Video-intuboscopic monitoring of tracheal intubation in pediatric patients

PURPOSE: To evaluate the efficacy of video-intuboscopic monitoring during orotracheal intubation in a pediatric anesthesia teaching unit. METHODS: In 100 pediatric patients direct laryngoscopy performed by residents or nurse anesthetists was monitored on a video display using a flexible, ultralight video-endoscopic system (O.D. 2.8 mm/length 1.8 m) within the endotracheal tube (ETT). Best direct laryngoscopic view was assessed by the intubator. The instructor observed the intubation procedure on the video display and noted number of intubation attempts, best laryngoscopic monitor view, tube passage through the larynx and final tube position. If required he gave instructions or corrections. After removal of the laryngoscope, tracheal tube position was adjusted using the monitor view. Difficulties attributed to the fibreoptic endoscope during intubation and removal from the ETT were recorded. RESULTS: The trachea was successfully intubated at the first attempt in all patients. The supervisor detected one esophageal and 12 endobronchial intubations that were immediately corrected before starting ventilation. Final visualized endotracheal tube adjustment above the carina was possible in all patients except in one with copious tracheal secretions. Compared with direct laryngoscopy the video display provided an improved view of the vocal cords during intubation. In six patients direct laryngoscopy was difficult but the tracheas were intubated using the monitor view. No difficulties with the equipment were encountered except that the black coated endoscope compromised recognition of the black ETT depth-markings in small tubes. CONCLUSIONS: Video-intuboscopic monitoring is a useful monitor of tracheal intubation. "The improved view of the cords may provide assistance during difficult laryngoscopy.     

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.     

Airway length in adults: estimation of the optimal endotracheal tube length for orotracheal intubation

STUDY OBJECTIVE: To estimate the optimal endotracheal tube (ETT) length in orotracheally intubated patients. DESIGN: Prospective study. SETTING: Operating room of a medical center hospital. PATIENTS: 293 ASA physical status I and II patients (150 male and 143 female), requiring general anesthesia and orotracheal intubation. INTERVENTIONS: We used fiberoptic bronchoscope within the ETT to identify the carina and vocal cords. MEASUREMENTS: The length from carina to vocal cords, vocal cords to right mouth angle (corner), and carina to right mouth angle were measured. The optimal ETT tip was defined as 5 cm above the carina. Patient's height and sternum length were recorded. MAIN RESULTS: The correlation between airway length and body height was significant. By linear regression, a formula was obtained to estimate the optimal ETT length in orotracheally intubated patients: the length from 5 cm above carina to right mouth angle (cm) =< body height (cm)/5> - 13. CONCLUSION: The optimal insertion length of the ETT for orotracheally intubated adult patients with the head placed in a neutral position is correlated with body height. The proposed formula can provide a useful guide to determine the optimal ETT tip position in most of the patients who required orotracheal intubation.     

Fibreoptic bronchoscopic nasotracheal intubation of a neonate with Pierre Robin syndrome

A case of nasotracheal intubation using a fibreoptic bronchoscope and the Seldinger technique is described. A guide wire was passed through the suction channel of the fiberscope after the epiglottis and the vocal cords were seen; the fiberscope was removed and a nasotracheal tube passed over the wire into the trachea.     

A fibreoptic scoring system to assess the position of laryngeal mask airway devices. Interobserver variability and a comparison between the standard, flexible and intubating laryngeal mask airways

We determined the interobserver reliability of a fibreoptic scoring system for assessing the position of the laryngeal mask airway (LMA), the flexible laryngeal mask airway (FLMA) and the intubating laryngeal mask airway (ILM). We also compare fibreoptic position between the devices. Thirty anaesthetised adult patients were studied in random order in a triple crossover manner. Two observers blinded to each others findings scored the fibreoptic position as follows: 4, only vocal cords visible; 3, vocal cords plus posterior epiglottis visible; 2, vocal cords plus anterior epiglottis visible; 1, vocal cords not seen. Interobserver reliability was examined using intraclass correlation coefficient (ICC). Interobserver reliability was graded as excellent for the LMA (ICC = 0.89), FLMA (ICC = 0.87) and ILM (ICC = 0.79). Fibreoptic scores were higher for the LMA and FLMA compared with the ILM (both p < 0.001). We conclude that interobserver reliability for the fibreoptic scoring system is excellent for the LMA, FLMA and ILM. Fibreoptic position is better for the LMA and FLMA compared with the ILM. Fibreoptic scoring has potential utility for research and clinical practice with laryngeal mask devices.     

