Oral Tracheal Intubation Research Articles

Pentax-Airway Scope for tracheal intubation breaks through the limitation of neck motion in an ankylosing spondylitis patient wearing halo vest–A case report

The Airway Scope ® (AWS) provides better glottic view than the conventional direct laryngoscopy in tracheal intubation. With it, the endotracheal tube can be more easily inserted into the tracheal lumen easily. We hereby presented a 24-year-old ankylosing spondylitis (AS) patient wearing a halo vest who was successfully intubated for undergoing cervical spine surgery involving C1 and C2 under general anesthesia. Pre-operative airway assessment revealed that he was a case of difficult intubation. An AWS was used for oral tracheal intubation which was achieved smoothly in the first attempt. AWS can be an alternative device for airway management in a patient wearing halo vest.

Blind oral endotracheal intubation of rats using a ventilator to verify correct placement

Endotracheal intubation in rats is challenging due to difficulties visualizing the epiglottis and vocal cords. No visualization of these structures results in repeated intubation attempts which can cause trauma to the oral cavity and/or oesophagus, and death of the animal due to respiratory failure. Here, we describe a simple blind oral tracheal intubation technique in the rat that decreases the frequency of repeated intubations using an intubation device that comprises a 16 G intravenous catheter and a modified 18 G epidural needle, and a rodent ventilator. The epidural needle is bent in such a way that it curves in conformity with the rat's oral airway in order to direct the catheter into the larynx, and the rodent ventilator is used to verify its correct placement. The first attempt success rate of endotracheal intubation using the blind oral tracheal intubation technique with a rodent ventilator was greater than the first attempt success rate using the blind oral tracheal intubation technique without using a rodent ventilator. Although this method is a simple modification of a previously described method of blind oral endotracheal intubation, our method is easy to learn, inexpensive and does not require specialized equipment.

General anaesthesia for a patient with Williams–Beuren syndrome: is sevoflurane and ketamine contraindicated?

General anaesthesia for a patient with Williams–Beuren syndrome: is sevoflurane and ketamine contraindicated?

The Usefulness of Design of Experimentation in Defining the Effect Difficult Airway Factors and Training Have on Simulator Oral-Tracheal Intubation Success Rates in Novice Intubators

This exploratory study examined novice intubators and the effect difficult airway factors have on pre- and posttraining oral-tracheal simulation intubation success rates. Using a two-level, full-factorial design of experimentation (DOE) involving a combination of six airway factors (curved vs. straight laryngoscope blade, trismus, tongue edema, laryngeal spasm, pharyngeal obstruction, or cervical immobilization), 64 airway scenarios were prospectively randomized to 12 critical care nurses to evaluate pre- and posttraining first-pass intubation success rates on a simulator. Scenario variables and intubation outcomes were analyzed using a generalized linear mixed-effects model to determine two-way main and interactive effects. Interactive effects between the six study factors were nonsignificant (p = 0.69). For both pre- and posttraining, main effects showed the straight blade (p = 0.006), tongue edema (p = 0.0001), and laryngeal spasm (p = 0.004) significantly reduced success rates, while trismus (p = 0.358), pharyngeal obstruction (p = 0.078), and cervical immobilization did not significantly change the success rate. First-pass intubation success rate on the simulator significantly improved (p = 0.005) from pre- (19%) to posttraining (36%). Design of experimentation is useful in analyzing the effect difficult airway factors and training have on simulator intubation success rates. Future quality improvement DOE simulator research studies should be performed to help clarify the relationship between simulator factors and patient intubation rates.

