Home News Archive Publications Conferences Latest Evidence Contact Details
Background Search/ Site Map Presentations Guidelines Regional Groups Links

Regional Activity

Each regional group will report their current clinical effectiveness activity on these pages.

Wales
Last updated 18/06/01

Should Paramedics Bougie on Down?

Pitt, K., Woollard, M. Should paramedics bougie on down? Pre-hospital Immediate Care. 2000;4:68-70. Reproduced with the permission of BMJ Publishing Group.

This is copyrighted and must not be reproduced without permission of the authors.  

Authors
Karen Pitt, Welsh Ambulance Services NHS Trust, Central and West Region, Welsh Ambulance Services NHS Trust
Malcolm Woollard, Pre-hospital Emergency Research Unit, University of Wales College of Medicine / Welsh Ambulance Services NHS Trust

Corresponding Author:

Malcolm Woollard
Pre-hospital Emergency Research Unit
Lansdowne Hospital
Sanatorium Road
Cardiff
CF1 8UL
Tel: 02920 233651 ext. 2930
Fax: 02920 237930
Email: [email protected]

Should Paramedics Bougie on Down?

Abstract

Objective

The objective of this literature search was to find evidence to support (or refute) the use of the gum elastic bougie type endotracheal tube introducer by paramedics.

Methods

An on-line literature search was made of the Cochrane Library, Medline and the World Wide Web. Information retrieved from the Web was utilised as a source of further references only. A hand search of the Annals of Emergency Medicine was also conducted. The key text words utilised were ‘bougie,’ ‘elastic,’ ‘gum bougie’ and ‘Eschmann.’ References from retrieved papers were also sought and reviewed where available. A critical appraisal was conducted of each paper to determine internal and external validity.

Results

Seven papers were ultimately considered. None addressed the use of the bougie by paramedics. One RCT showed a 30% difference in successful intubation rates in favour of the bougie, which was highly significant (p<0.001, 95% CI = 0.15 to 0.45). A second RCT also found a higher success rate with the bougie (p<0.02). A third RCT demonstrated that maintaining laryngoscopy and rotating the bevel of the ETT to face posteriorly resulted in a 52% improvement in first time success rates. A fourth RCT showed the median intubation time was quicker for direct visualisation (18 versus 28 seconds, p<0.001) although three patients could only be intubated using a bougie. A further study reported the efficacy of feeling for clicks and bougie ‘hold up’ as a means of verifying tracheal placement. No study reported any serious sequelae to bougie use or increased incidence of minor complications.

Conclusions

The bougie appears to increase the first time intubation success rate. It does not seem to result in a significant reported incidence of minor or serious complications. As it’s use by paramedics is unproven its introduction should be accompanied by a detailed outcome audit.

Key Words

Bougie, paramedic, endotracheal, introducer, difficult intubation.

Introduction

But for the gum elastic bougie, many difficult endotracheal intubations could not be accomplished without the use of more invasive techniques. This re-usable instrument, also known as the Eschmann tracheal tube introducer (Portex Limited, Hythe, UK), is a 60cm long, 15 French Gauge flexible device with a J (coudé) angle at its distal tip. During use a curve is also formed towards its distal end. A disposable equivalent is also available (Portex, op cit).

When used to assist in the intubation of a patient with an anterior glottis, the bougie is advanced anterior to the arytenoid cartilages and in the mid-line, under direct laryngoscopy. The tip is advanced into the trachea whilst the intubator feels for clicks as it passes over the tracheal rings. The endotracheal tube (ETT) is then rail-roaded over the bougie, which is held firmly in place. Once the ETT is in situ the laryngoscope and bougie are withdrawn, and correct placement in the trachea is confirmed using standard techniques. The bougie is considerably more flexible than a stylet inserted in an endotracheal tube and it has been argued that it is therefore relatively atraumatic in use.[1]

The gum elastic bougie was introduced into anaesthetic practice in 1949 by Sir Robert Macintosh.[2] Since this time it has become an important adjunct in the management of difficult intubation by anaesthetists. One survey conducted in 1988 showed that a bougie was used as the first strategy in managing ninety percent of cases of difficult intubation.[3] According to Latto, the preference of anaesthetists has changed in favour of the bougie at the cost of the malleable stylet.[3] Gataure hypothesised that this was as a result of a growing realisation by anaesthetists that the bougie was superior to the stylet under such circumstances.[1]

This paper seeks to address the question of whether the bougie is an appropriate device for use by paramedics in the pre-hospital milieu.

