You are here

  • Home
  • Archive
  • Volume 27, Issue 3
  • A critical reassessment of ambulance service airway management in prehospital care: Joint Royal Colleges Ambulance Liaison Committee Airway Working Group, June 2008

Article Text

Article menu

Download PDFPDF

Prehospital care
A critical reassessment of ambulance service airway management in prehospital care: Joint Royal Colleges Ambulance Liaison Committee Airway Working Group, June 2008
  1. Charles D Deakin1,
  2. Tom Clarke2,
  3. Jerry Nolan3,
  4. David A Zideman4,
  5. Carl Gwinnutt5,
  6. Fionna Moore6,
  7. Michael Ward7,
  8. Carl Keeble8,
  9. Wim Blancke9
  1. 1South Central Ambulance Service, Otterbourne, UK
  2. 2Newcastle upon Tyne Hospitals NHS Foundation Trust, Freeman Hospital, Newcastle upon Tyne, UK
  3. 3Royal United Hospital NHS Trust, Bath, UK
  4. 4Imperial College Healthcare NHS Trust, Hammersmith Hospital, London, UK
  5. 5Salford Royal NHS Foundation Trust, Salford, UK
  6. 6London Ambulance Service NHS Trust, London, UK
  7. 7Nuffield Department of Anaesthetics, John Radcliffe Hospital, Oxford, UK
  8. 8East Midlands Ambulance Service NHS Trust, Nottingham, UK
  9. 9Frenchay Hospital, Frenchay, Bristol, UK
  1. Correspondence to Dr Charles D Deakin, South Central Ambulance Service, Southern House, Sparrowgrove, Otterbourne SO21 2RU, UK; charlesdeakin{at}doctors.org.uk

Abstract

Paramedic tracheal intubation has been practised in the UK for more than 20 years and is currently a core skill for paramedics. Growing evidence suggests that tracheal intubation is not the optimal method of airway management by paramedics and may be detrimental to patient outcomes. There is also evidence that the current initial training of 25 intubations performed in-hospital is inadequate, and that the lack of ongoing intubation practice may compound this further. Supraglottic airway devices (eg, laryngeal mask airway), which were not available when extended training and paramedic intubation was first introduced, are now in use in many ambulance services and are a suitable alternative prehospital airway device for paramedics.

  • Airway
  • clinical assessment
  • competence
  • ECG
  • emergency ambulance systems
  • guidelines
  • paramedic
  • supraglottic airway
  • tracheal intubation
  • training

https://doi.org/10.1136/emj.2009.082115

Statistics from Altmetric.com

    Request Permissions

    If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.

    Executive Summary

    There is a paucity of evidence to suggest that tracheal intubation without the use of drugs is of benefit to patients or improves outcomes. The weight of evidence suggests that prehospital intubation without the use of drugs can worsen patient outcomes.

    The Joint Royal Colleges Ambulance Liaison Committee Airway Working Group (JRCALC) Airway Working Group believes that tracheal intubation without the use of drugs has little value in prehospital practice.

    The current format of paramedic training is inadequate for training prehospital intubation. Improving training for all paramedics (and other similar providers) is not considered feasible, both for operational reasons and difficulties in delivering the training. The majority of those managing patient airways in the prehospital setting should be trained to insert a supraglottic airway device (SAD) instead of a tracheal tube. Tracheal intubation should be developed as a specialist skill for selected providers and should include the provision of drug-assisted intubation. Very significant improvements in initial and ongoing training and education would be required to develop this as an autonomous specialist skill. Current Association of Anaesthetists of Great Britain and Ireland (AAGBI) guidelines outline the standards required to undertake this skill.

    SAD have been shown to be safe and effective devices in elective and emergency hospital procedures. Their use in airway management in prehospital care is increasing, and evidence suggests that they are suitable alternatives to tracheal intubation.

    Training in the use of SAD is already mandatory for UK paramedic registration. Ambulance trusts should be encouraged to adopt and use these devices as an alternative to tracheal intubation.

    When ventilation proves impossible, particularly when there is a history of possible choking, and other manual techniques have failed, laryngoscopy may be used to attempt to remove any foreign body. This does not require training in laryngoscopy to the same extent as that necessary for tracheal intubation and can be incorporated within the current clinical airway management training.

    When prehospital tracheal intubation is undertaken, the following should apply: an intubating bougie should be available routinely; the correct position of the tracheal tube must be verified using both a stethoscope and carbon dioxide detector. (Caution should be exercised when measuring and interpreting exhaled carbon dioxide during low cardiac output states such as cardiac arrest).

    Our conclusions are consistent with the recent National Confidential Enquiry into Patient Outcome and Death (NCEPOD) report1 that states “Airway management in trauma patients is often challenging. The pre-hospital response for these patients should include someone with the skill to secure the airway (including the use of rapid sequence intubation) and maintain adequate ventilation.”

    Introduction

    Although some ambulance personnel were practising tracheal intubation as early as 1968, intubation skills were first widely introduced into paramedic practice in the mid-1980s and are now a core component of the paramedic curriculum. The aim of introducing this skill to the prehospital environment was to provide patients with what was thought at the time to be optimal airway management. Subsequently, tracheal intubation has become expounded as a ‘gold standard’ in airway care.

    Intubation training has traditionally been undertaken by paramedics on hospital attachments, and there was generally no difficulty in obtaining adequate practical experience in the skill. As paramedics matured professionally and evidence-based practice was introduced into ambulance care, the benefits of intubation began to be questioned. This was reflected in the Joint Recommendation from the AETAG/JRCALC Airway Group, published in November 2004.2 More recently, the initial training requiring 25 intubations has become more difficult to provide; fewer patients undergoing general anaesthesia require tracheal intubation as the use of SAD has become more widespread, and concerns over patient consent raised by the AAGBI3 have resulted in fewer intubation opportunities in most hospitals. For paramedics who are qualified, ongoing competence has also been questioned; most paramedics undertake tracheal intubation relatively rarely, with figures ranging from an average of three to four per paramedic per annum in the London Ambulance Service (F Moore, 2009, personal communication) to just one per paramedic per annum in the South Central Ambulance Service (Hampshire Division).4 The benefits of tracheal intubation, particularly in light of recent evidence,5 6 the difficulties in training in this procedure, and the recent availability of other SAD necessitate a review of this area of practice.

    JRCALC is mandated to recommend the most effective, evidence-based treatment for patients requiring emergency and urgent care. JRCALC has recommended that this area of clinical practice is examined in more detail to produce guidance and recommendations for future practice, and requested that a group is formed to undertake this review.

    This group has therefore been formed from experts in the field of prehospital airway management to examine current practice, review evidence of the effectiveness of prehospital paramedic tracheal intubation, discuss the adequacy of current training arrangements and report their findings and recommendations to the JRCALC committee.

