Anaesthesia for the parturient with obesity

Abstract

Learning objectivesBy reading this article, you should be able to:•Discuss the preoperative considerations for the parturient with obesity.•Describe the neuraxial and non-neuraxial options for delivering analgesia and anaesthesia in the peripartum period.•Discuss the complications associated with obesity in pregnancy.Key points•Maternal obesity is increasing worldwide and is associated with adverse outcomes for both mother and baby.•Multidisciplinary team involvement is vital for managing the parturient with obesity.•Neuraxial analgesia should be offered early in labour.•Continuous neuraxial techniques are optimal for Caesarean delivery.•General anaesthesia poses significant risk in these high-risk patients. By reading this article, you should be able to:•Discuss the preoperative considerations for the parturient with obesity.•Describe the neuraxial and non-neuraxial options for delivering analgesia and anaesthesia in the peripartum period.•Discuss the complications associated with obesity in pregnancy. •Maternal obesity is increasing worldwide and is associated with adverse outcomes for both mother and baby.•Multidisciplinary team involvement is vital for managing the parturient with obesity.•Neuraxial analgesia should be offered early in labour.•Continuous neuraxial techniques are optimal for Caesarean delivery.•General anaesthesia poses significant risk in these high-risk patients. Obesity is a worldwide health problem; its prevalence is increasing in all age groups, including those of childbearing age. Currently in the UK, 23.1% of the antenatal population is obese, with prevalence being highest amongst minority ethnic groups and those from low socio-economic background.1Denison F.C. Aedla N.R. Keag O. et al.Care of women with obesity in pregnancy: green-top guideline no. 72.BJOG. 2019; 126: 62-106Crossref Scopus (63) Google Scholar,2Centre for Maternal and Child EnquiriesMaternal obesity in the UK: findings from a national project. Report for healthcare professionals, London2010Google Scholar Similar data have been reported from the USA and Australia.3Sullivan E.A. Dickinson J.E. Vaughan G.A. et al.Maternal super-obesity and perinatal outcomes in Australia: a national population-based cohort study.BMC Pregnancy Childbirth. 2015; 15: 322Crossref PubMed Scopus (32) Google Scholar Although once thought to be a disease of high-income countries, the rate of maternal obesity is also increasing in countries, such as India, Bangladesh and Nepal, highlighting the global nature of the disease.4Balarajan Y. Villamor E. Nationally representative surveys show recent increases in the prevalence of overweight and obesity among women of reproductive age in Bangladesh, Nepal, and India.J Nutr. 2009; 139: 2139-2144Crossref PubMed Scopus (102) Google Scholar These rising rates of obesity are a significant concern for obstetric units, as they are associated with adverse outcomes for both mother and baby. Table 1 summarises the key maternal and fetal complications associated with obesity. Most worrying is the association between maternal obesity and maternal mortality. In the UK, the Confidential Enquiry into Maternal Deaths (CEMD) reports since 2003 have consistently identified that obesity is over-represented in parturients who died from direct causes. In the most recent triennial CEMD report (2015–2017), 34% of women who died were obese and 24% were overweight.5Knight M. Bunch K. Tuffnell D. Jayakody H. Shakespeare J. Kotnis R. Saving lives, improving mothers’ care: lessons learned to inform maternity care from the UK and Ireland Confidential Enquiries into Maternal Deaths and Morbidity 2015-17. National Perinatal Epidemiology Unit, University of Oxford, Oxford2019https://www.npeu.ox.ac.uk/assets/downloads/mbrrace-uk/reports/MBRRACE-UK%20Maternal%20Report%202019%20-%20WEB%20VERSION.pdfDate accessed: February 6, 2021Google Scholar Although the overall contribution of anaesthesia to maternal death remains low, obesity is a risk factor for anaesthesia-related maternal morbidity and mortality in CEMD reports since 2010. It is therefore not surprising that current guidance for managing pregnant patients with obesity advocates enhanced antepartum monitoring and detailed delivery planning with multidisciplinary involvement. As such, it is essential that all anaesthetists working on delivery units are able to anticipate and manage the challenges associated with these high-risk patients.Table 1Maternal and neonatal complications associated with obesity.Maternal complicationsNeonatal complicationsGestational diabetesPreterm deliveryGestational hypertension and pre-eclampsiaMiscarriageObstructive sleep apnoeaSmall for gestational ageCardiovascular diseaseLarge for gestational ageThromboembolismMacrosomiaInfection and sepsisStillbirthInstrumental deliveryShoulder dystociaFailed instrumental deliveryNeural tube defectsCaesarean deliveryNeonatal deathPostpartum