Plasmatic catecholamines after neuraxial labour analgesia: A randomised controlled trial comparing epidural versus combined spinal-epidural.

BACKGROUND: Combined spinal-epidural technique (CSE) for labour analgesia has been associated with fetal bradycardia and uterine hypertonia when compared with epidural analgesia (EA), possibly due to a decrease in epinephrine levels following neuraxial anaesthesia. However, there are no recent studies comparing plasmatic catecholamines levels between those two techniques. This study aimed to compare CSE versus EA regarding pre- and post-analgesia catecholamines levels, uterine tone and fetal heart rate.

PATIENTS AND METHODS: Randomised clinical trial with 47 labouring patients divided in two groups (CSE and EA). 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.

RESULTS: For CSE group, the median decrease of plasmatic epinephrine was 0 pg/mL [(-) 480-(+) 41] and for norepinephrine was -21 pg/mL [(-) 2507-(+) 94]. For EA group, the median decrease for epinephrine was 0 pg/mL [(-) 326-(+) 15] and for norepinephrine was -5 pg/mL [(-) 190-(+76)]. There were no differences between groups (p = 0.96 and p = 0.63 for epinephrine and norepinephrine, respectively). There were no differences for secondary outcomes.

CONCLUSIONS: There was no evidence of a more significant decrease of catecholamines with CSE when compared with EA. Catecholamines decrease theory may not be valid for modern labour analgesia techniques.