Methods

A literature search was undertaken using the facilities of the University of Wales College of Medicine and the Post-Graduate Medical Centre of the West Wales General Hospital. An on-line search was made of the Cochrane Library, Medline and the World Wide Web. Information retrieved from the Web was utilised as a source of further references only. A hand search of the Annals of Emergency Medicine was also conducted. The key text words utilised were ‘bougie,’ ‘elastic,’ ‘gum bougie’ and ‘Eschmann.’ References from retrieved papers were also sought and reviewed where available. A critical appraisal was conducted of each paper to determine internal and external validity.

Results

Seven papers from peer reviewed medical journals were ultimately considered. The papers included four randomised controlled trials, [1], [4], [5], [6] one intervention study, [7] one case report [8] and one discussion paper. [9]

No papers, with the exception of the case report, addressed the use of the gum-elastic bougie by paramedics or in the pre-hospital environment.

Gataure , et al. [1] in a randomised controlled trial of 100 patients, compared the efficacy of the bougie versus the stylet in patients with simulated difficult intubation. This trial showed a 30% difference in success rates in favour of the bougie which was highly significant (p<0.001, 95% CI = 0.15 to 0.45).

Nolan et al. [4] compared the use of bougies against direct visual intubation in patients held in manual in-line stabilisation of the cervical spine with cricoid pressure applied. Of 157 patients the view of the larynx was reduced in 45% and nothing beyond the epiglottis was visible in 22%. Seventy-nine patients were randomised to direct visual intubation and seventy-eight to bougie-assisted intubation. Five patients in the direct visual group could not be intubated, but all patients (including the failures from the first group) were successfully intubated using the bougie (p<0.02). The trial also found that whilst the mean intubation time was quicker in the visualisation group this included eleven patients where the procedure took longer than forty five seconds. Conversely, none of the procedures in the bougie group took longer than forty-five seconds (p<0.001).

Dogra et al [5] examined the efficacy of different intubation techniques (all using a bougie) in 100 patients. These included withdrawing the laryngoscope prior to passing the ETT over the pre-positioned bougie, leaving the laryngoscope in situ, and rotation of the ETT so that the bevel faced posteriorly. Patients were randomised in equal numbers to passage of the ETT with a laryngoscope in situ or intubation with the laryngoscope withdrawn. There was a 74% first time success rate in the former group compared with 22% in the latter (p<0.000001). When the laryngoscope was left in situ there was a 52% improvement in first time success rates if the ETT was rotated so that its bevel faced posteriorly during its passage over the bougie.

Nolan et al [6] examined 149 patients who were randomised to either a simulated ‘epiglottis-only’ view with intubation assisted by use of a bougie and tube rotation, or direct visual laryngoscopy without simulation of an epiglottis-only view. Whilst the median intubation time was quicker for the laryngoscopy group (18 versus 28 seconds, p<0.001) three patients could not be intubated in this sample. These individuals were subsequently intubated with the assistance of a gum-elastic bougie. This study also compared the incidence of sore throat in each group. No statistically significant difference was noted.

Kidd et al. [7] examined 100 patients with real or simulated difficult intubations to determine the reliability of the presence of tracheal ring ‘clicks’ and bougie ‘hold-up’ (which occurs when the tip reaches the small bronchi) as a means of confirming correct placement of a bougie. Actual placement was verified under direct vision with a laryngoscope. In 78 patients the bougie was laryngoscopically confirmed as being positioned in the trachea. Clicks were felt in 89.7% of this group, and hold-up of the bougie occurred in 100%. Oesophageal placement occurred in twenty-two patients. Neither clicks nor hold-up occurred in any of these. The authors cautioned against the use of excessive force when utilising this procedure due to the theoretical risk of causing damage to a bronchus.

Nocera’s case study [8] describes the use of a bougie in the pre-hospital environment to facilitate intubation in a patient with head injuries following rapid sequence induction. The patient was trapped and this resulted in a very limited view of the epiglottis being obtained. The author of this paper states that since “…the view of the larynx was rotated in two planes, the use of a stylet-mounted tube would have totally obscured the available view of the larynx.”

In their paper discussing difficult intubation in obstetric patients Cormack et al. [9] recommend the use of the Macintosh technique, which includes insertion of a gum elastic bougie.

Discussion

When called upon to intubate, paramedics are often working under less than ideal conditions. Patients may be poorly positioned, in hostile weather conditions, and without the availability of adequate lighting. Further, they may not be fully relaxed as no anaesthetic will have been given. Intubation is widely accepted as the gold standard for airway management. [10] Consequently, paramedics must be equipped and trained to maximise their success rate in utilising this technique under all such circumstances.

The internal validity of the studies described has been assessed using critical appraisal techniques, [11] including consideration of the study design and statistical methodology and results. However, our review highlights a lack of external validity since we were unable to find any trials involving paramedics or the pre-hospital environment. This could, in part, be due to the fact that the bulk of pre-hospital research is conducted in the USA where the gum bougie is, by tradition, rarely used. [12]But, as Cochrane is often quoted as stating, ‘absence of evidence of effect is not evidence of absence of effect’ [13] and it is not, therefore, unreasonable to assume that some patients may benefit from paramedics having access to this technique.

