Case report: A normal capnogram despite esophageal intubation

PURPOSE: To report a case of accidental esophageal intubation which could not be detected by capnography. CLINICAL FEATURES: A 43-yr-old man with osteogenic sarcoma of the mandible underwent mandibulectomy, radical neck dissection, reconstruction of the mandible and radiation therapy. He was scheduled for revision surgery to the mandible. He had a limited mouth opening and neck movement after operation and radiation. After the cuffed oropharyngeal airway (COPA) was inserted, anesthesia was induced with sevoflurane, and fibreoptic nasotracheal intubation attempted, but it was impossible to insert the fibrescope into the trachea because of a deformed larynx. While equipment for tracheostomy was prepared, one last attempt was made to insert the tube blindly into the trachea. The capnograph showed apparently normal carbon dioxide waveforms, and the reservoir bag inflated and deflated regularly. However, immediately after inflation of the cuff of the tracheal tube the reservoir bag movement stopped and CO(2) waveforms disappeared. Fibreoptic bronchoscopy showed that the tube was in fact in the esophagus. It was then noticed that the patient was still breathing spontaneously through the cuffed airway. The patient was awakened and tracheostomy performed. It was considered that egress of the expired gas was partially prevented by the cuffed airway, pooled in the oral cavity, aspirated down the esophagus during inspiration (likely to be due to negative intrathoracic pressure) and pushed out through the tube during expiration; inflation of the cuff prevented the gas entering the esophagus. CONCLUSION: Under such exceptional circumstances, apparently normal carbon dioxide waveforms were observed despite esophageal intubation in a spontaneously breathing patient.     

Intubation via LMA in pediatric patients with difficult airways

PURPOSE: To report two cases of successful tracheal intubation in difficult pediatric airways using a conventional laryngeal mask airway (LMA) with an extended polyvinyl chloride (PVC) tube after laryngeal assessment with a fibreoptic device. CLINICAL FEATURES: Two cases, Dandy-Walker and Pierre Robin syndromes, were scheduled for surgery. They were premedicated with 0.5 mg x kg(-1) promethazine p.o. 90 min before surgery. Both patients arrived in the operating room sedated, with dry mouth, and without evidence of increased intracranial tension or airway obstruction. Inhalational induction with isoflurane 0.5-3% was commenced. Conventional tracheal intubation was impossible in both cases. In each an LMA was inserted to maintain ventilation, anesthesia, and to facilitate intubation. Fibreoptic bronchoscopy was used to assess the larynx, followed by blind intubation via the LMA using extended PVC tracheal tube (TT). Anesthesia was maintained during intubation using Mapleson F anesthesia circuit attached to a connector with fibreoptic bronchoscope adapter. CONCLUSION: This report describes the assessment of the airway with fibreoptic bronchoscopy after LMA insertion facilitated blind tracheal intubation in two children with difficult airways.     

Large goitre causing difficult intubation and failure to intubate using the intubating laryngeal mask airway: lessons for next time

A 63-yr-old woman was anaesthetized for sub-total thyroidectomy. The thyroid gland was large, deviating the trachea to the right and causing 30% tracheal narrowing at the level of the suprasternal notch. Mask ventilation was easy but laryngoscopy was Cormack and Lehane grade 3. Despite being able to see the tip of the epiglottis, tracheal intubation was impossible. An intubating laryngeal mask was inserted and although the airway was clear and ventilation easy, it was not possible to intubate the trachea either blindly or with the fibreoptic bronchoscope. Tracheal intubation was eventually achieved using a 6.5- mm cuffed oral tracheal tube via a size 4 laryngeal mask under fibreoptic control. We describe the case in detail and discuss the use of the intubating laryngeal mask, its potential limitations and how to optimize its use in similar circumstances.      

The intubating laryngeal mask for a patient with cerebrospinal fluid rhinorrhea and pneumocephalus

A 53-year-old male was scheduled for repairs of cerebrospinal fluid (CSF) rhinorrhea and pneumocephalus under general anesthesia. He had undergone a neck clipping for a ruptured anterior communicating aneurysm 13 days before. As he had a difficult airway, Trachlight was used for successful tracheal intubation. To avoid tension pneumocephalus, an intubating laryngeal mask (ILM) was inserted with rapid sequence induction without positive pressure ventilation. A 7.0 mm ID straight silicone reinforced tube was then inserted through the ILM using a fiberscope. A fiberscope guided tracheal intubation via the ILM is recommended for patients with CSF rhinorrhea and pneumocephalus especially when the trachea is difficult to intubate under direct laryngoscopy.     