Uso del videolaringoscopio de McGrath junto con la guía Frova en el manejo de la vía aérea difícil

The McGrath video laryngoscope is a new airway management device. It is similar to the Macintosh laryngoscope but incorporates a blade at a 60 degrees angle and a camera that sends an image to a color display screen connected to the handle. The device, which requires use of an anti-fog substance and an introducer to guide the angled blade, has been reported to aid in the management of difficult airways. We present 3 cases of difficult oral-tracheal intubation managed with the McGrath video laryngoscope and a Frova intubating introducer. Advantages of this introducer are that it offers the possibility of administering oxygen or changing the size of the endotracheal tube if the first choice proves inappropriate. We discuss whether or not tests to predict difficult airways are applicable when the McGrath video laryngoscope is being used, given that it is not necessary to align the axes of the 3 airways. We conclude it may be useful to combine the McGrath video laryngoscope and the Frova introducer to manage difficult airways.

Usefulness of Endoflex endotracheal tube for oral and nasal tracheal intubations

We investigated the usefulness of an Endoflex tracheal tube, the tip of which can be bent forward by pulling on a wire held in the hand, for oral and nasal endotracheal intubations without a stylet, in comparison with tracheal intubation using a conventional endotracheal tube and a stylet/Magill forceps. The study participants comprised 40 patients for oral intubation and 20 patients for nasal intubation. Each group was then divided into control and Endoflex subgroups. In the oral intubation study, controls were intubated using a standard Macintosh-type laryngoscope with a conventional endotracheal tube with adjuvant use of a stylet, whereas the Endoflex group was intubated using a Macintosh-type laryngoscope with an Endoflex tube. In the nasal intubation study, controls were intubated by a standard Macintosh-type laryngoscope with an endotracheal tube for nasal intubation. Under direct vision, Magill forceps were used to guide the tip of the endotracheal tube into the glottis. Patients in the Endoflex group were intubated using a Macintosh-type laryngoscope with an Endoflex tube. Although haemodynamic changes during tracheal intubation did not differ between the groups, the duration of intubation was significantly shortened in the Endoflex groups in both studies. The Endoflex endotracheal tube represents a beneficial tool for smooth oral and nasal intubation without requiring assistance or adjuvant equipment.

Role of beta-dsfensin-3 in lung tissue in a rat model of ventilator-associated pneumonia

Objective To investigate the role of beta-defensin-3 (BD-3) in lung tissue in a rat model of ventilator-associated pneumonia. Methods Twenty pathogen-free male SD rats weighing 240-290 g were randomly divided into 2 groups (n=10 each): non-ventilator-associated pneumonia group (group N) and wentilator-associated pneumonia group (group V). The animals were anesthetized with intraperitoneal (IP) 20% urethane 1.3 g/kg. Oral tracheal intubation was performed under direct vision. In group N the animals kept spontaneous breathing. MRSA suspension (1010 cfu/ml) 0.2 ml was introduced into bronchus immediately after tracheal intubation. The animals were then extubated. In group V the animals were mechanically ventilated (VT 6 ml/kg, RR 88 bpm, PEEP 5 cm H2O, FiO2 21%) for 4 h. MRSA suspension (1010 cfu/ml) 0.2 ml was introduced into bronchus at the end of 4 h mechanical ventilation. The animals were killed at 48 h after inoculation in both groups. The lungs were removed for microscopic examination of pathologic changes which were scored. Wet lung weight/body weight ratio (WW/BW) was measured. Lung bacterial counts and spleen eulture were performed. The expression of BD-3 in lung tissue was detected by immuno-histochemical staining. Results WW/BW, lung pathology scores, lung bacterial counts and the incidence of bacteremia were significantly higher in group V than in group N, while BD-3 expression in lung tissue was significantly lower in group V than in group N. Conclusion The pathogenesis of ventilator-associated pneumonia is related to the down-regulation of BD-3 expression in rat lung tissue. Key words: Respiration, artificial; Pneumonia, baeterial; beta-Defensins

Results of surgical treatment in multinodular goiter with an intrathoracic component

