A quantitative evaluation of aerosol generation during awake tracheal intubation

Aerosol-generating procedures are medical interventions considered high risk for transmission of airborne pathogens. Tracheal intubation of anaesthetised patients is not high risk for aerosol generation; however, patients often perform respiratory manoeuvres during awake tracheal intubation which may generate aerosol. To assess the risk, we undertook aerosol monitoring during a series of awake tracheal intubations and nasendoscopies in healthy participants. Sampling was undertaken within an ultraclean operating theatre. Procedures were performed and received by 12 anaesthetic trainees. The upper airway was topically anaesthetised with lidocaine and participants were not sedated. An optical particle sizer continuously sampled aerosol. Passage of the bronchoscope through the vocal cords generated similar peak median (IQR [range]) aerosol concentrations to coughing, 1020 (645–1245 [120–48,948]) vs. 1460 (390–2506 [40–12,280]) particles.l^-1 respectively, p = 0.266. Coughs evoked when lidocaine was sprayed on the vocal cords generated 91,700 (41,907–166,774 [390–557,817]) particles.l^-1 which was significantly greater than volitional coughs (p < 0.001). For 38 nasendoscopies in 12 participants, the aerosol concentrations were relatively low, 180 (120–525 [0–9552]) particles.l^-1, however, five nasendoscopies generated peak aerosol concentrations greater than a volitional cough. Awake tracheal intubation and nasendoscopy can generate high concentrations of respiratory aerosol. Specific risks are associated with lidocaine spray of the larynx, instrumentation of the vocal cords, procedural coughing and deep breaths. Given the proximity of practitioners to patient-generated aerosol, airborne infection control precautions are appropriate when undertaking awake upper airway endoscopy (including awake tracheal intubation, nasendoscopy and bronchoscopy) if respirable pathogens cannot be confidently excluded.     

Use of intubation introducers through a supraglottic airway to facilitate tracheal intubation: a brief review

Purpose

This article is a narrative review regarding the usage and effectiveness of introducers or catheters to facilitate tracheal intubation through a supraglottic airway (SGA) as an alternative intubation technique in normal and difficult airway management.

Sources

Relevant articles were obtained through Medline (1948-July 2011). The articles were subsequently cross-referenced for additional literature, and only articles published in English were included.

Principal findings

In this review, we consider 32 reports using the LMA Classic?, LMA Unique?, LMA ProSeal?, LMA Supreme?, AuraOnce?, and i-gel? as SGA conduits for intubation. In 13 articles, the use of an Aintree Intubation Catheter was described as an intubation introducer and resulted in high success rates in both elective and emergent situations. Eight studies used a guidewire exchange catheter technique. Although blind intubation using a guidewire resulted in a high failure rate, these studies found that using a bronchoscope improved successful intubation. Ten studies showed that insertion of a gum elastic bougie with a bronchoscope as an intubation introducer has high success rates compared with blind bougie insertion. One article described the use of a small endotracheal tube as an intermediary for tracheal intubation.

Conclusions

In failed intubation scenarios, supraglottic airways, such as the LMA Classic? or LMA ProSeal? can serve as a conduit for tracheal intubation. A number of techniques using introducers or catheters can facilitate the insertion of an adequately sized endotracheal tube, particularly guided by a bronchoscope. Usage of introducers or catheters through a supraglottic airway may be a useful alternative intubation technique in difficult airway management.     

