- Email: [email protected]
Bougie assisted left molar approach to laryngoscopy after failed intubation with Bonfils intubation fiberscope in a patient with anticipated difficult airway
c u r r e n t m e d i c i n e r e s e a r c h a n d p r a c t i c e x x x ( 2 0 1 4 ) 1 e4
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.elsevier.com/locate/cmrp
Case Report
Bougie assisted left molar approach to laryngoscopy after failed intubation with Bonfils intubation fiberscope in a patient with anticipated difficult airway Anju Gupta* Department of Anaesthesiology, Delhi State Cancer Institute, Dilshad Garden, Delhi, India
article info
abstract
Article history:
Management of Difficult airway (DA) remains a challenge for the anesthetists globally.
Received 1 March 2014
Recent literature recommends numerous devices like various supraglottic devices, fiber-
Accepted 16 April 2014
optic bronchoscopes, video laryngoscopes, etc. Most of us are inclined to use advanced
Available online xxx
intubation gadgets in a scenario of difficult intubation. But these may have limitations like non-availability, unfamiliarity, time taken to assemble them etc. Present case report
Keywords:
highlights the importance of a simple technique of bougie assisted left molar approach to
Airway
direct laryngoscopy with OELM in a DA scenario where an advanced gadget like Bonfils
Intubation methods
intubation fiberscope could not help in securing the airway.
Left molar laryngoscopy
Copyright © 2014, Sir Ganga Ram Hospital. Published by Reed Elsevier India Pvt. Ltd. All rights reserved.
1.
Introduction
Difficult airway (DA) is the worst feared anesthetic scenario. Various airway management techniques have been used in such scenarios (awake blind nasal, fiberoptic bronchoscopy, gum elastic bougie, light wand, Bonfils intubation fiberscope [BIF], Intubating laryngeal mask airway, MC Coy Laryngoscopy and video laryngoscope).1 BIF is rigid optical stylet which has been used in DA scenarios with high success rates (up to 95% in DA).2,3 However, it may be difficult to intubate with BIF in some cases due to fogging, secretions and inability to maneuver the rigid device beneath long and floppy epiglottis. Left molar (LM) approach has been used to facilitate intubation in unanticipated and simulated DA scenarios.4,5 This approach to direct laryngoscopy has been shown to consistently improve the glottic view in DA situations.5,6 The only problem
with LM approach is that a good view does not always translate into a successful intubation due to reduced space available to guide the endotracheal tube (ETT) into glottis.7 This can be overcome with the use of intubation adjuncts like intubation stylet,6 gum elastic bougie,8 light wand and smaller size ETT.9 The use of LM approach with ventilating bougie in an anticipated DA scenario has not been reported previously. The patient reviewed the case report and consented to publish the case report with photographs.
2.
Case report
A 48-year-old, American Society of Anesthesiologists grade I, female patient weighing 60 kg with uterine prolapse was
* 437, Pocket A Sarita Vihar, New Delhi 110076, India. Tel.: þ91 (0) 8800190650. E-mail address: [email protected]. http://dx.doi.org/10.1016/j.cmrp.2014.04.003 2352-0817/Copyright © 2014, Sir Ganga Ram Hospital. Published by Reed Elsevier India Pvt. Ltd. All rights reserved.