(1) To determine the clinical profile of intrathoracic multinodular goiter (IMG); (2) to evaluate the results of surgery, and (3) to analyze the incidence of malignancy and its evolution. Two hundred and forty-seven operated cases of IMG were reviewed. These cases of IMG had all been diagnosed according to Eschapse's definition (>3cm below the sternal manubrium). The morbidity and postoperative evolution were analyzed. A comparative study was carried out on a group of 425 cases of nonintrathoracic goiter. We applied the chi(2) test, Student's t-test, and a logistical regression analysis. Intrathoracic MG occurs in patients over 60 years of age, with goiter which has a long evolution time (>12 years), and more than 60% are symptomatic. Oral tracheal intubation was difficult in 10% (n = 24) of the cases, and 7 required the use of a fibrobronchoscope. In 8 cases (3%) a thoracic approach was necessary. Morbidity occurred in 24% (n = 59), most notably 29 recurring lesions (12%), of which 2 were definitive (0.8%), and 31 hypoparathyroidisms (13%), of which 1 was definitive (0.4%). No significant difference was found in the postsurgical morbidity between the intrathoracic MG and the nonintrathoracic cases. Regarding the remission of the symptoms, the results were excellent. In 14 cases (5.7%) thyroid carcinoma was related with, most of these being papillary microcarcinoma. In 10 of the 49 cases of partial surgery (20%) a relapse of the goiter was observed. Intrathoracic MG is usually asymptomatic and it occurs in goiter with a long time of evolution. Surgery is a good therapeutic option given that the goiter can be removed via the neck, with low morbidity, a remission of the symptoms, malignancy is ruled out, and recurrence can be avoided if a total thyroidectomy is performed.

Un año con GlideScope® Lo-Pro Color Adult. Experiencia en 350 casos

The aim of this study was to describe our experience in managing the new adult color model of the Lo-Pro GlideScope in a diverse group of patients. Prospective, descriptive study of 350 ASA 1-5 patients who underwent oral or nasal tracheal intubation with the Lo-Pro Adult Color GlideScope. Patients whose maximum mouth opening was inadequate were excluded. We recorded the following data: demographic variables, predictors of difficult direct laryngoscopy, Cormack-Lehane grade, presence of morbid obesity, adjusting maneuvers required, intubations in awake patients, intubations with a selective double lumen tube, rescues of failed intubations, oropharyngeal lesions, postoperative sore throat, and failed intubation. Cormack-Lehane grade was 1 in 80.6% of the cases, 2 in 16.9%, and 3 in 2.6%. There were no Cormack-Lehane 4 patients. Rotation of the tube was necessary when entering the glottis in 38%. There were no significant differences in the incidence of oropharyngeal lesions between oral and nasal intubations. There were no abandoned attempts. The rate of successful tracheal intubation is high with the new Lo-Pro Adult Color GlideScope when it is used by trained staff, even in patients with difficult airways. It is also a useful device for intubating awake patients.

Paramedic Tracheal Intubation Using the Intubating Laryngeal Mask Airway

Objective. Tracheal intubation through the intubating laryngeal mask airway (ILMA) has been evaluated, in controlled settings, as an acceptable alternative to laryngoscopic intubation. Our observational study was designed to examine the success rate of tracheal intubation using the ILMA in the prehospital setting after mannequin-based training. Methods. We examined all oral tracheal intubations performed by the Tasmanian Ambulance Service (TAS) from April 2005 to April 2006. TAS paramedics are occasional intubators, as defined in the study by Reeves et al., on average performing two intubations per paramedic per year. Fifty-eight paramedics received training in tracheal intubation through the ILMA. The primary outcome measure was tracheal intubation success. Our hypothesis was that paramedics would be able to successfully perform out-of-hospital tracheal intubation using the ILMA with minimal training. Results. During the study period, 106 patients had out-of-hospital tracheal intubation performed by ambulance paramedics. Comparisons were made between the intubations with the ILMA andby laryngoscopy. The overall intubation success rate was 91% with the laryngoscope and92% with the ILMA. The success rate for the first attempt at intubation was higher with the ILMA (81%) than with direct laryngoscopy (57%) (RR (95% CI): 1.74 (95% CI: 1.18–2.59, p = 0.009), regardless of ultimate success. The success rate when intubating unconscious patients using the ILMA was significantly higher (88%) than intubation using the laryngoscope (63%). These intubations were achieved without the administration of any sedation or paralytic medication. Conclusions. Intubation via the ILMA was as successful as conventional laryngoscopic intubation, requiring fewer attempts, although this was not statistically significant.

