Airway Exchange Research Articles

Recent developments in airway management

Most airway management in anaesthesia is safe, but infrequent disasters still occur and these were brought into focus by the 4th National Audit Project (NAP4) of the Royal College of Anaesthetists and Difficult Airway Society (DAS) ( Cook et al, 2011a ). Advances in airway management have included continued development of new devices in the last few years. Second-generation supraglottic airway devices, videolaryngoscopes and equipment for emergency surgical airway are the most notable. The complications associated with the use of some devices (e.g. airway exchange catheters) have been brought into focus. Safe airway management has also been supported by an increasing understanding of the human factors involved in successful, and unsuccessful, airway management and by the introduction of guidelines (particularly those of the Difficult Airway Society). This article reviews all these topics and other recent advances.

A simulator study of tube exchange with three different designs of double-lumen tubes.

We sought to determine whether the design of 3 different double-lumen endobronchial tubes (DLT) (Rusch, Mallinckrodt, Fuji) has an effect on the ease of placement over an airway exchange catheter (AEC) using a video laryngoscope. A convenience sample of 17 anesthesia residents and fellows with at least 3 years of anesthesia training was recruited from teaching hospitals in Toronto for a randomized crossover trial. Each participant passed each DLT over an AEC in an airway simulator, visualized and video recorded via a video laryngoscope (GlideScope). The order of exchange was randomized by blindly pulling the name of the manufacturer of a DLT from a box. The primary outcome was time to intubate, defined as time from the bronchial lumen entering the GlideScope view to the bronchial lumen passing the vocal cords. Also recorded were participants' subjective rating of the ease of use and failure rate, defined as an attempt >150-second duration. Time to intubate was faster with the Fuji-Phycon DLT (median 2 seconds) compared with both the Rusch (median 27 seconds, P = 0.0144) and Mallinckrodt (median 21 seconds, P = 0.0117). On a scale of 1 to 10, with 10 being very easy to use and 1 being very difficult, the Fuji-Phycon was judged to be easier to use (median 10 seconds) compared with the Rusch (median 3, P = 0.0186) and the Mallinckrodt (median 4 seconds, P = 0.0123). The Rusch was associated with significantly more failures than the other DLTs, P = 0.002. The Fuji-Phycon DLT was easier to pass over an AEC in this simulator trial and warrants consideration in patients with difficult airways who require 1-lung ventilation.

Intubation with a tube exchanger on an intubation trainer. Influence of tube tip position on successful intubation

Securing the airway using a tube exchanger catheter is an important and useful technique in anesthesia. Its success is mainly hampered by tube tip impingement of laryngeal structures. Advancing the tracheal tube along its normal curvature via a tube exchanger catheter has a high risk of tube tip impingement mainly of right laryngeal structures. The authors achieved successful clinical experience by rotating the tracheal tube 90° anticlockwise (ventral tube tip position) before railroading the tube via a tube exchanger catheter or a fiber optic bronchoscope through the larynx. The aim of the study was to investigate the influence of the tracheal tube tip position while intubating an airway trainer over a tube exchange catheter. Volunteer anesthetists with varying years of professional experience were asked to intubate an intubation mannequin (Laerdal Airway Management Trainer) using the orotracheal route with an established tube exchange catheter (Cook Airway Exchange Catheter, 11F). Two different brands of tracheal tubes (Rüsch and Covidien, ID 7.0mm) were used in a randomized order, each with the tracheal tube tip at first positioned right (90°), then ventrally (0°), left (270°) and finally dorsally (180°), resulting in eight intubation attempts for each participant. To ensure the correct tube tip position the tube was withdrawn before every intubation attempt until the tube tip position was visualized. The oropharnyx, larynx, trachea and tube were sufficiently lubricated with silicon spray (Rüsch Silikospray). The tube and airway exchange catheter size selection were made according to the clinical trial of Loudermilk et al. Successful endotracheal intubation without resistance was recorded for each tube tip position and tracheal tube brand. In total 20 anesthetists (13 consultants and 7 residents) with a median of 9.5 years (range 3-37 years) of professional experience participated in the study. Overall 160 intubation attempts were performed, 2 participants showed no successful intubation attempts at all and 38 out of 160 intubation attempts (23.8 %) were successful. Intubation success with the tracheal tube tip placed ventrally (0°) was 60 % followed by the left (270°) and right (90°) tracheal tube tip positions with 27.5% and 7.5 % intubation success, respectively. With the tube tip placed dorsally (180°) none of the 40 intubation attempts were successful. Intubation attempts with the Rüsch tube were more successful (28.8 %) than those with the Covidien tube (18.8 %). Placing the tracheal tube tip ventrally, the Rüsch tube was twice as successful as the Covidien tube with 16 (80 %) versus 8 attempts (40 %, p = 0.011). There was no correlation between professional experience and intubation success (p = 0.362). Tube insertion via an airway exchange catheter or a fiberoptic bronchoscope is a basic technique in anesthesia. Knowledge about the difficulties and their prevention are essential for every anesthetist. The gap between the airway exchange catheter, the fiber bronchoscope and the tube diameters is one of the major reasons for tube tip impingement. This investigation showed that intubation success via a tube exchange catheter, as investigated in an intubation mannequin, is considerably influenced by the tracheal tube tip position. A 90° anticlockwise rotation, placing the tracheal tube tip ventrally, considerably increased intubation success. This is of particular importance if an anesthesia department has no appropriately sized tube exchange catheters or fiber bronchoscope for every age group of patients.

