Corrigendum to 'Analgesia for Caesarean section' [BJA Education 22 (2022) 197-203].

[This corrects the article DOI: 10.1016/j.bjae.2021.12.008.].

What is the impact of dexamethasone on postoperative pain in adults undergoing general anaesthesia for elective abdominal surgery: a systematic review and meta-analysis.

BACKGROUND: Previous meta-analysis of heterogeneous surgical cohorts demonstrated reduction in postoperative pain with perioperative intravenous dexamethasone, but none have addressed adults undergoing elective abdominal surgery. The aim of this study was to determine the impact of intravenous perioperative dexamethasone on postoperative pain in adults undergoing elective abdominal surgery under general anaesthesia. METHODS: This review was prospectively registered on the international prospective register of systematic reviews (CRD42020176202). Electronic databases Medical Analysis and Retrieval System Online (MEDLINE), Exerpta Medica Database (EMBASE), (CINAHL) Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science and trial registries were searched to January 28 2021 for randomised controlled trials, comparing dexamethasone to placebo or alternative antiemetic, that reported pain. The primary outcome was pain score, and secondary outcomes were time to first analgesia, opioid requirements and time to post-anaesthesia care unit (PACU) discharge. RESULTS: Fifty-two studies (5768 participants) were included in the meta-analysis. Pain scores ≤ 4 hour (h) were reduced in patients who received dexamethasone at rest (mean difference (MD), - 0.54, 95% confidence interval (CI) - 0.72 to - 0.35, I2 = 81%) and on movement (MD - 0.42, 95% CI - 0.62 to - 0.22, I2 = 35). In the dexamethasone group, 4-24 h pain scores were less at rest (MD - 0.31, 95% CI - 0.47 to - 0.14, I2 = 96) and on movement (MD - 0.26, 95% CI - 0.39 to - 0.13, I2 = 29) and pain scores ≥ 24 h were reduced at rest (MD - 0.38, 95% CI - 0.52 to - 0.24, I2 = 88) and on movement (MD - 0.38, 95% CI - 0.65 to - 0.11, I2 = 71). Time to first analgesia (minutes) was increased (MD 22.92, 95% CI 11.09 to 34.75, I2 = 98), opioid requirements (mg oral morphine) decreased (MD - 6.66, 95% CI - 9.38 to - 3.93, I2 = 88) and no difference in time to PACU discharge (MD - 3.82, 95% CI - 10.87 to 3.23, I2 = 59%). CONCLUSIONS: Patients receiving dexamethasone had reduced pain scores, postoperative opioid requirements and longer time to first analgesia. Dexamethasone is an effective analgesic adjunct for patients undergoing abdominal surgery.

Incidence of accidental awareness during general anaesthesia in obstetrics: a multicentre, prospective cohort study.

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.

General anaesthetic and airway management practice for obstetric surgery in England: a prospective, multicentre observational study.

There are no current descriptions of general anaesthesia characteristics for obstetric surgery, despite recent changes to patient baseline characteristics and airway management guidelines. This analysis of data from the direct reporting of awareness in maternity patients' (DREAMY) study of accidental awareness during obstetric anaesthesia aimed to describe practice for obstetric general anaesthesia in England and compare with earlier surveys and best-practice recommendations. Consenting patients who received general anaesthesia for obstetric surgery in 72 hospitals from May 2017 to August 2018 were included. Baseline characteristics, airway management, anaesthetic techniques and major complications were collected. Descriptive analysis, binary logistic regression modelling and comparisons with earlier data were conducted. Data were collected from 3117 procedures, including 2554 (81.9%) caesarean deliveries. Thiopental was the induction drug in 1649 (52.9%) patients, compared with propofol in 1419 (45.5%). Suxamethonium was the neuromuscular blocking drug for tracheal intubation in 2631 (86.1%), compared with rocuronium in 367 (11.8%). Difficult tracheal intubation was reported in 1 in 19 (95%CI 1 in 16-22) and failed intubation in 1 in 312 (95%CI 1 in 169-667). Obese patients were over-represented compared with national baselines and associated with difficult, but not failed intubation. There was more evidence of change in practice for induction drugs (increased use of propofol) than neuromuscular blocking drugs (suxamethonium remains the most popular). There was evidence of improvement in practice, with increased monitoring and reversal of neuromuscular blockade (although this remains suboptimal). Despite a high risk of difficult intubation in this population, videolaryngoscopy was rarely used (1.9%).