haemorrhageNeonatal ICU admissionLonger hospital stay Open table in a new tab Obesity is defined as an excessive or abnormal fat accumulation posing significant health risk. The WHO uses BMI to classify degree of obesity. A BMI between 18.9 and 24.9 kg m−2 is normal, BMI 25–29.99 kg m−2 is overweight and BMI >30 kg m−2 is obese. Obesity is further subclassified as Class 1 (BMI 30–34.9 kg m−2), Class 2 (BMI 35–39.9 kg m−2) and Class 3 (BMI >40 kg m−2). Further definitions for Class 3 obesity include morbid obesity (BMI 40–49.9 kg m−2), super obesity (BMI 50–59.9 kg m−2) and super-super obesity (BMI >60 kg m−2). There is a lack of consensus on optimal weight gain during pregnancy, and current guidance suggests focusing on a healthy diet may be more applicable than targeted weight gains.1Denison F.C. Aedla N.R. Keag O. et al.Care of women with obesity in pregnancy: green-top guideline no. 72.BJOG. 2019; 126: 62-106Crossref Scopus (63) Google Scholar The anatomical and physiological changes of pregnancy coupled with those of obesity make these parturients a particularly high-risk population. As such, the Royal College of Obstetricians and Gynaecologists recommends that women with BMI >40 kg m−2 should have a formal consultation with an anaesthetist in the third trimester of pregnancy.1Denison F.C. Aedla N.R. Keag O. et al.Care of women with obesity in pregnancy: green-top guideline no. 72.BJOG. 2019; 126: 62-106Crossref Scopus (63) Google Scholar Ideally, the consultation should be conducted early in the third trimester to allow time for further investigations and optimisation before delivery, if needed. A senior anaesthetist should conduct the preoperative assessment, and the anaesthesia plan for delivery should be clearly documented in the patient's notes. Table 2 shows the preoperative considerations for the anaesthetist in parturients who are obese.Table 2Preoperative considerations for parturients with obesity.SystemSpecific considerationsAirwayIncreased risk of difficult intubation in the parturient with obesity•Detailed examination, including Mallampati score, thyromental distance, mouth opening and jaw protrusionRespiratoryIncreased risk of OSA•Detailed history exploring features of OSA or its sequelae•Referral for sleep studies and opinion from pulmonologist if deemed appropriateCardiovascularIncreased risk of cardiovascular disease (hypertension, ischaemic heart disease and cardiomyopathy)•Focused cardiac history: chest pain, palpitations, reduced exercise tolerance, orthopnoea and paroxysmal nocturnal dyspnoea•Focused examination: pedal oedema, bibasal crackles and raised jugular venous pressure•Low threshold for ECG, echocardiogram and cardiology referral for optimisationGastrointestinalIncreased risk of aspiration associated with hiatus hernia and reflux disease•Appropriate starvation times before elective surgery; consider clear fluids only in labour•Premedication with H2 antagonist and antacid•Consider premedication with metoclopramide for prokinesisMetabolicIncreased risk of pre-existing insulin resistance and gestational diabetes•History of microvascular and macrovascular complications of insulin resistance•Referral to endocrinologist for optimisation Open table in a new tab The consultation should include a standard history with specific attention to screening for potential comorbidities associated with obesity, such as obstructive sleep apnoea (OSA), hypertension, cardiac disease, gastro-oesophageal reflux and diabetes. A detailed physical examination of the airway, respiratory and cardiovascular systems should also be conducted. Some clinical features of cardiorespiratory disease, such as dyspnoea and pedal oedema, may be difficult to distinguish from changes associated with pregnancy, and there should always be low threshold for ordering an ECG and transthoracic echocardiogram. The spine should also be examined to identify patients in whom neuraxial placement could be challenging, and it may be beneficial to use ultrasound (US) before any neuraxial procedures. The consultation also provides an opportunity for patient education and counselling. Patients should be informed of their risk for dysfunctional labour and higher Caesarean delivery (CD) rate. As a consequence, they should be advised to have an epidural catheter sited early in labour for two main reasons. Firstly, epidural catheter placement is likely to be challenging, requiring multiple attempts, and may be more successful when the patient is calm and compliant with positioning before strong contraction pain commences. Secondly, patients with obesity are at higher risk of epidural catheter failure compared with women of normal BMI.6Uyl N. de Jonge E. Uyl-de Groot C. van der Marel C. Duvekot J. Difficult epidural placement in obese and non-obese pregnant women: a systematic review and meta-analysis.Int J Obstet Anesth. 