The Safe Use of an Airway Exchange Catheter

The Safe Use of an Airway Exchange Catheter

The traffic light bougie: a study of a novel safety modification

Use of a bougie is not without risk, and insertion too far may cause airway injury. We designed a new bougie with a 'traffic light' system to indicate depth of insertion. Forty anaesthetists were randomly assigned to insert either a conventional single-coloured bougie or a novel traffic light bougie. Depth of insertion was measured before and after railroading a tracheal tube. Participants were not informed as to the purpose of the colouring system. The median (IQR [range]) insertion depth of the traffic light bougie was 22 (21-24 [19-27])cm and for the conventional bougie was 28 (21-32 [20-35])cm (p=0.011). Median (IQR [range]) insertion depth after railroading for the traffic light bougie was 25 (25-28 [21-34])cm and for the conventional bougie was 30.5 (27-35 [23-40])cm (p=0.003). This simple colouring system appears to allow intuitive use and significantly reduced the depth of bougie insertion. This system could be also used with other airway exchange devices to improve safety.

Angiographic catheter as airway exchange device through laryngeal airway mask in unanticipated difficult airway in emergency department

Sir, Angiographic catheter (AC) is commonly used in intervention cardiology, but its application outside cardiac catheterization laboratory (CCL) is seldom reported. AC has been used for nasogastric tube insertion.[1] We used AC as an airway exchange catheter through ProSeal laryngeal airway mask (PLMA) in an unanticipated difficult airway in emergency department (ED). A 42-year-old man admitted at midnight to our ED with diagnosis of severe acute pancreatitis with respiratory failure with apparent normal airway. After preoxygenation rapid sequence intubation was tried with cricoid pressure but unable to intubate even after removal of cricoid pressure for a moment. Immediately airway was secured with size 4 PLMA. The patient needs definite airway for prolonged mechanical ventilation. But we did not have sophisticated airway gadgets in our resuscitation kit. Then we used a 9 Fr sterile AC (Medtronic, Minnesota, USA) with guide wire [Figure 1] lubricated with lignocaine 2% gelly as airway exchange catheter in airway port of PLMA [Figure 2] keeping suction catheter in gastric port. It passed smoothly into trachea and a tactile sensation was felt by keeping the palm on trachea. After 35 cm of insertion, PLMA was removed. Apnea oxygenation was supplied to the patient through the angiographic catheter after removing guide wire and an 8 mm internal diameter endotracheal tube (ET) was exchanged. ET confirmed with capnometry and 5-point chest auscultation. Figure 1 Angiographic catheter with guidewire Figure 2 Angiography catheter inside ProSeal laryngeal airway mask Repeated attempts of laryngoscopy for tracheal intubation in difficult airway are associated with decreased success, increase complications, and morbidities. Alternative airway devices like gum elastic bougies, rigid or flexible fiberoptic bronchoscope, intubating laryngeal mask airway (LMA), video laryngoscope, light wand, and cricothyroidotomy are very effective in this situation.[2]. Airway management in ED is often more difficult than operation theater due to unavailability of difficult airway gadgets, improper environment, and untrained medical stuff. As an intubation conduit LMA is used in different way like blind ET passage after proper LMA placement, using a premounted ET in LMA, bougie-aided intubation via LMA, light wand-aided intubation through LMA, fiberscope aided intubation via LMA, and so on. PLMA having narrower airway tube will not allow to pass larger ET, but absence of aperture bar allow smooth passage of AC. Above all, PLMAs have gastric drainage tube to reduced incidence of aspiration, prevent gastric insufflation, and allow ventilation with higher pressure as it was required in our patient. People used fiberoptic aided intubation through the LMA-Supreme using an Aintree Intubating Catheter (AIC) in manikin.[3] Cook et al.,[4] reported seven case of difficult intubation via PLMA using AIC. AIC are long length, atraumatic, ability to oxygenate, and ventilate during exchange process. But the guidewire in it is too thin and soft for support. We used sterilized AC with atramatic guide wire which have same function as AIC but minimum cost and easily available from CCL. This AC was previously used for angiography but sterilized with 2% glutaraldehyde for 10 min before use in this patient.[5] In conclusion, emergency resuscitation and airway kit must contain classic LMA and LMA for rescue ventilation and oxygenation, while a resterilized AC can also be a useful gadget in difficult airway situation with limited resource.

