Using a Disposable Flexible Fiberoptic Scope as a Bougie for Difficult Intubation

Abstract

In this case report, we describe two difficult intubations in which an endotracheal tube was threaded over a fiberoptic bronchoscope that was acting as a bougie. Our patients initially presented with limited neck extension, narrow mouth opening, and restricted view of the glottic region. A fiberoptic bronchoscope was guided through while the patient was oxygenated through a laryngeal mask. After the scope provided an unrestricted view of the vocal cords, the digital module was removed by cutting the fiberoptic thread, and an endotracheal tube was passed through. After proper confirmation of the endotracheal tube position, the intubation was deemed successful and thereby, we share our experience with the novel technique. This technique may potentially improve critical patient outcomes whether in trauma or an unexpectedly difficult intubation.

INTRODUCTION

Condensing difficult airway-failed intubation prevails in gravity to the anesthesiology community.[1] Failure rates vary depending on the definition of difficult airways yet recent additions to tools such as videolaryngoscopy have captured compelling clinical relevance.[2] Glottic vision being the focal point of such technology reduces failed intubation however crowding the epiglottic region and sharp angulation may inhibit the ability to pass the tracheal tube or maneuvering the bougie or a stylet.[3,4] Our report describes a technique developed by the authors in which the disposable fiberoptic scope was used to obtain visualization of the vocal cords and then altered to be used as a bougie to pass the endotracheal tube through it. The authors have obtained written consent from the patients involved.

CASE REPORTS

Case 1

A 41-year-old woman presented to the bariatric surgery clinic with difficulty losing weight after many conservative therapy trials failed. With a body mass index of 51 kg/m², she was scheduled for a sleeve gastrectomy. Medical history includes diabetes mellitus Type II, hypertension, obstructive sleep apnea, and hypothyroidism. Preoperative assessment enclosed the American Society of Anesthesiologists (ASA) rating of 2 and cleared the patient for general anesthesia. On arrival at the operating room, standard anesthesia induction was initiated using rocuronium, propofol, and fentanyl. After adequate preoxygenation, intubation attempts were met with difficulty caused by limited mouth opening, restricted head extension, and a locked jaw that was not previously disclosed during preoperative assessment, therefore the laryngoscope could not be passed over her tongue. The senior anesthetist was urgently consulted.

On the arrival of the senior anesthetist, a mouth opening was gauged to be a finger-width with no maneuverability of the mandible. A supraglottic airway device was inserted to maintain oxygenation of the patient (i-gel, supraglottic airway, size 4, Intersurgical Ltd, Berkshire, UK). A disposable fiberoptic scope was then used to obtain a better visual assessment of the perilaryngeal anatomy. Modified Cormack–Lehane classification was noted as 2b. Due to the limited ability to pass the endotracheal tube, the fiber optic digital head was disassembled and removed while keeping it in place in between the vocal cords. The supraglottic airway was then removed. The endotracheal tube was then quickly passed over the fiberoptic scope which was acting as bougie and a successful intubation was achieved [Figure 1].

Figure 1.

(a) Where the scissors were used to cut the digital module from the fiberoptic tube. (b and c) shows the endotracheal tube threaded over the fiberoptic tube). The endotracheal tube placement was confirmed by the presence of breathing sounds in the axilla, condensation of the tube, and lack of breathing sounds in the epigastric area. The correct placement was further confirmed by CO₂ colorimetric detectors

The patient was discharged with minimal laryngeal edema after recovering and ambulating from the sleeve gastrectomy after 5 days from the operation.

Case 2

A 56-year-old woman was admitted through the emergency department for a ruptured ovarian cyst. Medical history included rheumatoid arthritis and the patient had a previous emergent tracheostomy 30 years ago. After the patient was rushed to the operating suite, a preoperative assessment revealed limited neck mobility and mouth opening as well as neck stiffness. Mouth opening was measured as 2 cm and head extension was also not possible. ASA rating was 3 as the patient was also hypotensive. The senior anesthetist was informed and the fiberoptic scope was prepared for the patient as well as a standby ear, nose, and throat specialist in case an urgent thoracostomy was needed. Upon supraglottic airway was inserted (i-gel, supraglottic airway, size 4, Intersurgical Ltd, Berkshire, UK) and the fiberoptic scope was first passed nasally to reveal a patent pharynx, normal looking epiglottis, and mild arytenoid congestion. The scope was then passed orally and after visualization of the vocal cord, the fiberoptic scope was disassembled and maintained its place between the vocal cords. The supraglottic airway was then passed followed by the introduction of the endotracheal tube over the fiberoptic scope tube which was acting as bougie. Endotracheal tube placement confirmation protocol deemed the attempt successful with minimal trauma to the larynx. The patient had no complications and was discharged 3 days after the operation.

DISCUSSION

A paramount cause of mortality in anesthesia stems from challenging airway intubations.[5] Despite all pre-operative standardized and nonstandardized assessments, the risk of difficult airway intubation may not be diminished. In fact, anesthetists may encounter difficult intubations with up to 8.5% incidence rate.[6] The ability to visualize the vocal cords during the procedure is considered to be a significant factor in successful tracheal intubations and there are many newly developed devices that improve visibility of the vocal cords thereby significantly improving success rates and patient mortality.

Using camera technologies in high-grade Cormack and Lehane patients significantly reduced the number of failed intubations especially when limited neck extension is associated with the difficulties borne. A bougie which aids the introduction of the endotracheal tube would also factor into a successful intubation by granting tracheal access when supported by a visual view of the vocal cords.[7] However, when dealing with not only limited neck extension and mouth opening but also a restricted visual view, having a scope, a bougie, and an endotracheal tube can crowd the pharyngeal space and complicate the intubation process. New fiberoptic scope technologies with introducer blades can significantly improve outcomes; however, adopting it into clinical practice has been challenging due to the prolonged time to intubate and most importantly training opportunities.

Disposable fiberoptic bronchoscopes have been previously described to be used in emergent settings to confirm the position of endotracheal tubes.[8] Bronchoscopes can be threaded through previously placed endotracheal tubes and have been proven to be accurate, quick, and relatively easy to do. Inspired by use of bronchoscopes, the senior anesthetist who performed the intubation mentioned in the cases described, chose to disassemble the digital head to thread the endotracheal tube after confirming the placement of the bronchoscope tip between the vocal cords. The excellent view of the glottis, vocal cords, and trachea warranted a successful intubation despite the limitations in neck extension, mouth opening, and restricted glottic view.

Further evaluation of the technique described is needed in terms of cost-effectiveness, applicability in remote medical services with limited resources, and patient safety. Patients who arrive at the emergency department due to trauma have an added risk of difficult intubations compared to the general patient population.[9,10] A cervical neck collar, fixed head braces, and spinal immobilization can also factor in the difficulties faced when intubating a trauma patient. As this maneuver does not require head extension or a wide mouth opening, the use of a disposable bronchoscope can significantly improve the quality of care and predicaments of endotracheal tube placements.

CONCLUSION

A disposable fiberoptic scope can be used in many different ways to aid the anesthetist in critical situations. As the device can only be used one time, MacGyvering a disposable bronchoscope as a properly placed bougie to thread the endotracheal tube through can vastly improve the rates of difficult intubations and mortality associated with it.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patients have given their consent for their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Research quality and ethics statement

The authors followed applicable EQUATOR Network (https://www.equator-network.org/) guidelines, notably the CARE guideline, during the conduct of this report.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.