Background: Combined spinal-epidural technique for labor analgesia has been associated with fetal bradycardia and uterine hypertonia, when compared with epidural analgesia, possibly due to asymmetric decrease in catecholamine levels (epinephrine and norepinephrine) following neuraxial block. However, there are no studies comparing plasmatic catecholamine levels between those two techniques. This study aimed to compare spinal-epidural versus epidural regarding pre and post-analgesia catecholamine levels, uterine tone and fetal heart rate.~Methods: Randomized clinical trial with 47 laboring patients divided in two groups. Primary outcome was plasmatic catecholamine measurements before and after neuraxial block. Secondary outcomes were fetal heart rate changes, uterine hypertonia, hypotension episodes, pain relief and fetal outcomes.
Combined spinal-epidural (CSE) for labor analgesia has been associated with fetal bradycardia and uterine hypertonia, possibly due to asymmetric decrease in catecholamine levels, when compared with epidural analgesia (EP).