Anaesthesia 2014, 69, 511–526
a clear and concise account of its likely benefits for individual care and public health. Using both fixed demographic and modifiable personal data, Big Data could enable the creation of a pre-operative avatar that would allow an individual patient not only to access bettermatched clinical outcome data, but also to define personal risk-reduction strategies that might modify his/her peri-operative risk profile. Modification of the avatar’s bodyweight, blood pressure, smoking and drinking habits, for example, could be used to illustrate visually how patients might improve their postoperative recovery. We would encourage those designing Big Data systems to consider that data ‘of the people’ should not only be used ‘for the people’ but should also be usable ‘by the people’. Such a strategy might help lessen public opposition to some of these projects. Big Data could be truly enormous. C. Lister M. Davies Royal Liverpool & Broadgreen University Hospitals NHS Trust Liverpool, UK Email: [email protected] No external funding and no competing interests declared. Previously posted on the Anaesthesia correspondence website: www.anaesthesia correspondence.com.
Reference 1. Sessler DI. Big Data – and its contributions to peri-operative medicine. Anaesthesia 2014; 69: 100–5. doi:10.1111/anae.12674
514
Correspondence
Traffic light bougie: what is the safe zone? The innovation shown by Paul et al. in their recent study [1] is to be commended, but I did have one significant concern with the design of their ‘traffic light’ bougie: that is, what length of the safe zone is actually safe? The potential for injury from use of bougies is recognised by Paul et al. [1] and others [2], and the authors refer to the several cases of morbidity directly due to bougies reported in the 4th National Audit Project [2]. However, it is worth recognising that there is potential for harm by not having a bougie inserted far enough, risking displacement and consequent failure of, or oesophageal, intubation. Therefore, insertion of less than 21 cm is not necessarily safe, as suggested. Situations where a bougie is used often predispose to displacement of the bougie, for several reasons. Firstly, use of a bougie is indicated when there is a suboptimal view at laryngoscopy [3], which may also obscure observation of a bougie’s displacement. Indeed, after initial observation, ‘railroading’ of the tracheal tube over the bougie is performed blind in a significant proportion of cases [3]. The same study found that 7.5% of bougieassisted intubations failed on the first attempt, although the failure rate is often higher [4]. However, because of a poor view it is impossible to quantify how many of these are displaced (from the trachea) rather than misplaced (i.e. never in the trachea). Secondly, without a
proper view and by restraining from use of the hold-up endpoint [5], the operator relies on subjectively feeling tracheal rings at the bougie’s tip [4], which does not give an indication of depth of insertion [3]. Lastly, use of a bougie is a twoperson technique, which introduces difficulties related to co-ordination of direction and force, potentially leading to displacement. Displacement, then, is more likely when the bougie’s tip is introduced to a shorter depth. Once 12–15 cm (distance from teeth to vocal cords [6]) + ~33 cm (length of tracheal tube and connector) + 4 cm (for anaesthetic assistant to grip during railroading) are subtracted from a standard bougie length of 60 cm [7], only 8–11 cm of bougie remain within the trachea, and it would not take a great deal of movement in various directions between the two operators to displace this length from the trachea. The traffic light bougie may allow even less. I suggest that the traffic light bougie should be redesigned to include a green/safe zone sandwiched between two red zones, the distal (tip) zone alerting the operator to insufficient insertion depth, and the proximal zone to too great an insertion depth, thus reducing the patient-specific risks associated with incorrect length of bougie insertion [2]. J. Campbell Royal Victoria Hospital Belfast, UK Email: [email protected] No external funding and no competing interests declared. Previously
© 2014 The Association of Anaesthetists of Great Britain and Ireland
Correspondence
Anaesthesia 2014, 69, 511–526
posted on the Anaesthesia correspondence website: www.anaesthesia correspondence.com.
References 1. Paul A, Gibson AA, Robinson ODG, Koch J. The traffic light bougie: a study of a novel safety modification. Anaesthesia 2014; 69: 214–8. 2. Cook T, Woodall N, Frerk C. Major complications of airway management in the United Kingdom. 4th National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society: Report and findings. London: RCoA, March 2011. 3. Latto IP, Stacey M, Mecklenburgh J, Vaughan RS. Survey of the use of the gum elastic bougie in clinical practice. Anaesthesia 2002; 57: 379–84. 4. Rai MR. The humble bougie. . .forty years and still counting? Anaesthesia 2014; 69: 199–203. 5. Marson BA, Anderson E, Wilkes AR, Hodzovic I. Bougie-related airway trauma: dangers of the hold-up sign. Anaesthesia 2014; 69: 219–23. 6. Stone DJ, Bogdonoff DL. Airway considerations in the management of patients requiring long-term endotracheal intubation. Anesthesia and Analgesia 1992; 74: 276–87. 7. El-Orbany MI, Salem MR, Joseph NJ. The Eschmann tracheal tube introducer is not gum, elastic, or a bougie. Anesthesiology 2004; 101: 1240. doi:10.1111/anae.12699
Bougies – or capnography? We read with interest the concerns raised about the bougie hold-up sign causing airway trauma [1]. The use of this sign in determining the position of the bougie is superior to tracheal ‘clicks’ alone, as shown by Kidd and colleagues [2]. In the article by Paul and colleagues [3], the novel use of a traffic light depth gauge actively discourages the use of hold-up as an endpoint, relying solely on clicks. If we are to avoid
the hold-up sign, then the accuracy of bougie positioning may be reduced, and perhaps it is time to look for another way of confirming bougie position. The use of capnography, as described by Millar and colleagues [4], may offer such confirmation. F. A. Millar G. L. Hutchison Ninewells Hospital Dundee, UK Email: [email protected] No external funding or competing interests declared. Previously posted on the Anaesthesia correspondence website: www.anaesthesiacorrespon dence.com.
