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Supraglottic airway devices for Caesarean delivery under general anaesthesia: for all, for none, or for some?

2020; Elsevier BV; Volume: 125; Issue: 1 Linguagem: Inglês

10.1016/j.bja.2020.02.012

1471-6771

Yavor Metodiev, Mary Mushambi,

Trauma Management and Diagnosis

The gold standard for airway management in obstetric general anaesthesia remains rapid sequence induction and tracheal intubation because of the perceived risk of regurgitation and aspiration in pregnant women. However, there has been a change in attitude to airway management and a gradual acceptance of the use of supraglottic airway (SGA) devices in obstetric anaesthesia. A survey in the UK in 1995 showed that 72% of anaesthetists would only use the Teleflex Laryngeal Mask Airway® (Teleflex Medical Ltd, Athlone, Ireland) to maintain oxygenation when tracheal intubation and face-mask ventilation had failed, and 11% did not think this SGA had a place in obstetric anaesthesia.1Gataure P.S. Hughes J.A. The laryngeal mask airway in obstetrical anaesthesia.Can J Anaesth. 1995; 42: 130-133Crossref PubMed Scopus (41) Google Scholar Recent evidence has shown that, since the late 1990s, there has been a gradual increase in the use of SGA devices to continue anaesthesia when failed tracheal intubation has been declared.2Kinsella S.M. Winton A.L. Mushambi M.C. et al.Failed tracheal intubation during obstetric general anaesthesia: a literature review.Int J Obstet Anesth. 2015; 24: 356-374Abstract Full Text Full Text PDF PubMed Scopus (152) Google Scholar Furthermore, second-generation SGA devices that have better, although not complete, protection against aspiration are now recommended as rescue airway devices after failed tracheal intubation, particularly in patients at increased risk of aspiration.3Mushambi M.C. Kinsella S.M. Popat M. et al.Obstetric Anaesthetists' Association and Difficult Airway Society guidelines for the management of difficult and failed tracheal intubation in obstetrics.Anaesthesia. 2015; 70: 1286-1306Crossref PubMed Scopus (307) Google Scholar Since 2001, there is emerging evidence for use of an SGA device as the primary airway device during general anaesthesia for Caesarean delivery.1Gataure P.S. Hughes J.A. The laryngeal mask airway in obstetrical anaesthesia.Can J Anaesth. 1995; 42: 130-133Crossref PubMed Scopus (41) Google Scholar,4Amin S. Fathy S. Can I-gel replace endotracheal tube during elective Cesarean section?.J Anesth Clin Res. 2016; 7: 1000605Crossref Google Scholar, 5Panneer M. Babu S. Murugaiyan P. Comparison of I-gel versus endotracheal tube in patients undergoing elective cesarean section: a prospective randomized control study.Anesth Essays Res. 2017; 11: 930-933Crossref PubMed Google Scholar, 6Ahmed F. Hasan A. I-gel versus cuffed endotracheal tube in elective cesarean section (double-blind randomized study).Ain-Shams J Anaesthesiol. 2015; 8: 511-515Crossref Google Scholar, 7Fang X. Xiao Q. Xie Q. et al.General anesthesia with the use of SUPREME laryngeal mask airway for emergency Cesarean delivery: a retrospective analysis of 1039 parturients.Sci Rep. 2018; 8: 13098Crossref PubMed Scopus (8) Google Scholar, 8Li S.Y. Yao W.Y. Yuan Y.J. et al.Supreme™ laryngeal mask airway use in general anesthesia for category 2 and 3 Cesarean delivery: a prospective cohort study.BMC Anesthesiol. 2017; 17: 169Crossref PubMed Scopus (14) Google Scholar, 9Yao W.Y. Li S.Y. Sng B.L. Lim Y. Sia A.T. The LMA Supreme™ in 700 parturients undergoing Cesarean delivery: an observational study.Can J Anaesth. 2012; 59: 648-654Crossref PubMed Scopus (57) Google Scholar, 10Yao W.Y. Li S.Y. Yuan Y.J. et al.Comparison of Supreme laryngeal mask airway versus endotracheal intubation for airway management during general anesthesia for cesarean section: a randomized controlled trial.BMC Anesthesiol. 2019; 19: 123Crossref PubMed Scopus (13) Google Scholar, 11Ezri T. Szmuk P. Stein A. Konichezky S. Hagai T. Geva D. Peripartum general anaesthesia without tracheal intubation: incidence of aspiration pneumonia.Anaesthesia. 2000; 55: 421-426Crossref PubMed Scopus (56) Google Scholar, 12Preston R. The evolving role of the laryngeal mask airway in obstetrics.Can J Anaesth. 2001; 48: 1061-1065Crossref PubMed Scopus (12) Google Scholar, 13Saini S. Ahuja S. Guleria K. To evaluate the use of ProSeal laryngeal mask airway in patients undergoing elective lower segment cesarean section under general anesthesia: a prospective randomized controlled study.J Obstet Anaesth Crit Care. 2016; 6: 11-15Crossref Google Scholar, 14Geng Z.Y. Wang D.X. Laryngeal mask airway for cesarean delivery: a 5-year retrospective cohort study.Chin Med J (Engl). 2017; 130: 404-408Crossref PubMed Scopus (11) Google Scholar, 15Halaseh B.K. Sukkar Z.F. Haj Hassan L. Sia A.T.H. Bushnaq W.A. Adarbeh H. The use of ProSeal laryngeal mask airway in caesarean delivery—experience in 3000 cases.Anaesth Intensive Care. 2010; 38: 1023-1028Crossref PubMed Google Scholar, 16Han T.H. Brimacombe J. Lee E.J. Yang H.S. The laryngeal mask airway is effective (and probably safe) in selected healthy parturients for elective Cesarean section: a prospective study of 1067 cases.Can J Anaesth. 