    Although the initial remit was to review paramedic airway management, it was recognised that ambulance trusts use the services of other professional groups such as nurses and doctors. It is also recognised that some doctors are able to deliver drug-assisted airway management on scene. Although this paper discusses paramedic practice, the conclusions are applicable to other prehospital care professionals who are trained to similar or lesser standards as paramedics. The review specifically does not address issues relating to drug-assisted intubation, which in the UK is currently undertaken only by doctors, and has been reviewed by a working party from the AAGBI.

    Intubation by paramedics: risk–benefit analysis

    Intubation for cardiopulmonary resuscitation

    Tracheal intubation has long been regarded as a fundamental and essential component of cardiopulmonary resuscitation (CPR). It has been assumed that tracheal intubation improves the chances of survival from cardiac arrest. There are no robust scientific data to support this belief, and there are several reasons why attempted intubation can be harmful, particularly when undertaken by inexperienced individuals.7 The Ontario Prehospital Advanced Life Support (OPALS) study documented no improved survival to hospital discharge when the skills of intubation and cardiac drug administration were added to an optimised basic life support automated external defibrillator system.8

    The potential benefits of placing a cuffed tube in the trachea during CPR include: (1) enabling effective ventilation, particularly when lung and/or chest compliance is poor; (2) minimising gastric inflation and therefore the risk of regurgitation; (3) protection against pulmonary aspiration of gastric contents; (4) enabling ventilation while continuing chest compressions uninterrupted. This increases the number of compressions delivered in each minute.9

    It is known that the oesophageal sphincter pressure decreases rapidly from 20 to 5 cmH2O immediately after cardiac arrest and this predisposes to the regurgitation of gastric contents.10 Regurgitation is documented in approximately a third of out-of-hospital cardiac arrests and in two-thirds of these cases it occurs before the arrival of ambulance personnel.11 Pulmonary aspiration after cardiac arrest has been documented in 20% of survivors,12 although the impact on outcome is unknown. The chances of successful intubation and the risk of complications are highly dependent on the skill of the individual undertaking the procedure. Several studies indicate that in inexperienced hands the success rate is as low as 50% and complication rates are unacceptably high.13 14 This is largely because tracheal intubation does not ‘fail safe’. The risks of attempting tracheal intubation include: (1) hypoxaemia, especially during prolonged attempts without oxygen supplements, and hypercarbia, when time perception by the rescuer is poor; (2) harmful, physiological stress to the patient, in particular when performing laryngoscopy; (3) unrecognised oesophageal intubation: 2.9–16.7% in cardiac arrest studies;14–17 (4) unrecognised main stem bronchial intubation;18 (5) unrecognised dislodgement; (6) interruption of chest compressions during the procedure; (7) trauma to the oropharyngeal tissues.

    In the apnoeic patient, unrecognised oesophageal intubation is almost certainly fatal. In an emergency medical services system with significant rates of unrecognised oesophageal intubation, correctly placed tracheal tubes would have to improve outcomes for many other patients in order to offset these disasters. Such a benefit for tracheal intubation in cardiac arrest is very unlikely.8

    The only prospective randomised trial of prehospital tracheal intubation compared with management of the airway with a bag-valve mask has been undertaken in children.18 This showed no overall benefit for tracheal intubation, and in a subgroup of children with primary respiratory arrest, the outcome was worse in the tracheal intubation group.

    Intubation for trauma

    Training in tracheal intubation and skills retention is increasingly problematical. SAD are now used in up to 80% of anaesthetics in the UK, and this reduces the number of opportunities for paramedics to intubate patients. One study of anaesthesia residents showed that a 90% inhospital intubation success rate was achieved only after 57 intubation attempts;19 furthermore, intubation is much easier under the conditions of elective anaesthesia than it is in the prehospital setting. Among paramedics, the intubation success rate has been shown to correlate with the intubation experience of individual paramedics and not with their length of service.20 Some studies have documented much higher intubation success rates by paramedics but these have generally been retrospective or by self-reporting.21 22 The use of end-tidal carbon dioxide monitoring will reduce the incidence of unrecognised oesophageal intubation,23 but during cardiac arrest, carbon dioxide may not be detected even if the tracheal tube is placed correctly.24

    Data to support paramedic intubation of trauma patients are also scarce. One retrospective study from San Diego concluded that prehospital intubation of patients with severe head injury improves survival.25 However, given that these patients were intubated without drugs, the reported survival rate is remarkably high. Furthermore, there was no correction for case mix and there was no mention of how many attempted, but failed, intubations occurred—these would be included in the no intubation group. In contrast, there was just one survivor out of 492 prehospital trauma patients who were intubated without drugs by paramedics or doctors working with the London helicopter emergency medical service.26 The only other published research showing improved survival after paramedic intubation was a small Finnish study involving head-injured children.27 More recently, a prospective study of rapid sequence induction in 243 severe brain-injured patients by the San Diego group reported that, compared with historical non-intubated matched controls, mortality was significantly higher (33.0% vs 24.2%) in those who were intubated.28 Paramedics intubated after giving midazolam and suxamethonium, and after confirmation of correct tube placement gave rocuronium. Using this technique, intubation still failed in 13% of patients. One third of the study group turned out to have a minor concussion or no head injury. In another study involving a subgroup of 54 patients from the same cohort, 57% became hypoxaemic (peripheral oxygen saturation <90%) during the intubation attempt.29 The same investigators have shown that hypoxaemia and hyperventilation (identified by end-tidal carbon dioxide monitoring) are associated with increased mortality.30 A recent review of prehospital tracheal intubation concluded that not only was there no evidence of benefit, but that there was increasing evidence of harm.5

    Alternative airway devices continue to improve and some of the more recently introduced SAD may enable oxygenation and ventilation without the risks associated with tracheal intubation. In particular, insertion is independent of factors used to predict or score difficult tracheal intubation.31 32 These issues apply to any professional group that is not experienced in tracheal intubation, not just paramedics.

    Training requirements for tracheal intubation

    How much training is necessary to become competent in tracheal intubation?

    Current Institute of Healthcare Development (IHCD) standards require trainee paramedics to achieve 25 intubations during hospital training, of which five must be unassisted. To the best of our knowledge, this figure was chosen because it was considered to be a reasonable number to provide paramedic training, rather than a number based on a scientific assessment of learning curves for intubation.