Please cite this article in press as: Gupta A, Bougie assisted left molar approach to laryngoscopy after failed intubation with Bonfils intubation fiberscope in a patient with anticipated difficult airway, Current Medicine Research and Practice (2014), http://dx.doi.org/10.1016/j.cmrp.2014.04.003
2
c u r r e n t m e d i c i n e r e s e a r c h a n d p r a c t i c e x x x ( 2 0 1 4 ) 1 e4
electively posted for laparoscopic assisted vaginal hysterectomy with pelvic floor repair under general anesthesia. The systemic examination was normal. The airway examination revealed a mouth opening of 2.1 cm, a Mallampati class 3, a thyromental distance of 6.7 cm, sternomental distance of 12 cm, short thick neck and mildly restricted neck extension (Figs. 1 and 2). Considering her to be potential DA she was councelled for an awake intubation but she refused to consent. It was then decided to proceed with intubation under general anesthesia. The airway cart was assembled and devices like BIF, Macintosh laryngoscopes (size 3 and 4), different sizes of endotracheal tubes, classic LMA size 3 and 4, intubating stylet, ventilating bougie, and emergency cricothyroidotomy set were kept ready. Surgeons and the patient were explained about the intubation difficulty, possible need for surgical airway management and possibility of postponement of case in case of failure to secure the airway. Considering it was an anticipated DA, fiberoptic bronchoscope (FOB) guided intubation was our first choice but unfortunately the only FOB in the department was not working. Hence, we planned to do a BIF (Fig. 3) guided intubation under anesthesia (plan A). In case of failure of plan A, left molar approach for laryngoscopy and intubation was kept as plan B. Appropriate size LMA classic was our plan C in case of failure of both the above mentioned plans. An anesthesiologist experienced with both BIF and LM approach to direct laryngoscopy attempted intubation. In the operation theater standard monitors were attached and an 18 G intravenous cannula was secured. The patient received IV glycopyrrolate 0.2 mg, midazolam 2 mg and fentanyl 100 mg. She was preoxygenated with 100% oxygen for 3 min and the anesthesia was induced with 2 mg/kg propofol. After confirming the ability to ventilate, 100 mg succinyl choline was given. The patient was ventilated with sevoflurane 3e5% in oxygen for 1 min and subsequently BIF loaded
Fig. 1 e Side profile of the patient.
Fig. 2 e Intubated patient with ventilating bougie in situ.
with #7 ETT (with oxygen at a flow rate of 3 L/min attached for defogging and oxygenation during the procedure) was introduced through retro molar approach. However, we could barely visualize the tip of epiglottis which was lying onto the posterior pharynx and there was no space to negotiate the tip of BIF underneath the epiglottis. The BIF was reinserted after mandibular lift by the operator with non-dominant hand, manual lifting of lower jaw by an assistant and use of Macintosh blade to create space in oral cavity by displacing the tongue and facilitate intubation. However, we were not successful in negotiating the BIF tip below the overhanging epiglottis despite the above mentioned maneuvers. The patient had started breathing spontaneously at this time but her SpO2 had decreased to 88%. So, an oral airway was inserted immediately and the patient was ventilated with 100% oxygen with two hand technique. Having faced difficulty in bag mask ventilation and expecting difficult laryngeal view we decided against use of muscle relaxant. The anesthesia was deepened with propofol 50 mg and 3e5% sevoflurane in 100% O2 and plan B i.e. LM approach in spontaneously breathing anesthetized patient was considered. LM laryngoscopy with #3
Fig. 3 e Bonfils intubation fiberscope.
Please cite this article in press as: Gupta A, Bougie assisted left molar approach to laryngoscopy after failed intubation with Bonfils intubation fiberscope in a patient with anticipated difficult airway, Current Medicine Research and Practice (2014), http://dx.doi.org/10.1016/j.cmrp.2014.04.003
c u r r e n t m e d i c i n e r e s e a r c h a n d p r a c t i c e x x x ( 2 0 1 4 ) 1 e4
Macintosh blade revealed a grade IIIa Cormack Lehane (C/L) view which improved to IIa view with optimum external laryngeal manipulation (OELM). A 14 F ventilating bougie (5 mm diameter, 750 mm long) could be guided into the larynx under vision. A size 7 mm ID ETT was then threaded over the bougie, into the trachea under laryngoscopic vision. All this while patient's vitals remained stable and SpO2 remained more than 95%. The correct placement of the ETT was confirmed by auscultation and capnography trace. There was no mucosal bleed or trauma. The neuromuscular blockade was achieved with vecuronium bromide 0.08 mg/kg (5 mg) and anesthesia was maintained with sevoflurane 1e2% in O2: N2O to achieve a MAC of 1.3. The surgery proceeded uneventfully thereafter. At the end of surgery the patient was extubated over a tube exchanger and shifted to intensive care unit for observation. There was no blood smeared over the bougie or ETT. The patient was discharged the next day without any airway morbidity. The patient was given a card mentioning the DA warning for future reference.