2019; 40: 52-61Abstract Full Text Full Text PDF PubMed Scopus (11) Google Scholar Early placement allows time to ensure that the catheter is working adequately should assisted or operative delivery be needed, and therefore reduces the risk of needing GA in a parturient with a potentially difficult airway. Patients should also be educated about the potential need to use US to assist with i.v. and epidural catheter placement, and possible need for arterial line placement for arterial blood pressure monitoring. The anaesthetic consultation should not only highlight to the patient that she is high risk, but also provide reassurance that the modifications in her anaesthetic care are being taken to maximise safety for her and her baby. Women with obesity should only have their baby delivered in obstetric units that have services adequate to meet their potentially complex care needs. All maternity units should regularly assess their capabilities for managing women with BMI >30 kg m−2, including staffing, equipment and accessibility. In the UK, women with BMI >35 kg m−2 should be delivered in a consultant-led unit with appropriate anaesthesia and neonatal services.1Denison F.C. Aedla N.R. Keag O. et al.Care of women with obesity in pregnancy: green-top guideline no. 72.BJOG. 2019; 126: 62-106Crossref Scopus (63) Google Scholar It is important that delivery units have adequate staffing with advanced clinical training to manage these patients throughout the peripartum period. Caregivers should attend manual handling courses and use transfer equipment (patient lifts and hover air mattress) wherever possible to minimise risk to patients and staff. Specialised anaesthetic equipment should be readily available, such as difficult airway equipment, US machines, long spinal and epidural needles, appropriately sized non-invasive blood pressure (NIBP) cuffs and invasive arterial monitoring. Invasive arterial monitoring should be directed by the patient's comorbidities and possible problems affecting the accuracy and reliability of NIBP measurements. Poor fitting of NIBP cuffs in women who are obese occurs because of problems with size and the conical shape of the upper arm, which can cause overestimation of the blood pressure and discomfort for the patient. An NIBP cuff on the forearm may be used if it is not possible to use an appropriately sized blood pressure cuff on the upper arm.7Eley V.A. Christensen R. Kumar S. Callaway L.K. A review of blood pressure measurement in obese pregnant women.Int J Obstet Anesth. 2018; 35: 64-74Abstract Full Text Full Text PDF PubMed Scopus (7) Google Scholar This method of NIBP measurement will provide consistent blood pressures that are correlated with upper arm pressures, albeit slightly higher. Venous access might be challenging, necessitating US-guided peripheral i.v. catheter placement. Central venous access may also need to be established if peripheral access is difficult or other comorbidities are present. Long spinal and epidural needles should also be available. Institutions managing patients who are obese for delivery should have operating tables, labour beds and wheelchairs with higher weight-bearing capacities. Similarly, appropriately sized gowns, pneumatic compression devices and stockings should be routinely available. Even with appropriate equipment, transporting women with BMI >50 kg m−2 to the operating theatre in the event of an emergency can be challenging. Continuous communication with the obstetric team is needed to identify women likely to need operative delivery early, so patients can be moved in a timely manner. Special consideration may also be given to labouring those patients in an operating theatre, if feasible, as a means to reduce decision-to-delivery times. Neuraxial techniques are the ideal option for labour analgesia in parturients with obesity. They provide the most effective analgesia with the fewest adverse effects for both mother and baby. Furthermore, with neuraxial techniques, labour analgesia can be readily converted to surgical anaesthesia should the need for CD arise, therefore avoiding the need for GA with its associated risks in patients who are obese. Epidural catheter placement or modification of the technique (combined spinal–epidural [CSE] and dural puncture epidural [DPE]) remains the most common mode for delivering neuraxial analgesia in obese parturients. However, intrathecal catheters (ITCs) can be considered in certain situations. Placement of epidural catheters can be notoriously challenging in these patients because of the increased amount of subcutaneous tissue that makes anatomical landmarks difficult to palpate. The sitting, flexed position is preferred, as it allows better appreciation of the midline and reduces the distance from the skin to the epidural space compared with the lateral position.8D’Alonzo R.C. White W.D. Schultz J.R. Jaklitsch P.M. Habib A.S. Ethnicity and the distance to the epidural space in parturients.Reg Anesth Pain Med. 2008; 33: 24-29Crossref PubMed Google Scholar Using US before the procedure can also help