Fibreoptic bronchoscopy for tracheal and endobronchial intubation with a double-lumen tube

A 68-year-old patient was scheduled for a thoracotomy. A double-lumen endobronchial tube was requested by the surgeon to facilitate operating conditions. Initial attempts at intubation by conventional methods were unsuccessful. The proximal ends of a 37F double-lumen tube were then shortened and a 4-mm fibreoptic bronchoscope was passed through the bronchial lumen. The patient's larynx was easily visualized and the bronchoscope was passed into the trachea. The double lumen tube was then advanced over the bronchoscope and correctly positioned. Shortening a double-lumen tube allows the use of a fibreoptic bronchoscope to aid in tracheal intubation in a patient whose larynx is difficult to visualize by conventional methods.     

Comparison of times to achieve tracheal intubation with three techniques using the laryngeal or intubating laryngeal mask airway

We compared the times to intubate the trachea using three techniques in 60 healthy patients with normal airways: (i) fibreoptic intubation with a 6.0-mm reinforced tracheal tube through a standard laryngeal mask airway (laryngeal mask-fibreoptic group); (ii) fibreoptic intubation with a dedicated 7.0-mm silicone tracheal tube through the intubating laryngeal mask airway (intubating laryngeal mask-fibreoptic group); (iii) blind intubation with the dedicated 7.0-mm silicone tracheal tube through the intubating laryngeal mask airway (intubating laryngeal mask-blind group). Mean (SD) total intubation times were significantly shorter in the intubating laryngeal mask-blind group (49 (20) s) than in either of the other two groups (intubating laryngeal mask-fibreoptic 74 (21) s; laryngeal mask-fibreoptic group 75 (36) s; p < 0.001). However, intubation at the first attempt was less successful with the intubating laryngeal mask-blind technique (15/20 (75%)) than in the other two groups (intubating laryngeal mask-fibreoptic 19/20 (95%) and laryngeal mask-fibreoptic 16/20 (80%)) although these differences were not statistically significant. We conclude that in this patient group, all three techniques yield acceptable results. If there is a choice of techniques available, the intubating laryngeal mask-blind technique would result in the shortest intubation time.     

Orotracheal intubation with an AirWay Scope in a patient with Treacher Collins syndrome

Treacher Collins syndrome (TCS) is a congenital malformation of craniofacial development; in these patients conventional direct laryngoscopy is very difficult and often unsuccessful because of the upper airway malformation. A 20-year-old man with TCS was scheduled for elective tympanoplasty. The patient showed the characteristic facial appearance of TCS, and a difficult airway was anticipated. After careful anesthesia induction, direct laryngoscopy with Macintosh blade no. 4 of a direct laryngoscope failed to visualize the epiglottis, even with cricoid pressure, resulting in a grade 4 Cormack and Lehane view. Next, the AirWay Scope was easily inserted, and his glottic opening was clearly visualized. An 8.0-mm-internal-diameter tracheal tube was then advanced into the trachea without any difficulty. The AirWay Scope is a very useful airway device for orotracheal intubation; it provides an excellent view of the glottis without requiring alignment of the oral, pharyngeal, and laryngeal axes, and appears to be promising for use in patients with a difficult airway.     

The intubating laryngeal mask. II: a preliminary clinical report of a new means of intubating the trachea

We have assessed the efficacy of a new laryngeal mask prototype, the intubating laryngeal mask airway (ILMA), as a ventilatory device and blind intubation guide. The ILMA consists of an anatomically curved, short, wide bore, stainless steel tube sheathed in silicone which is bonded to a laryngeal mask and a guiding handle. It has a single moveable aperture bar, a guiding ramp and can accommodate an 8 mm tracheal tube (TT). After induction of anaesthesia with propofol 2.5 mg kg-1 and fentanyl 2.5 micrograms kg-1, the device was inserted successfully at the first attempt in all 150 (100%) patients and adequate ventilation achieved in all, with minor adjustments required in four patients. Placement did not require movement of the head and neck or insertion of the fingers in the patient's mouth. Blind tracheal intubation using a straight silicone cuffed TT was attempted after administration of atracurium 0.5 mg kg-1. If resistance was felt during intubation, a sequence of adjusting manoeuvres was used based on the depth at which resistance occurred. Tracheal intubation was possible in 149 of 150 (99.3%) patients. In 75 (50%) patients no resistance was encountered and the trachea was intubated at the first attempt, 28 (19%) patients required one adjusting manoeuvre and 46 (31%) patients required 2-4 adjusting manoeuvres before intubation was successful. There were 13 patients with potential or known airway problems. The lungs of all of these patients were ventilated easily and the trachea intubated using the ILMA. In 10 of 13 (77%) of these patients, no resistance was encountered and the trachea was intubated at the first attempt; three of 13 (23%) patients required one adjusting manoeuvre. Tracheal intubation required significantly fewer adjusting manoeuvres in patients with a predicted or known difficult airway (P < 0.05). We conclude that the ILMA appeared on initial assessment to be an effective ventilatory device and intubation guide for routine and difficult airway patients not at risk of gastric aspiration.      

