Association of free maternal and fetal ropivacaine after epidural analgesia for intrapartum caesarean delivery: a prospective observational trial

J Amian; C F Weber; M Sonntagbauer; L Messroghli; F Louwen; H Buxmann; A Paulke; K Zacharowski

doi:10.1016/j.ijoa.2024.103975

Association of free maternal and fetal ropivacaine after epidural analgesia for intrapartum caesarean delivery: a prospective observational trial

Int J Obstet Anesth. 2024 May:58:103975. doi: 10.1016/j.ijoa.2024.103975. Epub 2024 Jan 11.

Authors

J Amian¹, C F Weber², M Sonntagbauer³, L Messroghli⁴, F Louwen⁵, H Buxmann⁶, A Paulke⁷, K Zacharowski⁴

Affiliations

¹ Department of Anaesthesiology, Intensive Care and Emergency Medicine, Asklepios Clinics Hamburg, AK Wandsbek, Germany.
² Department of Anaesthesiology, Intensive Care and Emergency Medicine, Asklepios Clinics Hamburg, AK Wandsbek, Germany; Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Frankfurt, Goethe University, Frankfurt, Germany. Electronic address: c.weber@asklepios.com.
³ Department of Intensive Care Medicine, University Medical Center Hamburg-Eppendorf, Germany.
⁴ Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Frankfurt, Goethe University, Frankfurt, Germany.
⁵ Department of Gynaecology and Obstetrics, University Hospital Frankfurt, Goethe University, Frankfurt, Germany.
⁶ Department for Children and Adolescents, Division for Neonatology, University Hospital Frankfurt, Goethe University, Frankfurt, Germany.
⁷ Institute of Legal Medicine, University of Frankfurt, Goethe University, Frankfurt, Germany.

PMID: 38508960
DOI: 10.1016/j.ijoa.2024.103975

Abstract

Background: Ropivacaine is present in plasma in both protein-bound and free forms. The free form is responsible for the occurrence of toxic side effects. During obstetric epidural analgesia, free ropivacaine enters the fetal circulation depending on various factors. The aim of this study was to analyse a potential association between ropivacaine concentrations in maternal and fetal plasma and hence the extent of fetal exposure to ropivacaine.

Methods: In this prospective monocentre study, parturients who met the following criteria were included in the study: 1. epidural administration as part of obstetric anaesthesia, and 2. subsequent intrapartum caesarean delivery, which 3. was performed after an epidural bolus administration of ropivacaine within the existing epidural analgesia. Total and free ropivacaine concentrations were analysed in maternal blood at baseline, prior to epidural bolus administration for caesarean delivery, and in maternal and fetal (umbilical venous, oxygenated) blood at delivery. The results are presented as mean ± SD or median (25/75th percentile).

Results: We screened 128 parturients who went into labour at term and requested epidural analgesia, of whom 39 were ultimately included in the study. An intrapartum caesarean delivery was performed after the epidural application of 207 (166/276) mg ropivacaine during an epidural treatment period of 577 (360/1010) min. Total and free ropivacaine concentrations were 1402 ± 357 ng/ml and 53 ± 46 ng/ml, respectively, in maternal venous blood and 457 ± 243 ng/ml and 43 ± 27 ng/ml, respectively, in fetal blood. The maternal total and free ropivacaine concentrations were significantly correlated (r = 0.873; P < 0.0001).

Conclusion: The results of the present study suggest that determining the concentration of free ropivacaine in maternal blood may be a feasible option for estimating neonatal exposure to ropivacaine.

Keywords: Epidural analgesia; Local anaesthetic systemic toxicity; Obstetric anaesthesia; Ropivacaine.

Publication types

Observational Study

MeSH terms

Adult
Amides
Analgesia, Epidural* / methods
Analgesia, Obstetrical* / methods
Anesthetics, Local* / administration & dosage
Cesarean Section*
Female
Fetal Blood / chemistry
Humans
Infant, Newborn
Pregnancy
Prospective Studies
Ropivacaine*

Substances

Ropivacaine
Anesthetics, Local
Amides