localise the midline and provide estimation of the depth to the epidural space. In addition, it has also been shown to reduce the number of attempts and number of needle redirections for successful epidural catheter placement. It is therefore important that anaesthetists managing labour units are adequately trained and skilled at using US for labour epidural catheter placement. In extreme circumstances, a standard-length epidural needle may not be sufficient, and a longer needle will be required to identify the epidural space. Nonetheless, it is advisable to use a standard-length epidural needle for the first attempt, as longer needles might be more challenging to control with the potential for causing complications. Continuous communication with the patient during epidural catheter placement is vital: it educates the patient about optimal positioning and alleviates her anxiety. In addition, feedback from the patient can help the anaesthetist redirect the needle towards the midline if encountering difficulties. Once the epidural catheter has been placed, it is important that it is secured appropriately to reduce migration and dislodgement. The patient should be asked to move from the sitting flexed position to the sitting upright position before securing the catheter with tape. Changing position from flexed to sitting causes redistribution of subcutaneous tissue, and the catheter frequently appears to be drawn inwards. Securing the catheter to the skin before position change may risk leaving an inadequate depth or having the catheter pulled out of the epidural space.9Hamilton C.L. Riley E.T. Cohen S.E. Changes in the position of epidural catheters associated with patient movement.Anesthesiology. 1997; 86 (discussion 29A): 778-784Crossref PubMed Scopus (86) Google Scholar The technical difficulty of epidural catheter placement in patients with obesity is associated with increased risk of accidental dural puncture (ADP) compared with patients of normal BMI (4% vs 1%).10Peralta F. Higgins N. Lange E. Wong C.A. McCarthy R.J. The relationship of body mass index with the incidence of postdural puncture headache in parturients.Anesth Analg. 2015; 121: 451-456Crossref PubMed Scopus (62) Google Scholar However, the impact of BMI on developing postdural puncture headache (PDPH) in the event of ADP is conflicting. Whilst some studies have shown that the risk of developing PDPH is reduced in parturients with high BMI, other studies have not confirmed this finding. Overall, the evidence suggests that high BMI may offer some protection against developing PDPH, with the effect probably being most noticeable in parturients with BMI >50 kg m−2.11Franz A.M. Jia S.Y. Bahnson H.T. Goel A. Habib A.S. The effect of second-stage pushing and body mass index on postdural puncture headache.J Clin Anesth. 2017; 37: 77-81Crossref PubMed Scopus (14) Google Scholar Furthermore, even though the risk of developing PDPH may be reduced in women who are obese, the incidence of developing PDPH still remains considerable with rates of at least 40–45% being reported.12Taylor C.R. Dominguez J.E. Habib A.S. Obesity and obstetric anesthesia: current insights.Local Reg Anesth. 2019; 12: 111-124Crossref PubMed Scopus (13) Google Scholar In addition, whilst pushing during the second stage of labour increases the risk of PDPH and women with obesity might be less likely to push given the high CD rate, data suggest that high BMI may reduce the risk of PDPH even after controlling for pushing.10Peralta F. Higgins N. Lange E. Wong C.A. McCarthy R.J. The relationship of body mass index with the incidence of postdural puncture headache in parturients.Anesth Analg. 2015; 121: 451-456Crossref PubMed Scopus (62) Google Scholar,11Franz A.M. Jia S.Y. Bahnson H.T. Goel A. Habib A.S. The effect of second-stage pushing and body mass index on postdural puncture headache.J Clin Anesth. 2017; 37: 77-81Crossref PubMed Scopus (14) Google Scholar There are no studies specifically comparing traditional epidural to CSE technique for labour analgesia in parturients who are obese. A labour CSE technique provides fast, reliable analgesia without sacral sparing. In addition, when epidural catheters are placed as part of a CSE technique, they have lower failure rates compared with traditional epidural techniques.13Lee S. Lew E. Lim Y. Sia A.T. Failure of augmentation of labor epidural analgesia for intrapartum cesarean delivery: a retrospective review.Anesth Analg. 2009; 108: 252-254Crossref PubMed Scopus (53) Google Scholar,14Pan P.H. Bogard T.D. Owen M.D. Incidence and characteristics of failures in obstetric neuraxial analgesia and anesthesia: a retrospective analysis of 19,259 deliveries.Int J Obstet Anesth. 