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.     

Fiberoptic intubation through an I-gel supraglottic airway in two patients with predicted difficult airway and intellectual disability

We describe successful fiberoptic-guided tracheal intubation through the novel supraglottic "I-gel" airway in two uncooperative adult patients with genetic syndromes, learning disability, and predicted difficult airway, scheduled for complex dental treatment under general anesthesia. The I-gel maintained the airway immediately after induction, allowing oxygenation and ventilation. Location of the laryngeal inlet was successful on the first attempt with a fiberscope, and the tracheal tube was inserted into the trachea over the endoscope without complication in both patients. This report suggests another option for management of predicted difficult airways.     

Subcutaneous emphysema and pneumomediastinum after translaryngeal intubation: tracheal perforation due to unsuccessful fiberoptic tracheal intubation

A 77-year-old man was scheduled to undergo a cervical lymph node biopsy under general anesthesia. Although awake, nasotracheal fiberoptic intubation was initially planned because of an anticipated difficult airway, the attempt was unsuccessful. Orotracheal intubation was subsequently performed under direct laryngoscopy without difficulty. After initiating positive pressure mechanical ventilation, subcutaneous and mediastinal emphysema developed. The cause of this emphysema was considered to be tracheal perforation after an unsuccessful attempt at fiberoptic tracheal intubation.     

Intubation in a patient with lingual tonsil hypertrophy using an intubating laryngeal mask airway in combination with fiberoptic intubation

A 66-yr-old man was scheduled for colon resection under general anesthesia. There were no findings suggesting difficulty of airway management. After induction of anesthesia, manual ventilation via a facemask was suboptimal, but increased fresh gas flow improved it. At direct laryngoscopy after achieving muscular relaxation, the arytenoids and epiglottis could not be seen even by an expert anesthesiologist. Intubating laryngeal mask airway (ILMA) was inserted to patient's larynx and ventilation could be continued. Tracheal intubation through ILMA was impossible because of hard resistance for inserting the endotracheal tube. Fiberoptic bronchoscopy revealed that the hypertrophied lingual tonsil obstructed the aperture of ILMA. Several attempts were made for intubation using fiberoptic tracheal intubation technique through ILMA and finally the patient's trachea was intubated without any bleeding or swelling of laryngeal tissues. The effectiveness of ILMA for the patient with lingual tonsil hypertrophy is still unknown, but the insertion of ILMA might be considered for safe airway management in combination with a fiberscope.     

Comparison of cuffed and uncuffed preformed oral pediatric tracheal tubes

BACKGROUND: In preformed cuffed tracheal tubes the position of the cuff within the airway is given by its distance to the tube bend placed at the lower teeth. The aim of this study was to compare the design of cuffed and uncuffed preformed pediatric oral tracheal tubes with regard to anatomical landmarks. METHODS: Complete series of cuffed and uncuffed preformed oral pediatric tracheal tubes sized from internal diameter 3.0-7.0 mm if available were ordered from five different manufacturers. The distance from the bend to the distal tube tip and to the upper border of the cuff were measured and compared with anatomical airway landmarks in the developing child. RESULTS: Between cuffed and uncuffed tracheal preformed tubes up to 37 mm differences in the bend-to-tracheal tube tip distances were found for given age groups. Thus uncuffed preformed tracheal tubes were more at risk for inadvertent endobronchial intubation than cuffed preformed tracheal tubes. Comparison of bend-to-upper border of the cuff distances with teeth-to-vocal cord distances calculated from anatomical data revealed that several of the tracheal tube cuffs become positioned within the subglottic larynx or even within the vocal cords when inserted according to the bend. CONCLUSIONS: There is a need for improvement in cuffed preformed pediatric tracheal tubes, namely a standard bend-to-tracheal tube tip distance to allow a safe insertion depth, a short cuff placed on the tube shaft as distally as possible and an intubation depth mark to verify a proper position of the cuff in the trachea.     

