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Summary: 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%). [ABSTRACT FROM AUTHOR]

The authors discuss practice implications of Difficult Airway Society (DAS) guidelines for airway management in critical illness. Topics discussed include the emphasis of the guidelines that the target group of patients is those who are "critically ill," barrier to strategic planning for airway management, and the focus of DAS on the development and investigation of devices.

Throat packs are commonly inserted by anaesthetists after induction of anaesthesia for dental, maxillofacial, nasal or upper airway surgery. However, the evidence supporting this practice as routine is unclear, especially in the light of accidentally retained throat packs which constitute 'Never Events' as defined by NHS England. On behalf of three relevant national organisations, we therefore conducted a systematic review and literature search to assess the evidence base for benefit, and also the extent and severity of complications associated with throat pack use. Other than descriptions of how to insert throat packs in many standard texts, we could find no study that sought to assess the benefit of their insertion by anaesthetists. Instead, there were many reports of minor and major complications (the latter including serious postoperative airway obstruction and at least one death), and many descriptions of how to avoid complications. As a result of these findings, the three national organisations no longer recommend the routine insertion of throat packs by anaesthetists but advise caution and careful consideration. Two protocols for pack insertion are presented, should their use be judged necessary. [ABSTRACT FROM AUTHOR]

The article discusses research being done on airway support to patients. It references the study "Prediction of Difficult Mask Ventilation Using a Systematic Assessment of Risk Factors Versus Existing Practice - A Cluster Randomised Clinical Trial in 94,006 Patients," by A. K. Nørskov et al. in the 2017 issue. The variables considered include diagnostic sensitivity and level of difficulty of intubation, negative predictive values (NPV) and positive predictive values (PPV).

There is little doubt that these guidelines incorporate advances made in airway management since 2004. They will change day-to-day practice of anaesthesia, as outlined above, from pre-operative airway assessment, to integrating the WHO team briefing, to the use and provision of equipment and drugs, and the recording of information on the anaesthesia chart. They will inform the later analysis of any critical airway incidents, especially as documentation and postoperative management are addressed, and they will encourage training in a range of techniques. Taken together, not quite a revolution but certainly a very 'radical evolution'.Assessment of the utility of the new guidelines should consider if they can be used as tools to enhance knowledge and training, or in addition as a prosthesis to bridge the gap between the requirements of and our abilities during emergencies. Formal testing may reveal which aspects of their design, complex as it is, may distract from, rather than enhance, airway management during crises.All guidelines represent a standard of care or a normative approach to a clinical problem. As such, they not only help guide clinicians, but they also provide the broader community with the opportunity to improve standards, to ensure equipment is available, and that training for the skills and processes required are in place to ensure successful adoption. [ABSTRACT FROM AUTHOR]

We present the main findings of the 5th National Audit Project (NAP5) on accidental awareness during general anaesthesia (AAGA). Incidences were estimated using reports of accidental awareness as the numerator, and a parallel national anaesthetic activity survey to provide denominator data. The incidence of certain/probable and possible accidental awareness cases was ∼1:19 600 anaesthetics (95% confidence interval 1:16 700–23 450). However, there was considerable variation across subtypes of techniques or subspecialities. The incidence with neuromuscular block (NMB) was ∼1:8200 (1:7030–9700), and without, it was ∼1:135 900 (1:78 600–299 000). The cases of AAGA reported to NAP5 were overwhelmingly cases of unintended awareness during NMB. The incidence of accidental awareness during Caesarean section was ∼1:670 (1:380–1300). Two-thirds (82, 66%) of cases of accidental awareness experiences arose in the dynamic phases of anaesthesia, namely induction of and emergence from anaesthesia. During induction of anaesthesia, contributory factors included: use of thiopental, rapid sequence induction, obesity, difficult airway management, NMB, and interruptions of anaesthetic delivery during movement from anaesthetic room to theatre. During emergence from anaesthesia, residual paralysis was perceived by patients as accidental awareness, and commonly related to a failure to ensure full return of motor capacity. One-third (43, 33%) of accidental awareness events arose during the maintenance phase of anaesthesia, mostly due to problems at induction or towards the end of anaesthesia. Factors increasing the risk of accidental awareness included: female sex, age (younger adults, but not children), obesity, anaesthetist seniority (junior trainees), previous awareness, out-of-hours operating, emergencies, type of surgery (obstetric, cardiac, thoracic), and use of NMB. The following factors were not risk factors for accidental awareness: ASA physical status, race, and use or omission of nitrous oxide. We recommend that an anaesthetic checklist, to be an integral part of the World Health Organization Safer Surgery checklist, is introduced as an aid to preventing accidental awareness. This paper is a shortened version describing the main findings from NAP5—the full report can be found at http://www.nationalauditprojects.org.uk/NAP5_home. [ABSTRACT FROM AUTHOR]

The author reflects on conducting observational studies rather than randomised controlled trials (RCTs) in anaesthetic research. He states that the key data in an observational study are often presented as point estimates, which is the specific value obtained. An overview of the study by V. Alexiev and colleagues which offer the first observational report of a relatively new supraglottic airway is offered. The author suggests that observational studies can yield baseline data.