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.     

Endotracheal intubation device with a charge couple device camera

We developed an orotracheal intubation device equipped with a charge couple device (CCD) camera, providing a wide field of vision. We used this device to perform endotracheal intubations in 62 anesthetized patients undergoing dental treatment and oral surgery. The time required to perform an endotracheal intubation with this system was examined. The use of this system is described below. The wand with the CCD camera was inserted into the oropharyngeal cavity. The oropharynx, including the epiglottis and glottis, could be visualized on the monitor screen. The tube introducer was inserted into the trachea through the vocal cords via the side tube of the wand. The wand with the CCD camera was withdrawn, leaving the tube introducer in the trachea. The endotracheal tube was then inserted into the trachea by using the tube introducer as a guide. The time required for the procedure was determined. The mean total time for the procedure was 41.2 s (maximum, 155 s; minimum, 14 s). There were no significant differences in this procedure when the patients were grouped according to the Cormack and Lehane classification. There was no failure to intubate using this system. Because the device can extensively visualize not only the larynx, glottis, and vocal cords, but also the movement of the tube introducer, on the monitor screen via the CCD camera, endotracheal intubation can be easily performed while the vocal cords are visualized on the monitor screen.     

Laryngoscopy and fibreoptic intubation in acromegalic patients

Acromegaly is recognized as a cause of difficulty in airway management and tracheal intubation. We evaluated prospectively the conditions for laryngoscopy and fibreoptic intubation in 15 acromegalic patients. Each patient served as his or her own control. Ventilation of the lungs with a face mask was successful in all patients. In five of 15 patients the vocal cords could not be seen using the Macintosh laryngoscope with a size 5 blade. Difficult laryngoscopy was associated significantly with the number of attempts required to see the vocal cords with the fibrescope (P < 0.01, Spearman rank correlation). The larynx could not be seen with both techniques in one patient, and the trachea was intubated blindly with the help of an introducer. Our results showed that fibreoptic intubation may prove difficult or fail in acromegalic patients. Difficulties in seeing the vocal cords with a fibrescope were present most often in patients who also had probable intubation difficulties with a rigid laryngoscope.      

Ease of laryngeal passage during fibreoptic intubation: a comparison of three endotracheal tubes

BACKGROUND: The use of a fibreoptic bronchoscope to facilitate endotracheal intubation is well established in modern anaesthetic practice. Difficulty may be encountered when inserting an endotracheal tube over the fibrescope as the bevelled tip can impinge on the vocal cords or epiglottis and impede advancement through the laryngeal inlet. Intavent have recently developed a tapered tip tube for use with their Intubating Laryngeal Mask Airway. A randomised, double-blind study was performed to compare the ease of railroading three different tubes over a fibrescope placed in the trachea. METHODS: We studied 54 patients presenting for elective dental surgery. General anaesthesia was induced with propofol 2-3 mg/kg, fentanyl 1-1.5 microg/kg, and atracurium 0.5 mg/kg and maintained with oxygen (5 l/min) and isoflurane 1-2%. Nasotracheal fibreoptic intubation was attempted in all patients. In each case the ease of tube advancement over the fibrescope and into the trachea was evaluated by the blinded observer, using the classification system (Grade 0-2) described by Jones et al. RESULTS/CONCLUSION: The Intavent tube was found to be superior for nasotracheal fibreoptic intubation to either the Mallinckrodt reinforced tube (P<0.034) or the Portex Blue Line tube (P<0.004).     