Flexible nasal bronchoscopy vs. Airtraq® videolaryngoscopy for awake tracheal intubation: a randomised controlled non-inferiority study

Videolaryngoscopy is a suitable alternative to flexible bronchoscopy to facilitate awake tracheal intubation. The relative effectiveness of these techniques in clinical practice is unknown. We compared flexible nasal bronchoscopy with Airtraq^® videolaryngoscopy in patients with an anticipated difficult airway scheduled for awake tracheal intubation. Patients were allocated randomly to flexible nasal bronchoscopy or videolaryngoscopy. All procedures were performed with upper airway regional anaesthesia blockade and a target-controlled intravenous infusion of remifentanil. The success rate with the allocated technique was the primary outcome. A non-inferiority analysis with a predefined limit of 8% was planned. Seventy-eight patients were recruited, allocated randomly and analysed. The rate of successful intubation was 97% and 82% in the flexible bronchoscopy and videolaryngoscopy groups, respectively, p = 0.032. The median (IQR [range]) time to tracheal intubation was shorter with the Airtraq, 163 (105–332 [40–1004]) vs. 217 (180–364 [120–780]) s, p = 0.030. There were no significant differences for complications found between the groups. The median visual analogue scale for ease of intubation was 8 (7–9 [0–10]) for Airtraq vs. 8 (7–9 [0–10]) for flexible bronchoscopy, p = 0.710. The median visual analogue scale for patient comfort for Airtraq was 8 (6–9 [2–10]) vs. 8 (7–9 [3–10]) for flexible bronchoscopy, p = 0.370. The Airtraq videolaryngoscope is not non-inferior to flexible bronchoscopy for awake tracheal intubation in a clinical setting when awake tracheal intubation is indicted. It may be a suitable alternative when judged on a case-by-case basis.     

The air-Q as a conduit for fiberoptic aided tracheal intubation in adult patients undergoing cervical spine fixation: A prospective randomized study

The air-Q? intubating laryngeal airway is a supraglottic airway device which was designed to allow adequate patient ventilation and reliable blind endotracheal tube intubation.ObjectivesTo investigate the efficacy of air-Q as a conduit for fiberoptic endotracheal intubation in adult patients with limited cervical spine mobility compared with fiberoptic-guided intubation alone.DesignProspective randomized study.PatientsSixty adult (12 female) patients, ASA physical status I and II scheduled for cervical spine fixation under general anesthesia. Patients were randomized into two parallel groups. Exclusion criteria includes, history of difficult airway, mouth opening <3 cm, Mallampati class ?III and, increased risk of aspiration of gastric contents.InterventionIn the first group, endotracheal intubation was aided with the fiberoptic scope while patients in the second group were intubated with the fiberoptic scope guided with the air-Q as a conduit. The number of attempts and time to successful insertion of air-Q and endotracheal tube were recorded. The fiberoptic quality of the vocal cords view as seen through the air-Q and ease of endotracheal tube insertion were also assessed.ResultsThe air-Q was easily inserted in all patients of the second group with mean insertion time (22.6 ± 4.3 s). The air-Q provided a good fiberoptic view of the vocal cords and successful tracheal intubation in 29 (96.7%) patients of the second group on the first attempt. Time to tracheal intubation in the second group was significantly shorter than the first group (21.6 ± 5.7 and 29.8 ± 6.2 s respectively). The air-Q was easily removed without any complications.ConclusionsThe air-Q as a conduit for fiberoptic scope provided a better view of the vocal cords and, less insertion time of the endotracheal compared to fiberoptic-aided endotracheal intubation in adult patients with limited cervical spine mobility scheduled for cervical spine fixation.     

A survey of Canadian anesthesiologists’ preferences in difficult intubation and “cannot intubate,cannot ventilate” situations

Introduction

The purpose of this survey was to determine the equipment that anesthesiologists prefer in difficult tracheal intubation and “cannot intubate, cannot ventilate” (CICV) situations.

Methods

A questionnaire was e-mailed to members of the Canadian Anesthesiologists’ Society to ascertain their preferences, experience, and comfort level with regard to their use of airway equipment in difficult intubation and CICV situations in adult patients. A Chi square test was used to analyse the data. All reported P values are two-sided.