    The attainment of 25 tracheal intubations cannot be taken as assurance of subsequent ability. The use of a logbook to record tracheal intubation has been challenged because it ‘…gives no clear idea of skill or of progress and merely records “exposure” to a skill or technique.33 Setting of a numerical standard also does not guarantee competence of any given skill, and in a group of individuals there will always be variation in the rate of skill acquisition, with some individuals requiring more training than others.34

    Some recent studies have attempted to define the number of attempts needed to perform a given procedure in order to be competent. The learning curve for anaesthetic trainees learning tracheal intubation with two new tracheal tubes has been reported (figure 1). The estimate of learning half-life (half the total number of procedures necessary to be performed in order to be competent at a given procedure) was 15 intubations, irrespective of the type of tube used.34 Similar results were reported in a study examining first-year anaesthetic residents in which it was found that 57 attempts at tracheal intubation were required to achieve a 90% success rate (figure 2).19 35 More recently, an abstract detailing training requirements for tracheal intubation, reported that 32 intubations were necessary for a 75% success rate and 53 for a 90% success rate.36 These figures are similar to those reported in the two earlier studies.19 35

    Figure 1
    Figure 1

    Intubation time versus serial number of the intubation for the 62 cases in which intubation was successful at the first attempt. ○=Oxford tube, ●=Portex tube. Reproduced from West et al35 by permission of Oxford University Press.

    Figure 2
    Figure 2

    Rate of success for tracheal intubation versus number of performed procedures for first-year anaesthetic residents.19 Reproduced from Konrad et al, by permission of LWW.

    It is clear from these studies that for the majority of those training in tracheal intubation, the 25 attempts at tracheal intubation currently recommended is unlikely to be adequate to attain competence. To reach a 90% success rate with the first intubation attempt, an average laryngoscopist needs at least 57 intubation attempts.19 By applying the results of the three studies19 35 36 to current paramedic training, we estimate that under ideal intubation conditions, the average paramedic is likely to achieve an intubation success rate of 70–75% at best; with little scope for further improvement in skills performance in practice after initial training.

    Skill fade

    There are few studies on skill fade in relation to tracheal intubation. Skill fade is faster with more complex tasks. It is therefore likely that skill fade with tracheal intubation occurs at a greater rate than that with more simple airway skills, such as SAD insertion. Skill fade is accelerated by a lack of ongoing practical experience. The average paramedic intubates an average of just one to four patients per annum.4 There is a significant correlation between the number of patients intubated each year by a paramedic and the intubation success rate (p<0.001, r=0.32).20 37 In medical students given practical instruction in tracheal intubation and re-assessed at 6 months, there was a significant decline in performance, as shown by an increase in the failure rate, an increase in attempts at intubation, increased time to achieve intubation and increased dental trauma.38

    With incomplete initial training and the subsequently limited opportunity to practise tracheal intubation skills, tracheal intubation performance is likely to be suboptimal in paramedics trained within the current infrastructure and practice.

    Opportunities for training

    Current paramedic training involves the intubation of 25 patients during the trainee's hospital attachment. It is widely recognised that this is becoming more of a challenge because airway management during general anaesthesia is moving away from tracheal intubation and therefore provides fewer opportunities. Medicolegal considerations and the recent statement from the AAGBI3 about consent for paramedics to practise clinical airway management have also contributed to the decline in practical opportunities for tracheal intubation.

    Some of the basic intubation skills and knowledge can be acquired using simulation with a manikin. Although simulators are improving all the time, they are not a complete substitute for the training required on real patients. Refresher courses including manikin training may help skills retention.

    Supraglottic airway devices

    The first successful and widely used SAD was invented in 1981 by Archie Brain, a consultant anaesthetist at the Royal London Hospital. His aim was to produce an airway for use in anaesthesia that was more practical than a face mask but less invasive than a tracheal tube, obtaining a continuous clear airway, closer to the natural anatomical and physiological pathway than via a tracheal tube, with the subsequent added benefit of providing a tracheal intubation aid.39 The first paper describing its use was published in 1983,40 and the device became commercially available in 1988. Since its introduction, it is now estimated that there are more than 3000 publications relating to this device, and it has been used on more than 200 million occasions worldwide. The device was originally designed as a reusable airway for use in anaesthetised patients breathing spontaneously, and although this remains its main application, it plays an important role in several other situations, for example resuscitation,41 and is used increasingly by non-medical healthcare professionals.32

    Since 1988, the laryngeal mask airway (LMA) has evolved into a number of different forms that are suitable for a variety of circumstances: (1) a reinforced version to enable the tube to be flexed without the risk of kinking; (2) the intubating laryngeal mask that once inserted acts as a conduit to enable the insertion of a tracheal tube without the need for direct laryngoscopy; (3) the ProSeal (PLMA), with an additional posterior cuff to improve the seal around the glottis and facilitate positive pressure ventilation, and an extra oesophageal drain tube that can guide correct positioning of the device;42 (4) disposable versions of the classic LMA, the PLMA (LMA Supreme) and the intubating laryngeal mask to reduce the risk of cross-infection.

    Once the original patent expired, other manufacturers were quick to produce similar devices. Not all of these have been successful, but there are now several disposable (or single use) devices available, all with slight design variations compared with the original, the latter now referred to as the classic LMA (cLMA). Brain's device has also stimulated a wide range of interest in the production of alternative devices to provide a secure means of managing the airway without the need for laryngoscopy. All of these devices are now grouped together as SAD, although some are designed to function if placed either above or below the glottis. The following devices are available:

    • Glottic aperture seal

    • Pharyngeal airway xpress

    • Cobra perilaryngeal airway

    • Laryngeal tube

    • Airway management device

    • Elisha airway device

    • Combitube

    • Easytube

    • Streamlined liner of the pharynx airway

    • I-gel

    Despite their designation as SAD, these devices vary considerably in their design and function. Consequently, it is increasingly difficult to determine the advantages and disadvantages of the different designs. Furthermore, the situation is made more difficult by published trials in which there is no consistency in approach. There are currently: trials in anaesthetised patients; insertion by anaesthetists, nurses, medical students, paramedics and fire-fighters; trials in manikins; trials in different makes of manikins; trials of insertion in cadavers; use with spontaneous and controlled ventilation; trials comparing dissimilar devices; varying numbers in trials; anecdotal evidence of the use of devices.

    All of this makes comparisons and recommendations about devices, or the circumstances in which different devices may be useful, almost impossible. It must also be remembered that none of these devices have anything like the accumulated experience of usage associated with the LMA.