Severe tracheal distortion secondary to kyphoscoliosis

SummaryWe describe the airway management of a patient with severe kyphoscoliosis presenting for urgent laparotomy. Reasonable laryngeal views were obtained but intubating the trachea proved challenging and required a complex series of steps using the flexible intubating fibreoptic scope (Pentax Model: F1‐10RBS, PENTAX Canada, Inc) and ultra‐flexible tip guidewire from the Arndt airway exchange catheter with rapid‐fit®adapters set (COOK Medical Inc. Bloomington, IN 47402‐4195, USA) Postoperative computed tomography (CT) imaging revealed two‐stage distortion of the trachea with the right brachiocephalic trunk running in close proximity. What made this case unique, was the inability to apply the unanticipated difficult airway algorithm to successfully secure the airway in our patient.

Alternative technique for changing from nasal to oral endotracheal tube for orthognathic and nasal surgery by using an airway exchange catheter: a case report.

A 28-year-old male patient with right maxillar, zygomatic arch, orbital wall, and nasal bone fractures had an orthognathic and nasal surgery. Naso-endotracheal intubation is the first choice during surgical correction of dentofacial deformities in an orthognathic surgery; however, its presence can interfere with concomitant surgical procedures on the nose. Traditionally, the naso-endotracheal tube will be removed and replaced with an oro-endotracheal tube. We changed the endotracheal tube from nasal to oral by using an airway exchange catheter.

Efficacy of Ventilation through a Customized Novel Cuffed Airway Exchange Catheter: a Tracheal/Lung Model Study

Efficacy of Ventilation through a Customized Novel Cuffed Airway Exchange Catheter: a Tracheal/Lung Model Study

Airway Exchange Failure and Complications with the Use of the Cook Airway Exchange Catheter®

There are limited data on rates of failure and airway injury with the use of airway exchange catheters. We performed a single-center retrospective analysis of airway exchange catheters to determine the incidence and associated factors for tube exchange failure and airway injury. Among 1177 cases, failed intubation during attempted tube exchange was noted in 73/527 (13.8%). Airway exchange failure rates were greatest during exchange catheter use for double-lumen tube insertion and when intubation was attempted over the catheter postoperatively. Pneumothorax was noted after 1.5% of attempted tube exchanges. Difficult tube exchange was encountered in 6 of 8 patients with pneumothorax.

Tracheal extubation with a laryngeal mask airway and exchange catheter in a patient with a difficult airway