2001; 48: 1117-1121Crossref PubMed Scopus (118) Google Scholar Accurate assessment of gastric contents and quantifying the risk of aspiration in pregnant women are important when planning airway management. Currently, there is no routine or objective method of assessment. The recently introduced qualitative and quantitative assessment of gastric contents using ultrasound in non-pregnant subjects has the potential to address this in pregnant women, and may help inform our choice of airway technique during general anaesthesia for Caesarean delivery. This editorial examines the evidence and consider whether SGA devices should replace tracheal tubes for elective Caesarean delivery under general anaesthesia in selected patients. Maternal morbidity and mortality from failed intubation and aspiration remain the most feared complications of general anaesthesia in the parturient. However, maternal mortality from pulmonary aspiration has declined to negligible levels.17Hunter A.R. Moir D.D. Confidential enquiry into maternal deaths.Br J Anaesth. 1983; 55: 367-369Abstract Full Text PDF PubMed Scopus (19) Google Scholar, 18Cooper G.M. McClure J.H. Maternal deaths from anaesthesia. An extract from why mothers die 2000–2002, the confidential enquiries into maternal deaths in the United Kingdom: chapter 9: anaesthesia.Br J Anaesth. 2005; 94: 417-423Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar, 19McClure J.H. Cooper G.M. Clutton-Brock T.H. Centre for Maternal and Child Enquiries Saving mothers' lives: reviewing maternal deaths to make motherhood safer: 2006–8: a review.Br J Anaesth. 2011; 107: 127-132Abstract Full Text Full Text PDF PubMed Scopus (83) Google Scholar, 20McDonnell N.J. Paech M.J. Clavisi O.M. Scott K.L. Difficult and failed intubation in obstetric anaesthesia: an observational study of airway management and complications associated with general anaesthesia for caesarean delivery.Int J Obstet Anesth. 2008; 17: 292-297Abstract Full Text Full Text PDF PubMed Scopus (157) Google Scholar, 21Quinn A.C. Milne D. Columb M. Gorton H. Knight M. Failed tracheal intubation in obstetric anaesthesia: 2 yr national case-control study in the UK.Br J Anaesth. 2013; 110: 74-80Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar, 22Knight M. Bogod D. Lucas D.N. Quinn A.K.J. Pulmonary aspiration during pregnancy or immediately postpartum in the UK: a two-year national descriptive study.Int J Obstet Anesth. 2016; : S13Google Scholar This decline has been attributed to greater use of neuraxial anaesthesia, acid prophylaxis, stricter adherence to fasting guidelines, airway control with rapid sequence induction and tracheal intubation, development and adherence to difficult airway guidelines, and better training.18Cooper G.M. McClure J.H. Maternal deaths from anaesthesia. An extract from why mothers die 2000–2002, the confidential enquiries into maternal deaths in the United Kingdom: chapter 9: anaesthesia.Br J Anaesth. 2005; 94: 417-423Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar,20McDonnell N.J. Paech M.J. Clavisi O.M. Scott K.L. Difficult and failed intubation in obstetric anaesthesia: an observational study of airway management and complications associated with general anaesthesia for caesarean delivery.Int J Obstet Anesth. 2008; 17: 292-297Abstract Full Text Full Text PDF PubMed Scopus (157) Google Scholar,21Quinn A.C. Milne D. Columb M. Gorton H. Knight M. Failed tracheal intubation in obstetric anaesthesia: 2 yr national case-control study in the UK.Br J Anaesth. 2013; 110: 74-80Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar A study by Olsson and colleagues23Olsson G.L. Hallen B. Hambraeus-Jonzon K. Aspiration during anaesthesia: a computer-aided study of 185,358 anaesthetics.Acta Anaesthesiol Scand. 1986; 30: 84-92Crossref PubMed Scopus (461) Google Scholar in 1986 reported an incidence of pulmonary aspiration of 1:661 in women undergoing Caesarean delivery, whereas more recent studies show a lower incidence of between 1:1095 and 1:4500.20McDonnell N.J. Paech M.J. Clavisi O.M. Scott K.L. Difficult and failed intubation in obstetric anaesthesia: an observational study of airway management and complications associated with general anaesthesia for caesarean delivery.Int J Obstet Anesth. 2008; 17: 292-297Abstract Full Text Full Text PDF PubMed Scopus (157) Google Scholar, 21Quinn A.C. Milne D. Columb M. Gorton H. Knight M. Failed tracheal intubation in obstetric anaesthesia: 2 yr national case-control study in the UK.Br J Anaesth. 2013; 110: 74-80Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar, 22Knight M. Bogod D. Lucas D.N. Quinn A.K.J. Pulmonary aspiration during pregnancy or immediately postpartum in the UK: a two-year national descriptive study.Int J Obstet Anesth. 2016; : S13Google Scholar Having achieved such a high safety profile of obstetric general anaesthetic, it is with some concern that a more liberal approach to fasting and reduced antacid use are being advocated at the same time that alternative airway management strategies are being introduced. Recent National Institute for Health and Care Excellence guidelines on the intrapartum care of pregnant women recommend allowing women in 'low'-risk labour to drink and have a light diet, and those with 'high'-risk labour to drink only.24National Institute for Health and Care ExcellenceIntrapartum care for healthy women and babies [CG190].2014: 89https://www.nice.org.uk/guidance/cg190Date accessed: March 12, 2020Google Scholar In contrast, the American Practice Guidelines for Obstetric Anesthesia are more restrictive in oral intake during labour, especially when solid food is concerned, and recommend considering the administration of non-particulate antacid prophylaxis, histamine receptor (H2) antagonists, or prokinetics.25Practice guidelines for obstetric anesthesia: an updated report by the American society of anesthesiologists task force on obstetric anesthesia and the society for obstetric anesthesia and perinatology.Anesthesiology. 