Summary [ABSTRACT FROM AUTHOR]

The authors reflect on the lessons from the fourth National Audit Project (NAP4) by the Royal College o0f Anaesthetists (RCoA), which given the Difficult Airway Society (DAS) a guidance in coordinating research initiatives of the airway management community in Great Britain. They say that NAP4 offers information on factors contributing to major adverse events in anaesthesia. They note that the findings have led DAS to adopt a strategy of transforming into a committed national research network.

The article offers views on the paper "A case series of the use of the ProSeal laryngeal mask airway (PLMA) in emergency lower abdominal surgery," by J. Fabregat-López and colleagues. According to the author, the researchers wished to investigate their view that using a PLMA was safe for the circumstances they describe. The author believes the researchers tool something of a gamble with a limited sample size and they observed no complications.

This study compared the efficacy of an anterior jaw lift manoeuvre with that of the Berman airway in clearing the upper airway during oral fibreoptic tracheal intubation in anaesthetised, paralysed patients. Fifty patients were randomly assigned to undergo fibreoptic-assisted intubation with one method, followed by crossover to the alternative method. The time taken to view the vocal cords was the primary endpoint, and we also noted the rate of failure to view the cords, i.e. cords not seen after 120 s of endoscopy. Anterior jaw lift yielded significantly shorter times to view the vocal cords (median [interquartile range; range]: 22 [17–46; 7–120] s vs 40 [29–67; 21–120] s, p = 0.001) and a higher success rate (49/50 vs 42/50, p = 0.014). We conclude that the anterior jaw lift is more effective than the Berman device for achieving airway clearance in this setting. [ABSTRACT FROM AUTHOR]

Summary We conducted a two-part study to assess the practice of withholding neuromuscular blockade until the ability to ventilate the lungs using a bag and face mask (mask ventilation) has been established following induction of anaesthesia. The first part of the study consisted of a postal survey (71% response rate) of 188 anaesthetists in the Oxford region to assess their current practice. Thirty per cent of respondents always checked mask ventilation before administering a neuromuscular blocking drug, whereas 39% of respondents (all them consultants) never did this. A further 31% only did so in the case of known or anticipated difficulty with the airway. In the second part of the study, we measured inspired (V TI ) and expired ( V TE ) tidal volumes before and after neuromuscular blockade in 30 patients undergoing general anaesthesia. The ratio V TE / V TI was used as a measure of the efficiency of ventilation. There was no difference in V TE / V TI before [mean (SD) 0.47 (0.13)] and after [0.45 (0.13)] neuromuscular blockade. We conclude that neuromuscular blockade does not affect the efficiency of mask ventilation in patients with normal airways. [ABSTRACT FROM AUTHOR]

SummaryWe compared the times to intubate the trachea using three techniques in 60 healthy patients with normal airways: (i) fibreoptic intubation with a 6.0-mm reinforced tracheal tube through a standard laryngeal mask airway (laryngeal mask-fibreoptic group); (ii) fibreoptic intubation with a dedicated 7.0-mm silicone tracheal tube through the intubating laryngeal mask airway (intubating laryngeal mask-fibreoptic group); (iii) blind intubation with the dedicated 7.0-mm silicone tracheal tube through the intubating laryngeal mask airway (intubating laryngeal mask-blind group). Mean (SD) total intubation times were significantly shorter in the intubating laryngeal mask-blind group(49 (20) s) than in either of the other two groups (intubating laryngeal mask-fibreoptic 74 (21) s; laryngeal mask-fibreoptic group 75 (36) s; p < 0.001). However, intubation at the first attempt was less successful with the intubating laryngeal mask-blind technique (15/20 (75%)) than in the other two groups (intubating laryngeal mask-fibreoptic 19/20 (95%) and laryngeal mask-fibreoptic 16/20 (80%)) although these differences were not statistically significant. We conclude that in this patient group, all three techniques yield acceptable results. If there is a choice of techniques available, the intubating laryngeal mask-blind technique would result in the shortest intubation time. [ABSTRACT FROM AUTHOR]

A response from the authors of the article "Radical evolution: the 2015 Difficult Airway Society guidelines for managing unanticipated difficult or failed tracheal intubation," by S. D. Marshall and J. J. Pandit is presented

An introduction to the journal is presented in which the editor discusses various articles published within on topics including mass ventilation, supraglottic airways and emergency tracheal access.

A response by J.J. Pandit to a letter to the editor about his article that emphasizes the importance of rapid sequence induction (RSI) as a benchmark for evaluating laryngeal mask airway is presented.

Summary Airway management is primarily designed to avoid hypoxia, yet hypoxia remains the main ultimate cause of anaesthetic-related death and morbidity. Understanding some of the physiology of hypoxia is therefore essential as part of a 'holistic' approach to airway management. Furthermore, it is strategically important that national specialist societies dedicated to airway management do not only focus upon the technical aspects of airway management, but also embrace some of the relevant scientific questions. There has been a great deal of research into causation of hypoxia and the body's natural protective mechanisms and responses to it. This enables us to think of ways in which we might manipulate the cellular and molecular responses to confer greater protection against hypoxia-induced tissue injury. This article reviews some of those aspects. [ABSTRACT FROM AUTHOR]