To the Editor, Exchanging an endotracheal tube (ETT) for a supraglottic airway (SGA) has been described for smooth tracheal extubation and to help the patient avoid coughing at the time of emergence from anesthesia. This technique is also one of the three advanced extubation methods recommended by the Difficult Airway Society in their recent extubation guidelines. Nevertheless, there is a possibility of losing the airway during the exchange procedure. We describe a novel technique to establish a bridging SGA by utilizing an airway exchange catheter in a patient with a difficult airway. Patient consent for publication was obtained. A 38-yrold woman weighing 60 kg was scheduled for a total thyroidectomy. Her airway assessment revealed limited neck extension, receding chin, and a Mallampati grade 3 view. Direct laryngoscopy showed a grade 3 view with external laryngeal pressure, and the patient’s trachea was intubated with a 7.5-mm internal diameter ETT over an Eschmann tracheal tube introducer (gum elastic bougie). At the end of the surgery, the surgeon requested a smooth extubation with minimal cough. We planned on a bridging laryngeal mask airway (LMA) extubation technique. End-tidal sevoflurane was increased from 1 to 1.5 MAC, and 2% lidocaine 3 mL was sprayed endotracheally. The patient was maintained with positive pressure ventilation. An airway exchange catheter (19F, Cook Inc., Bloomington, IN, USA) was then inserted inside the ETT up to the 30-cm mark at the incisors and the ETT was removed. The exchange catheter was inserted into the airway tube lumen of a size-3 LMA-ProSeal (Canada Teleflex Medical, Markham, ON, Canada), and the LMA was placed into the pharynx without the metal introducer. An elbow connector with a bronchoscopy port was connected to the LMA-ProSeal with the proximal end of the exchange catheter protruding through the port (Figure). The proximal tip of the exchange catheter was occluded with tape to avoid backward air leak. The exchange catheter was removed after ensuring adequate positioning of the LMA-ProSeal by normal capnography waveform and confirming no cuff leak. The patient was then allowed to emerge from anesthesia, at which time, she could obey commands, spontaneous breathing was observed, and the LMA-ProSeal was removed without the patient coughing. If either positive pressure or spontaneous ventilation via the LMA-ProSeal had been inadequate, the ETT could have been reintroduced over the exchange catheter, followed by a conventional extubation technique. Two techniques of exchanging an ETT for a SGA at emergence have been described previously: 1) ETT removal followed by blind SGA insertion, or 2) the Bailey maneuver with insertion of a SGA behind an ETT followed by ETT removal. We consider our exchange technique to offer two potential advantages. First, because the SGA was inserted into the pharynx, over an exchange catheter, the LMA was probably positioned more precisely than with a blind insertion. Second, with the exchange catheter remaining in situ after ETT removal, reinsertion of an ETT could be readily accomplished should ventilation through the SGA fail. To perform this exchange technique, any SGA and exchange catheter or intubation introducer can be used. During this exchange process, it is essential to maintain adequate levels of anesthesia to avoid stimulation of the airway. R. Raveendran, MD S. G. Sastry, MBBS D. T. Wong, MD (&) Department of Anesthesia, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, ON, Canada e-mail: David.Wong@uhn.ca

Airway management and oxygenation in obese patients

The purpose of this Continuing Professional Development module is to describe anatomic and physiologic challenges in obese patients, review their effects on oxygenation and airway management, and propose strategies for perioperative management. The combination of excess adipose tissue deposition, increased oxygen consumption, reduced lung volumes, and increased airway resistance in obese patients increases the risk of a difficult airway and rapid oxygen desaturation in the perioperative period. Preoxygenation can be optimized by a head-up or reverse Trendelenburg position, continuous positive airway pressure, and pressure support ventilation. Difficulties in bag and mask ventilation may occur. Laryngeal exposure during direct laryngoscopy is best achieved with the patient in the "ramped" position. Tracheal tube introducers or intubating stylets can assist tracheal intubation when suboptimal laryngeal views are obtained, and video laryngoscopy may help improve the glottic view and success of tracheal intubation. New generation double-lumen supraglottic airway devices provide higher leak pressures and may be safer in obese patients, and they can also provide a conduit for bronchoscopic intubation. In patients with anticipated difficult airways, preparations should be made for awake tracheal intubation. Intraoperatively, ventilatory strategies, such as recruitment maneuvers with positive end-expiratory pressure, may reduce atelectasis and improve oxygenation. Tracheal extubation in the head-up position and continuous positive airway pressure reduce postoperative hypoxemia. Following a difficult tracheal intubation, extubation over an airway exchange catheter should be considered. Rapid oxygen desaturation may occur in obese patients. Potential difficulties in airway management should be assessed and anticipated, and oxygenation, ventilation, and airway management strategies should be optimized perioperatively.