2016; 124: 270-300Crossref PubMed Scopus (328) Google Scholar Compared with tracheal tube insertion, SGA device placement requires less expertise and time for insertion, and is associated with fewer complications, especially at extubation and in the postoperative period,26Kwanten L.E. Madhivathanan P. Supraglottic airway devices: current and future uses.Br J Hosp Med (Lond). 2018; 79: 31-35Crossref PubMed Scopus (8) Google Scholar which account for their popularity in elective and emergency non-obstetric general anaesthesia. Until recently, their SGA use in obstetrics has been limited to airway rescue after failed intubation. However, use of an SGA as the primary airway device in selected patients having Caesarean delivery under general anaesthesia has been shown in several prospective, retrospective, and randomised studies (Table 1) in more than 8000 patients.1Gataure P.S. Hughes J.A. The laryngeal mask airway in obstetrical anaesthesia.Can J Anaesth. 1995; 42: 130-133Crossref PubMed Scopus (41) Google Scholar,4Amin S. Fathy S. Can I-gel replace endotracheal tube during elective Cesarean section?.J Anesth Clin Res. 2016; 7: 1000605Crossref Google Scholar, 5Panneer M. Babu S. Murugaiyan P. Comparison of I-gel versus endotracheal tube in patients undergoing elective cesarean section: a prospective randomized control study.Anesth Essays Res. 2017; 11: 930-933Crossref PubMed Google Scholar, 6Ahmed F. Hasan A. I-gel versus cuffed endotracheal tube in elective cesarean section (double-blind randomized study).Ain-Shams J Anaesthesiol. 2015; 8: 511-515Crossref Google Scholar, 7Fang X. Xiao Q. Xie Q. et al.General anesthesia with the use of SUPREME laryngeal mask airway for emergency Cesarean delivery: a retrospective analysis of 1039 parturients.Sci Rep. 2018; 8: 13098Crossref PubMed Scopus (8) Google Scholar, 8Li S.Y. Yao W.Y. Yuan Y.J. et al.Supreme™ laryngeal mask airway use in general anesthesia for category 2 and 3 Cesarean delivery: a prospective cohort study.BMC Anesthesiol. 2017; 17: 169Crossref PubMed Scopus (14) Google Scholar, 9Yao W.Y. Li S.Y. Sng B.L. Lim Y. Sia A.T. The LMA Supreme™ in 700 parturients undergoing Cesarean delivery: an observational study.Can J Anaesth. 2012; 59: 648-654Crossref PubMed Scopus (57) Google Scholar, 10Yao W.Y. Li S.Y. Yuan Y.J. et al.Comparison of Supreme laryngeal mask airway versus endotracheal intubation for airway management during general anesthesia for cesarean section: a randomized controlled trial.BMC Anesthesiol. 2019; 19: 123Crossref PubMed Scopus (13) Google Scholar, 11Ezri T. Szmuk P. Stein A. Konichezky S. Hagai T. Geva D. Peripartum general anaesthesia without tracheal intubation: incidence of aspiration pneumonia.Anaesthesia. 2000; 55: 421-426Crossref PubMed Scopus (56) Google Scholar, 12Preston R. The evolving role of the laryngeal mask airway in obstetrics.Can J Anaesth. 2001; 48: 1061-1065Crossref PubMed Scopus (12) Google Scholar, 13Saini S. Ahuja S. Guleria K. To evaluate the use of ProSeal laryngeal mask airway in patients undergoing elective lower segment cesarean section under general anesthesia: a prospective randomized controlled study.J Obstet Anaesth Crit Care. 2016; 6: 11-15Crossref Google Scholar, 14Geng Z.Y. Wang D.X. Laryngeal mask airway for cesarean delivery: a 5-year retrospective cohort study.Chin Med J (Engl). 2017; 130: 404-408Crossref PubMed Scopus (11) Google Scholar, 15Halaseh B.K. Sukkar Z.F. Haj Hassan L. Sia A.T.H. Bushnaq W.A. Adarbeh H. The use of ProSeal laryngeal mask airway in caesarean delivery—experience in 3000 cases.Anaesth Intensive Care. 2010; 38: 1023-1028Crossref PubMed Google Scholar, 16Han T.H. Brimacombe J. Lee E.J. Yang H.S. The laryngeal mask airway is effective (and probably safe) in selected healthy parturients for elective Cesarean section: a prospective study of 1067 cases.Can J Anaesth. 2001; 48: 1117-1121Crossref PubMed Scopus (118) Google Scholar The biggest single study to date included 3000 patients who underwent Caesarean delivery with the LMA® ProSeal™ (Teleflex Medical Ltd), and there was one case of regurgitation, and no aspiration.15Halaseh B.K. Sukkar Z.F. Haj Hassan L. Sia A.T.H. Bushnaq W.A. Adarbeh H. The use of ProSeal laryngeal mask airway in caesarean delivery—experience in 3000 cases.Anaesth Intensive Care. 2010; 38: 1023-1028Crossref PubMed Google ScholarTable 1Studies of women undergoing general anaesthesia for Caesarean delivery using supraglottic airway devices. El, elective; Em, emergency; n, number studied; TT, tracheal tube.Author (year)DevicenRCTEl/EmFasting (h)Average weight (kg)Induction agentNeuromuscular blocking agentsHan and colleagues16Han T.H. Brimacombe J. Lee E.J. Yang H.S. The laryngeal mask airway is effective (and probably safe) in selected healthy parturients for elective Cesarean section: a prospective study of 1067 cases.Can J Anaesth. 2001; 48: 1117-1121Crossref PubMed Scopus (118) Google Scholar (2001)LMA1067NoEl667ThiopentalSuxamethonium chloride; vecuroniumHalaseh and colleagues15Halaseh B.K. Sukkar Z.F. Haj Hassan L. Sia A.T.H. Bushnaq W.A. Adarbeh H. The use of ProSeal laryngeal mask airway in caesarean delivery—experience in 3000 cases.Anaesth Intensive Care. 2010; 38: 1023-1028Crossref PubMed Google Scholar (2010)ProSeal™3000NoEl8—PropofolRocuroniumYao and colleagues9Yao W.Y. Li S.Y. Sng B.L. Lim Y. Sia A.T. The LMA Supreme™ in 700 parturients undergoing Cesarean delivery: an observational study.Can J Anaesth. 2012; 59: 648-654Crossref PubMed Scopus (57) Google Scholar (2012)Supreme™700NoMixed465PropofolRocuroniumAhmed and Hasan6Ahmed F. Hasan A. I-gel versus cuffed endotracheal tube in elective cesarean section (double-blind randomized study).Ain-Shams J Anaesthesiol. 