2004; 13: 227-233Abstract Full Text Full Text PDF PubMed Scopus (269) Google Scholar This has been attributed to the confirmation of CSF return when using a needle through a needle technique that provides some reassurance that the epidural space has been located and that the epidural catheter is likely to be midline. Similarly, a DPE technique can be used. In the DPE technique, the epidural space is identified, the dura is punctured without giving intrathecal medications and an epidural catheter is threaded in the routine manner. When compared with traditional epidural technique for labour analgesia, DPE may be associated with better sacral spread and less unilateral or patchy block.15Chau A. Bibbo C. Huang C.C. et al.Dural puncture epidural technique improves labor analgesia quality with fewer side effects compared with epidural and combined spinal epidural techniques: a randomized clinical trial.Anesth Analg. 2017; 124: 560-569Crossref PubMed Scopus (74) Google Scholar It is presumed that the dural hole acts as a conduit, allowing delivery of small amounts of local anaesthetic into the intrathecal space from the epidural space. Furthermore, similar to the CSE technique, return of CSF with dural puncture helps to confirm correct and midline placement, therefore increasing the chances for a successful block. Although the DPE technique has not been specifically investigated in patients with obesity, it would seem logical that the perceived benefits of the technique may prove advantageous. Once an epidural catheter has been sited, delivery of local anaesthetic mixtures through the epidural catheter can be achieved with continuous epidural infusion, patient-controlled epidural analgesia or programed intermittent epidural bolus. These maintenance strategies have not been compared in parturients with obesity, and local anaesthetic delivery should be commenced as per departmental protocols. An ITC can also be placed to provide continuous labour analgesia. Whilst placement of an ITC is usually only considered after inadvertent ADP, elective placement in women with BMI >50 kg m−2 may be an option for neuraxial analgesia, especially in those patients with clinical features suggesting potential difficult airway management. Intrathecal catheters allow safe, reliable delivery of labour analgesia and can be carefully extended to provide surgical anaesthesia should CD be needed, thereby reducing the particular risks of GA in the labouring patient with obesity. However, managing ITCs requires specific training, and communication with all members of the labour and delivery team is vital to avoid potential drug errors. Ideally, departments should have protocols in place to safely manage an ITC. Furthermore, it is important to note that there is at least a 40–50% risk of PDPH associated with their use. Irrespective of the neuraxial technique chosen, patients should be routinely reassessed to allow for early detection of poorly functioning catheters and timely replacement if needed. A well-functioning neuraxial catheter for labour analgesia ultimately mitigates the risk for GA should CD be needed, and also improves patient satisfaction. In the event that neuraxial analgesia is contraindicated or not possible, non-neuraxial options for analgesia should be offered. Inhaled nitrous oxide and oxygen mixtures are routinely available in the UK and can provide some analgesia, albeit inferior to neuraxial options, without adverse effects on mother and baby. Opioids should be judiciously used in parturients with obesity because the incidence of OSA and the risk of respiratory depression are both increased. Alternative therapies, such as acupuncture and transcutaneous electrical nerve stimulation, could also be considered, although the effectiveness of these therapies is unproved in general and has not been specifically investigated in managing patients who are obese. Irrespective of whether neuraxial anaesthesia or GA has been chosen as the primary anaesthetic, all patients with obesity should be placed in the ‘ramped position’ with left uterine displacement. This position can be achieved by using commercially available devices, such as a Troop Elevation Pillow, (Mercury Medical, Clearwater, FL, USA) or by placing blankets under the upper body and shoulders so the head is above the chest. This position will improve respiratory mechanics, but more importantly, it has been shown to improve the laryngeal view compared with the traditional 'sniffing' position should intubation be needed. Special attention should also be given to ensuring pressure points are protected, as the risk of perioperative nerve injuries is higher in patients with obesity. Retraction of the panniculus may be needed for adequate exposure for surgery especially when Pfannenstiel incision is used. Many obstetricians choose to tape the panniculus in the cephalad direction. However, commercially available self-retaining retractors, such as the traxi Panniculus Retractor (Clinical Innovations, Salt Lake City, Utah, USA), can also be used. Cephalad retraction is associated with aortocaval compression that can lead to maternal hypotension and non-reassuring fetal heart tones.16Hodgkinson R. Husain F.J. Caesarean section associated with gross obesity.Br J Anaesth. 