Is It Possible to Perform Oral Tracheal Intubation in Chemical Protective Ensembles, in a Clinical Useful Time?

Introduction/Aim: Emergency oral tracheal intubation in the pre-hospital setting is always performed without the optimal conditions. In the presence of patients who have been contaminated by hazardous agents it is necessary that the medical personnel attending these patients use the appropriate personal protective equipment (PPE), which make the conditions even more difficult, particularly procedures like oral tracheal intubation. We analyze the time spent to perform oral tracheal intubation by medical personnel using different levels of PPE.

Submandibular approach for tracheal intubation in patients with panfacial fractures

The oral route for tracheal intubation can interfere with some maxillofacial surgical procedures. At the same time, the nasal route can be contraindicated or impossible. Tracheostomy is the usual solution in these circumstances, but it carries a high incidence of complications. We tested the submandibular route for tracheal intubation as an alternative to tracheostomy in such situations. The procedure was performed in 13 patients suffering from panfacial fractures associated with a fracture of skull base or a displaced nasal fracture, and in one patient with post-caustic burn scar affecting most of the face including the nose and requiring a full thickness skin flap surrounding the mouth. The technique was found easy and satisfactory for both the surgeon and the anaesthetist. It allowed uninterrupted surgical techniques and a secure airway. In six of the 13 patients, the submandibular tracheal tube was left in place for up to 44 h in the intensive care unit after the operation without complications or difficulties. Accidental dislodgement of the tube to the right main bronchus occurred in two patients while carrying out the procedure; it was rapidly detected and corrected. In another two patients, postoperative superficial infection occurred that responded well to local treatment. No other complications were encountered. Submandibular tracheal intubation is a simple and effective technique for upper airway management in some maxillofacial surgical patients when both oral and nasal tracheal intubations are not convenient.

Single-Lung Ventilation for Right-Sleeve Pneumonectomy With a Modified Nasal RAE Endotracheal Tube

Single-Lung Ventilation for Right-Sleeve Pneumonectomy With a Modified Nasal RAE Endotracheal Tube

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Isolation and Characterization of an Antifactor VIII Antibody from a Patient with Acquired Hemophilia A and a Severe Hemorrhagic Syndrome.