2015; 8: 511-515Crossref Google Scholar (2015)I-gel™ vs TT40YesEl677ThiopentalRocuroniumSaini and colleagues13Saini S. Ahuja S. Guleria K. To evaluate the use of ProSeal laryngeal mask airway in patients undergoing elective lower segment cesarean section under general anesthesia: a prospective randomized controlled study.J Obstet Anaesth Crit Care. 2016; 6: 11-15Crossref Google Scholar (2016)ProSeal vs TT30YesEl651ThiopentalSuxamethonium chloride; vecuroniumAmin and Fathy4Amin S. Fathy S. Can I-gel replace endotracheal tube during elective Cesarean section?.J Anesth Clin Res. 2016; 7: 1000605Crossref Google Scholar (2016)I-gel1000NoEl882PropofolRocuroniumLi and colleagues8Li S.Y. Yao W.Y. Yuan Y.J. et al.Supreme™ laryngeal mask airway use in general anesthesia for category 2 and 3 Cesarean delivery: a prospective cohort study.BMC Anesthesiol. 2017; 17: 169Crossref PubMed Scopus (14) Google Scholar (2017)Supreme584NoEm4—PropofolSuxamethonium chloride; rocuroniumGeng and Wang14Geng Z.Y. Wang D.X. Laryngeal mask airway for cesarean delivery: a 5-year retrospective cohort study.Chin Med J (Engl). 2017; 130: 404-408Crossref PubMed Scopus (11) Google Scholar (2017)Supreme vs TT56NoMixed075PropofolSuxamethonium chloridePanneer and colleagues5Panneer M. Babu S. Murugaiyan P. Comparison of I-gel versus endotracheal tube in patients undergoing elective cesarean section: a prospective randomized control study.Anesth Essays Res. 2017; 11: 930-933Crossref PubMed Google Scholar (2017)I-gel vs TT40YesEl650PropofolSuxamethonium chloride; vecuroniumFang and colleagues7Fang X. Xiao Q. Xie Q. et al.General anesthesia with the use of SUPREME laryngeal mask airway for emergency Cesarean delivery: a retrospective analysis of 1039 parturients.Sci Rep. 2018; 8: 13098Crossref PubMed Scopus (8) Google Scholar (2018)Supreme1039NoEm067PropofolCisatracuriumYao and colleagues10Yao W.Y. Li S.Y. Yuan Y.J. et al.Comparison of Supreme laryngeal mask airway versus endotracheal intubation for airway management during general anesthesia for cesarean section: a randomized controlled trial.BMC Anesthesiol. 2019; 19: 123Crossref PubMed Scopus (13) Google Scholar (2019)Supreme vs TT460YesEl665.6PropofolSuxamethonium chloride; rocuronium Open table in a new tab Currently, the LMA® Supreme™ (Teleflex Medical Ltd) is the most extensively studied device and has been investigated in five studies (two randomised) in a total of 2839 patients.7Fang X. Xiao Q. Xie Q. et al.General anesthesia with the use of SUPREME laryngeal mask airway for emergency Cesarean delivery: a retrospective analysis of 1039 parturients.Sci Rep. 2018; 8: 13098Crossref PubMed Scopus (8) Google Scholar, 8Li S.Y. Yao W.Y. Yuan Y.J. et al.Supreme™ laryngeal mask airway use in general anesthesia for category 2 and 3 Cesarean delivery: a prospective cohort study.BMC Anesthesiol. 2017; 17: 169Crossref PubMed Scopus (14) Google Scholar, 9Yao W.Y. Li S.Y. Sng B.L. Lim Y. Sia A.T. The LMA Supreme™ in 700 parturients undergoing Cesarean delivery: an observational study.Can J Anaesth. 2012; 59: 648-654Crossref PubMed Scopus (57) Google Scholar, 10Yao W.Y. Li S.Y. Yuan Y.J. et al.Comparison of Supreme laryngeal mask airway versus endotracheal intubation for airway management during general anesthesia for cesarean section: a randomized controlled trial.BMC Anesthesiol. 2019; 19: 123Crossref PubMed Scopus (13) Google Scholar,14Geng Z.Y. Wang D.X. Laryngeal mask airway for cesarean delivery: a 5-year retrospective cohort study.Chin Med J (Engl). 2017; 130: 404-408Crossref PubMed Scopus (11) Google Scholar The LMA Supreme was compared with tracheal intubation in 920 elective Caesarean deliveries10Yao W.Y. Li S.Y. Yuan Y.J. et al.Comparison of Supreme laryngeal mask airway versus endotracheal intubation for airway management during general anesthesia for cesarean section: a randomized controlled trial.BMC Anesthesiol. 2019; 19: 123Crossref PubMed Scopus (13) Google Scholar with no difference between groups. The same device was used as the airway of choice in 584 parturients undergoing Category 2 or 3 Caesarean delivery.8Li S.Y. Yao W.Y. Yuan Y.J. et al.Supreme™ laryngeal mask airway use in general anesthesia for category 2 and 3 Cesarean delivery: a prospective cohort study.BMC Anesthesiol. 2017; 17: 169Crossref PubMed Scopus (14) Google Scholar There were no reported cases of aspiration in any of those studies. Four of the studies investigating the LMA Supreme were conducted in the same hospital by the same team, and hence, the ease in reproducing similar clinical conditions.7Fang X. Xiao Q. Xie Q. et al.General anesthesia with the use of SUPREME laryngeal mask airway for emergency Cesarean delivery: a retrospective analysis of 1039 parturients.Sci Rep. 2018; 8: 13098Crossref PubMed Scopus (8) Google Scholar, 8Li S.Y. Yao W.Y. Yuan Y.J. et al.Supreme™ laryngeal mask airway use in general anesthesia for category 2 and 3 Cesarean delivery: a prospective cohort study.BMC Anesthesiol. 2017; 17: 169Crossref PubMed Scopus (14) Google Scholar, 9Yao W.Y. Li S.Y. Sng B.L. Lim Y. Sia A.T. The LMA Supreme™ in 700 parturients undergoing Cesarean delivery: an observational study.Can J Anaesth. 2012; 59: 648-654Crossref PubMed Scopus (57) Google Scholar, 10Yao W.Y. Li S.Y. Yuan Y.J. et al.Comparison of Supreme laryngeal mask airway versus endotracheal intubation for airway management during general anesthesia for cesarean section: a randomized controlled trial.BMC Anesthesiol. 2019; 19: 123Crossref PubMed Scopus (13) Google Scholar The I-gel™ (Intersurgical Ltd, Wokingham, UK), introduced in 2007, has the advantages of easier insertion and creation of greater seal pressure without the need of cuff inflation when compared with other SGA devices.27Levitan R.M. Kinkle W.C. Initial anatomic investigations of the I-gel airway: a novel supraglottic airway without inflatable cuff.Anaesthesia. 