Laryngeal mask application for a case of unpredictable adult tracheal stenosis

A 69-year-old man with chronic renal failure was scheduled for artero-venous shunt surgery for sustained hemodialysis. On the pre-anesthesia interview, the patient complained of no respiratory symptom. Chest x-ray showed some tracheal deviation. There was no past history of the respiratory system such as bronchitis, bronchial asthma, tumor, trauma or previous tracheal intubation. General anesthesia was induced smoothly with thiopental and suxamethonium. Face mask ventilation could be done easily. The vocal cord was exposed fully by standard McIntosh laryngoscope. However, a neither ID 7.5 nor 6.5 mm tracheal tube could be inserted into the trachea. Then, a size 4.0 laryngeal mask airway (LMA) was inserted smoothly and ventilation was maintained adequately. The surgery was done smoothly. Seven days after, bronchofiber scopic findings showed tracheal stenosis. The cause was unknown but not from inflammation or tumor. The patient complained no respiratory distress after the surgery. In such unpredictable tracheal stenosis with easy mask ventilation, LMA is a considerable option for respiratory management.     

Airway management of a patient with tracheal stenosis for surgery in the prone position

PURPOSE: When tracheal intubation is required in a patient with an uncollapsible tracheal stenosis, the tip of the tube is usually positioned proximal to the stenosis. Only the tip of the tube may be in the trachea and the tube can be dislodged. We report the successful airway management of a patient with an uncollapsible tracheal stenosis who underwent cranial surgery in the prone position. CLINICAL FEATURES: A 49-yr-old man with the saber-sheath trachea (stenosis of the entire intrathoracic trachea) was scheduled for a posterior fossa surgery for resection of a cerebellar tumour. Anesthesia was induced by allowing the patient to inhale spontaneously oxygen and increasing concentrations of sevoflurane up to 5%, without airway obstruction. After injection of vecuronium, an airway exchange catheter was inserted orally into the trachea. A laryngeal mask airway was then inserted with the exchange catheter in place and, with the aid of a fibrescope, a 6.0-mm reinforced tracheal tube was passed through the laryngeal mask into the trachea so that the tip of the tube was about 1 cm proximal to the stenosis. The patient was turned to the prone position and the operation proceeded uneventfully. CONCLUSIONS: The laryngeal mask and an airway exchange catheter were used as backups to tracheal intubation in this patient with tracheal stenosis in the prone position. Should the trachea be extubated accidentally, it may be re-intubated through the laryngeal mask and ventilation may be possible through the laryngeal mask or the exchange catheter.     

The LMA Fastrach™ facilitates fibreoptic intubation in oral cancer patients

PURPOSE: To compare ease of endotracheal intubation with the Intubating Laryngeal Mask Airway (ILMA) tracheal tube (TT; for LMA-Fastrach) and regular PVC TT (Portex) for nasotracheal fibreoptic intubation in oral cancer patients with a difficult airway. METHODS: 40 patients of physical status ASA I-II with a history of previous oral cancer surgery and/or postoperative radiotherapy scheduled for oral cancer surgery were randomly allocated by sealed envelopes to undergo tracheal intubation with either the ILMA TT or a standard TT. Ease of nasal passage of the TT and ease of tracheal intubation over the fibrescope was assessed. Peak airway pressures were assessed intraoperatively and postoperatively for 12 hr. RESULTS: The use of the ILMA TT increased the ease of nasotracheal intubation by increasing the percentage of successful tube placements at the first attempt (80%) in comparison with standard TT (35%); (P < 0.05). Peak airway pressures were found to remain low with the ILMA TT. None of the patients experienced any airway related complications. CONCLUSIONS: Use of a soft, flexible, nonkinking ILMA TT with a tapered tip design facilitates passage into the trachea over a fibreoptic bronchoscope and allows maintenance of lower airway pressures. The ILMA TT may be a useful adjunct for management of the difficult airway in oral cancer surgery.     