3.
Discussion
A plethora of airway gadgets are available to us today to manage a difficult airway scenario.1 Awake fiberoptic intubation has been regarded as a gold standard to manage recognized difficult airway.2 However, its utility may be limited by various factors such as availability, lack of expertise and patient cooperation. In the present case report the airway assessment parameters suggested the need of an awake intubation but the patient was uncooperative and refused to consent. The only flexible FOB in the department was nonfunctional so BIF guided intubation was planned after induction of anesthesia. BIF is a 40 cm long, rigid optical stainless steel stylet with an external diameter of 5.0 mm and a fixed anterior 40 curvature at its tip (Fig. 3). Recently there are many reports suggesting its usefulness to intubate patients with normal10 and difficult airways (expected or unexpected).11,12 It has been successfully used in patients with limited neck mobility,13 reduced mouth opening (7 mm)14 and patients with unstable cervical spine.15 It has also been used for awake intubation in predicted DA.14 Our patient had reduced mouth opening (2.1 cm), thick short neck and a limited neck extension. Since, the anesthesiologists were also well experienced with the use of BIF at our center, we decided to keep BIF guided intubation as our primary plan. In our case intubation with BIF failed even with the use of all recommended maneuvers (tongue e jaw lift, Macintosh laryngoscope, external jaw thrust by an assistant). This was probably because of anterior larynx and floppy epiglottis which made it difficult to negotiate the BIF tip underneath the epiglottis. Moreover due to large tongue and restricted mouth opening, the BIF stylet could not be maneuvered freely into the oropharynx to get an optimum view of larynx. Wong et al succeeded in 86% of cases only during intubation attempt with BIF.3 They could not intubate 5 patients out of which in 3 cases the glottis could not be located. They also mentioned that fogging of lens and difficulty in disengaging the ETT from the collar are common reasons for difficulty to intubate. In
3
another study, authors faced failure in 18% cases despite using Macintosh blade to assist BIF guided intubation in patients with simulated DA.13 Following failure with BIF, the ventilating bougie assisted LM approach was tried. In LM approach, the laryngoscope is introduced from left side above the molars and then the tip of the blade is directed postero medial between the tongue and the tonsil until the epiglottis to visualize the glottis.5 The left molar approach of laryngoscopy has been reported to improve the glottic view by atleast one C/L grade because of reduced the distance from patient's teeth to larynx decreases the need to incline the oropharyngeal axis with the laryngeal axis.6 The intubation may however be difficult despite a good view due to narrow passage created for ETT insertion and difficult alignment of the ETT tip with glottis due to bulging of the tongue on the medial side. Also, because of the small space available, the view to the laryngoscopist may get obscured when ETT is being introduced into the glottis after laryngoscopy resulting in possibility of esophageal intubation despite good view. In a study by Saini et al on simulated difficult airway with a semi rigid collar, intubation could not be achieved in one patient despite getting a 2a view with LM approach and having used an intubation stylet.6 We had anticipated the problem of difficulty in intubation and we had used a ventilating bougie was used to guide the tube into the glottis. Along with other parameters of DA our patient also had a restricted neck movement which made LM approach a good alternative in case of failure to intubate with BIF. In our case, on laryngoscopy with LM approach, initially a CL grade IIIa view was obtained which improved to CL IIa on OELM. But the bougie could not be introduced from left side because of large tongue. We advanced the bougie from the other angle of the mouth towards the glottis. A 7 mm ID ETT was threaded over it and with 90 rotation of the bevel at glottis the placement