    A systematic review of randomised controlled trials of tracheal intubation versus alternative airways for the management of acutely ill and injured patients revealed just three studies.43 Two studies of tracheal intubation versus the Combitube in out-of-hospital cardiac arrest showed a significant difference in survival;44 45 the third study was a trial of children requiring airway intervention in the prehospital environment in which there was no difference in survival between paramedic intubation versus bag mask ventilation and later hospital intubation by emergency physicians.18

    A summary of the current predicament is expressed succinctly by Cook: ‘New developments in supraglottic airways may offer benefits over the current preferred devices. Considerable further research in this area is justified. This might include an examination of the appropriateness of training in tracheal intubation to those who rarely use it.’32

    Several studies involving either manikins or anaesthetised patients have shown that paramedics are more successful and faster in securing the airway when using SAD instead of a tracheal tube.46–50

    Some of the SAD have been evaluated for airway management during CPR32; the cLMA51–54 and the Combitube15 44 54 55 are the most extensively studied. The favourable early data on the use of the Combitube during CPR44 have been countered by two recent studies: one reports a complication rate of 21%56 and the other a failure rate of 28% when insertion was attempted by paramedics.57 Other SAD that have been used during CPR include the laryngeal tube,58–60 the new disposable laryngeal tube,61 intubating LMA,62–64 and the I-gel.65 None of the studies on the use of SAD during CPR have been powered adequately to study survival as a primary endpoint; instead, most researchers have studied insertion and ventilation success rates. The SAD are easier to insert than a tracheal tube and, unlike tracheal intubation, they can generally be inserted without interrupting chest compressions. In a manikin study, chest compressions were continued while the time taken to insert either a tracheal tube, cLMA, PLMA or I-gel were measured.66 Insertion of the I-gel was 50% faster than the other devices. The I-gel was also the fastest to insert when compared with several other SAD in another manikin study.67 The median leak pressure achieved with the I-gel is 24–25 cmH2O,68 69 which is significantly higher than the 18–21 cmH2O achieved with the cLMA.70 71

    The PLMA has been studied extensively in anaesthetised patients, but there are no studies of its function and performance during CPR.32 72 It has several attributes that, in theory, make it more suitable than the cLMA for use during CPR: a better laryngeal seal with a leak pressure of 27–31 cmH2O (based on nine studies with 1470 patients), the inclusion of a gastric drain tube enabling venting of liquid regurgitated gastric contents from the upper oesophagus, and passage of a gastric tube to drain liquid gastric contents and the inclusion of a bite block. The PLMA is slightly more difficult to insert than a cLMA.72 A disposable version of the PLMA, the LMA Supreme, has recently become available and is undergoing clinical evaluation. Two cohort studies in anaesthetised patients indicate that the median seal pressure achieved with the LMA Supreme is in the range 24–28 cmH2O.73 74

    During CPR, coronary perfusion is maximised when chest compressions are not paused during ventilation. A correctly placed tracheal tube enables ventilation at 10 breaths per minute without interrupting chest compressions. The lower sealing pressures of SAD compared with tracheal tubes may result in a leak when attempting ventilation without interrupting chest compressions, and this may cause gastric inflation and regurgitation. The effectiveness of ventilation via a SAD without interrupting chest compressions has not been studied and remains an important knowledge gap.

    Methods to increase intubation success and safety

    The intubating bougie

    The bougie is commonly available in hospital to assist with difficult intubation, and its use increases intubation success rates when intubation is difficult.75–78 A study of a physician-led German helicopter emergency medical service documented the use of an intubating bougie in 93.6% of 342 prehospital trauma intubations.79 Despite being recommended to support prehospital intubation,80 few ambulance services train and equip their paramedics with bougies.81 Intubation in the prehospital setting is particularly challenging and it is logical for a bougie to be used routinely.

    Availability of devices for confirming tracheal tube placement

    Confirmation of correct tracheal tube placement by physical examination alone is unreliable; in cardiac arrest studies, unrecognised oesophageal intubation rates of 2.9–16.7% have been reported.14–17

    Exhaled carbon dioxide or oesophageal detection devices can be used to identify the correct tube position. The detection of exhaled carbon dioxide has good specificity for confirming that a tracheal tube is an airway (it does not exclude bronchial intubation), but following mouth-to-mouth ventilation it is possible to detect carbon dioxide from a tube placed in the oesophagus.82 In the presence of a perfusing rhythm, the absence of carbon dioxide has good specificity for detecting an oesophageal intubation, but in cardiac arrest carbon dioxide may not be detected despite correct tracheal placement of the tube, which may then be removed unnecessarily.83 84 Confirmation of tracheal tube placement using capnometry is a mandatory minimum monitoring standard in UK anaesthetic and emergency departments. The use of the oesophageal detector device is an alternative technique but is less reliable and does not provide continuous monitoring as does capnometry.84

    A survey in 2004 showed that virtually no UK ambulance service used either device routinely,81 although we understand that since that report was published, most UK ambulance trusts are moving towards the introduction of capnometry or capnography as an adjunct to tracheal intubation. Minimum standards for monitoring inhospital intubation have been implemented widely;85; despite higher risks of intubation failure in the prehospital environment, these minimum standards are not yet applied.

    Discussion

    The group's aim was to evaluate critically the need for tracheal intubation as a core skill in ambulance practice, and to make recommendations about the optimal prehospital airway management by UK ambulance services. This was primarily in relation to paramedic practice, but encompassing all those who undertake prehospital tracheal intubation without the assistance of anaesthetic drugs. The evidence for the benefit, or not, of prehospital intubation without the use of anaesthetic drugs was reviewed and debated in detail, as were the associated topics relating to current training in this procedure and the availability of alternative airway devices. A systematic review of prehospital airway management was not undertaken as part of this exercise because it was considered that the recent reviews and expertise within the group covered all the main publications in this area, and the costs and delay associated with performing a systematic review would have been significant.

    The committee was in general agreement that there is little evidence that prehospital intubation without the use of anaesthetic drugs improves outcomes in seriously ill or injured patients. Although some studies are of limited quality, the balance of evidence suggests that paramedic intubation may be associated with a worse outcome than basic airway management using the bag mask device. The reasons for this are not entirely clear, but may be related to difficulties in securing the airway, resulting in significant hypoxaemia during the attempts at intubation.

    Intubation is a complex motor skill that requires adequate initial training and sufficient ongoing experience to maintain competency. Current paramedic training was reviewed against the limited evidence for training requirements. Most studies have demonstrated that in order to be competent in the procedure, initial training requires the successful placement of 50–60 tracheal tubes, compared with the 25 that is currently required. Concerns were also expressed that most paramedics do not have sufficient ongoing intubation experience to remain competent in the procedure.

    Simple intubation adjuncts (eg, intubating bougie) are not used by most UK ambulance services, and these have been shown to improve tracheal intubation success rates in hospital airway management. Their use in prehospital tracheal intubation is recommended. In addition, prehospital capnometry should be mandatory for tracheal intubation in order to minimise the incidence of unrecognised oesophageal intubation. This would bring prehospital practice in line with minimum monitoring standards for hospital practice.

    Alternatives to tracheal intubation were discussed. SAD have many advantages over tracheal intubation, particularly in relation to training and maintenance of practical skills. They also do not risk unrecognised oesophageal intubation. Their use in the prehospital setting is limited but growing, and LMA and their variants are now standard airway devices in use by many UK ambulance services.