2005; 60: 1022-1026Crossref PubMed Scopus (165) Google Scholar It provides a more stable haemodynamic profile at insertion with lower mean arterial pressure and heart rate than tracheal intubation in patients undergoing elective Caesarean delivery.5Panneer M. Babu S. Murugaiyan P. Comparison of I-gel versus endotracheal tube in patients undergoing elective cesarean section: a prospective randomized control study.Anesth Essays Res. 2017; 11: 930-933Crossref PubMed Google Scholar Its use in elective Caesarean deliveries has been shown to provide comparable control of the airway (in 9 vs 10 s),6Ahmed F. Hasan A. I-gel versus cuffed endotracheal tube in elective cesarean section (double-blind randomized study).Ain-Shams J Anaesthesiol. 2015; 8: 511-515Crossref Google Scholar but was associated with fewer airway complications, such as bronchospasm, sore throat, regurgitation, and dysphagia.5Panneer M. Babu S. Murugaiyan P. Comparison of I-gel versus endotracheal tube in patients undergoing elective cesarean section: a prospective randomized control study.Anesth Essays Res. 2017; 11: 930-933Crossref PubMed Google Scholar,6Ahmed F. Hasan A. I-gel versus cuffed endotracheal tube in elective cesarean section (double-blind randomized study).Ain-Shams J Anaesthesiol. 2015; 8: 511-515Crossref Google Scholar Most of the aforementioned studies included fasted non-obese patients and excluded patients with gastro-oesophageal reflux or anticipated difficult airway. Such stringent patient selection criteria were not universal amongst the 11 studies (Table 1). In one retrospective study, all 1039 women undergoing emergency Caesarean delivery under general anaesthesia with the LMA Supreme were unfasted and included high-risk groups, such as those with ASA physical status 3 or 4, preeclampsia, and obesity (181 women had BMI >30 kg m−2).7Fang X. Xiao Q. Xie Q. et al.General anesthesia with the use of SUPREME laryngeal mask airway for emergency Cesarean delivery: a retrospective analysis of 1039 parturients.Sci Rep. 2018; 8: 13098Crossref PubMed Scopus (8) Google Scholar The majority of studies used one or more antacid prophylaxis medications, such as oral or i.v. ranitidine and metoclopramide, or sodium citrate.4Amin S. Fathy S. Can I-gel replace endotracheal tube during elective Cesarean section?.J Anesth Clin Res. 2016; 7: 1000605Crossref Google Scholar, 5Panneer M. Babu S. Murugaiyan P. Comparison of I-gel versus endotracheal tube in patients undergoing elective cesarean section: a prospective randomized control study.Anesth Essays Res. 2017; 11: 930-933Crossref PubMed Google Scholar, 6Ahmed F. Hasan A. I-gel versus cuffed endotracheal tube in elective cesarean section (double-blind randomized study).Ain-Shams J Anaesthesiol. 2015; 8: 511-515Crossref Google Scholar,9Yao W.Y. Li S.Y. Sng B.L. Lim Y. Sia A.T. The LMA Supreme™ in 700 parturients undergoing Cesarean delivery: an observational study.Can J Anaesth. 2012; 59: 648-654Crossref PubMed Scopus (57) Google Scholar,13Saini S. Ahuja S. Guleria K. To evaluate the use of ProSeal laryngeal mask airway in patients undergoing elective lower segment cesarean section under general anesthesia: a prospective randomized controlled study.J Obstet Anaesth Crit Care. 2016; 6: 11-15Crossref Google Scholar,15Halaseh B.K. Sukkar Z.F. Haj Hassan L. Sia A.T.H. Bushnaq W.A. Adarbeh H. The use of ProSeal laryngeal mask airway in caesarean delivery—experience in 3000 cases.Anaesth Intensive Care. 2010; 38: 1023-1028Crossref PubMed Google Scholar,16Han T.H. Brimacombe J. Lee E.J. Yang H.S. The laryngeal mask airway is effective (and probably safe) in selected healthy parturients for elective Cesarean section: a prospective study of 1067 cases.Can J Anaesth. 2001; 48: 1117-1121Crossref PubMed Scopus (118) Google Scholar The choice of anaesthetic drugs was variable, but neuromuscular blockers were often used to ensure paralysis for insertion of the SGA device and for surgery. The benefits of avoiding muscle paralysis have not been studied in pregnant patients. Cricoid force was used in seven studies.6Ahmed F. Hasan A. I-gel versus cuffed endotracheal tube in elective cesarean section (double-blind randomized study).Ain-Shams J Anaesthesiol. 2015; 8: 511-515Crossref Google Scholar,8Li S.Y. Yao W.Y. Yuan Y.J. et al.Supreme™ laryngeal mask airway use in general anesthesia for category 2 and 3 Cesarean delivery: a prospective cohort study.BMC Anesthesiol. 2017; 17: 169Crossref PubMed Scopus (14) Google Scholar, 9Yao W.Y. Li S.Y. Sng B.L. Lim Y. Sia A.T. The LMA Supreme™ in 700 parturients undergoing Cesarean delivery: an observational study.Can J Anaesth. 2012; 59: 648-654Crossref PubMed Scopus (57) Google Scholar, 10Yao W.Y. Li S.Y. Yuan Y.J. et al.Comparison of Supreme laryngeal mask airway versus endotracheal intubation for airway management during general anesthesia for cesarean section: a randomized controlled trial.BMC Anesthesiol. 2019; 19: 123Crossref PubMed Scopus (13) Google Scholar,14Geng Z.Y. Wang D.X. Laryngeal mask airway for cesarean delivery: a 5-year retrospective cohort study.Chin Med J (Engl). 2017; 130: 404-408Crossref PubMed Scopus (11) Google Scholar, 15Halaseh B.K. Sukkar Z.F. Haj Hassan L. Sia A.T.H. Bushnaq W.A. Adarbeh H. The use of ProSeal laryngeal mask airway in caesarean delivery—experience in 3000 cases.Anaesth Intensive Care. 2010; 38: 1023-1028Crossref PubMed Google Scholar, 16Han T.H. Brimacombe J. Lee E.J. Yang H.S. The laryngeal mask airway is effective (and probably safe) in selected healthy parturients for elective Cesarean section: a prospective study of 1067 cases.Can J Anaesth. 