Table 1 Demographic characteristics and anesthesia information

Age (years)

32.0 ± 4.7

32.9 ± 4.6

0.400

Height (cm)

160.4 ± 4.4

159.9 ± 4.8

0.659

Weight (kg)

67.9 ± 8.4

69.1 ± 7.6

0.491

Gestational age (d)

275 ± 9

274 ± 6

0.468

HR (bpm)^c

77 ± 6

85 ± 12

 < 0.001※

ΔHR (bpm)^a

 − 2 ± 5

 − 3 ± 7

0.532

Upper sensory block level (dermatome)

T6 (T4–T6)

T6 (T4–T6)

0.761

Bupivacaine dose (mL)

2.5 (2.5–2.7)

2.5 (2.5–2.5)

0.412

Intravascular fluid volume (mL)

389 ± 119

400 ± 88

0.627

Time from anesthesia to surgery start (min)

16.9 ± 7.3

16.6 ± 4.6

0.778

Time from surgery start to delivery (min)

5.4 ± 2.8

5.8 ± 3.6

0.513

Average phenylephrine dosage per patient (µg)

0 (0–0)

200 (100–300)

 < 0.001※

Patients requiring atropine [n (%)]

1 (3.2%)

4 (7.0%)

0.653

Maternal adverse reaction [n (%)]

1 (3.2%)

19^b (33.3%)

0.001※

 Nausea (n)

0

5

 Vomiting (n)

0

0

 Shortness of breath (n)

1

12

 Dizziness (n)

0

3