    The committee concluded that prehospital tracheal intubation, as currently practised by paramedics, could not be endorsed. What evidence there is suggests that this procedure is more likely to be harmful than beneficial.

    The way forward was discussed. It was considered impractical to recommend that all paramedics should be trained to an adequate intubation standard and maintain these standards after qualifying. Although these standards have yet to be defined, they are likely to be to a significantly higher standard than those currently practised and would have parallels with the initial training of doctors entering anaesthesia as a speciality. Training would also necessitate the removal of paramedics from front-line practice for considerable periods, which may not be endorsed by ambulance trusts with significant performance pressures. We agree with the recent NCEPOD report that recommended that the prehospital response for trauma patients should include someone with the skill to secure the airway (including the use of rapid sequence induction and tracheal intubation).85 The way in which this is delivered would be the responsibility of each ambulance trust. If ambulance trusts were to permit tracheal intubation as a specialist skill for some providers, these individuals should receive enough training to become competent in the provision of drug-assisted intubation. Very significant improvements in initial and ongoing training and education would be required to develop this as an autonomous specialist skill. This may be best achieved through a physician-based system commonly seen in most other European countries. Increasing medicalisation of UK specialist prehospital services may meet much of the need.

    For the majority of paramedics, this committee recommends that tracheal intubation should be withdrawn and greater emphasis placed on airway management using an appropriate SAD. (The importance of training to a high degree of proficiency in basic airway management skills should not be overlooked during training.) Several SAD are in clinical use. It is not the scope of this review to recommend specific SAD and ambulance trusts should discuss the options with their local clinical advisory groups. More prehospital research is urgently needed to understand the factors influencing morbidity and mortality in relation to airway management and to establish the optimal device(s) with which the airway should be secured.

    When ventilation proves impossible, particularly when there is a history of possible choking, and other manual techniques have failed, laryngoscopy may be used to attempt to remove any foreign body. This does not require training in laryngoscopy to the same level of competence as that necessary for tracheal intubation and can be incorporated with current clinical airway management training.

    A small but significant number of patients with partly or completely obstructed airways cannot be managed without the use of drug-assisted techniques. Trauma patients and those with obstructed airways not manageable with basic airway adjuncts or a SAD may need to be treated by a practitioner competent in prehospital rapid sequence induction of anaesthesia and intubation, for which there is currently little provision in the UK. The recent NCEPOD review of trauma management1 found that 13.7% of patients with major trauma arriving by ambulance did so with a partly or completely obstructed airway, suggesting that current paramedic training does not equip them with sufficient skills and tools to manage these patients adequately. In 28.6% cases, patients were not intubated when reviewers believed that it should have been attempted. The report concluded that ‘…if pre-hospital intubation is to be part of pre-hospital trauma management then it needs to be in the context of a physician-based pre-hospital care system.’ This may be one option that ambulance trusts should consider in delivering appropriately trained providers to care for those with difficult airways, ‘…to ensure that they are seen at the right time, in the right place and by staff with the most appropriate skills’.86

    The committee concluded that paramedic tracheal intubation can no longer be recommended as a mandatory component of paramedic practice, and should not be continued to be practised in its current format. If prehospital tracheal intubation is to be undertaken, it requires considerably more education and training than that currently provided for paramedics or the use of physicians with appropriate training in advanced airway skills. SAD are suitable alternatives to tracheal intubation. SAD should be introduced into all ambulance services, and ambulance trusts should ensure that both paramedics and technicians receive adequate initial and ongoing training in the use of these devices.

    The timescale for the introduction of any changes in paramedic practice should be decided at a local level. Changes to training and practice in both tracheal intubation and SAD use will need to be reviewed by individual ambulance services to decide the most appropriate way forward.

    Acknowledgments

    We thank Roland Furber and Malcolm Wollard for their contribution to the discussion and preparation of this report.