References 1. Marson BA, Anderson E, Wilkes AR, Hodzovic I. Bougie-related airway trauma: dangers of the hold-up sign. Anaesthesia 2014; 69: 219–23. 2. Kidd JF, Dyson A, Latto IP. Successful difficult intubation. Use of the gum elastic bougie. Anaesthesia 1988; 43: 437–8. 3. Paul A, Gibson AA, Robinson ODG, Koch J. The traffic light bougie: a study of a novel safety modification. Anaesthesia 2014; 69: 214–8. 4. Millar FA, Hutchison GL, Glavin R. Gum elastic bougie, capnography and apnoeic oxygenation. European Journal of Anaesthesiology 2001; 18: 51–3.
Preloading bougies We read with interest the report of airway trauma related to the use of gum-elastic bougies during airway management [1]. The accompanying editorial succinctly summarises the past, present and possible future of the ‘humble’ bougie [2]. In our bariatric anaesthesia practice, we have found wide use for the bougie and often use it electively in super-morbidly obese patients. The bougie is very useful when there is an occlusive proliferation of oropharyngeal soft tissues, as seen in obstructive sleep apnoea and obesity, keeping the time to tracheal intubation as short as possible and avoiding having to implement a rescue ‘Plan B’ [3]. We have developed a simple innovation for use of the bougie in bariatric anaesthesia (that may be applicable to other situations), the Preloaded Bougie Technique, in which the bougie is electively preloaded into the tracheal tube and held in place by the pilot balloon (Fig. 1). After induction of anaesthesia and under direct laryngoscopy, the anaesthetist holds the bougie and inserts its curved distal
doi:10.1111/anae.12701
Figure 1 Preloaded bougie.
© 2014 The Association of Anaesthetists of Great Britain and Ireland
515
a clear and concise account of its likely benefits for individual care and public health. Using both fixed demographic and modifiable personal data, Big Data could enable the creation of a pre-operative avatar that would allow an individual patient not only to access bettermatched clinical outcome data, but also to define personal risk-reduction strategies that might modify his/her peri-operative risk profile. Modification of the avatar’s bodyweight, blood pressure, smoking and drinking habits, for example, could be used to illustrate visually how patients might improve their postoperative recovery. We would encourage those designing Big Data systems to consider that data ‘of the people’ should not only be used ‘for the people’ but should also be usable ‘by the people’. Such a strategy might help lessen public opposition to some of these projects. Big Data could be truly enormous. C. Lister M. Davies Royal Liverpool & Broadgreen University Hospitals NHS Trust Liverpool, UK Email: [email protected] No external funding and no competing interests declared. Previously posted on the Anaesthesia correspondence website: www.anaesthesia correspondence.com.
Reference 1. Sessler DI. Big Data – and its contributions to peri-operative medicine. Anaesthesia 2014; 69: 100–5. doi:10.1111/anae.12674
514
Correspondence
Traffic light bougie: what is the safe zone? The innovation shown by Paul et al. in their recent study [1] is to be commended, but I did have one significant concern with the design of their ‘traffic light’ bougie: that is, what length of the safe zone is actually safe? The potential for injury from use of bougies is recognised by Paul et al. [1] and others [2], and the authors refer to the several cases of morbidity directly due to bougies reported in the 4th National Audit Project [2]. However, it is worth recognising that there is potential for harm by not having a bougie inserted far enough, risking displacement and consequent failure of, or oesophageal, intubation. Therefore, insertion of less than 21 cm is not necessarily safe, as suggested. Situations where a bougie is used often predispose to displacement of the bougie, for several reasons. Firstly, use of a bougie is indicated when there is a suboptimal view at laryngoscopy [3], which may also obscure observation of a bougie’s displacement. Indeed, after initial observation, ‘railroading’ of the tracheal tube over the bougie is performed blind in a significant proportion of cases [3]. The same study found that 7.5% of bougieassisted intubations failed on the first attempt, although the failure rate is often higher [4]. However, because of a poor view it is impossible to quantify how many of these are displaced (from the trachea) rather than misplaced (i.e. never in the trachea). Secondly, without a
proper view and by restraining from use of the hold-up endpoint [5], the operator relies on subjectively feeling tracheal rings at the bougie’s tip [4], which does not give an indication of depth of insertion [3]. Lastly, use of a bougie is a twoperson technique, which introduces difficulties related to co-ordination of direction and force, potentially leading to displacement. Displacement, then, is more likely when the bougie’s tip is introduced to a shorter depth. Once 12–15 cm (distance from teeth to vocal cords [6]) + ~33 cm (length of tracheal tube and connector) + 4 cm (for anaesthetic assistant to grip during railroading) are subtracted from a standard bougie length of 60 cm [7], only 8–11 cm of bougie remain within the trachea, and it would not take a great deal of movement in various directions between the two operators to displace this length from the trachea. The traffic light bougie may allow even less. I suggest that the traffic light bougie should be redesigned to include a green/safe zone sandwiched between two red zones, the distal (tip) zone alerting the operator to insufficient insertion depth, and the proximal zone to too great an insertion depth, thus reducing the patient-specific risks associated with incorrect length of bougie insertion [2]. J. Campbell Royal Victoria Hospital Belfast, UK Email: [email protected] No external funding and no competing interests declared. Previously
© 2014 The Association of Anaesthetists of Great Britain and Ireland
Correspondence
Anaesthesia 2014, 69, 511–526
posted on the Anaesthesia correspondence website: www.anaesthesia correspondence.com.