2001; 48: 1117-1121Crossref PubMed Scopus (118) Google Scholar It was released after the SGA device was in place in all but one study, in which it was briefly released during the insertion.15Halaseh B.K. Sukkar Z.F. Haj Hassan L. Sia A.T.H. Bushnaq W.A. Adarbeh H. The use of ProSeal laryngeal mask airway in caesarean delivery—experience in 3000 cases.Anaesth Intensive Care. 2010; 38: 1023-1028Crossref PubMed Google Scholar An orogastric tube was inserted in the majority of studies using second-generation SGA devices.4Amin S. Fathy S. Can I-gel replace endotracheal tube during elective Cesarean section?.J Anesth Clin Res. 2016; 7: 1000605Crossref Google Scholar,5Panneer M. Babu S. Murugaiyan P. Comparison of I-gel versus endotracheal tube in patients undergoing elective cesarean section: a prospective randomized control study.Anesth Essays Res. 2017; 11: 930-933Crossref PubMed Google Scholar,8Li S.Y. Yao W.Y. Yuan Y.J. et al.Supreme™ laryngeal mask airway use in general anesthesia for category 2 and 3 Cesarean delivery: a prospective cohort study.BMC Anesthesiol. 2017; 17: 169Crossref PubMed Scopus (14) Google Scholar, 9Yao W.Y. Li S.Y. Sng B.L. Lim Y. Sia A.T. The LMA Supreme™ in 700 parturients undergoing Cesarean delivery: an observational study.Can J Anaesth. 2012; 59: 648-654Crossref PubMed Scopus (57) Google Scholar, 10Yao W.Y. Li S.Y. Yuan Y.J. et al.Comparison of Supreme laryngeal mask airway versus endotracheal intubation for airway management during general anesthesia for cesarean section: a randomized controlled trial.BMC Anesthesiol. 2019; 19: 123Crossref PubMed Scopus (13) Google Scholar,15Halaseh B.K. Sukkar Z.F. Haj Hassan L. Sia A.T.H. Bushnaq W.A. Adarbeh H. The use of ProSeal laryngeal mask airway in caesarean delivery—experience in 3000 cases.Anaesth Intensive Care. 2010; 38: 1023-1028Crossref PubMed Google Scholar,16Han T.H. Brimacombe J. Lee E.J. Yang H.S. The laryngeal mask airway is effective (and probably safe) in selected healthy parturients for elective Cesarean section: a prospective study of 1067 cases.Can J Anaesth. 2001; 48: 1117-1121Crossref PubMed Scopus (118) Google Scholar The success rate of laryngeal mask airway insertion was 99%, whereas all studies that used second-generation SGA devices had a 100% success rate. There was one case of regurgitation at the point of applying fundal pressure to deliver the baby,15Halaseh B.K. Sukkar Z.F. Haj Hassan L. Sia A.T.H. Bushnaq W.A. Adarbeh H. The use of ProSeal laryngeal mask airway in caesarean delivery—experience in 3000 cases.Anaesth Intensive Care. 2010; 38: 1023-1028Crossref PubMed Google Scholar which meant that, out of the 8000 women studied so far, there was one case of regurgitation and no cases of aspiration. As a result of the one case of regurgitation, reduction of fundal pressure at delivery was recommended in seven studies.4Amin S. Fathy S. Can I-gel replace endotracheal tube during elective Cesarean section?.J Anesth Clin Res. 2016; 7: 1000605Crossref Google Scholar,5Panneer M. Babu S. Murugaiyan P. Comparison of I-gel versus endotracheal tube in patients undergoing elective cesarean section: a prospective randomized control study.Anesth Essays Res. 2017; 11: 930-933Crossref PubMed Google Scholar,5Panneer M. Babu S. Murugaiyan P. Comparison of I-gel versus endotracheal tube in patients undergoing elective cesarean section: a prospective randomized control study.Anesth Essays Res. 2017; 11: 930-933Crossref PubMed Google Scholar,8Li S.Y. Yao W.Y. Yuan Y.J. et al.Supreme™ laryngeal mask airway use in general anesthesia for category 2 and 3 Cesarean delivery: a prospective cohort study.BMC Anesthesiol. 2017; 17: 169Crossref PubMed Scopus (14) Google Scholar, 9Yao W.Y. Li S.Y. Sng B.L. Lim Y. Sia A.T. The LMA Supreme™ in 700 parturients undergoing Cesarean delivery: an observational study.Can J Anaesth. 2012; 59: 648-654Crossref PubMed Scopus (57) Google Scholar, 10Yao W.Y. Li S.Y. Yuan Y.J. et al.Comparison of Supreme laryngeal mask airway versus endotracheal intubation for airway management during general anesthesia for cesarean section: a randomized controlled trial.BMC Anesthesiol. 2019; 19: 123Crossref PubMed Scopus (13) Google Scholar,16Han T.H. Brimacombe J. Lee E.J. Yang H.S. The laryngeal mask airway is effective (and probably safe) in selected healthy parturients for elective Cesarean section: a prospective study of 1067 cases.Can J Anaesth. 2001; 48: 1117-1121Crossref PubMed Scopus (118) Google Scholar Complications, such as sore throat and blood on the cuff of the SGA device, were few. However, in the studies that were randomised, there was a higher incidence of problems in the tracheal tube group, such as failed intubation13Saini S. Ahuja S. Guleria K. To evaluate the use of ProSeal laryngeal mask airway in patients undergoing elective lower segment cesarean section under general anesthesia: a prospective randomized controlled study.J Obstet Anaesth Crit Care. 2016; 6: 11-15Crossref Google Scholar and laryngospasm at extubation.6Ahmed F. Hasan A. I-gel versus cuffed endotracheal tube in elective cesarean section (double-blind randomized study).Ain-Shams J Anaesthesiol. 2015; 8: 511-515Crossref Google Scholar The landmark paper by Mendelson28Mendelson C.L. The aspiration of stomach contents into the lungs during obstetric anesthesia.Am J Obstet Gynecol. 