Use of a fibreoptic stylet to visually evaluate tracheal intubation technique

To compare the tracheal intubation by novices with that of instructors, we videotaped the view obtained through a fibreoptic stylet during standard tracheal intubations with a Macintosh direct laryngoscope. The duration of visualization of the vocal cords was longer during intubation by instructors than during trainee attempts. The tracheal tube contact (with pharyngeal wall) time duration was higher during intubation attempts by trainees than instructors. The quality of the image of the vocal cords through the stylet was related to these video-view parameters. Our results demonstrated that visualization of the vocal cords by direct laryngoscope and manipulation of the tracheal tube in the oral cavity were different between anaesthesia trainees and instructors, and suggested that visually monitoring the tracheal intubation procedure through a fibreoptic stylet might be useful for the education of anaesthesia trainees.     

Effects of the jaw‐thrust manoeuvre in the semi‐sitting position on securing a clear airway during fibreoptic intubation

Securing a clear airway is important for successful fibreoptic intubation. We investigated whether the jaw‐thrust manoeuvre in the 25° semi‐sitting position improves airway clearance compared with the supine position in 88 anaesthetised patients randomly assigned to the two positions. After induction of anaesthesia, the fibreoptic bronchoscope was advanced into the mouth along the dorsum of the tongue during the jaw‐thrust manoeuvre. Airway clearance was assessed at the level of the soft palate and epiglottis. Patients in the 25° semi‐sitting position had clearer airways (judged subjectively by a three‐level scale) than those in the supine position at the soft palate level (p = 0.012). At the level of the epiglottis, airway clearance was equally good in both positions. The mean (SD) times to view the vocal cord and carina were shorter in the 25° semi‐sitting position (4 (1) s and 8 (1) s, respectively) compared with the supine position (6 (3) s and 11 (3) s; p < 0.001, respectively). The time to achieve intubation was also shorter in the 25° semi‐sitting position (21 (5) s) than in the supine position (25 (7) s; p = 0.018).     

Orotracheal fibreoptic intubation for rapid sequence induction of anaesthesia

We assessed whether flexible fibreoptic-guided orotracheal intubation could be rapidly and successfully achieved during a simulated rapid sequence induction in 30 anaesthetised and paralysed patients. Rapid sequence induction was simulated by applying practised cricoid pressure. Using a flexible fibreoptic laryngoscope with camera and closed circuit television, an anaesthetist experienced with the technique performed orotracheal endoscopy and intubation with a cuffed 7.0-mm Portex tracheal tube through a VBM Bronchoscope Airway. Fibreoptic intubation was successful at the first attempt in 28 patients (93%); two patients required two attempts. Mean (SD) time from removal of the facemask from the patient's face to the appearance of carbon dioxide in the expired breath after intubation was 111 (46) s (median 100 s; range 54-195 s). There were one or more difficulties in 13 patients (43%). These difficulties were largely avoidable and included problems with fibreoptic equipment, the Bronchoscope Airway, copious secretions, cricoid pressure or railroading of the tracheal tube. Flexible fibreoptic-guided orotracheal intubation may have a place in the management of failed intubation during a rapid sequence induction.     

Intubation depth markings allow an improved positioning of endotracheal tubes in children

OBJECTIVES: To evaluate the position of the new Microcuff pediatric tracheal tube, based upon intubation depth markings. METHODS: With Institutional Ethics Committee approval and informed parental consent, we included patients from birth (> or = 3 kg) to 16 yr undergoing interventional cardiac catheterization requiring general anesthesia with orotracheal intubation. The intubation depth mark of the tracheal tube was placed between the vocal cords by direct laryngoscopy. The distance between tube tip and tracheal carina was measured from routinely taken cardiac catheterization posterior-anterior x-ray computer images with the patient supine and the head in a neutral position. Evaluation was performed for 20 tubes size 3.0 mm internal diameter (ID) and for ten tubes of each size from 3.5 to 7.0 mm ID. RESULTS: 100 patients were studied (47 girls; 53 boys). Tracheal tube tip advancement into the trachea ranged from 40.6% to 68.6% (median 51.4%). The shortest distance from tube tip to the tracheal carina was 15.7 mm using a 3.0 mm ID tube. Using a standard formula for tube insertion in children aged > or = two years [12 cm + (age/2)], in one patient the tube tip would have been below the carina and in seven patients the tube cuffs would have been placed within the larynx. CONCLUSIONS: The intubation depth markings of the new Microcuff pediatric tracheal tube allow safe placement of the tracheal tube with a cuff-free laryngeal zone without the risk for endobronchial intubation. Placement using the intubation depth markings was superior to predicted insertion using a standard formula.     