Results

Nine hundred ninety-seven of 2,532 questionnaires (39%) were returned. In an unanticipated difficult direct laryngoscopic intubation situation, 893 of 997 (90%) respondents chose a video laryngoscope as the first-choice rescue technique, while 41 (4%) and 21 (2%) of respondents chose a flexible bronchoscope and an intubating laryngeal mask airway device, respectively. The majority of anesthesiologists had experience and were comfortable with using a flexible bronchoscope or a video laryngoscope. Regarding CICV, 294 of 955 (31%) respondents stated that they had never encountered it. Wire-guided cricothyroidotomy was chosen as the first-choice surgical airway by 375 of 955 (39%) respondents, while intravenous catheter cricothyroidotomy and “defer to tracheostomy by surgeon” were selected by 266 (28%) and 215 (23%) respondents, respectively. Seven hundred eighty-five of 997 (78%) respondents were familiar with the exact steps of the American Society of Anesthesiologists’ difficult airway algorithm, while 448 (47%) had attended an airway workshop within the past five years.

Conclusions

In a difficult intubation situation, the most frequently selected first-choice airway device was a video laryngoscope, followed by a flexible bronchoscope. In a CICV situation, the most frequently selected first-choice surgical airway technique was a wire-guided cricothyroidotomy, followed by an intravenous catheter cricothyroidotomy.     

The intubating laryngeal mask airway in failed fibreoptic intubation

PURPOSE: Prediction of difficult tracheal intubation is not always reliable and management with fibreoptic intubation is not always successful. We describe two cases in which blind intubation through the intubating laryngeal mask airway (ILMA FasTrach) succeeded after fibreoptic intubation failed. CLINICAL FEATURES: The first patient, a 50 yr old man, was scheduled for elective craniotomy for intracerebral tumour. Difficulty with intubation was not anticipated. Manual ventilation was easily performed following induction of general anesthesia, but direct laryngoscopy revealed only the tip of the epiglottis. Intubation attempts with a styletted 8.0 mm endotracheal tube and with the fibreoptic bronchoscope were unsuccessful. A #5 FasTrach was inserted through which a flexible armored cuffed 8.0 mm silicone tube passed into the trachea at the first attempt. The second patient, a 43 yr old man, presented with limited mouth opening, swelling of the right submandibular gland that extended into the retropharynx and tracheal deviation to the left. He was scheduled for urgent tracheostomy. Attempted awake fibreoptic orotracheal intubation under topical anesthesia showed gross swelling of the pharyngeal tissues and only fleeting views of the vocal cords. A #4 FasTrach was easily inserted, a clear airway obtained and a cuffed 8.0 mm silicone tube passed into the trachea at the first attempt. CONCLUSION: The FasTrach may facilitate blind tracheal intubation when fibreoptic intubation is unsuccessful.     

Use of the laryngeal mask for fibrescope–aided tracheal intubation in an awake patient with a deviated larynx

I report a case in which fibrescope–aided awake tracheal intubation was achieved using a laryngeal mask, in a patient with a mediastinal goitre in whom tracheal intubation with both a laryngoscope and a fibreoptic bronchoscope had failed. The tumour extended to the upper part of the mediastinum. The larynx and the upper segment of the trachea were displaced by the tumour. Awake tracheal intubation with both a laryngoscope and a fibreoptic bronchoscope failed. The laryngeal mask was then inserted without difficulty. After a fibreoptic bronchoscope had been covered by a plastic tube, the combination was passed through the laryngeal mask into the trachea. The fibreoptic bronchoscope and the laryngeal mask were removed, and a reinforced endotracheal tube was then inserted over the plastic tube into the trachea. The time for tracheal intubation was about 70 s. The laryngeal mask may allow easier location of the laryngeal inlet with a fibreoptic bronchoscope, and this technique is a useful alternative to the conventional technique of tracheal intubation in the patient with a deviated larynx.     

Intubation über den Tubuswechsler an einem Intubationstrainer

Background

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.

Aim

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.

Material and methods

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 7.0 mm) 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.

Results

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).

Conclusion

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.     