1946; 52: 191-205Abstract Full Text PDF PubMed Scopus (939) Google Scholar in 1946 described 66 cases of aspiration of gastric contents in pregnant patients who received anaesthesia with 'gas, oxygen, and ether' delivered by face mask. He concluded that gastric retention of food and liquid was prolonged in labour and that pulmonary aspiration could occur when laryngeal reflexes were abolished during general anaesthesia. In the 1958–63 Confidential Enquiry into Maternal Deaths, there were 33 maternal deaths attributable to aspiration. After the enquiries, tracheal intubation was recommended to protect the lungs from aspiration in pregnant women undergoing general anaesthesia.29Ministry of Health Confidential Enquiries into maternal Deaths in England and Wales, 1958–1960.in: Report on public health and medical subjects, London. 1963Google Scholar The anaesthetic technique of i.v. induction, muscle blockade, and rapid tracheal intubation for Caesarean delivery was described by Hodges and colleagues30Hodges R.J.H. Bennett J.R. Tunstall M.E. Knight R.F. General anaesthesia for operative obstetrics: with special reference to the use of thiopentone and suxamethonium.Br J Anaesth. 1959; 31: 152-163Abstract Full Text PDF PubMed Scopus (37) Google Scholar in 1959. In 1970, the classic rapid sequence induction and tracheal intubation technique with the use of cricoid force was described as the standard of care for obstetric airway management by Stept and Safar.31Stept W.J. Safar P. Rapid induction-intubation for prevention of gastric-content aspiration.Anesth Analg. 1970; 49: 633-636Crossref PubMed Scopus (141) Google Scholar In the biggest audit of complications of airway management in the UK, the National Audit Project 4 (NAP4) published in 2011, aspiration was the commonest cause of death accounting for 50% of anaesthesia-related deaths in the general population.32Cook T.M. Woodall N. Frerk C. Fourth national audit Project. Major complications of airway management in the UK: results of the fourth national audit Project of the royal college of anaesthetists and the difficult airway society. Part 1: anaesthesia.Br J Anaesth. 2011; 106: 617-631Abstract Full Text Full Text PDF PubMed Scopus (1170) Google Scholar There was one case of aspiration in an obstetric patient that occurred as a complication of failed intubation. A key recommendation from NAP4 was that the risk of aspiration should be assessed, and where higher than baseline risk was identified, consideration should be given to minimising volume and raising pH of gastric contents and performing rapid sequence induction and tracheal intubation to protect the lungs. In an editorial, Asai33Asai T. Editorial II: who is at increased risk pulmonary aspiration?.Br J Anaesth. 2004; 93: 497-500Abstract Full Text Full Text PDF PubMed Scopus (77) Google Scholar discussed ways to assess the risk of aspiration, patient factors, anaesthetic factors, surgical factors, and device factors. The increased risk of pulmonary aspiration in pregnancy is primarily because of hormonal and mechanical factors that reduce lower oesophageal barrier pressure. However, there is still the question of whether the pregnant woman should be considered to have a full stomach at all times, including when fasted, and hence require routine rapid sequence induction and tracheal intubation to protect against regurgitation and aspiration.34Kinsella S.M. The 'full stomach': full time for sloppy terminology?.Anaesthesia. 2018; 73: 1189-1190Crossref PubMed Scopus (8) Google Scholar Alternatively, could accurate assessment of gastric content allow consideration of the use of an SGA device as the primary airway device if the volume of gastric content is below a threshold, above which there is a risk of aspiration, and could this be applied to emergency or elective general anaesthetics?35Van de Putte P. Vernieuwe L. Perlas A. Term pregnant patients have similar gastric volume to non-pregnant females: a single-centre cohort study.Br J Anaesth. 2019; 122: 79-85Abstract Full Text Full Text PDF PubMed Scopus (18) Google Scholar Point-of-care ultrasound examination of gastric contents is now a well-described method to directly assess quantitative (antral cross-sectional area) and qualitative (Perlas score) gastric contents in non-pregnant adults,36Van de Putte P. Perlas A. Ultrasound assessment of gastric content and volume.Br J Anaesth. 2014; 113: 12-22Abstract Full Text Full Text PDF PubMed Scopus (218) Google Scholar but the results of studies using ultrasound to assess gastric emptying after oral intake are inconsistent.37Hakak S. McCaul C.L. Crowley L. Ultrasonographic evaluation of gastric contents in term pregnant women fasted for six hours.Int J Obstet Anesth. 2018; 34: 15-20Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar, 38Arzola C. Perlas A. Siddiqui N.T. Carvalho J.C. Bedside gastric ultrasonography in term pregnant women before elective Cesarean delivery: a prospective cohort study.Anesth Analg. 2015; 121: 752-758Crossref PubMed Scopus (50) Google Scholar, 39Rouget C. Chassard D. Bonnard C. Pop M. Desgranges F.P. Bouvet L. Changes in qualitative and quantitative ultrasound assessment of the gastric antrum before and after elective caesarean delivery in term pregnant women: a prospective cohort study.Anaesthesia. 2016; 71: 1284-1290Crossref PubMed Scopus (21) Google Scholar, 40Barboni E. Mancinelli P. Bitossi U. et al.Ultrasound evaluation of the stomach and gastric emptying in pregnant women at term: a case-control study.Minerva Anestesiol. 2016; 82: 543-549PubMed Google Scholar, 41Nascimento A.C. Goveia C.S. Guimarães G.M.N. Filho R.P.L. Ladeira L.C.A. Silva H.B.G. Assessment of gastric emptying of maltodextrin, coffee with milk and orange juice during labour at term using point of care ultrasound: a non-inferiority randomised clinical trial.Anaesthesia. 