Pe. Nielsen et al., FETAL HEART-RATE CHANGES AFTER INTRATHECAL SUFENTANIL OR EPIDURAL BUPIVICAINE FOR LABOR ANALGESIA - INCIDENCE AND CLINICAL-SIGNIFICANCE, Anesthesia and analgesia, 83(4), 1996, pp. 742-746
The objective of this study was to compare the incidence of intrapartu
m fetal heart tracing CFHT) abnormalities and the obstetric outcome af
ter intrathecal sufentanil (ITS) versus epidural bupivacaine (EB). Dur
ing the period from April to September 1994, 129 patients who met incl
usion criteria were prospectively identified during labor at a single
university-affiliated hospital. Inclusion criteria included: singleton
, gestational age greater than or equal to 36 wk, and cephalic present
ation. In the ITS group, epidural anesthesia was not administered befo
re 60 min after ITS. Sixty-five consecutive ITS patients were compared
to 64 consecutive EB patients. Each FHT was reviewed independently by
two obstetricians blinded to the type of analgesia. The FHT character
istics evaluated included baseline rate, variability, and periodic cha
nges. No differences in the incidence of clinically significant FHT ab
normalities (recurrent late decelerations and/or bradycardia) were obs
erved between the two groups (ITS 21.5% versus EB 23.4%). The rates of
clinically significant FHT abnormalities in both groups was not diffe
rent when patients with hypotension and medical complications were exc
luded (16.9% vs 17.1%). In addition, equal rates of hypotension (18.5%
vs 17.2%) were noted between the groups. In both groups there was a s
ignificantly higher risk of cesarean section in patients whose previou
sly normal FHT became abnormal postanalgesia when compared to patients
without a new onset FHT abnormality (ITS 28.6% [4/14] versus 2.0% [1/
51], P < 0.01; EB 33.3% [5/15] versus 8.2% [4/49], P < 0.05). This inc
reased risk was associated with an increase in cesarean section for no
nreassuring FHT in both groups (ITS 14.3% [2/14] versus 0% [0/51], P =
0.04; EB 13.3% [2/15] versus 0% [0/49], P = 0.05). These results supp
ort the conclusion that the incidence of clinically significant FHT ab
normalities and hypotension is equivalent in patients receiving ITS wh
en compared to EB within the first hour of administration. During this
period, patients should have continuous FHT monitoring since a new on
set FHT abnormality unveils and alerts the physicians to a possible co
mpromised fetal condition and a corresponding increased risk of cesare
an section.