General anaesthesia for obstetric surgery has distinct characteristics that may contribute towards a higher risk of accidental awareness during general anaesthesia. The primary aim of this study was to investigate the incidence, experience and psychological implications of unintended conscious awareness during general anaesthesia in obstetric patients. From May 2017 to August 2018, 3115 consenting patients receiving general anaesthesia for obstetric surgery in 72 hospitals in England were recruited to the study. Patients received three repetitions of standardised questioning over 30 days, with responses indicating memories during general anaesthesia that were verified using interviews and record interrogation. A total of 12 patients had certain/ probable or possible awareness, an incidence of 1 in 256 (95%CI 149-500) for all obstetric surgery. The incidence was 1 in 212 (95%CI 122-417) for caesarean section surgery. Distressing experiences were reported by seven (58.3%) patients, paralysis by five (41.7%) and paralysis with pain by two (16.7%). Accidental awareness occurred during induction and emergence in nine (75%) of the patients who reported awareness. Factors associated with accidental awareness during general anaesthesia were: high BMI (25-30 kg.m -2 ); low BMI (<18.5 kg.m -2 ); out-of-hours surgery; and use of ketamine or thiopental for induction. Standardised psychological impact scores at 30 days were significantly higher in awareness patients (median (IQR [range]) 15 (2.7-52.0 [2-56]) than in patients without awareness 3 (1-9 [0-64]), p = 0.010. Four patients had a provisional diagnosis of post-traumatic stress disorder. We conclude that direct postoperative questioning reveals high rates of accidental awareness during general anaesthesia for obstetric surgery, which has implications for anaesthetic practice, consent and follow-up.

Invasive arterial blood pressure monitoring is the standard of practice in terms of intraoperative blood pressure surveillance during liver transplantation. While this is an ideal, achieving reliable arterial access can be extremely challenging in the paediatric and neonatal population, repeated attempts at arterial cannulation are not without risk and alternative best practice means of haemodynamic monitoring are not clearly established. We describe a case of paediatric liver transplantation in a 3.9 kg infant that was complicated by difficult arterial cannulation, and we suggest that, when reasonable attempts to achieve intra-arterial access have failed, it is safe to proceed with paediatric liver transplantation with non-invasive blood pressure monitoring at 2 min intervals throughout the case and 1 min intervals at reperfusion. We recognise the unique technical challenges in paediatric liver transplant anaesthesia, and we advocate for the establishment of formal clinical training competencies in line with adult practice recommendations. We recommend the use of the Seldinger technique under ultrasound guidance as a first-line approach when difficult arterial cannulation is anticipated, and we discuss techniques for alternative approaches. We suggest that additional alternative means of haemodynamic monitoring should be considered when arterial access cannot be established; however, as no method demonstrates absolute superiority, one or a combination of techniques should be considered, depending on local availability and expertise.