A prospective, up-down sequential allocation study investigating the effectiveness of vital capacity breaths using high-flow nasal oxygenation versus a tight-fitting face mask to pre-oxygenate term pregnant women.

BACKGROUND: The role of high flow nasal oxygenation (HFNO) for pre-oxygenation before obstetric general anaesthesia remains unclear. This study aimed to determine the number of vital capacity breaths using HFNO required to pre-oxygenate 90% of parturients to an end-tidal oxygen concentration fraction (FETO2) of ≥0.90 (termed EN90). METHODS: Using up-down, sequential allocation trial design, volunteer term parturients undergoing caesarean delivery were investigated with HFNO with their mouth closed, followed by mouth open, and if FETO2 ≥0.90 was not achieved after a maximum of 20 vital capacity breaths, pre-oxygenation was attempted with a face mask. The primary outcome was the number of vital capacity breaths required using HFNO (mouth open and closed) to achieve EN90. Secondary outcomes included assessment of EN90 using mouth open versus mouth closed and face mask pre-oxygenation, maternal satisfaction and evaluation of fetal cardiotocography. RESULTS: Twenty women at term were recruited. Successful pre-oxygenation occurred in 4 (20%), 3 (15%) and 14 (70%) women with HFNO mouth closed, HFNO mouth open, and via face mask respectively. At up to 20 vital capacity breaths, face mask pre-oxygenation was more successful at achieving EN90 compared with both HFNO with a closed (P=0.006) or open (P=0.001) mouth. Closed mouth HFNO did not outperform open mouth pre-oxygenation. CONCLUSION: Face mask pre-oxygenation is more effective at achieving EN90 compared with to HFNO within a clinically acceptable number of vital capacity breaths. Further studies are needed to determine the role of HFNO in optimising the time before desaturation and for apnoeic oxygenation in term parturients.

Quadratus lumborum block vs. transversus abdominis plane block for caesarean delivery: a systematic review and network meta-analysis.

Caesarean delivery is the most commonly performed inpatient surgical procedure globally. Pain after caesarean delivery is moderate to severe if not adequately treated, and is a primary anaesthetic concern for patients. Transversus abdominis plane and quadratus lumborum blocks are fascial plane blocks that have the potential to improve analgesia following caesarean delivery. Although proponents of the quadratus lumborum block suggest that this technique may provide better analgesia compared with transversus abdominis plane block, there are limited data directly comparing these two techniques. We, therefore, performed a systematic review and network meta-analysis to compare transversus abdominis plane and quadratus lumborum block approaches, seeking randomised controlled trials comparing both techniques to each other, or to control, with or without intrathecal morphine. In all, 31 trials with 2188 patients were included and our primary outcome, the cumulative intravenous morphine equivalent consumption at 24 h, was reported in 12 trials. In the absence of intrathecal morphine, transversus abdominis plane and quadratus lumborum blocks were equivalent, and both were superior to control (moderate-quality evidence). In the presence of intrathecal morphine, no differences were found between control, transversus abdominis plane and quadratus lumborum blocks (moderate-quality evidence). Similar results were found for resting and active pain scores at 4-6 h, 8-12 h, 24 h and 36 h, although quadratus lumborum block was associated with lower pain scores at 36 h when compared with transversus abdominis plane block (very low-quality evidence). However, transversus abdominis plane block was associated with a reduced incidence of postoperative nausea and vomiting (moderate-quality evidence) and sedation when compared with inactive control following intrathecal morphine administration (low-quality evidence). There are insufficient data to draw definitive conclusions, but transversus abdominis plane and quadratus lumborum block appear to be superior to control in the absence of intrathecal morphine, but provide limited additional benefit over inactive control when intrathecal morphine is also used.

A cross-sectional study of immune seroconversion to SARS-CoV-2 in frontline maternity health professionals.