Case report: Nasotracheal intubation — look before leaping to assess the laryngeal view

PURPOSE: To describe an airway management plan, including oral to nasal endotracheal tube exchange, when nasal intubation is required in the unanticipated difficult airway. CLINICAL FEATURES: A nasal intubation was required for a patient undergoing oropharyngeal surgery. Following loss of consciousness and paralysis, a Cormack-Lehane class 3 view was obtained, and pressure over the thyroid cartilage failed to reveal the vocal cords. An Eschmann bougie was inserted into the oropharynx and blindly entered the trachea. An orotracheal tube was advanced into the trachea over the bougie, and the patient was ventilated with 100% O2 following the bougie's removal. An endotracheal tube was then guided through the right nostril into the hypopharynx. An Eschmann bougie was inserted into the nasal tube, and advanced towards the glottic opening under laryngoscopic view. Digital pressure applied to the oral tube at the base of the tongue brought the vocal cords into view. The oral endotracheal cuff was deflated, and the bougie (inserted into the nasal tube) was advanced into the trachea alongside the orotracheal tube. The orotracheal tube was withdrawn, and the nasal tube was advanced into the trachea over the bougie. The patient's O2 saturation and end-tidal CO2 concentration remained at 99-100% and 30-33 mmHg, respectively, during these maneuvers, which required only a few minutes to perform. CONCLUSION: When nasotracheal intubation is required, a plan of airway management is required to safely secure the airway. We emphasize the importance of direct laryngoscopy prior to insertion of an endotracheal tube through the nose, and describe a strategy for oral to nasal tracheal tube exchange.     

Fastrach intubation in patients with cervical disease

The Fastrach laryngeal mask for intubation is a new device designed for blind orotracheal intubation in patients with criteria predictive of difficult airway control. The new device looks like the conventional laryngeal mask but offers a series of design changes that allow orotracheal intubation to be accomplished without visualization of the glottis. The rigid metal tube is bent and incorporates a metal handle; the two fixed bars that prevent the epiglottis from falling and blocking the opening have been replaced by a moveable bar that rises with the passage of the endotracheal tube and the exit of the V-shaped metal tube guides the endotracheal tube that was specially designed for this use. We describe three patients with cervical disease, one with advanced ankylosing spondylitis, one with traumatic luxation of the C6-C7 articulation and one diagnosed of two cervical disk hernias. All their tracheas were intubated without difficulty through the Fastrach mask with the patients' heads in neutral position. Although fiberoptic bronchoscopy is the method of choice in patients with cervical problems, the non-availability of the technique and the need for training in its use make the Fastrach mask an alternative worth considering for such patients.     

The usefulness of the processed nasal airway for fiberscope guided nasotracheal intubation

BACKGROUND: The fiberscopy has become an essential tool for tracheal intubation. As we realized that nasal airway acts like a conduit to guide a fiberscope toward the larynx, we have devised a unique nasal airway named "Osaka airway" which is suitable for fiberoptic naso-tracheal intubation. This airway has two pre-cut line from the head to the tip which can be peeled off easily after the insertion of fiberscope. To verify this advantages, we measured the length of nares-vocal cords and assessed the fiberoptic visibility of vocal cords under the aid of nasal airway. METHODS: At the end of operation, 54 patients were extubated and nasal airway was inserted to measure the length of nares-vocal cords and to observe vocal cords and epiglottis. Then, in another series, two beginners conducted fiberoptic intubation on several cases with the aid of Osaka airway. RESULTS: The length of nares-vocal cords of male was 20.2 +/- 1.0 S.D.cm, and that of female 17.3 +/- 1.1 S.D.cm. The length correlated with the body height. In 34 patient, we could see vocal cords just below the airway tip. Two beginners could complete the intubation within 2 min in almost all cases. CONCLUSION: Osaka airway was a help for fiberoptic naso-tracheal intubation for beginners.     

