Journal Article

Snapshot of Obstetric National Audit and Research Project (SONAR1): aprotocol for an international observational cohort study

Hou, Bo, Carvalho, Brendan, Stanford, Susanna, Lucas, Nuala, Sultan, Pervez, O’Carroll, James, Eley, Victoria, Craig, Robert, Moonesinghe, S Ramani, Patel, Reshma, Hill, Samantha, Kua, Justin, El Sharawi, Nadir, O’Brien, Pat

2025

Overview

IntroductionCaesarean birth (CB) under neuraxial anaesthesia (NA) is the most performed inpatient operation in the UK. The incidence of intraoperative pain during caesarean delivery performed under neuraxial anaesthesia is unclear, with limited data that used patient-reported measures to investigate intraoperative pain. The short- and medium-term impacts on patients of this adverse event are unknown.Methods and analysisWe will undertake a multicentre, prospective observational cohort study to evaluate the incidence and impact of pain experienced by patients during CB performed under neuraxial anaesthesia. Routine audit data will be collected for all patients undergoing caesarean delivery for any indication during a 1 week window at participating hospitals within the UK and Queensland, Australia. The dataset will include patient, anaesthetic, obstetric and neonatal risk factors for intraoperative pain. Local investigators will then seek informed consent from patients either before or within 24 hours of delivery to record patient experience and patient-reported outcomes at 24 hours and 6 weeks postdelivery. Local investigators at participating hospitals will also complete a survey evaluating compliance with evidence-based structural standards at their sites. The patient characteristics, structures, processes and outcomes will be described. Inferential techniques will be used to evaluate the relationship between risk factors and postoperative outcomes.Ethics and disseminationThis study received ethical approval from the Leicester Health Research Authority and Care Research Wales, REC reference 24/EM/0084) on 24 May 24. The study received ethical approval from the Human Research Ethics Committee of Metro North Health in Australia on 25 March 2024 (REC Ref HREC/2024/MNHA/103767). The results of the study will be reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology statement. The results will be disseminated via conference presentations, peer-reviewed academic journals and reports prepared for patients, the public and policy makers.Trial registration numberISRCTN15269213.

• Publisher: British Medical Journal Publishing Group,BMJ Publishing Group LTD,BMJ Publishing Group
• Subject: Adult anaesthesia / Anaesthesia in obstetrics / Anesthesia, Obstetrical - adverse effects / Cesarean Section / Cesarean Section - adverse effects / Childbirth & labor / Clinical Protocols / Clinical Trial / Cohort analysis / Consent / Data collection / Epidural / Female / General anesthesia / Health Services Research / Humans / Multicenter Studies as Topic / Observational Studies as Topic / Obstetrics / Pain / Pain management / Patients / Postpartum period / Pregnancy / Prospective Studies / Protocol / Queensland - epidemiology / Research Design / Risk Factors / Surgery / United Kingdom - epidemiology