BACKGROUND:Norepinephrine has recently been suggested to be as effective as phenylephrine for the prevention of hypotension after spinal anesthesia for cesarean delivery. Moreover, compared to phenylephrine, norepinephrine may be superior in maintaining heart rate (HR) and consequently, cardiac output (CO). A recent study demonstrated that norepinephrine given as a single intravenous bolus is approximately 13 times more potent than phenylephrine. However, it is uncertain whether this finding can be applied when these vasopressors are administered as infusions. Therefore, the optimum infusion rate of norepinephrine remains unknown. We aimed to determine the median effective dose (ED 50 ; defined as the rate of vasopressor infusion required to prevent spinal hypotension in 50% of subjects) of both drugs needed to maintain maternal systolic blood pressure within 20% of the baseline after spinal anesthesia for cesarean delivery and to derive the relative potency ratio. METHODS:Sixty healthy patients undergoing elective cesarean delivery with standardized spinal anesthesia were randomized into 2 groups. The first patient in group 1 received phenylephrine 1200 µg in normal saline 0.9% w/v 60 mL at 60 mL/h infusion rate (20 µg.min -1 ). The first patient in group 2 received norepinephrine 96 µg in normal saline 0.9% w/v 60 mL at 60 mL/h infusion rate (1.6 µg.min -1 ). Using up-down sequential allocation technique, the vasopressor dose for every subsequent patient was determined by the response in the previous patient. If effective, the next patient received a dose reduced by 150 µg of phenylephrine (2.5 µg.min -1 ) or 12 µg (0.2 µg.min -1 ) of norepinephrine. If ineffective, the dose for the next patient was increased by the same amount. The ED50s were determined according to the Dixon-Massey formula. Stroke volume (SV), HR, and CO were also measured. RESULTS:The ED 50 was 12.7 µg.min -1 (95% CI, 10.5-14.9) for phenylephrine and 1.01 µg.min -1 (95% CI, 0.84-1.18) for norepinephrine, giving a potency ratio of 12.6 (95% CI, 9.92-15.9). HR, SV, and CO did not differ between the groups. CONCLUSIONS:Norepinephrine is more potent than phenylephrine by a factor of approximately 13 when administered as infusion for equivalent maternal blood pressure control. Based on these findings, we recommend a variable rate prophylactic infusion of norepinephrine to be initiated at 1.9 to 3.8 µg.min - 1 for the management of hypotension during cesarean delivery under spinal anesthesia.

This review discusses neuropathies intrinsic to the process of labour itself, and those related to obstetric central neuraxial block. The focus is on lower limb pathology. A general approach to the evaluation of patients is provided, emphasising the importance of identifying time-critical conditions. Recent work has focussed on the incidence of postpartum neuropathy and confirms how rarely anaesthesia is a causative factor. International guidelines have been developed to minimise the risk of neuraxial-related injury, and to optimise both monitoring of patients with neuraxial block and investigation of abnormal findings. Obstetric anaesthetists are frequently asked to see patients with abnormal neurology in the postpartum period. A clear understanding of common pathology and the core tenets of evaluation and management are crucial for safe patient care. While rare, complications related to neuraxial anaesthesia can be devastating, and appropriate preventative measures should be employed to minimise risk.

Patients with tracheal stenosis may exhibit various signs and symptoms of respiratory compromise, depending on the degree of stenosis. Proper identification and prompt intervention are crucial to ensure the best possible outcomes for patients with tracheal stenosis.We present a case of a woman scheduled for an elective gynaecological surgery under general anaesthesia, where the ordinary tracheal tube was unable to progress in spite of Cormack-Lehane Grade I during direct laryngoscopy" The patient's medical history revealed that they had undergone endotra-cheal intubation during childhood for unknown reasons. The patient had a skin scar on the front of her neck and a hoarseness of voice since childhood. This case underscores the importance of a thorough medical history and physical examination in identifying and managing conditions such as a tracheal stenosis, which might go unnoticed and pose a significant risk to patient health.The successful intubation was achieved using a straw size tube, (Tritube)(R), with a small ID of 2.4 mm and an OD of 4.4 mm. The Tritube was inserted over a urinary guide wire and assisted with a fibreoptic scope and video-laryngoscope with a D blade. Despite the complexities of the situation the patient's airway was secured successfully in a timely manner.A neck scar should serve as a red flag for healthcare professionals to conduct further investigations into a patient's airway, even if the patient appears to be in good health.(c) 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