Évaluation de l'apprentissage de l'intubation à l'aide d'un laryngoscope rigide à fibres optiques (UpsherScope™)

ObjectiveTo evaluate the learning of tracheal intubation with a new rigid fibreoptic laryngoscope (UpsherScope™).Study designOpen prospective study.PatientsFive investigators used the UpsherScope™ to intubate the trachea in 164 patients scheduled for gynaecological surgery requiring tracheal intubation. All patients were of physical class ASA I or II and criteria for difficult intubation were negative.MethodsAfter muscle relaxation, 120 seconds were allowed to intubate the trachea with the UpsherScope™. If intubation had not been achieved by that time, the attempt was considered as a failure and the trachea was intubated using conventional laryngoscopy.ResultsThe overall success rate with the UpsherScope™ was 73%. Forty-five tracheas could not be intubated with the device within 120 seconds. The inability to insert the tracheal tube through the vocal cords despite a good view of the larynx (23/45) or the inability to visualise the glottis because of secretions (21/45), were the two main causes of failure.ConclusionThe UpsherScope™, a new rigid fibreoptic laryngoscope devised for routine and difficult intubation, is robust and allows the view of the tracheal tube passing between the vocal cords. However, in this study the intubation success rate remained low and was not improved by further experience. No benefit was found with the UpsherScope™ in patients with normal airways. Further studies are necessary to assess its efficiency in cases of difficult intubation.     

Parálisis bilateral tardía de cuerdas vocales trasintubación endotraqueal por neumonía COVID-19

Vocal cord paralysis is a rare but severe complication after orotracheal intubation. The most common cause is traumatic, due to compression of the recurrent laryngeal nerve between the orotracheal tube cuff and the thyroid cartilage. Other possible causes are direct damage to the vocal cords during intubation, dislocation of the arytenoid cartilages, or infections, especially viral infections. It is usually due to a recurrent laryngeal nerve neuropraxia, and the course is benign in most patients. We present the case of a man who developed late bilateral vocal cord paralysis after pneumonia complicated with respiratory distress due to SARS-CoV-2 that required orotracheal intubation for 11 days. He presented symptoms of dyspnea 20 days after discharge from hospital with subsequent development of stridor, requiring a tracheostomy. Due to the temporal evolution, a possible contribution of the SARS-CoV- 2 infection to the picture is pointed out.     

Oral styletted intubation under video control in a patient with a large mobile glottic tumour and a difficult airway

PURPOSE: With fibreoptic intubation, advancement of the endotracheal tube (ETT) through the glottis is blind. Thus, in patients with a laryngeal tumour, there is a potential for damage to the tumour. Previously, we proposed the use of a fibreoptic bronchoscope (FOB)-video camera system to permit visualization of tube passage. We used this technique successfully in a patient with a known difficult airway and a large glottic tumour. CLINICAL FEATURES: A 61-yr-old man with a known history of difficult laryngoscopic intubation underwent laryngeal microsurgery for recurrence of a glottic tumour. As preoperative indirect laryngoscopy revealed a large, mobile, and pedunculated glottic lesion obstructing the glottic opening, we planned a conventional awake fibreoptic intubation. Endoscopy showed that the tumour partially obstructed the glottis and the space between the tumour and the glottic opening was very narrow. To avoid damage to the tumour, we changed to an alternative fibreoptic intubation technique. The FOB attached to a video camera was passed nasally and a jaw thrust manoeuver was applied, providing an excellent view of the larynx. An anesthesiologist inserted the ETT with a curved stylet orally, and carefully advanced the tube tip into the space between the tumour and the glottic opening under video control. Absence of damage to the tumour and passage of the tube between the cords were confirmed visually. CONCLUSION: This alternative intubation technique, providing a view of the tube passage into the glottis, was a reasonable method to avoid potential damage to the glottic tumour by blind tube passage during conventional fibreoptic intubation.