    References

    1. ↵
      NCEPOD. National Confidential Enquiry into Patient Outcome and Death (NCEPOD) Trauma: who cares? London, UK: NCEPOD 2007.
    2. ↵
      Joint Recommendation from AETAG/JRCALC Airway Group. IHCD training requirement for endotracheal intubation. 2004. http://jrcalc.org.uk/publications/Endotracheal_Intubation.pdf (accessed Jun 2008).
    3. ↵
      1. Bogod DG
      . Consent for Anaesthesia. Revised Edition. London: AAGBI, 2006.
    4. ↵
      1. Deakin CD,
      2. King P,
      3. Thompson F
      . Pre-hospital advanced airway management by ambulance technicians and paramedics: is clinical practice sufficient to maintain skills? Emerg Med J 2009;26:888–91.
      OpenUrlAbstract/FREE Full Text
    5. ↵
      1. Wang HE,
      2. Yealy DM
      . Out-of-hospital endotracheal intubation: where are we? Ann Emerg Med 2006;47:532–41.
      OpenUrlCrossRefPubMedWeb of Science
    6. ↵
      1. Wang HE,
      2. Yealy DM
      . Out-of-hospital endotracheal Intubation—it's time to stop pretending that problems don't exist. Acad Emerg Med 2005;12:1245.
      OpenUrlPubMedWeb of Science
    7. ↵
      1. Nolan JD
      . Prehospital and resuscitative airway care: should the gold standard be reassessed? Curr Opin Crit Care 2001;7:413–21.
      OpenUrlCrossRefPubMed
    8. ↵
      1. Stiell IG,
      2. Wells GA,
      3. Field B,
      4. et al
      . Advanced cardiac life support in out-of-hospital cardiac arrest. N Engl J Med 2004;351:647–56.
      OpenUrlCrossRefPubMedWeb of Science
    9. ↵
      1. Kramer-Johansen J,
      2. Wik L,
      3. Steen PA
      . Advanced cardiac life support before and after tracheal intubation—direct measurements of quality. Resuscitation 2006;68:61–9.
      OpenUrlCrossRefPubMed
    10. ↵
      1. Gabrielli A,
      2. Wenzel V,
      3. Layon AJ,
      4. et al
      . Lower esophageal sphincter pressure measurement during cardiac arrest in humans: potential implications for ventilation of the unprotected airway. Anesthesiology 2005;103:897–9.
      OpenUrlCrossRefPubMedWeb of Science
    11. ↵
      1. Simons RW,
      2. Rea TD,
      3. Becker LJ,
      4. et al
      . The incidence and significance of emesis associated with out-of-hospital cardiac arrest. Resuscitation 2007;74:427–31.
      OpenUrlCrossRefPubMed
    12. ↵
      1. Virkkunen I,
      2. Ryynanen S,
      3. Kujala S,
      4. et al
      . Incidence of regurgitation and pulmonary aspiration of gastric contents in survivors from out-of-hospital cardiac arrest. Acta Anaesthesiol Scand 2007;51:202–5.
      OpenUrlCrossRefPubMedWeb of Science
    13. ↵
      1. Bradley JS,
      2. Billows GL,
      3. Olinger ML,
      4. et al
      . Prehospital oral endotracheal intubation by rural basic emergency medical technicians. Ann Emerg Med 1998;32:26–32.
      OpenUrlCrossRefPubMedWeb of Science
    14. ↵
      1. Sayre MR,
      2. Sakles JC,
      3. Mistler AF,
      4. et al
      . Field trial of endotracheal intubation by basic EMTs. Ann Emerg Med 1998;31:228–33.
      OpenUrlCrossRefPubMedWeb of Science
    15. ↵
      1. Rumball C,
      2. Macdonald D,
      3. Barber P,
      4. et al
      . Endotracheal intubation and esophageal tracheal Combitube insertion by regular ambulance attendants: a comparative trial. Prehosp Emerg Care 2004;8:15–22.
      OpenUrlCrossRefPubMed
    16. ↵
      1. Pelucio M,
      2. Halligan L,
      3. Dhindsa H
      . Out-of-hospital experience with the syringe esophageal detector device. Acad Emerg Med 1997;4:563–8.
      OpenUrlCrossRefPubMedWeb of Science
    17. ↵
      1. Katz SH,
      2. Falk JL
      . Misplaced endotracheal tubes by paramedics in an urban emergency medical services system. Ann Emerg Med 2001;37:62–4.
      OpenUrlCrossRefPubMedWeb of Science
    18. ↵
      1. Gausche M,
      2. Lewis RJ,
      3. Stratton SJ,
      4. et al
      . Effect of out-of-hospital pediatric endotracheal intubation on survival and neurological outcome: a controlled clinical trial. JAMA 2000;283:783–90.
      OpenUrlCrossRefPubMedWeb of Science
    19. ↵
      1. Konrad C,
      2. Schupfer G,
      3. Wietlisbach M,
      4. et al
      . Learning manual skills in anesthesiology: is there a recommended number of cases for anesthetic procedures? Anesth Analg 1998;86:635–9.
      OpenUrlCrossRefPubMedWeb of Science
    20. ↵
      1. Garza AG,
      2. Gratton MC,
      3. Coontz D
      . Effect of paramedic experience on orotracheal intubation success rates. J Emerg Med 2003;25:251–6.
      OpenUrlCrossRefPubMedWeb of Science
    21. ↵
      1. Wang HE,
      2. Sweeney TA,
      3. O'Connor RE,
      4. et al
      . Failed prehospital intubations: an analysis of emergency department courses and outcomes. Prehosp Emerg Care 2001;5:134–41.
      OpenUrlCrossRefPubMed
    22. ↵
      1. Wayne MA,
      2. Friedland E
      . Prehospital use of succinylcholine: a 20-year review. Prehosp Emerg Care 1999;3:107–9.
      OpenUrlCrossRefPubMed
    23. ↵
      1. Silvestri S,
      2. Ralls GA,
      3. Krauss B,
      4. et al
      . The effectiveness of out-of-hospital use of continuous end-tidal carbon dioxide monitoring on the rate of unrecognized misplaced intubation within a regional emergency medical services system. Ann Emerg Med 2005;45:497–503.
      OpenUrlCrossRefPubMedWeb of Science
    24. ↵
      1. Sanchi O,
      2. Calder I
      . Capnography and the difference between tracheal and oesophageal intubation. Anaesthesia 1999;54:604–5.
      OpenUrlCrossRefPubMedWeb of Science
    25. ↵
      1. Winchell RJ,
      2. Hoyt DB
      . Endotracheal intubation in the field improves survival in patients with severe head injury. Trauma Research and Education Foundation of San Diego. Arch Surg 1997;132:592–7.
      OpenUrlCrossRefPubMedWeb of Science
    26. ↵
      1. Lockey D,
      2. Davies G,
      3. Coats T
      . Survival of trauma patients who have prehospital tracheal intubation without anaesthesia or muscle relaxants: observational study. BMJ 2001;323:141.
      OpenUrlFREE Full Text
    27. ↵
      1. Suominen P,
      2. Baillie C,
      3. Kivioja A,
      4. et al
      . Intubation and survival in severe paediatric blunt head injury. Eur J Emerg Med 2000;7:3–7.
      OpenUrlPubMed
    28. ↵
      1. Davis DP,
      2. Ochs M,
      3. Hoyt DB,
      4. et al
      . Paramedic-administered neuromuscular blockade improves prehospital intubation success in severely head-injured patients. J Trauma 2003;55:713–19.
      OpenUrlPubMedWeb of Science
    29. ↵
      1. Dunford JV,
      2. Davis DP,
      3. Ochs M,
      4. et al
      . Incidence of transient hypoxia and pulse rate reactivity during paramedic rapid sequence intubation. Ann Emerg Med 2003;42:721–8.