of ETT could be achieved. These maneuvers have been previously mentioned to troubleshoot difficult placement of the ETT during LM approach to direct laryngoscopy.5 We were successful in a potential disastrous situation by a simple technique which does not require the use of expensive gadgets. The ventilating bougie is thinner and longer than ETT and can be easily maneuvered into the trachea because of distal anterior curvature of its tip. Also, the smaller diameter provides advantage in maintaining glottic view during insertion. Its placement under vision almost guarantees subsequent successful placement of an ETT. The use of ventilating bougie in such a scenario has not been reported previously. We came across only one report on searching the literature, which was a case of an unanticipated difficult airway, where the author had used Gum elastic bougie as an adjunct to left molar approach to direct laryngoscopy.8 Ventilating bougie has a relatively stiff shaft and has a smooth friction free surface which makes it easy to insert. Moreover, its inner lumen can be used for oxygenation and ventilation. We had been using this LM approach for quite some time and so we had kept this as our plan B. Since the surgery was laparoscopy assisted vaginal hysterectomy in trendelenburg position and was expected to last long (5e6 h),we not comfortable in using classic LMA as a
Please cite this article in press as: Gupta A, Bougie assisted left molar approach to laryngoscopy after failed intubation with Bonfils intubation fiberscope in a patient with anticipated difficult airway, Current Medicine Research and Practice (2014), http://dx.doi.org/10.1016/j.cmrp.2014.04.003
4
c u r r e n t m e d i c i n e r e s e a r c h a n d p r a c t i c e x x x ( 2 0 1 4 ) 1 e4
primary airway device So, the classic LMA was kept as a rescue device (plan C) in our patient. Present report highlights the potential utility of LM approach assisted with a ventilating bougie. After having a good success record with this technique, we would like to recommend its more widespread use in anticipated and unanticipated DA scenarios. We have been successful to intubate trachea in simulated DA conditions using a rigid collar with ventilating bougie assisted LM approach in a study being conducted in our department. In our opinion, this approach can be handy especially in an unanticipated DA scenario when a sense of urgency in securing the airway is present and assembling of advanced gadgets can further consume the precious time. This approach can be useful in emergency pre hospital settings also as a feasible and economical alternative to conventional intubation technique in a DA scenario and should be used more often.
Conflicts of interest The author has none to declare.
references
1. Apfelbaum JL, Hagberg CA, Caplan RA, et al. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology. 2013;118:251e270. 2. Mihai R, Blair E, Kay H, Cook TM. A quantitative review and meta-analysis of performance of non-standard laryngoscopes and rigid fiberoptic intubation aids. Anaesthesia. 2008;63:745e760. 3. Wong P. Intubation times for using the Bonfils intubation fibrescope. Br J Anaesth. 2003;91:757.
4. Bozdogan N, Sener M, Bilen A, Donmez A, Arslan G. Does left molar approach to laryngoscopy make difficult intubation easier than conventional midline approach? Eur J Anaesthesiol. 2008;25:681e684. 5. Yamamoto K, Tsubokawa T, Ohmura S, Itoh H, Kobayashi T. Left-molar approach improves the laryngeal view in patients with difficult laryngoscopy. Anesthesiology. 2000;92:70e74. 6. Saini S, Bala R, Singh R. Left-molar approach improves the laryngeal view in patients with simulated limitation of cervical movements. Acta Anaesthesiol Scand. 2008;52:829e833. 7. Cuvas O, Basar H, Gursoy N, Culhaoglu S, Demir A. Left-molar approach for direct laryngoscopy: is it easy? J Anesth. 2009;23:36e40. 8. Cuvas O. The use of the left-molar approach for direct laryngoscopy combined with a gum-elastic bougie. Eur J Emerg Med. 2010;17:355e356. 9. Mahajan R, Shafi F, Manhas A. Use of trachlight to assist intubation using left molar approach to laryngoscopy. Acta Anaesthesiol Scand. 2009;53:691e692. 