Demographic data
Of the 266 recruited parturients, 28 were excluded, 238 were included in the study, and 235 successfully completed the study (Fig. 1). The parturient’ s demographics (age, weight, height, BMI) and baseline of the parameter (SBP, DBP, MAP, HR, CO, SV, SVR) were similar in all three groups (Table 1). There was no significant difference among the three groups. The median sensory block height at skin incision reached T4 in all three groups. The urine output, amount of blood loss, and the total volume of infusion were also similar in all groups. There was no significant difference in the duration of delivery, anesthesia, and operation, and the APGAR score among the three groups (Table 2).
Hemodynamic parameters
SBP in Phenylephrine Group were significantly higher than control group at T4,5 timepoints. T4: 109.8±19.09 vs 91.63±19.30 (P=0.002697); T5: 121.6±17.88 vs 106.0±15.66 (P=0.016501). SBP in Norepinephrine were also significantly higher than control group at T4,5 timepoints: T4: 120.3±16.60 vs 91.63±19.30 (P <0.000001); T5: 115.4±14.33 vs 106.0±15.66 (P=0.002804). DBP in Phenylephrine Group were significantly higher than control group at T3, 4,5,6 timepoints. T3: 71.2314.86± vs 63.21±15.44 (P=0.002474); T4: 67.30±14.72 vs 47.18±13.98 (P<0.000001); T5: 73.01±13.69 vs 65.26±12.91 (P=0.003311); T6: 71.39±11.99 vs 64.87±12.19 (P=0.020635). DBP in Norepinephrine significantly were higher than control group at T3,4 timepoints: T3: 71.80±14.86 vs 63.21±15.44 (P=0.001132); T4: 70.00±14.72 vs 47.1±13.98 (P <0.000001). MAP in Phenylephrine Group were significantly higher than control group at T4, 5 timepoints. T4: 78.52±15.61 vs 64.96±18.44 (P<0.000001); T5: 81.75±11.94 vs 73.01±14.02 (P=0.001162). MAP in Norepinephrine Group were also significantly higher than control group at T4, 5 timepoints. T4: 86.39±15.97 vs 64.96±18.44 (P<0.000001); T5: 87.95±15.78 vs 73.01±14.02 (P<0.000001). MAP in Phenylephrine Group was significantly higher than Norepinephrine group at T4 timepoints: T4: 78.52± vs 86.39±15.97 (P=0.009866). HR in Phenylephrine Group were significantly lower than control group at T3,4, 5,6,7,8 timepoints. T3: 85.27±16.87 vs 94.13± 17.43 (P=0.001804); T4: 79.31±19.55 vs 88.59±15.98 (P=0.001077); T5: 73.14±14.47 vs 85.12±14.46 (P=0.000009); T6: 70.41±14.74 vs 87.37±16.63 (P<0.000001). T7: 71.72±13.93 vs 88.67±15.56 (P<0.000001); T8: 79.08±15.88 vs 86.72±15.60 (P=0.007320); T9: 77.79 ±14.61vs 86.34±13.74 (P=0.002531); HR in Phenylephrine Group were significantly lower than Norepinephrine group at T5,6,7,8,9 timepoints. T5: 73.14±14.47 vs 81.54±14.91 (P=0.002737); T6: 70.41±14.74 vs 80.65±12.33 (P=0.000177); T7: 71.72±13.93 vs 86.73±14.32 (P<0.000001); T8: 79.08±15.88 vs 87.72±13.84 (P=0.002530); T9: 77.79±14.61 vs 86.41±13.94 (P=0.002530).(Fig. 2A). SVR in Phenylephrine Group significantly were higher than Control group at T4,5,6 timepoints. T4: 957.4±590.3 vs 590.1±273.7 (P<0.000001); T5: 1104±468.0 vs 789.4±376.2 (P=0.000002). T6: 1084±524.8 vs 825.2± 428.6 (P=0.000188); SVR in Norepinephrine Group was significantly higher than Control group at T4 timepoints. T4: 865.0±360.1 vs 590.1±±273.7 (P=0.000043) (Fig. 2B).