COVID-19, the respiratory disease caused by SARS-CoV-2, is thought to cause a milder illness in pregnancy with a greater proportion of asymptomatic carriers. This has important implications for the risk of patient-to-staff, staff-to-staff and staff-to-patient transmission among health professionals in maternity units. The aim of this study was to investigate the prevalence of previously undiagnosed SARS-CoV-2 infection in health professionals from two tertiary-level maternity units in London, UK, and to determine associations between healthcare workers' characteristics, reported symptoms and serological evidence of prior SARS-CoV-2 infection. In total, 200 anaesthetists, midwives and obstetricians, with no previously confirmed diagnosis of COVID-19, were tested for immune seroconversion using laboratory IgG assays. Comprehensive symptom and medical histories were also collected. Five out of 40 (12.5%; 95%CI 4.2-26.8%) anaesthetists, 7/52 (13.5%; 95%CI 5.6-25.8%) obstetricians and 17/108 (15.7%; 95%CI 9.5-24.0%) midwives were seropositive, with an overall total of 29/200 (14.5%; 95%CI 9.9-20.1%) of maternity healthcare workers testing positive for IgG antibodies against SARS-CoV-2. Of those who had seroconverted, 10/29 (35.5%) were completely asymptomatic. Fever or cough were only present in 6/29 (21%) and 10/29 (35%) respectively. Anosmia was the most common symptom occurring in 15/29 (52%) seropositive participants and was the only symptom that was predictive of positive seroconversion (OR 18; 95%CI 6-55). Of those who were seropositive, 59% had not self-isolated at any point and continued to provide patient care in the hospital setting. This is the largest study of baseline immune seroconversion in maternity healthcare workers conducted to date and reveals that one out of six were seropositive, of whom one out of three were asymptomatic. This has significant implications for the risk of occupational transmission of SARS-CoV-2 for both staff and patients in maternity units. Regular testing of staff, including asymptomatic staff should be considered to reduce transmission risk.

Gastric point-of-care ultrasound (PoCUS) during pregnancy and the postpartum period: a systematic review.

Personalised risk assessment of the likelihood of pulmonary aspiration is recommended for pregnant women undergoing general anaesthesia and gastric point-of-care ultrasound (PoCUS) may help to achieve this. Traditionally, risk assessment is based upon adherence to fasting times, but gastric emptying may vary during pregnancy and surgery often needs to be expedited. We systematically reviewed the evidence for gastric PoCUS up to August 2018 in pregnant and postpartum women to determine whether it can identify and quantify stomach contents, provide aspiration risk assessment via qualitative or quantitative means, and determine how gastric emptying is affected by pregnancy. Twenty-two articles comprising 1050 participants were included and studies were classified by qualitative or quantitative findings. The evidence suggests that gastric PoCUS is a reliable and feasible method of imaging the stomach in pregnancy in clinical practice. Qualitative assessment via the Perlas grading system can provide rapid assessment of gastric volume states. If fluid is visible, identification of patients at high risk of pulmonary aspiration requires measurement of antral cross-sectional area. Cut-off values of 608 mm2 and 960 mm2 are recommended in the semi-recumbent and right lateral semi-recumbent positions, respectively. Validated methods to quantify stomach volumes are available, however their usefulness is currently restricted to research. Gastric PoCUS also provides evidence that gastric emptying of ingested food is delayed by term pregnancy, labour and during the early postpartum period. However, the passage of fluids through the stomach appears unaffected throughout the peripartum period.

Novel coronavirus SARS-CoV-2 and COVID-19. Practice recommendations for obstetric anaesthesia: what we have learned thus far.

SARS-CoV-2 is a novel coronavirus causing a global pandemic of a severe respiratory illness known as COVID-19. To date, globally, over 30,000 people have died from this emerging disease. As clinicians and healthcare systems around the world are rapidly adapting to manage patients with COVID-19, limited data are emerging from different patient populations to support best-practice and improve outcomes. In this review, we present a summary of emerging data in the obstetric population and offer obstetric and anaesthetic clinicians around the world a set of evidence-driven, practice-based recommendations for the anaesthetic management of pregnant women with suspected or confirmed COVID-19.

Protocol for direct reporting of awareness in maternity patients (DREAMY): a prospective, multicentre cohort study of accidental awareness during general anaesthesia.