Efficacy of the Airtraq? laryngoscope with a fiberoptic bronchoscope compared with that of Airtraq? alone for tracheal intubation: a manikin study

Purpose  

Successful intubation using the Airtraq^? requires optimal positioning of the glottis in the middle of the viewfinder. If the glottic view cannot be optimized, some glottic manipulation is essential for the Airtraq-assisted successful intubation. We evaluated the efficacy of the combined use of the Airtraq and a fiberoptic bronchoscope (FOB) compared with that of the Airtraq alone for tracheal intubation in simulated airway scenarios.     

Pentax-AWS airway Scope as an alternative for awake flexible fiberoptic intubation of a morbidly obese patient in the semi-sitting position

For anesthesia induction in a morbidly obese patient with a full stomach, awake flexible fiberoptic bronchoscope (FOB) intubation in the semi-sitting position may be a suitable choice. A new rigid indirect videolaryngoscope, the Pentax-AWS system, has a unique feature of an adjustable built-in monitor and is designed to be used in patients in various positions. However, the efficacy of its use in such situations has not been investigated or reported. We used the Pentax-AWS system for the intubation of a morbidly obese patient (body mass index >50) who was at risk of regurgitation, anticipated difficult intubation, and supine hypotensive syndrome due to inferior vena cava compression by a huge ovarian cyst. The patient was placed in the sitting position during the intubation procedure. The patient’s trachea was intubated with the Pentax-AWS by an anesthesiologist positioned at the patient’s right and facing her. The Pentax-AWS offered easy intubation under good visualization of the glottic aperture as a consequence of its adjustable integrated monitor, in contrast to difficult intubation with other videolaryngoscopes which require an external monitor. This report illustrates that the Pentax-AWS is useful as an alternative for flexible fiberoptic intubation under these circumstances, as a consequence of its adjustable built-in monitor and integrated tube channel.     

Proseal喉罩与支纤镜联合Aintree导管用于颈椎不稳患者气管插管的临床研究

目的 通过与清醒经鼻支纤镜插管对比,研究Proseal喉罩与支纤镜联合Aintree导管用于颈椎不稳患者气管插管的有效性和安全性。方法 因颈椎骨折或严重颈椎间盘突出拟行颈椎减压内固定手术的患者40例,随机分配至以下两组：A组20例,清醒表麻后行经鼻支纤镜引导插管,然后麻醉诱导;B组20例,常规麻醉诱导后置入Proseal喉罩,沿喉罩在支纤镜引导下将Aintree导管插入气管内,退出喉罩后经Aintree导管置入气管插管。监测插管前（T0）、开始插管（T1）、插管成功时（T2）、插管成功后1min（T3）、插管成功后3min（T4）的平均动脉压（MAP）和心率（HR）;记录支纤镜插管时间、插管总时间（表麻时间或置喉罩时间加支纤镜插管时间）和插管相关并发症。结果 A组有1例因不能配合改为诱导后支纤镜插管,B组所有病例插管成功。T2和T3两时点,A组HR（92±17次/分,95±18次/分）显著高于B组（78±13次/分,83±17次/分）;T3时点A组MAP（93±28mmHg）显著高于B组（80±24mmHg）（P<0.05）;A组在T2、T3两时点的HR、MAP均显著高于各自的T0时点基础值（P<0.05）。插管的总时间两组相当（A组184±55s,B组179±27s,P>0.1）,而B组支纤镜插管时间较短（A组62±32s,B组39±18s,P<0.05）。两组患者术后无任何插管相关并发症。结论 Proseal喉罩与支纤镜联合Aintree导管用于颈椎不稳患者气管插管与传统支纤镜清醒插管效果相当,但血流动力学更平稳,是安全有效的困难气道处理新技术。     

Retromolar fibreoptic orotracheal intubation in a patient with severe trismus undergoing nasal surgery

Purpose

A considerable challenge arises when passage of an endotracheal tube between the teeth is impossible because of severe trismus and the presence of concomitant contraindications to nasotracheal intubation. We report a novel technique to circumvent the need for tracheostomy by using the retromolar space for oral fibreoptic intubation.

