BACKGROUND AND OBJECTIVES: The association of an opioid with a local anesthetic 
improves the quality of labor analgesia and reduces the risk of systemic 
toxicity of the local anesthetic. However, opioids are not devoid of side 
effects. The aim of this study was to compare the side effects of subarachnoid 
sufentanil associated with bupivacaine to those caused by epidural sufentanil 
associated with ropivacaine in the doses used in the Anesthesiology Department 
in pregnant women undergoing labor analgesia.
METHODS: Sixty pregnant women, ASA physical status I and II, ages between 15 and 
42 years, at term and with healthy fetuses, undergoing labor analgesia were 
enrolled in this study. They were randomly divided in two groups: G1 - combined 
spinal epidural anesthesia - 0.5% bupivacaine (2.5 mg) and subarachnoid 
sufentanil (5 microg); G2 - Epidural Block - 0.2% ropivacaine (20 mg), and 
epidural sufentanil (10 microg). Complementary doses of 0.2% ropivacaine (12 mg) 
were administered whenever necessary, and 1% ropivacaine (50 mg) was 
administered for labor resolution. Patients were evaluated after analgesia (M1) 
regarding the presence of hypotension, maternal bradycardia, pruritus, nausea, 
vomiting, respiratory depression, and sedation. They were also evaluated 
postoperatively (M2) regarding the presence of nausea, vomiting, pruritus, 
sedation, urinary retention, and pain. Newborns were evaluated by the Apgar 
score. The test t Student, Mann-Whitney test, and Chi-Square test were used for 
the statistical analysis.
RESULTS: Both groups were similar regarding age, weight, height, duration of 
labor after analgesia, Apgar score of the newborns, hypotension, maternal 
bradycardia, nausea, vomiting, pruritus, and urinary retention. Sedation was 
more frequent in patients in G2 at M1 (50%), which was statistically 
significant.
CONCLUSION: Subarachnoid or epidural sufentanil, in the doses used in this 
study, associated with local anesthetics, had the same effect on the duration of 
labor after analgesia and in the Apgar score of newborns. Sedation was the most 
frequent side effect in patients receiving epidural sufentanil.