In control group, compare with T1(122.5±13.63), the SBP was significantly decreased at T3, 110.4±20.67 (P <0.0001), T4, 92.33±19.30 (P <0.0001),T5,106.9±15.66 (P <0.0001),T6, 105.9±15.30(P <0.0001), T7, 113.7±13.33(P=0.0050). In norepinephrine group, compare with T1, 120.6±12.38, the SBP was slightly decreased at T6, 110.4±19.57 (P=0.0014). In control group, compare with T1(68.49±13.05), the DBP was significantly decreased at T4, 47.18 ±13.98 (P <0.0001), In norepinephrine group, compare with T1(69.54±11.98), the DBP was significantly decreased T10, 60.42 ±16.50 (P =0.0011). In phenylephrine group, compare with T1, 87.41±11.57, the HR was slightly decreased at T5, 73.14±14.47 (P<0.0001). T6, 70.41±14.74(P<0.0001), T7, 71.72±13.93(P<0.0001), T8, 79.08±15.88, (P=0.0084); T9, 77.79±14.61, (P=0.0013); T10, 78.34±14.35, (P=0.0030). In norepinephrine group, compare with T1, 91.16±10.54, the HR was slightly decreased at T4, 83.19±15.07 (P=0.0034). T5, 81.54±14.91 (P=0.0002), T6, 80.65±12.33 (P<0.0001). In control group, compare with T1(81.34±16.03), the MAP was significantly decreased at T4, 64.96±18.44 (P <0.0001), T5, 73.01±14.02 (P =0.0029). In norepinephrine group, compare with T1, 81.59±18.59, the MAP was slightly decreased at T10, 72.15±14.79 (P=0.0016) (Fig. 2A). In control group, compare with T1(8.381±2.451), the CO was significantly increased at T9, 10.03±2.849 (P =0.0033). In phenylephrine group, compare with T1(7.868±2.578), the CO was significantly increased at T8, 10.52±4.104 (P<0.0001), T9, 9.965±2.742 (P=0.0003). In control group, compare with T1 95.41±25.33, the SV was significantly increased at T7, 110.3±31.56, (P =0.0026), T8, 104.9±30.35, (P =0.0010). In control group, compare with T1 970.8±344.9, the SVR was significantly increased at T3, 738.2±358.3, (P =0.0003), T4: 590.1± 273.7(P <0.0001); T7, 735.3±350.0, (P =0.0002); T8, 696.5±348.3, (P <0.0001);T9, 654.9±289.7, (P <0.0001);T10, 766.5±286.6, (P =0.0022) (Fig. 2B).
Blood gas indices
The UV PO2 in Phenylephrine, 30.50±6.24 (P=0.0143) and norepinephrine, 30.62±6.91 (P=0.0093) significantly higher and SO2 values in Phenylephrine , 64.68±13.79 (P=0.0109) and norepinephrine, 64.49±15.76 (P=0.0123) than those in the control group,27.44±7.54; 57.26±17.92 . However, the UV lactate level,1.91±0.43 in the phenylephrine group was significantly lower than those in the control, 2.30±0.84 (P=0.0003) and norepinephrine groups 2.25±0.66 (P=0.0106). The UV BE value showed no significant difference among the three groups. The phenylephrine group had a relatively higher UV pH value7.37±0.03 (P=0.0113) than those in the control7.36±0.04, but the mean pH value in all three groups was within the normal clinical range. The UV AG value was significantly lower in the phenylephrine group-0.02±2.73 than those in the control1.49±2.96 (P=0.0005) and norepinephrine groups1.84±1.72 (P=0.0001) (Fig. 3A).
Regarding the UA parameters, there was no significant difference in the PO2, SO2, PCO2, pH, AG, and glucose values among the three groups. The UA lactate level in the phenylephrine group2.05±0.61 (P=0.0038) was significantly lower than that in the control group,2.53±1.01. Only the norepinephrine group showed a positive UA BE value 0.24±1.86when compared with the other two groups-0.53±1.84, -0.38±1.53 (P=0.0039) (P=0.0056) (Fig. 3B).
Regarding the maternal PV parameters, there were no significant differences in any of the parameters among the three groups (Fig. 3C).
Comparison of adverse reactions among the three groups
In the phenylephrine group, bradycardia occurred in two cases, but there was no significant difference compared with the other two groups. Administering prophylactic norepinephrine and phenylephrine infusion significantly reduced the incidence of tachycardia, intro-operative hypotension, and nausea during CD as compared with the control group. Control group has higher intraoperative hypotension (phenylephrine vs. control group, χ2 value=21.04, df=1, P <0.0001; norepinephrine vs. control group, χ2 value=24.44, df=1, P <0.0001). The phenylephrine group has lower Nausea incidence (phenylephrine vs. control group, χ2 value=8.088, df=1, P = 0.0045). Control group has relatively higher Tachycardia (phenylephrine vs. control group, χ2 value=7.695, df=1, P = 0.0055; norepinephrine vs. control group, χ2 value=8.011, df=1, P = 0.0046). When compare each group, after Bonferroni adjust, the P value <0.0167 indicated the significant different. There was no significant difference in the incidence of vomiting, dizziness, difficulty breathing among the three groups (Table 3).