2019; 74: 856-861Crossref PubMed Scopus (6) Google Scholar A recent paper found that 38% of term pregnant women had gastric fluid above the arbitrary risk threshold of 1.5 ml kg−1 after 6 h of fasting.37Hakak S. McCaul C.L. Crowley L. Ultrasonographic evaluation of gastric contents in term pregnant women fasted for six hours.Int J Obstet Anesth. 2018; 34: 15-20Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar Another study found that 95% of term fasting women (solid food 6 h and clear fluid 2 h) had gastric contents ≤1.5 ml kg−1.38Arzola C. Perlas A. Siddiqui N.T. Carvalho J.C. Bedside gastric ultrasonography in term pregnant women before elective Cesarean delivery: a prospective cohort study.Anesth Analg. 2015; 121: 752-758Crossref PubMed Scopus (50) Google Scholar The wide variations in results could be attributed to many factors: varying patient characteristics, positioning, differing ultrasound techniques or skills, and different meal compositions. Nevertheless, these results support the use of ultrasound to assess the gastric emptying for individual patients, rather than relying on arbitrary starvation intervals. Gastric ultrasound in pregnancy is more technically challenging because of the upward displacement of the stomach and its rotation by the gravid uterus, movement of the fetus, and increased ventilatory frequency. In addition, the relationship of antral cross-sectional area to volume of stomach contents determined for non-pregnant subjects may not apply to term pregnant women.39Rouget C. Chassard D. Bonnard C. Pop M. Desgranges F.P. Bouvet L. Changes in qualitative and quantitative ultrasound assessment of the gastric antrum before and after elective caesarean delivery in term pregnant women: a prospective cohort study.Anaesthesia. 2016; 71: 1284-1290Crossref PubMed Scopus (21) Google Scholar The position of the woman during measurement is critical to obtain accurate readings. These factors are likely to make accurate ultrasound assessment of gastric volume challenging, especially in the labouring parturient or before emergency Caesarean delivery. In addition, most studies on ultrasound assessment of gastric contents exclude parturients who are obese, have oesophageal reflux, or have higher American Society of Anesthesiologists (ASA) physical status classifications. We believe that accurate assessment of gastric contents in pregnant women is not at a stage where it can be used reliably to decide whether the stomach is empty enough to consider the use of an SGA device is a safe option in either emergency or elective situations. Currently, there is insufficient evidence to recommend universal or selective replacement of tracheal tubes with SGA devices during general anaesthesia for Caesarean delivery. Aspiration remains the main concern. However, with the current extremely low incidence of aspiration, a study in which pulmonary aspiration is the primary outcome would not be feasible. The quality of data currently available on the use of SGA devices for Caesarean delivery is low (randomised studies that are few and not powered enough to detect risk of aspiration, retrospective data collection, and dominance of studies from a single unit). The studies mentioned previously were carried out in countries, such as Korea, Jordan, Egypt, China, and India, where body habitus and diet differ from Europe and North America. Matters, such as patient selection criteria (e.g. fasting status, BMI, and co-morbidities), type of SGA device, and anaesthetic technique (induction agents, neuromuscular blocking agents, cricoid pressure, and orogastric tube) have yet to be addressed fully. Ultrasound assessment of gastric contents in pregnant women is evolving. With greater attention to patient position, mathematical models for antral cross-sectional area for pregnant women, and expertise in gastric ultrasonography, clinicians may be able to assess stomach contents and might aid decision-making particularly in the event of failed tracheal intubation.42Zieleskiewicz L. Bouvet L. Einav S. Duclos G. Leone M. Diagnostic point-of-care ultrasound: applications in obstetric anaesthetic management.Anaesthesia. 2018; 73: 1265-1279Crossref PubMed Scopus (32) Google Scholar, 43Roukhomovsky M. Zieleskiewicz L. Diaz A. et al.Ultrasound examination of the antrum to predict gastric content volume in the third trimester of pregnancy as assessed by magnetic resonance imaging: a prospective cohort study.Eur J Anaesthesiol. 2018; 35: 379-389Crossref PubMed Scopus (22) Google Scholar, 44Arzola C. Perlas A. Siddiqui N.T. Downey K. Ye X.Y. Carvalho J.C.A. Gastric ultrasound in the third trimester of pregnancy: a randomised controlled trial to develop a predictive model of volume assessment.Anaesthesia. 2018; 73: 295-303Crossref PubMed Scopus (30) Google Scholar The use of gastric ultrasound to obtain reliable information to aid in risk stratification and choice of airway device for obstetric anaesthesia requires further research. Whatever airway strategy modifications take place, it is important to remember that changing our practice of airway management in pregnant women should not go against decades of improving maternal safety. With further progress and more widely available expertise in gastric ultrasonography, we might be able to identify women at low risk of aspiration (non-solid contents and low volume), and depending on body habitus and co-morbidities, these women might be candidates for airway management with an SGA device. Study conception/design: both authors Drafting of article: both authors Critical revision of article: both authors Final approval of article: both authors. The authors declare that they have no conflicts of interest.