10. Halligan M, Charters P. A clinical evaluation of the Bonfils intubation fiberscope. Anaesthesia. 2003;58:1087e1091. € rges V. 11. Bein B, Yan M, Tonner PH, Scholz J, Steinfath M, Do Tracheal intubation using the Bonfils intubation fiberscope after failed direct laryngoscopy. Anaesthesia. 2004;59:1207e1209. 12. Bein B, Worthmann F, Scholz J, et al. A comparison of the intubating laryngeal mask airway and the Bonfils intubation fiberscope in patients with predicted difficult airways. Anaesthesia. 2004;59:668e674. 13. Byhahn C, Nemetz S, Breitkreutz R, Zwissler B, Kaufmann M, Meininger D. Brief report: tracheal intubation using the Bonfils intubation fiberscope or direct laryngoscopy for patients with a simulated difficult airway. Can J Anaesth. 2008;55:232e237. 14. Shollik NA, Ibrahim SM, Ismael A, Agnoletti V, Piraccini E, Corso RM. Use of the Bonfils intubation fiberscope in patients with limited mouth opening. Case Rep Anesthesiol. 2012;2012:297e306. 15. Rudolph C, Schneider JP, Wallenborn J, Schaffranietz L. Movement of the upper cervical spine during laryngoscopy: a comparison of the Bonfils intubation fiberscope and the Macintosh laryngoscope. Anaesthesia. 2005;60:668e672.
Please cite this article in press as: Gupta A, Bougie assisted left molar approach to laryngoscopy after failed intubation with Bonfils intubation fiberscope in a patient with anticipated difficult airway, Current Medicine Research and Practice (2014), http://dx.doi.org/10.1016/j.cmrp.2014.04.003
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.elsevier.com/locate/cmrp
Case Report
Bougie assisted left molar approach to laryngoscopy after failed intubation with Bonfils intubation fiberscope in a patient with anticipated difficult airway Anju Gupta* Department of Anaesthesiology, Delhi State Cancer Institute, Dilshad Garden, Delhi, India
article info
abstract
Article history:
Management of Difficult airway (DA) remains a challenge for the anesthetists globally.
Received 1 March 2014
Recent literature recommends numerous devices like various supraglottic devices, fiber-
Accepted 16 April 2014
optic bronchoscopes, video laryngoscopes, etc. Most of us are inclined to use advanced
Available online xxx
intubation gadgets in a scenario of difficult intubation. But these may have limitations like non-availability, unfamiliarity, time taken to assemble them etc. Present case report
Keywords:
highlights the importance of a simple technique of bougie assisted left molar approach to
Airway
direct laryngoscopy with OELM in a DA scenario where an advanced gadget like Bonfils
Intubation methods
intubation fiberscope could not help in securing the airway.
Left molar laryngoscopy
Copyright © 2014, Sir Ganga Ram Hospital. Published by Reed Elsevier India Pvt. Ltd. All rights reserved.
1.
Introduction
Difficult airway (DA) is the worst feared anesthetic scenario. Various airway management techniques have been used in such scenarios (awake blind nasal, fiberoptic bronchoscopy, gum elastic bougie, light wand, Bonfils intubation fiberscope [BIF], Intubating laryngeal mask airway, MC Coy Laryngoscopy and video laryngoscope).1 BIF is rigid optical stylet which has been used in DA scenarios with high success rates (up to 95% in DA).2,3 However, it may be difficult to intubate with BIF in some cases due to fogging, secretions and inability to maneuver the rigid device beneath long and floppy epiglottis. Left molar (LM) approach has been used to facilitate intubation in unanticipated and simulated DA scenarios.4,5 This approach to direct laryngoscopy has been shown to consistently improve the glottic view in DA situations.5,6 The only problem
with LM approach is that a good view does not always translate into a successful intubation due to reduced space available to guide the endotracheal tube (ETT) into glottis.7 This can be overcome with the use of intubation adjuncts like intubation stylet,6 gum elastic bougie,8 light wand and smaller size ETT.9 The use of LM approach with ventilating bougie in an anticipated DA scenario has not been reported previously. The patient reviewed the case report and consented to publish the case report with photographs.
