Plasmatic Catecholamines: Randomized Controlled Trial Comparing Epidural Versus Combined Spinal-epidural

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.

Inclusion criteria

Parturients aged over 18 years were included when they requested labor analgesia. The inclusion criteria were: patients between 37 and 42 gestational weeks, single pregnancy, in active labor (induced or spontaneous), requesting analgesia with 7 cm or less of cervical dilation. As it is a center that attends only high-risk pregnancies, ASA II or III

Exclusion criteria

Contraindications to interventions, either due to severe comorbidity or contraindication to neuraxial block; previous use of systemic opioids during labor, maternal amniotic infection or known fetal diseases