Clinical features

A 50-yr-old female with a history of pharyngeal cancers treated with surgery and radiotherapy presented for right dacryocystorhinostomy. She had undergone left dacryocystorhinostomy after nasotracheal intubation one week earlier. This time, orotracheal intubation was requested since surgery would involve the right nostril and left nasal intubation might dislodge the recently placed nasolacrimal tube. Due to severe trismus, the patient’s interincisor distance was only 9 mm, and it was impossible to pass a 6.0 mm endotracheal tube through that gap. A flexible bronchoscope loaded with a 6.0 mm tracheal tube was inserted through the retromolar space into the pharynx and maneuvered through the vocal cords for endotracheal intubation.

Conclusions

The retromolar space is located between the last molar and the ascending ramus of the mandible. Even with complete mandibular occlusion, it is usually able to accommodate a 7.0 mm endotracheal tube. Despite its hidden location, it can be used successfully for orotracheal fibreoptic intubation. With practice, the expertise achieved in performing this technique will confer a much needed option for securing the airway in this challenging situation.     

A United Kingdom national obstetric intubation equipment survey

BackgroundFailed intubation is relatively common in the obstetric patient. Overall, there has been a decline in experience of general anaesthesia in obstetrics. The level of anaesthetic preparedness in the event of a difficult obstetric intubation is unknown.MethodsWith approval from the Obstetric Anaesthetists’ Association, a national postal survey of obstetric units in the United Kingdom was conducted. The survey addressed airway equipment availability and existence of difficult airway algorithms and formal difficult airway drills. The number of deliveries, general anaesthetic cases and failed intubations in each unit was also ascertained.ResultsOne hundred and eighty-seven units completed the national obstetric intubation equipment survey questionnaire (78% response rate). All obstetric units possessed a laryngoscope with a normal handle and adult Macintosh blade, a bougie and a laryngeal mask airway. A 7.0 internal diameter endotracheal tube was most often used for securing the airway, and 90% of units stored all airway equipment on a designated difficult airway trolley. A fiberoptic bronchoscope was not readily available and on average it would take >10 min to obtain. A failed intubation incidence of 1:309 was reported. Only one third of units promoted difficult airway training.ConclusionEssential airway equipment was readily available in the event of a difficult obstetric intubation, with the exception of a fiberoptic bronchoscope. Few units conduct difficult airway training.     

Tracheal intubation using a guide wire for a 5-month-old baby with epiglottic cyst

We report anesthetic management for a 5-month-old baby with an epiglottic cyst causing stenosis of the upper airway and growth failure. A flexible guide wire was first inserted into the trachea through the forceps port of the fiberoptic bronchoscope (O.D. 3.5 mm) nasally. After removal of the bronchoscope, the trachea was then successfully intubated with a trachea tube (I.D. 3.5 mm) passed over it. Her symptom improved after removal of the cyst. A flexible guide wire combined with fiberoptic bronchoscope is useful in tracheal intubation for a baby with a difficult airway.     

Awake fibrecapnic intubation in head and neck cancer patients with difficult airways: new findings and refinements to the technique

Recently, we described an adaptation of awake fibreoptic intubation that we call awake fibrecapnic intubation. The aim of this study was to evaluate the efficacy and risk of complications with this novel technique in a consecutive case series of head and neck cancer patients known to have difficult airways. We prospectively studied 40 consecutive intubations in head and neck cancer patients prior to a diagnostic or surgical procedure. Following topical anaesthesia, a flexible bronchoscope was introduced into the pharynx; spontaneous respiration was maintained in all patients. A special suction catheter was advanced into the airway through the suction channel of the bronchoscope for carbon dioxide measurements. When four capnograms were obtained, the bronchoscope was railroaded over the catheter and a tracheal tube was placed. All adverse events and complications were recorded. There were no complications associated with the technique. The median (range) time to intubation was 3 min (1.5-15 min). All patients were intubated successfully, 39 (98%) of them using awake fibrecapnic intubation. There was one patient with severe tumour bleeding and acute airway obstruction caused by advancement of the tube over the bronchoscope. This was not considered to be a complication of the fibrecapnic technique. Awake fibrecapnic intubation is a safe and valuable technique in head and neck cancer patients with a difficult airway.     