Strategies of airway management for head and neck photo‐dynamic therapy

Photodynamic therapy (PDT) is a minimally invasive treatment modality which has great clinical implications, especially in head and neck oncology. Post-operative swelling is a well-documented consequence of PDT. It is paramount the airway remains patent for these patients. A tracheostomy remains the gold standard treatment modality for base of tongue tumours susceptible to post operative PDT inflammation, which can lead to a compromised airway. We have carried out a retrospective study to outline the airway management strategies employed for head and neck cancer patients treated with PDT and suggest recommendations for future management. This retrospective clinical study utilises 88 patients (53 males and 35 females) treated at the UCLH Head and Neck Center, London (between 2006 and 2013), for treatment of various lesions with superficial and/or interstitial PDT, when the airway could potentially be compromised. Of the 88 patients selected 60 had interstitial PDT (iPDT) and 13 had superficial PDT (sPDT). Fifteen patients were treated with both iPDT and sPDT. Among the iPDT patients 19 had a trachestomy; two patients a Quicktrach; four a Cook Airway Exchange Catheter (CEAC); one a percutaneous tracheostomy; one a needle tracheostomy and 33 patients did not receive any temporary airway pathways. Among the sPDT patients two had a trachestomy. Although the majority of patients did not suffer any major incidents, one sPDT patient required an emergency tracheostomy two days post-operatively. Airway management is vital when planning PDT treatment for tongue based tumours. Consider a more conventional approach when the lesion being targeted is located at a higher risk site: Floor of mouth/posterior tongue/tongue base or when multiple oral sites are being treated.

Airway exchange of highly soluble gases

Highly blood soluble gases exchange with the bronchial circulation in the airways. On inhalation, air absorbs highly soluble gases from the airway mucosa and equilibrates with the blood before reaching the alveoli. Highly soluble gas partial pressure is identical throughout all alveoli. At the end of exhalation the partial pressure of a highly soluble gas decreases from the alveolar level in the terminal bronchioles to the end-exhaled partial pressure at the mouth. A mathematical model simulated the airway exchange of four gases (methyl isobutyl ketone, acetone, ethanol, and propylene glycol monomethyl ether) that have high water and blood solubility. The impact of solubility on the relative distribution of airway exchange was studied. We conclude that an increase in water solubility shifts the distribution of gas exchange toward the mouth. Of the four gases studied, ethanol had the greatest decrease in partial pressure from the alveolus to the mouth at end exhalation. Single exhalation breath tests are inappropriate for estimating alveolar levels of highly soluble gases, particularly for ethanol.

Difficult Airway Society guidelines for the management of tracheal extubation

We read with concern the letter from Ms Ogilvie 1 in reaction to the recently published extubation guidelines by the Difficult Airway Society (DAS) 2. Ogilvie, representing Cook Medical (Limerick, Ireland), manufacturers of the Cook Airway Exchange Catheter (AEC), indicated that this device “is not intended to remain in the airway…for an extended period of time…” following extubation of a difficult airway. One of us (RMC) was involved in the development of the AEC, and this is precisely how he had intended that it be used. Our ability to predict successfully those patients who will tolerate extubation is far from perfect. Comparing patients with difficult airways whose tracheas were re-intubated with or without an AEC, Mort demonstrated that the AEC was associated with a very significant improvement in the first attempt success rate, the time required to complete re-intubation, and a reduction in severe hypoxia as well as bradycardia 3. Only 21/51 (41%) of the re-intubations involving an AEC took place within 2 h of extubation while 30/51 (59%) occurred between 2 h and 10 h. Thus, the major safety advantages of extubation over a tube exchanger are likely to be missed if the device is used exclusively to perform an exchange or if it is removed shortly following extubation of the difficult airway. The undersigned, representing DAS and the Society for Airway Management, strongly reaffirm the recommendations of the DAS guidelines and discourage the premature removal of tube exchangers until the probability of a required re-intubation seems very remote.

Usefulness of a Cook® airway exchange catheter in laryngeal mask airway-guided fiberoptic intubation in a neonate with Pierre Robin syndrome -A case report-

The case of a 33-day-old boy with Pierre Robin syndrome using a Cook® airway exchange catheter in laryngeal mask airway-guided fiberoptic intubation is presented. After induction with sevoflurane, classical reusable laryngeal mask airway (LMA) #1 was inserted and ultrathin fiberoptic bronchoscope (FOB) was passed through. A Cook® airway exchange catheter (1.6 mm ID, 2.7 mm OD) was passed through the LMA under the guidance of the FOB but failed to enter the trachea despite many trials. Then, an endotracheal tube (3.0 mm ID) was mounted on the FOB and railroaded over the FOB. After successful intubation, the Cook® airway exchange catheter was placed in the midtrachea through the lumen of the endotracheal tube. Even though the tracheal tube was accidentally displaced out of the trachea during LMA removal, the endotracheal tube could be easily railroaded over the airway exchange catheter.