Loss of the airway during tracheostomy: rescue oxygenation and re-establishment of the airway

PURPOSE: To describe loss of the airway during tracheostomy and suggest a method for re-establishment of the airway and providing rescue oxygenation. CLINICAL FEATURES: A 22-yr-old female diagnosed with encephalomyelopathy was admitted to the intensive care unit with a progressively deteriorating level of consciousness and respiratory failure requiring intubation and ventilation. Several weeks later, an elective tracheostomy was performed under anesthesia. The surgeon made an anterior tracheal wall incision and inserted a cuffed #6 Shiley tracheostomy tube. No end-tidal CO(2) was detected and the patient could not be ventilated. After another failed attempt at insertion of a second tracheostomy tube, the diagnosis was made of a false passage within the trachea. The Shiley tracheostomy tube was removed and a #6 regular endotracheal tube was introduced in the trachea through the tracheostomy incision. The patient now could be ventilated with difficulty and low readings of end-tidal CO(2) were noted. Despite all efforts to further ventilate the patient, the arterial oxygen saturation never recovered, resulting in cardiac arrest. CONCLUSION: To restore a lost airway during tracheostomy, we recommend that a jet ventilation airway exchange catheter (JVAE) be inserted in the endotracheal tube through a bronchoscope port attachment prior to surgical entry into the trachea. The JVAE will also ensure continued ability to oxygenate the patient.     

Anesthetic management of a patient with Saber-sheath trachea]

A 65-year-old man was scheduled for total gastrectomy. Preoperative chest radiograph showed significant narrowing of the trachea. On chest CT scan the trachea was U-shaped (tracheal index = 36%) and was diagnosed as saber-sheath trachea. During general anesthesia we took care to reduce the irritation by the endotracheal tube, particularly during intubation, and to avoid excessively high airway pressure. The trachea was watched carefully by bronchoscopy after intubation and during extubation not to neglect any complication. There was no complication after the operation.     

Anesthesia of the airway by aspiration of lidocaine

PURPOSE: Lidocaine instilled onto to the back of the tongue of a supine subject and aspirated has been reported to provide effective topical anesthesia of the airway. The purpose of this study was to observe endoscopically the fate of lidocaine so instilled and document the efficacy of anesthesia for awake fibreoptic intubation. METHODS: In Part I of the study, a fibreoptic bronchoscope was positioned in the pharynx of three volunteers lying supine and the route followed by tinted lidocaine solution instilled onto the back of the protruded tongue during mouth breathing was observed. In Part 2, the airway of 39 patients requiring awake fibreoptic intubation was anesthetized by having them gargle twice with 5 ml lidocaine 2%, followed by instillation of 0.2 ml-kg(-1) or 20 ml lidocaine 1.5% (whichever was less) onto the dorsum of their tongues as described above. The efficacy of anesthesia was scored by the patient reaction (coughing or gagging) to instrumentation in the pharynx, at the glottis, and in the trachea; to passage of the tracheal tube into the trachea; and to the presence of the tube in the trachea. RESULTS: Lidocaine instilled on to the back of the tongue was swallowed initially but ultimately pooled in the pharynx and was aspirated. In all patients the trachea was intubated without requiring supplemental lidocaine, and all but one patient tolerated the tracheal tube in situ. CONCLUSION: A combination of lidocaine gargles and lidocaine instilled on to the back of the tongue and aspirated provides effective anesthesia of the pharynx, larynx, and trachea for awake fibreoptic intubation.     

Anesthetic management of an infant with Cornelia de Lange syndrome

We report anesthetic management of an infant with Cornelia de Lange syndrome. A 12-month-old girl with Cornelia de Lange syndrome was scheduled for ureterocystoneostomy because of vesicoureteral reflux. Preoperative physical examination suggested difficult tracheal intubation. After induction of anesthesia with sevoflurane (5%) in nitrous oxide (70%) and oxygen, a laryngeal mask airway (# 1.5) was inserted. A guide wire was inserted in the trachea through a laryngeal mask airway under direct vision of a fiberoptic bronchoscope. A tube-exchanger stylet was inserted around the guide wire after the laryngeal mask airway and fiberoptic bronchoscope had been removed. An endotracheal tube (ID 4.0 mm) was easily intubated around the tube-exchanger stylet. During the surgery, anesthesia was maintained with sevoflurane (2-3%) in nitrous oxide (50%) and oxygen. There was no perioperative pulmonary complication.