BACKGROUND: Accidental awareness during general anaesthesia (AAGA) is a complex and rare outcome to investigate in surgical patient populations, particularly obstetric patients. We report the protocol of the Direct Reporting of Awareness in Maternity patients (DREAMY) study, illustrating how the research was designed to address practical and methodological challenges for investigating AAGA in an obstetric cohort. METHODS: This is the trial protocol of a prospective, multicentre cohort study of patients undergoing obstetric surgery under general anaesthesia. Accidental awareness during general anaesthesia will be detected using three repetitions of standardised direct questioning over 30 days, with responses indicating memories during general anaesthesia verified using structured interviews. Reports will be adjudicated, then classified, in accordance with pre-defined and pre-validated structures, including the Michigan Awareness Classification tool. Quantitative data will be collected on general anaesthesia conduct for all participants. This descriptive study is being conducted in England and aims to recruit a minimum of 2015 patients. RESULTS: The DREAMY study was prospectively registered (ClinicalTrials.gov Identifier: NCT03100396) and ethical approval granted. Participant recruitment began in May 2017 and one year follow up concluded in August 2019. Publication of the results is anticipated in 2020. CONCLUSIONS: The DREAMY study will provide data on incidence, experience and implications of AAGA for obstetric patients, using a robust methodology that will reliably detect and translate subjective AAGA reports into objective outcomes. In addition, the study is expected to improve vigilance for AAGA in participating hospitals and encourage adoption of recommendations for support of patients experiencing AAGA.

Cardiac output measurements during high-risk Cesarean section using electrical bioreactance or arterial waveform analysis: assessment of agreement.

OBJECTIVE: Maternal hemodynamics change significantly during Cesarean section complicated by massive hemorrhage or severe hypertensive disease. Cardiac output (CO) monitoring aids early, goal-directed hemodynamic therapy. The aim of this study was to record hemodynamic changes observed during Cesarean section in pregnancies at high risk of hemodynamic instability, using invasive (LiDCOrapid™) and non-invasive (NICOM®) devices, and to assess agreement between the two devices in measuring CO. METHODS: Simultaneous intraoperative hemodynamic measurements were taken using the LiDCOrapid and NICOM devices, following standardized techniques, in women at high risk of hemodynamic instability undergoing Cesarean section. Agreement in CO measurements between the two devices was assessed using Bland-Altman plots and the agreement:tolerability index (ATI). Agreement analyses were performed for repeated measures in subjects, using centiles. RESULTS: From 10 women, 307 paired measurements were analyzed. Mean bias (defined as the mean difference in CO measurements between the LiDCOrapid and NICOM devices) was 3.05 (95% CI, 1.89 to 4.21) L/min. Limits of agreement ranged from -1.58 (95% CI, -4.47 to -0.14) to 7.68 (95% CI, 6.24 to 10.56) L/min. The resulting agreement interval was 9.26 L/min which returned an ATI of 2.3. CONCLUSIONS: There are large mean differences between CO measurements obtained during Cesarean section using the LiDCOrapid and NICOM hemodynamic monitors in pregnant women at high risk of hemodynamic instability, indicating that they should not be considered interchangeable clinically. There is an unacceptably low level of agreement (ATI > 2) in CO measurements between the devices, conferring a high risk of clinical misclassification during massive hemorrhage. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

Intrapartum epidural fixation methods: a randomised controlled trial of three different epidural catheter securement devices.

This randomised controlled trial investigated the efficacy of Epi-Fix(™) , LockIt Plus(®) and Tegaderm(™) as fixation devices for intrapartum epidural catheters. One hundred and sixty-five women requesting intrapartum epidural analgesia were randomised to receive different fixation devices to secure their epidural catheter. The amount of epidural catheter migration (measured to the nearest 0.5 cm) was analysed for three devices: Epi-Fix (n = 55); LockIt Plus (n = 54); and Tegaderm dressing (n = 51). Median (IQR [range]) catheter migration for Epi-Fix was 1.0 cm (0.0-2.0 [-2.0 to 9.5]), vs 0.0 cm (0.0-0.5 [-1.0 to 5.5]) for LockIt Plus and 0.5 cm (0.0-1.8 [-1.5 to 8.0]) for Tegaderm (p = 0.003). Thirty-eight (69.1%) epidural catheters secured with Epi-Fix migrated < 2.0 cm, compared with 49 (90.7%) with LockIt Plus and 40 (78.4%) with Tegaderm. Sixteen epidural catheters required resiting due to failure of analgesia of which 12 (75.0%) occurred in patients with epidural catheters that had migrated ≥ 2.0 cm. This study shows that intrapartum epidural catheters secured with the LockIt Plus device exhibit less catheter migration compared with fixation with Epi-Fix and Tegaderm.