2.
Case report
A 48-year-old, American Society of Anesthesiologists grade I, female patient weighing 60 kg with uterine prolapse was
* 437, Pocket A Sarita Vihar, New Delhi 110076, India. Tel.: þ91 (0) 8800190650. E-mail address: [email protected]. http://dx.doi.org/10.1016/j.cmrp.2014.04.003 2352-0817/Copyright © 2014, Sir Ganga Ram Hospital. Published by Reed Elsevier India Pvt. Ltd. All rights reserved.
Please cite this article in press as: Gupta A, Bougie assisted left molar approach to laryngoscopy after failed intubation with Bonfils intubation fiberscope in a patient with anticipated difficult airway, Current Medicine Research and Practice (2014), http://dx.doi.org/10.1016/j.cmrp.2014.04.003
2
c u r r e n t m e d i c i n e r e s e a r c h a n d p r a c t i c e x x x ( 2 0 1 4 ) 1 e4
electively posted for laparoscopic assisted vaginal hysterectomy with pelvic floor repair under general anesthesia. The systemic examination was normal. The airway examination revealed a mouth opening of 2.1 cm, a Mallampati class 3, a thyromental distance of 6.7 cm, sternomental distance of 12 cm, short thick neck and mildly restricted neck extension (Figs. 1 and 2). Considering her to be potential DA she was councelled for an awake intubation but she refused to consent. It was then decided to proceed with intubation under general anesthesia. The airway cart was assembled and devices like BIF, Macintosh laryngoscopes (size 3 and 4), different sizes of endotracheal tubes, classic LMA size 3 and 4, intubating stylet, ventilating bougie, and emergency cricothyroidotomy set were kept ready. Surgeons and the patient were explained about the intubation difficulty, possible need for surgical airway management and possibility of postponement of case in case of failure to secure the airway. Considering it was an anticipated DA, fiberoptic bronchoscope (FOB) guided intubation was our first choice but unfortunately the only FOB in the department was not working. Hence, we planned to do a BIF (Fig. 3) guided intubation under anesthesia (plan A). In case of failure of plan A, left molar approach for laryngoscopy and intubation was kept as plan B. Appropriate size LMA classic was our plan C in case of failure of both the above mentioned plans. An anesthesiologist experienced with both BIF and LM approach to direct laryngoscopy attempted intubation. In the operation theater standard monitors were attached and an 18 G intravenous cannula was secured. The patient received IV glycopyrrolate 0.2 mg, midazolam 2 mg and fentanyl 100 mg. She was preoxygenated with 100% oxygen for 3 min and the anesthesia was induced with 2 mg/kg propofol. After confirming the ability to ventilate, 100 mg succinyl choline was given. The patient was ventilated with sevoflurane 3e5% in oxygen for 1 min and subsequently BIF loaded
Fig. 1 e Side profile of the patient.
Fig. 2 e Intubated patient with ventilating bougie in situ.
with #7 ETT (with oxygen at a flow rate of 3 L/min attached for defogging and oxygenation during the procedure) was introduced through retro molar approach. However, we could barely visualize the tip of epiglottis which was lying onto the posterior pharynx and there was no space to negotiate the tip of BIF underneath the epiglottis. The BIF was reinserted after mandibular lift by the operator with non-dominant hand, manual lifting of lower jaw by an assistant and use of Macintosh blade to create space in oral cavity by displacing the tongue and facilitate intubation. However, we were not successful in negotiating the BIF tip below the overhanging epiglottis despite the above mentioned maneuvers. The patient had started breathing spontaneously at this time but her SpO2 had decreased to 88%. So, an oral airway was inserted immediately and the patient was ventilated with 100% oxygen with two hand technique. Having faced difficulty in bag mask ventilation and expecting difficult laryngeal view we decided against use of muscle relaxant. The anesthesia was deepened with propofol 50 mg and 3e5% sevoflurane in 100% O2 and plan B i.e. LM approach in spontaneously breathing anesthetized patient was considered. LM laryngoscopy with #3
Fig. 3 e Bonfils intubation fiberscope.