1980; 52: 919-923Abstract Full Text PDF PubMed Scopus (37) Google Scholar Anecdotally, it also causes some difficulty in breathing and may increase the cephalad spread of spinal block. Therefore, vigilant monitoring whilst the retraction is being instituted is needed. As an alternative, vertical angled suspension of the panniculus has also been suggested to reduce the risks of hypotension and respiratory compromise associated with cephalad retraction. Obesity is a risk factor for surgical site infection after CD. Whilst some institutions give cefazolin 3 g to obstetric patients weighing >120 kg (rather than the standard dose of 2 g), the benefit of this increased dose is unclear and evidence is conflicting.17Committee on Practice Bulletins-ObstetricsACOG practice bulletin no. 199: use of prophylactic antibiotics in labor and delivery.Obstet Gynecol. 2018; 132: e103-e119Crossref PubMed Scopus (82) Google Scholar Re-dosing cefazolin at 2 h and giving cephalexin and metronidazole for 48 h postpartum have been suggested to maintain appropriate tissue concentrations and reduce surgical site infection.18Eley V.A. Christensen R. Ryan R. et al.Prophylactic cefazolin dosing in women with body mass index >35 kg·m–2 undergoing Cesarean delivery: a pharmacokinetic study of plasma and interstitial fluid.Anesth Analg. 2020; 131: 199-207Crossref PubMed Scopus (10) Google Scholar,19Valent A.M. DeArmond C. Houston J.M. et al.Effect of post-Cesarean delivery oral cephalexin and metronidazole on surgical site infection among obese women: a randomized clinical trial.JAMA. 2017; 318: 1026-1034Crossref PubMed Scopus (38) Google Scholar However, further studies validating this practice are needed before routine use can be recommended. Neuraxial anaesthesia is always preferred in patients with obesity presenting for CD unless contraindicated. Choice of neuraxial anaesthetic technique will depend on urgency of case, airway examination and surgical plan. Single-shot spinal anaesthesia can deliver fast onset, reliable anaesthesia and may be a viable option in patients with reassuring airway examination and without cardiopulmonary compromise. However, the finite duration of the spinal block limits its use in parturients with morbid obesity, when extra time for patient positioning and extra time from incision to delivery are expected. If the spinal block begins to regress before surgery has ended, GA with all its inherent risks may be required. Original concerns of using a standard intrathecal hyperbaric bupivacaine dose in parturients with obesity and the potential risk of high spinal block have not been supported by clinical trials.20Carvalho B. Collins J. Drover D.R. Atkinson Ralls L. Riley E.T. ED50 and ED95 of intrathecal bupivacaine in morbidly obese patients undergoing cesarean delivery.Anesthesiology. 2011; 114: 529-535Crossref PubMed Scopus (64) Google Scholar Dose reductions are therefore not recommended and may increase the risk of inadequate block and intraoperative pain.21Arzola C. Wieczorek P.M. Efficacy of low-dose bupivacaine in spinal anaesthesia for Caesarean delivery: systematic review and meta-analysis.Br J Anaesth. 2011; 107: 308-318Abstract Full Text Full Text PDF PubMed Scopus (103) Google Scholar However, patients with BMI >50 kg m−2 are likely to need lower intrathecal doses of bupivacaine for CD compared with women with lower BMI.22Lamon A.M. Einhorn L.M. Cooter M. Habib A.S. The impact of body mass index on the risk of high spinal block in parturients undergoing cesarean delivery: a retrospective cohort study.J Anesth. 2017; 31: 552-558Crossref PubMed Scopus (18) Google Scholar Giving a standard intrathecal dose in parturients with >50 kg m−2 may result in high spinal block, and therefore, single-shot spinal anaesthesia should only be used after careful consideration in these patients. Furthermore, single-shot spinal anaesthesia with a 25G pencil-point needle can be technically challenging in women with excessive truncal adiposity, especially when longer spinal needles are needed. Advancing a Tuohy needle may be technically easier, and once the epidural space has been located, it can be used as an introducer for the long spinal needle as part of a needle-through-needle CSE technique. More commonly, catheter-based techniques are chosen to deliver extended neuraxial anaesthesia for CD. If a patient has a labour epidural catheter in situ, this can be easily used to provide surgical anaesthesia. However, in the event new neuraxial anaesthesia needs to be established, epidural anaesthesia de novo carries a risk of patchy block and sacral sparing. It may be more prudent to use a CSE technique that combines the dense block of spinal anaesthesia with the flexibility to extend duration of the block with the epidural catheter if needed. Another advantage of the CSE technique is that it can be modified where a small dose of intrathecal bupivacaine can be admin