      OpenUrlCrossRefPubMedWeb of Science
    30. ↵
      1. Davis DP,
      2. Dunford JV,
      3. Poste JC,
      4. et al
      . The impact of hypoxia and hyperventilation on outcome after paramedic rapid sequence intubation of severely head-injured patients. J Trauma 2004;57:1–8.
      OpenUrlCrossRefPubMedWeb of Science
    31. ↵
      1. Brimacombe JR
      . Laryngeal mask anaesthesia: principles and practice, 2nd edn. Philadelphia: Saunders, 2005.
    32. ↵
      1. Cook TM,
      2. Hommers C
      . New airways for resuscitation? Resuscitation 2006;69:371–87.
      OpenUrlCrossRefPubMedWeb of Science
    33. ↵
      1. Lawler PG,
      2. Patla VR,
      3. Garcia E,
      4. et al
      . Assessment of training in anaesthesia and related skills. Anaesthesia 1991;46:597.
      OpenUrlPubMedWeb of Science
    34. ↵
      1. Kestin IG
      . A statistical approach to measuring the competence of anaesthetic trainees at practical procedures. Br J Anaesth 1995;75:805–9.
      OpenUrlAbstract/FREE Full Text
    35. ↵
      1. West MR,
      2. Jonas MM,
      3. Adams AP,
      4. et al
      . A new tracheal tube for difficult intubation. Br J Anaesth 1996;76:673–9.
      OpenUrlAbstract/FREE Full Text
    36. ↵
      1. Cormack RS,
      2. Smith JE
      . Training requirements for tracheal intubation (abstract). Dundee: Anaesthetic Research Society, Jun 22–23 2006.
    37. ↵
      1. Wang HE,
      2. Seitz SR,
      3. Hostler D,
      4. et al
      . Defining the learning curve for paramedic student endotracheal intubation. Prehosp Emerg Care 2005;9:156–62.
      OpenUrlCrossRefPubMed
    38. ↵
      1. Maharaj CH
      . Retention of tracheal intubation skills by novice personnel: a comparison of the Airtraq and Macintosh laryngoscopes. Anaesthesia 2007;62:272–8.
      OpenUrlCrossRefPubMedWeb of Science
    39. ↵
      1. Brain AIJ
      . The development of the laryngeal mask—a brief history of the invention, early clinical studies and experimental work from which the laryngeal mask evolved. Eur J Anaesthesiol 1991;4:5–17.
      OpenUrl
    40. ↵
      1. Brain AIJ
      . The laryngeal mask—a new concept in airway management. Br J Anaesth 1983;55:801–5.
      OpenUrlAbstract/FREE Full Text
    41. ↵
      1. Nolan JP,
      2. Deakin CD,
      3. Soar J,
      4. et al
      . European Resuscitation Council guidelines for resuscitation 2005. Section 4. Adult advanced life support. Resuscitation 2005;67(Suppl 1):S39–86.
      OpenUrlCrossRefPubMedWeb of Science
    42. ↵
      1. Brain AI,
      2. Verghese C,
      3. Strube PJ
      . The LMA ‘ProSeal’—a laryngeal mask with an oesophageal vent. Br J Anaesth 2000;84:650–4.
      OpenUrlAbstract/FREE Full Text
    43. ↵
      1. Lecky F,
      2. Bryden D,
      3. Little R,
      4. et al
      . Emergency intubation for acutely ill and injured patients. Cochrane Database Syst Rev 2008;(2):CD 001429.
    44. ↵
      1. Rabitsch W,
      2. Schellongowski P,
      3. Staudinger T,
      4. et al
      . Comparison of a conventional tracheal airway with the Combitube in an urban emergency medical services system run by physicians. Resuscitation 2003;57:27–32.
      OpenUrlCrossRefPubMedWeb of Science
    45. ↵
      1. Goldenberg IF,
      2. Campion BC,
      3. Siebold CM,
      4. et al
      . Esophageal gastric tube airway vs endotracheal tube in prehospital cardiopulmonary arrest. Chest 1986;90:90–6.
      OpenUrlCrossRefPubMedWeb of Science
    46. ↵
      1. Pennant JH,
      2. Walker MB
      . Comparison of the endotracheal tube and laryngeal mask in airway management by paramedical personnel. Anesth Analg 1992;74:531–4.
      OpenUrlPubMedWeb of Science
    47. ↵
      1. Wahlen BM,
      2. Roewer N,
      3. Lange M,
      4. et al
      . Tracheal intubation and alternative airway management devices used by healthcare professionals with different level of pre-existing skills: a manikin study. Anaesthesia 2009;64:549–54.
      OpenUrlCrossRefPubMedWeb of Science
    48. ↵
      1. Bollig G,
      2. Lovhaug SW,
      3. Sagen O,
      4. et al
      . Airway management by paramedics using endotracheal intubation with a laryngoscope versus the oesophageal tracheal Combitube and EasyTube on manikins: a randomised experimental trial. Resuscitation 2006;71:107–11.
      OpenUrlCrossRefPubMed
    49. ↵
      1. Abo BN,
      2. Hostler D,
      3. Wang HE
      . Does the type of out-of-hospital airway interfere with other cardiopulmonary resuscitation tasks? Resuscitation 2007;72:234–9.
      OpenUrlCrossRefPubMed
    50. ↵
      1. Deakin CD,
      2. Peters R,
      3. Tomlinson P,
      4. et al
      . Securing the prehospital airway: a comparison of laryngeal mask insertion and endotracheal intubation by UK paramedics. Emerg Med J 2005;22:64–7.
      OpenUrlAbstract/FREE Full Text
    51. ↵
      1. Baskett PJ
      . The laryngeal mask in resuscitation. Resuscitation 1994;28:93–5.
      OpenUrlCrossRefPubMed
    52. ↵
      1. Stone BJ,
      2. Leach AB,
      3. Alexander CA,
      4. et al
      . The use of the laryngeal mask airway by nurses during cardiopulmonary resuscitation. Results of a multicentre trial. Anaesthesia 1994;49:3–7.
      OpenUrlCrossRefPubMedWeb of Science
    53. ↵
      1. Rumball CJ,
      2. MacDonald D
      . The PTL, Combitube, laryngeal mask, and oral airway: a randomized prehospital comparative study of ventilatory device effectiveness and cost-effectiveness in 470 cases of cardiorespiratory arrest. Prehosp Emerg Care 1997;1:1–10.
      OpenUrlCrossRefPubMed
    54. ↵
      1. Tanigawa K,
      2. Shigematsu A
      . Choice of airway devices for 12,020 cases of nontraumatic cardiac arrest in Japan. Prehosp Emerg Care 1998;2:96–100.
      OpenUrlCrossRefPubMed
    55. ↵
      1. Lefrancois DP,
      2. Dufour DG
      . Use of the esophageal tracheal combitube by basic emergency medical technicians. Resuscitation 2002;52:77–83.
      OpenUrlCrossRefPubMed
    56. ↵
      1. Vezina MC,
      2. Trepanier CA,
      3. Nicole PC,
      4. et al
      . Complications associated with the Esophageal-Tracheal Combitube in the pre-hospital setting. Can J Anaesth 2007;54:124–8.
      OpenUrlCrossRefPubMedWeb of Science
    57. ↵
      1. Calkins TR,
      2. Miller K,
      3. Langdorf MI
      . Success and complication rates with prehospital placement of an esophageal-tracheal combitube as a rescue airway. Prehospital Disaster Med 2006;21:97–100.
      OpenUrlPubMed
    58. ↵
      1. Kette F,
      2. Reffo I,
      3. Giordani G,
      4. et al
      . The use of laryngeal tube by nurses in out-of-hospital emergencies: preliminary experience. Resuscitation 2005;66:21–5.