Please cite this article in press as: Gupta A, Bougie assisted left molar approach to laryngoscopy after failed intubation with Bonfils intubation fiberscope in a patient with anticipated difficult airway, Current Medicine Research and Practice (2014), http://dx.doi.org/10.1016/j.cmrp.2014.04.003
c u r r e n t m e d i c i n e r e s e a r c h a n d p r a c t i c e x x x ( 2 0 1 4 ) 1 e4
Macintosh blade revealed a grade IIIa Cormack Lehane (C/L) view which improved to IIa view with optimum external laryngeal manipulation (OELM). A 14 F ventilating bougie (5 mm diameter, 750 mm long) could be guided into the larynx under vision. A size 7 mm ID ETT was then threaded over the bougie, into the trachea under laryngoscopic vision. All this while patient's vitals remained stable and SpO2 remained more than 95%. The correct placement of the ETT was confirmed by auscultation and capnography trace. There was no mucosal bleed or trauma. The neuromuscular blockade was achieved with vecuronium bromide 0.08 mg/kg (5 mg) and anesthesia was maintained with sevoflurane 1e2% in O2: N2O to achieve a MAC of 1.3. The surgery proceeded uneventfully thereafter. At the end of surgery the patient was extubated over a tube exchanger and shifted to intensive care unit for observation. There was no blood smeared over the bougie or ETT. The patient was discharged the next day without any airway morbidity. The patient was given a card mentioning the DA warning for future reference.
3.
Discussion
A plethora of airway gadgets are available to us today to manage a difficult airway scenario.1 Awake fiberoptic intubation has been regarded as a gold standard to manage recognized difficult airway.2 However, its utility may be limited by various factors such as availability, lack of expertise and patient cooperation. In the present case report the airway assessment parameters suggested the need of an awake intubation but the patient was uncooperative and refused to consent. The only flexible FOB in the department was nonfunctional so BIF guided intubation was planned after induction of anesthesia. BIF is a 40 cm long, rigid optical stainless steel stylet with an external diameter of 5.0 mm and a fixed anterior 40 curvature at its tip (Fig. 3). Recently there are many reports suggesting its usefulness to intubate patients with normal10 and difficult airways (expected or unexpected).11,12 It has been successfully used in patients with limited neck mobility,13 reduced mouth opening (7 mm)14 and patients with unstable cervical spine.15 It has also been used for awake intubation in predicted DA.14 Our patient had reduced mouth opening (2.1 cm), thick short neck and a limited neck extension. Since, the anesthesiologists were also well experienced with the use of BIF at our center, we decided to keep BIF guided intubation as our primary plan. In our case intubation with BIF failed even with the use of all recommended maneuvers (tongue e jaw lift, Macintosh laryngoscope, external jaw thrust by an assistant). This was probably because of anterior larynx and floppy epiglottis which made it difficult to negotiate the BIF tip underneath the epiglottis. Moreover due to large tongue and restricted mouth opening, the BIF stylet could not be maneuvered freely into the oropharynx to get an optimum view of larynx. Wong et al succeeded in 86% of cases only during intubation attempt with BIF.3 They could not intubate 5 patients out of which in 3 cases the glottis could not be located. They also mentioned that fogging of lens and difficulty in disengaging the ETT from the collar are common reasons for difficulty to intubate. In
3
another study, authors faced failure in 18% cases despite using Macintosh blade to assist BIF guided intubation in patients with simulated DA.13 Following failure with BIF, the ventilating bougie assisted LM approach was tried. In LM approach, the laryngoscope is introduced from left side above the molars and then the tip of the blade is directed postero medial between the tongue and the tonsil until the epiglottis to visualize the glottis.5 The left molar approach of laryngoscopy has been reported to improve the glottic view by atleast one C/L grade because of reduced the distance from patient's teeth to larynx decreases the need to incline the oropharyngeal axis with the laryngeal axis.6 The intubation may however be difficult despite a good