Failed videolaryngoscope intubation in a patient with diffuse idiopathic skeletal hyperostosis and spinal cord injury

Purpose

A case of difficult intubation in a patient with cervical spinal cord injury with diffuse idiopathic skeletal hyperostosis (DISH) is described. The trachea could not be intubated with a videolaryngoscope, and successful intubation was achieved with a laryngeal mask airway device (LMAD) and a fibreoptic bronchoscope (FOB).

Clinical features

A 65-yr-old male developed sudden tetraplegia after a fall. Initial attempts at securing his airway were unsuccessful with a videolaryngoscope, but success was achieved with a LMAD and a FOB. Diagnostic imaging revealed no cervical spine fracture but demonstrated severe airway distortion from DISH and a spinal cord contusion accounting for his tetraplegia. Subcutaneous neck emphysema likely secondary to difficult intubation was also identified, but it did not result in additional morbidity.

Conclusions

Although often considered to be a benign entity, DISH can predispose patients to catastrophic cervical injury and difficult airway management. Careful review of plain radiographs in the spinal cord injury patient may assist with appropriate selection of airway interventions. The videolaryngoscope is useful for difficult airways, but its effectiveness may be compromised with an anteriorly displaced airway in combination with restricted cervical movement and limited oropharyngeal airspace.     

Stylet‐ or forceps‐guided tube exchanger to facilitate GlideScope® intubation in simulated difficult intubations – a randomised controlled trial

The GlideScope^® videolaryngoscope is widely used in the management of the difficult airway. However, passing the tracheal tube through the vocal cords can be awkward, and the use of a stylet to guide insertion is recommended. This randomised controlled trial evaluated a forceps‐guided tube exchanger as an alternative to the stylet to aid intubation with the GlideScope in patients undergoing anaesthesia, with a simulated difficult airway created by the application of a semi‐rigid cervical collar. Data were analysed from 178 patients randomly assigned to undergo intubation using either the stylet (n = 88) or a forceps‐guided tube exchanger (n = 90). All intubations were completed successfully, with first attempt rates of 93.2% using the stylet and 94.4% using the exchanger (p = 0.597). The mean (SD) intubation time was 67.8 (28.7) s in the stylet group and 66.1 (15.5) s in the forceps‐guided tube exchanger group (p = 0.11). The frequency of sore throat 1 h after extubation was 34.1% in the stylet group and 2.2% in the tube exchanger group (p < 0.001); 24 h after extubation the corresponding figures were 40.0% and 11.1% (p < 0.001). Using a forceps‐guided tube exchanger may offer an advantage over a stylet in guiding tracheal intubation when the GlideScope is used.     

Intubación en dos pacientes con vía aérea difícil y estenosis traqueal tras traqueostomía en cirugía torácica

Lung isolation in thoracic surgery is a challenge, this is even more complex in the presence of unknown tracheal stenosis (TS). We report two cases of unknown TS and its airway management. TS appears most frequently after long term intubation close to the endotracheal tube cuff or in the stoma of tracheostomy that appears as a consequence of the granulation tissue after the surgical opening of the trachea. Clinical history, physical examination, difficult intubating predictors and imaging tests (CT scans) are crucial, however most of tracheal stenosis may be unnoticed and symptoms depend on the degree of obstruction. In our cases, the patients presented anatomical changes due to surgery and previous tracheostomy that led to a TS without symptoms. There is scarce literature about the intubation in patients with previous tracheostomy in thoracic surgery. In the first case, a Univent^® tube was used using a flexible fiberscope but an acute tracheal hemorrhage occurred. In the second case, after intubation with VivaSight SL^® in an awake patient, the insertion of a bronchial blocker was performed through an endotracheal tube guided by its integrated camera without using flexible fiberscopy.