration of DEX in umbilical artery and umbilical vein was too low to be detected by High-Performance Liquid Chromatography Tandem Mass Spectrometry. The mean values of Apgar scores at 1st and 5th min were all beyond 8, which also showed no statistical significance. Moreover, the 30-days follow-up did not show any new onset of back, buttock or leg pain or paresthesia.
Table 4 Neonatal outcomes.
|
Group B (n=100)
|
Group FB (n=100)
|
Group DB (n=100)
|
P-Value
|
Umbilical artery
|
|
|
|
|
pH
|
7.3±0.3
|
7.3±0.2
|
7.3±0.4
|
0.581
|
PaO2 (mmHg)
|
15.6±2.0
|
15.0±2.3
|
15.4±2.4
|
0.217
|
PaCO2 (mmHg)
|
49.9±3.4
|
49.8±4.0
|
50.4±4.6
|
0.545
|
Umbilical vein
|
|
|
|
|
pH
|
7.4±0.2
|
7.4±0.1
|
7.4±0.5
|
0.711
|
PaO2 (mmHg)
|
30.0±3.4
|
30.7±4.4
|
30.80±3.5
|
0.277
|
PaCO2 (mmHg)
|
42.6±3.2
|
41.6±3.8
|
42.0±3.2
|
0.111
|
Apgar score
|
|
|
|
|
1 min
|
8.7±0.5
|
8.7±0.5
|
8.7±0.5
|
0.752
|
5 min
|
9.7±0.5
|
9.7±0.4
|
9.7±0.5
|
0.809
|
Notes: Data are presented as mean±SD; Group B = bupivacaine group; Group FB = bupivacaine and fentanyl group; Group DB = bupivacaine and dexmedetomidine group.
* P<0.017 Group DB or Group FB vs Group B; # P<0.017 Group DB vs Group FB.