      OpenUrlCrossRefPubMedWeb of Science
    59. ↵
      1. Asai T,
      2. Moriyama S,
      3. Nishita Y,
      4. et al
      . Use of the laryngeal tube during cardiopulmonary resuscitation by paramedical staff. Anaesthesia 2003;58:393–4.
      OpenUrlCrossRefPubMedWeb of Science
    60. ↵
      1. Genzwuerker HV,
      2. Dhonau S,
      3. Ellinger K
      . Use of the laryngeal tube for out-of-hospital resuscitation. Resuscitation 2002;52:221–4.
      OpenUrlCrossRefPubMedWeb of Science
    61. ↵
      1. Wiese CH,
      2. Semmel T,
      3. Muller JU,
      4. et al
      . The use of the laryngeal tube disposable (LT-D) by paramedics during out-of-hospital resuscitation-an observational study concerning ERC guidelines 2005. Resuscitation 2009;80:194–8.
      OpenUrlCrossRefPubMedWeb of Science
    62. ↵
      1. Timmermann A,
      2. Russo SG,
      3. Rosenblatt WH,
      4. et al
      . Intubating laryngeal mask airway for difficult out-of-hospital airway management: a prospective evaluation. Br J Anaesth 2007;99:286–91.
      OpenUrlAbstract/FREE Full Text
    63. ↵
      1. Tentillier E,
      2. Heydenreich C,
      3. Cros AM,
      4. et al
      . Use of the intubating laryngeal mask airway in emergency pre-hospital difficult intubation. Resuscitation 2007;77:30–34.
      OpenUrlCrossRefPubMed
    64. ↵
      1. Herff H,
      2. Wenzel V,
      3. Dorges V
      . Avoiding field airway management problems. Resuscitation 2007;77(1):4.
      OpenUrlPubMed
    65. ↵
      1. Soar J
      . The I-gel supraglottic airway and resuscitation–some initial thoughts. Resuscitation 2007;74:197.
      OpenUrlCrossRefPubMedWeb of Science
    66. ↵
      1. Gatward JJ,
      2. Thomas MJ,
      3. Nolan JP,
      4. et al
      . Effect of chest compressions on the time taken to insert airway devices in a manikin. Br J Anaesth 2008;100:351–6.
      OpenUrlAbstract/FREE Full Text
    67. ↵
      1. Jackson KM,
      2. Cook TM
      . Evaluation of four airway training manikins as patient simulators for the insertion of eight types of supraglottic airway devices. Anaesthesia 2007;62:388–93.
      OpenUrlCrossRefPubMedWeb of Science
    68. ↵
      1. Gatward JJ,
      2. Cook TM,
      3. Seller C,
      4. et al
      . Evaluation of the size 4 I-gel airway in one hundred non-paralysed patients. Anaesthesia 2008;63:1124–30.
      OpenUrlCrossRefPubMedWeb of Science
    69. ↵
      1. Gabbott DA,
      2. Beringer R
      . The iGEL supraglottic airway: a potential role for resuscitation? Resuscitation 2007;73:161–2.
      OpenUrlCrossRefPubMed
    70. ↵
      1. Cook TM,
      2. McCormick B,
      3. Asai T
      . Randomized comparison of laryngeal tube with classic laryngeal mask airway for anaesthesia with controlled ventilation. Br J Anaesth 2003;91:373–8.
      OpenUrlAbstract/FREE Full Text
    71. ↵
      1. Cook TM,
      2. McKinstry C,
      3. Hardy R,
      4. et al
      . Randomized crossover comparison of the ProSeal laryngeal mask airway with the Laryngeal Tube during anaesthesia with controlled ventilation. Br J Anaesth 2003;91:678–83.
      OpenUrlAbstract/FREE Full Text
    72. ↵
      1. Cook TM,
      2. Lee G,
      3. Nolan JP
      . The ProSeal laryngeal mask airway: a review of the literature. Can J Anaesth 2005;52:739–60.
      OpenUrlCrossRefPubMedWeb of Science
    73. ↵
      1. Cook TM,
      2. Gatward JJ,
      3. Handel J,
      4. et al
      . Evaluation of the LMA Supreme in 100 non-paralysed patients. Anaesthesia 2009;64:555–62.
      OpenUrlCrossRefPubMedWeb of Science
    74. ↵
      1. Timmermann A,
      2. Cremer S,
      3. Eich C,
      4. et al
      . Prospective clinical and fiberoptic evaluation of the Supreme laryngeal mask airway. Anesthesiology 2009;110:262–5.
      OpenUrlPubMedWeb of Science
    75. ↵
      1. Nolan JP,
      2. Wilson ME
      . Orotracheal intubation in patients with potential cervical spine injuries. An indication for the gum elastic bougie. Anaesthesia 1993;48:630–3.
      OpenUrlPubMedWeb of Science
    76. ↵
      1. Nolan JP,
      2. Wilson ME
      . An evaluation of the gum elastic bougie. Intubation times and incidence of sore throat. Anaesthesia 1992;47:878–81.
      OpenUrlPubMedWeb of Science
    77. ↵
      1. Gataure PS,
      2. Vaughan RS,
      3. Latto IP
      . Simulated difficult intubation. Comparison of the gum elastic bougie and the stylet. Anaesthesia 1996;51:935–8.
      OpenUrlCrossRefPubMedWeb of Science
    78. ↵
      1. Hodzovic I,
      2. Wilkes AR,
      3. Latto IP
      . To shape or not to shape. Simulated bougie-assisted difficult intubation in a manikin. Anaesthesia 2003;58:792–7.
      OpenUrlCrossRefPubMed
    79. ↵
      1. Helm M,
      2. Hossfeld B,
      3. Schafer S,
      4. et al
      . Factors influencing emergency intubation in the pre-hospital setting—a multicentre study in the German Helicopter Emergency Medical Service. Br J Anaesth 2006;96:67–71.
      OpenUrlAbstract/FREE Full Text
    80. ↵
      1. Pitt K,
      2. Woollard M
      . Should paramedics bougie on down? Pre-Hosp Immed Care 2000;4:68–70.
      OpenUrl
    81. ↵
      1. Ridgway S,
      2. Hodzovic I,
      3. Woollard M,
      4. et al
      . Prehospital airway management in ambulance services in the United Kingdom. Anaesthesia 2004;59:1091–4.
      OpenUrlCrossRefPubMedWeb of Science
    82. ↵
      1. Kramer-Johansen J,
      2. Dorph E,
      3. Steen PA
      . Detection of carbon dioxide in expired air after oesophageal intubation; the role of bystander mouth-to-mouth ventilation. Acta Anaesthesiol Scand 2008;52:155–7.
      OpenUrlPubMedWeb of Science
    83. ↵
      1. Li J
      . Capnography alone is imperfect for endotracheal tube placement confirmation during emergency intubation. J Emerg Med 2001;20:223–9.
      OpenUrlCrossRefPubMedWeb of Science
    84. ↵
      1. Anonymous
      . 2005 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Part 4: Advanced life support. Resuscitation 2005;67:213–47.
      OpenUrlCrossRefPubMed
    85. ↵
      1. Birks RJS
      . Recommendations for standards of monitoring during anaesthesia and recovery. 4th edn. London: AAGBI, 2007.
    86. ↵
      1. Alberti G
      . Emergency care ten years on: reforming emergency care. London, UK: Department of Health, 2007.
    View Abstract

    Footnotes

      fn-1

    • Linked articles 088443, 090316, 090381.

      • fn-3

    • Competing interests CDD, TC, FM, CK, WB and MW are members of the Joint Royal Colleges Ambulance Liaison Committee Airway Working Group.

      • fn-4

    • Provenance and peer review Not commissioned; externally peer reviewed.

    Linked Articles