BACKGROUND Currently, performing an epidural blood patch (EBP) for postdural puncture headache (PDPH) remains a subjective clinical decision. An evidence-based protocol may be of value in identifying women at high risk of developing a severe PDPH. OBJECTIVE To investigate a potential correlation between the extent of CSF spread in the epidural space, as noted on Magnetic Resonance Imaging (MRI), and the likelihood of development of severe PDPH in obstetric patients. DESIGN A prospective double-blind quasi-observational study. SETTING Eight tertiary obstetric units, from NHS hospitals. PATIENTS Parturients with accidental dural puncture (ADP) underwent T1 and T2-weighted MRI scans of the brain and lumbar spine within 48 h after delivery. All women were followed up, daily, for 1 week. MAIN OUTCOME MEASURES For each woman, a PDPH severity score was calculated using a four-point Verbal Reporting Scale (none = 0, mild = 1, moderate = 2, severe = 3), with additional points awarded for visual, auditory and emetic symptoms. MRIs were reported by a neuroradiologist, blind to the patient details, using a predefined MRI score. RESULTS Twenty-two parturients were recruited; 86% (n=19) developed PDPH and 10 of these (53%) required an EBP. The median (range) time for the onset of PDPH was 24 (4 to 126) hours. The median (range) cumulative PDPH severity score was 10 (0 to 21), whereas, the median (range) MRI score was 2.5 (0 to 12). Spearman (r s) analysis identified a significant positive correlation (r s = 0.46; P = 0.024) between cumulative PDPH severity and MRI scores. Of all the radiological features identified in an MRI (lumbar dural shift, caudal brain displacement, epidural or intrathecal blood), the presence of intrathecal blood was most strongly correlated with PDPH severity (P = 0.043). CONCLUSION Following an ADP, the extent of CSF spread in the epidural space correlates with the severity of subsequent PDPH. CLINICAL TRIAL NUMBER AND REGISTRY URL ISRCTN14959004, https://www.isrctn.com/.

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.© 2021 Association of Anaesthetists. PMID: 33434945 Funding information This work was supported by: Obstetric Anaesthetists' Association,

Read the full review for this Faculty Opinions recommended article: Transversus Abdominis Plane Block With Liposomal Bupivacaine for Pain After Cesarean Delivery in a Multicenter, Randomized, Double-Blind, Controlled Trial.

Purpose of Review The aim of this article is to provide an overview of the current strategies for managing spinal-induced hypotension during cesarean delivery with a particular focus on the evidence guiding the use of vasopressors. Recent Findings Phenylephrine is currently regarded as the first-line vasopressor in the prevention and treatment of spinal-induced hypotension following evidence that supports a favorable effect on neonatal acid-base status as well as reduced incidences of nausea and vomiting when compared with ephedrine. Norepinephrine and metaraminol are also effective in the prevention and treatment of hypotension. Summary The current consensus for vasopressor use in the treatment of spinal-induced hypotension has been shaped by data gathered from studies involving healthy parturients undergoing elective cesarean deliveries. While these results cannot necessarily be extrapolated to high-risk patients with impaired cardiovascular function or evidence of fetal compromise, these studies may help inform vasopressor choice and establish recommendations for clinical practice.

Numerous techniques are in use to provide analgesia for labor, of which central neuraxial block is widely considered superior to non-neuraxial options. Central neuraxial techniques have evolved over many years to provide greater efficacy, safety and maternal satisfaction. This narrative review focuses on the literature relating to central neuraxial labor analgesia from the past 5 years, from November 2010 to October 2015. We discuss the evidence related to the various central neuraxial techniques used, the increasingly widespread use of ultrasound guidance and the evidence surrounding other novel methods of central neuraxial block insertion. The timing of institution of central neuraxial analgesia in labor is considered, as are the advances in maintenance regimens for labor analgesia.