In almost all of the above studies, unassisted direct laryngoscopy was insufficient to allow successful intubation in a small number of patients, even when practised by experienced anaesthetists. Simple options for assisting intubation when the view is limited include the stylet and the bougie. Gataure et al. [1] unequivocally demonstrate the superior results obtained with the latter device.

Use of correct technique is vital in facilitating first time success in placing the ETT in the trachea. Nolan et al. [6] conclude that leaving the laryngoscope in situ and rotating the endotracheal tube so that the bevel faces the posterior wall of the pharynx significantly enhance success rates. The value of training operators to feel for clicks and bougie hold-up has been demonstrated by Kidd et al. [7] It can be safely advised that failure to detect clicks or hold-up is indicative of oesophageal placement of the bougie. However, we feel it prudent to suggest that the presence of clicks or hold-up should not be taken as a definitive indication of subsequent correct tracheal positioning of the ETT. Additional measures to confirm correct ETT placement on completion of the procedure are vital. These may include auscultation of the lung fields and epigastrium, and use of an oesophageal bulb device or quantitative end-tidal CO2 detector.[14]

Importantly, no serious adverse events related to the use of a bougie were reported in any of the papers reviewed. Whilst sore throat was documented to occur by Nolan et al. [6] the incidence was the same regardless of whether a bougie was used. However, a theoretical risk exists of causing damage to the structures of the airway as a result of the use of excessive force.[7]

Conclusion and Recommendations

This review has demonstrated the value of the gum elastic bougie in assisting difficult intubation. The risk of serious adverse events appears to be slight. Given the current climate of evidence-based medicine and best clinical practice, we feel it appropriate to recommend that paramedics be trained and authorised to employ this procedure, using the techniques discussed elsewhere in this paper. However, since no research has been conducted in the pre-hospital arena, it will be vital to conduct a sound outcome audit to confirm patient benefits. Training programmes must address the factors which increase the risk of damage to the structures of the airway when using a bougie, and emphasise the importance of using a range of strategies to confirm correct ETT position.

Acknowledgements

The authors gratefully acknowledge the assistance provided by two peer reviewers in improving an earlier draft of this paper.

Contributors

Karen Pitt conceived the idea of conducting this review and undertook the literature search. Critical appraisal of retrieved literature, writing and editing of this paper were undertaken jointly by Karen Pitt and Malcolm Woollard.

References

[1] Gataure, P.S., Vaughan, R.S., Latto, I.P. Simulated difficult intubation: comparison of the gum elastic bougie and the stylet. Anaesthesia, 1996;51:935-938.
[2] Macintosh, R.R. An aid to oral intubation. British Medical Journal, 1949;1:28
[3] Latto, I.P., Rosen, M. Difficulties in tracheal intubation. Eastbourne: Balliere Tindall / W.B. Saunders, 1985:103.
[4] Nolan, J.P., Wilson, M.E. Orotracheal intubation in patients with potential cervical spine injuries. Anaesthesia, 1993;48:630-633.
[5] Dogra, S., Falconer, R., Latto, I.P. Successful difficult intubation: tracheal tube placement over a gum elastic bougie. Anaesthesia, 1990;45:776-780.
[6] Nolan, J.P., Wilson, M.E. An evaluation of the gum elastic bougie: intubation times and incidence of sore throat. Anaesthesia, 1992;47:878-881.
[7] Kidd, J.F., Dyson, A., Latto, I.P. Successful difficult intubation: use of the gum elastic bougie. Anaesthesia, 1988;43:437-438.
[8] Nocera, A. A flexible solution for emergency intubation difficulties. Annals of Emergency Medicine, 1996;27(5):665-667.
[9] Cormack, R.S., Lehane, J. Difficult tracheal intubation in obstetrics. Anaesthesia, 1984;39:1105-1111.
[10] Guss, D.A., Posluszny, M. Paramedic orotracheal intubation: a feasibility study. Am J Emerg Med, 1984;2(5):399-401.
[11] Greenhalagh, T. How to read a paper: the basics of evidence based medicine. London: BMJ Publishing Group, 1997.
[12] McCarroll, S.M., Lamont, B.J., Buckland, M.R., et al. The gum elastic bougie: old but still useful. Anesthesiology, 1988;68:643-644.
[13] Cochrane, A.L. Effectiveness and Efficiency: Random Reflections on Health Services. Abingdon: the Nuffield Provincial Hospital Trust, 1971.
[14] Zaleski, L; Abello, D., Gold, M.I. The esophageal detector device. Does it work? Anesthesiology, 1993;79(2):244-7.