view due to narrow passage created for ETT insertion and difficult alignment of the ETT tip with glottis due to bulging of the tongue on the medial side. Also, because of the small space available, the view to the laryngoscopist may get obscured when ETT is being introduced into the glottis after laryngoscopy resulting in possibility of esophageal intubation despite good view. In a study by Saini et al on simulated difficult airway with a semi rigid collar, intubation could not be achieved in one patient despite getting a 2a view with LM approach and having used an intubation stylet.6 We had anticipated the problem of difficulty in intubation and we had used a ventilating bougie was used to guide the tube into the glottis. Along with other parameters of DA our patient also had a restricted neck movement which made LM approach a good alternative in case of failure to intubate with BIF. In our case, on laryngoscopy with LM approach, initially a CL grade IIIa view was obtained which improved to CL IIa on OELM. But the bougie could not be introduced from left side because of large tongue. We advanced the bougie from the other angle of the mouth towards the glottis. A 7 mm ID ETT was threaded over it and with 90 rotation of the bevel at glottis the placement of ETT could be achieved. These maneuvers have been previously mentioned to troubleshoot difficult placement of the ETT during LM approach to direct laryngoscopy.5 We were successful in a potential disastrous situation by a simple technique which does not require the use of expensive gadgets. The ventilating bougie is thinner and longer than ETT and can be easily maneuvered into the trachea because of distal anterior curvature of its tip. Also, the smaller diameter provides advantage in maintaining glottic view during insertion. Its placement under vision almost guarantees subsequent successful placement of an ETT. The use of ventilating bougie in such a scenario has not been reported previously. We came across only one report on searching the literature, which was a case of an unanticipated difficult airway, where the author had used Gum elastic bougie as an adjunct to left molar approach to direct laryngoscopy.8 Ventilating bougie has a relatively stiff shaft and has a smooth friction free surface which makes it easy to insert. Moreover, its inner lumen can be used for oxygenation and ventilation. We had been using this LM approach for quite some time and so we had kept this as our plan B. Since the surgery was laparoscopy assisted vaginal hysterectomy in trendelenburg position and was expected to last long (5e6 h),we not comfortable in using classic LMA as a
Please cite this article in press as: Gupta A, Bougie assisted left molar approach to laryngoscopy after failed intubation with Bonfils intubation fiberscope in a patient with anticipated difficult airway, Current Medicine Research and Practice (2014), http://dx.doi.org/10.1016/j.cmrp.2014.04.003
4
c u r r e n t m e d i c i n e r e s e a r c h a n d p r a c t i c e x x x ( 2 0 1 4 ) 1 e4
primary airway device So, the classic LMA was kept as a rescue device (plan C) in our patient. Present report highlights the potential utility of LM approach assisted with a ventilating bougie. After having a good success record with this technique, we would like to recommend its more widespread use in anticipated and unanticipated DA scenarios. We have been successful to intubate trachea in simulated DA conditions using a rigid collar with ventilating bougie assisted LM approach in a study being conducted in our department. In our opinion, this approach can be handy especially in an unanticipated DA scenario when a sense of urgency in securing the airway is present and assembling of advanced gadgets can further consume the precious time. This approach can be useful in emergency pre hospital settings also as a feasible and economical alternative to conventional intubation technique in a DA scenario and should be used more often.
Conflicts of interest The author has none to declare.
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Please cite this article in press as: Gupta A, Bougie assisted left molar approach to laryngoscopy after failed intubation with Bonfils intubation fiberscope in a patient with anticipated difficult airway, Current Medicine Research and Practice (2014), http://dx.doi.org/10.1016/j.cmrp.2014.04.003