References 1. Paul A, Gibson AA, Robinson ODG, Koch J. The traffic light bougie: a study of a novel safety modification. Anaesthesia 2014; 69: 214–8. 2. Cook T, Woodall N, Frerk C. Major complications of airway management in the United Kingdom. 4th National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society: Report and findings. London: RCoA, March 2011. 3. Latto IP, Stacey M, Mecklenburgh J, Vaughan RS. Survey of the use of the gum elastic bougie in clinical practice. Anaesthesia 2002; 57: 379–84. 4. Rai MR. The humble bougie. . .forty years and still counting? Anaesthesia 2014; 69: 199–203. 5. Marson BA, Anderson E, Wilkes AR, Hodzovic I. Bougie-related airway trauma: dangers of the hold-up sign. Anaesthesia 2014; 69: 219–23. 6. Stone DJ, Bogdonoff DL. Airway considerations in the management of patients requiring long-term endotracheal intubation. Anesthesia and Analgesia 1992; 74: 276–87. 7. El-Orbany MI, Salem MR, Joseph NJ. The Eschmann tracheal tube introducer is not gum, elastic, or a bougie. Anesthesiology 2004; 101: 1240. doi:10.1111/anae.12699
Bougies – or capnography? We read with interest the concerns raised about the bougie hold-up sign causing airway trauma [1]. The use of this sign in determining the position of the bougie is superior to tracheal ‘clicks’ alone, as shown by Kidd and colleagues [2]. In the article by Paul and colleagues [3], the novel use of a traffic light depth gauge actively discourages the use of hold-up as an endpoint, relying solely on clicks. If we are to avoid
the hold-up sign, then the accuracy of bougie positioning may be reduced, and perhaps it is time to look for another way of confirming bougie position. The use of capnography, as described by Millar and colleagues [4], may offer such confirmation. F. A. Millar G. L. Hutchison Ninewells Hospital Dundee, UK Email: [email protected] No external funding or competing interests declared. Previously posted on the Anaesthesia correspondence website: www.anaesthesiacorrespon dence.com.
References 1. Marson BA, Anderson E, Wilkes AR, Hodzovic I. Bougie-related airway trauma: dangers of the hold-up sign. Anaesthesia 2014; 69: 219–23. 2. Kidd JF, Dyson A, Latto IP. Successful difficult intubation. Use of the gum elastic bougie. Anaesthesia 1988; 43: 437–8. 3. Paul A, Gibson AA, Robinson ODG, Koch J. The traffic light bougie: a study of a novel safety modification. Anaesthesia 2014; 69: 214–8. 4. Millar FA, Hutchison GL, Glavin R. Gum elastic bougie, capnography and apnoeic oxygenation. European Journal of Anaesthesiology 2001; 18: 51–3.
Preloading bougies We read with interest the report of airway trauma related to the use of gum-elastic bougies during airway management [1]. The accompanying editorial succinctly summarises the past, present and possible future of the ‘humble’ bougie [2]. In our bariatric anaesthesia practice, we have found wide use for the bougie and often use it electively in super-morbidly obese patients. The bougie is very useful when there is an occlusive proliferation of oropharyngeal soft tissues, as seen in obstructive sleep apnoea and obesity, keeping the time to tracheal intubation as short as possible and avoiding having to implement a rescue ‘Plan B’ [3]. We have developed a simple innovation for use of the bougie in bariatric anaesthesia (that may be applicable to other situations), the Preloaded Bougie Technique, in which the bougie is electively preloaded into the tracheal tube and held in place by the pilot balloon (Fig. 1). After induction of anaesthesia and under direct laryngoscopy, the anaesthetist holds the bougie and inserts its curved distal
doi:10.1111/anae.12701
Figure 1 Preloaded bougie.
© 2014 The Association of Anaesthetists of Great Britain and Ireland
515