Endotracheal tube exchange and pneumothorax: A case report

Endotracheal intubation and extubation in intensive care unit (ICU) patients are difficult. Extubation will be more worrisome if patient has difficult intubation, sleep apnea, surgical procedure involving airway or surrounding structures. In such extubation airway exchange catheters (AEC) are used, as they are simple to use and able to provide oxygen to the patient. Rarely AEC use can cause potential life threatening complications. We report a case of pneumothorax following use of AEC in post-thyroidectomy patient. Case: A 32 years old male patient was admitted to our ICU, with difficult intubation after thyroidectomy. He was a known case of obtructive sleep apnea, hypertension and large goiter. In ICU for proper visualization of vocal cords and resecuring the airway, AEC was used, but patient had hypoxia with bradycardia. He was recovered with Ambu bag ventilation and required brief cardiopulmonary resuscitation. Post resuscitation he had left impending tension pneumothorax and lung laceration requiring chest drain, which was removed after tracheostomy and weaned from the ventilator. After 9 days supra glottic edema subsided and vocal cords were moving; His trachea was decanulated and he was discharged home. Conclusion: Rarely AEC use can cause life threatening injuries. Pneumothorax following the use of AEC is not always due to tracheobronchial injury; it can also occur as a result of alveolar injury.

Bronchial Injury and Pneumothorax after Reintubation using an Airway Exchange Catheter

Background and objectivesWe report a case of pneumothorax caused by a bronchial perforation during a reintubation using an airway exchange catheter (AEC) in a patient with a head and neck cancer. Case reportA 53 year old man with oropharynx carcinoma was admitted to ICU for severe pneumonia and severe acute respiratory distress syndrome (ARDS). The patient was recognized as a difficult-to-intubate patient and an endotracheal tube (ETT) was inserted through a bronchoscope. After one week of treatment, it was observed an endotracheal cuff perforation. Exchanging the endotracheal tube was necessary to achieve satisfactory pulmonary ventilation. An AEC Cook 14 was used to perform the reintubation. After reintubation, the patient presented a worsening in oxygen saturation and a chest radiography (CXR) revealed a large pneumothorax. A chest tube was inserted and we observed immediate improvement in oxygen saturation. A repeat CXR confirmed correct positioning of the chest tube and reexpansion of the right lung. A bronchoscopy performed showed a posterior laceration in the right main bronchus. The patient was extubated the following day. After four days, the chest tube was removed. A CXR performed a day after chest tube removal revealed a small right upper pneumothorax, but the patient remained asymptomatic. ConclusionsAirway exchange catheter is a valuable tool to handle with difficult-to-intubate patients. Although the physicians generally focus their attention in avoid barotrauma - caused by oxygen supplement or jet ventilation through AEC - concern for insertion technique can minimize life threatening complications and increase the safety of AEC.

The use of the Clarus Video System for double-lumen endobronchial tube intubation in a patient with a difficult airway

The use of the Clarus Video System for double-lumen endobronchial tube intubation in a patient with a difficult airway

Stridor in an Elderly Woman: An Unusual Presentation of a Giant Thyroglossal Cyst

Thyroglossal cysts are one of the most common midline neck masses. They usually present as midline painless cystic neck mass in the first three decades of life. These anomalies are very rare in elderly patients and may pose difficult diagnostic and therapeutic challenges. Here, we report a case of giant thyroglossal cyst in a 72-year-female patient who presented with stridor, hoarseness of voice, and vocal cord paresis with gross distortion of normal airway anatomy secondary to pressure effect of the mass. The gross distortion and displacement of airway along with respiratory distress in this patient posed a difficult situation in securing the airway. The airway was secured by a unique way of orotracheal intubation with the help of a ventilating airway exchange catheter. The cyst was excised in toto under general anaesthesia. The stridor completely resolved after surgery and tracheostomy was avoided.