Patients with hemophilia A usually develop inhibitory antibodies to factor VIII (fVIII) that are directed against epitopes in the A2 and C2 domains of the cofactor and result in increased morbidity and mortality because of an extended hemorrhagic syndrome. However, in some cases individuals spontaneously develop autoantibodies to fVIII resulting in acquired hemophilia A. While the etiology and mechanism of the disorder are still unknown, the study and determination of the properties of the autoantibodies is necessary to provide insights into their mechanism of generation. A 78-year-old woman was admitted to the Internal Medicine Department of the University-Hospital of Padua for severe anaemia and syncope. She developed an acute hemorrhagic syndrome characterized by the development of extended subcutaneous and mild intramuscular haematomas on both legs. The patient's family history was negative for hemorrhagic manifestations. Total body computed tomography (CT) scan confirmed the presence of small intramuscular haematomas. Preliminary laboratory analyses revealed a significant prolongation of the aPTT (activated partial thromboplastin time) to 60 sec and a mild prolongation of the PT (prothrombin time) to 15 sec. Mixing experiments with normal plasma failed to correct the patient's aPTT. Plasma fVIII levels were ~6%. Assay for fVIII inhibitor revealed a level of 6 Bethesda Units (BU). The patient was treated with high dose of steroids and recombinant fVIII (3,000 Units daily). Subsequently, she developed swelling to the neck in the sub maxillary region and symptoms consistent with an acute obstruction to the upper airways requiring oral-tracheal intubations and ventilation. These findings prompted the use of recombinant FVIIa to prevent progression of the hemorrhagic lesion. Three sessions of plasmapheresis were performed, which were followed by the administration of high dose immunoglobulin and the administration of immunosuppressive treatment. After 45 days, treatment was continued with steroids only. The patient recovered completely and no new bleeding episodes developed. The total immunoglobulin fraction was isolated from the patient's plasma and found to induce a prolongation of the clotting time in an aPTT assay using purified reagents. The immunoglobulin fraction was also found to inhibit intrinsic tenase activity in an assay using purified reagents and a chromogenic substrate that detects factor X activation. In contrast, the total immunoglobulin fraction purified from normal pooled plasma didn't prolong the aPTT nor inhibited intrinsic tenase activity. Immunoprecipitation experiments with the total immunoglobulins fraction purified from the patient's plasma revealed that the antibody recognizes epitopes on the light chain of the cofactor. Immunobloting experiments performed with the same material demonstrated that the antibody recognizes fVIII heavy and light chains. Following activation by thrombin it was found that the antibody recognizes the Mr 73,000 light chain and the A2 domain of the cofactor. These data demonstrate that the immunoglobulin fraction isolated from the patient's plasma has more than one epitope on the cofactor. Our findings provide the demonstration of a strong anti-fVIII acquired autoantibody with low titer which is not related to the presence of antiphospholipid antibodies and is responsible for a severe hemorrhagic syndrome.

An Evaluation of the Retromolar Space for Oral Tracheal Tube Placement for Maxillofacial Surgery in Children

The eruption of the first and second permanent molar teeth may influence the size of the retromolar space. In this study we evaluated the adequacy of the retromolar space for retromolar intubation and any effect of eruption of the first and second permanent molar teeth on this space in children. Children 3-15 yr of age, undergoing surgery other than facial surgery were included for evaluation of the retromolar space. After standard oral tracheal intubation, the endotracheal tube was shifted to the retromolar space and the mandible was slowly closed to achieve centric occlusion. At the same time, any increase in airway resistance or decrease in oxygen saturation was noted. In the second part of the study, the feasibility of retromolar intubation in pediatric patients undergoing maxillofacial surgery with intraoperative maxillomandibular fixation was assessed. There was enough space for endotracheal tube placement in the retromolar region. The eruption of the first and second permanent molar teeth did not affect intubation. It was possible to achieve centric occlusion in 79 of 80 children with the endotracheal tube positioned in the retromolar space. Retromolar intubation was successfully accomplished in six pediatric patients undergoing maxillomandibular fixation and maxillofacial surgery. The retromolar space can be safely used for intubation in children when intraoperative maxillomandibular fixation, and simultaneous access to the nose and oral cavity are needed.

A comparison of an anterior jaw lift manoeuvre with the Berman airway for assisting fibreoptic orotracheal intubation*

This study compared the efficacy of an anterior jaw lift manoeuvre with that of the Berman airway in clearing the upper airway during oral fibreoptic tracheal intubation in anaesthetised, paralysed patients. Fifty patients were randomly assigned to undergo fibreoptic-assisted intubation with one method, followed by crossover to the alternative method. The time taken to view the vocal cords was the primary endpoint, and we also noted the rate of failure to view the cords, i.e. cords not seen after 120 s of endoscopy. Anterior jaw lift yielded significantly shorter times to view the vocal cords (median [interquartile range; range]: 22 [17-46; 7-120] s vs 40 [29-67; 21-120] s, p = 0.001) and a higher success rate (49/50 vs 42/50, p = 0.014). We conclude that the anterior jaw lift is more effective than the Berman device for achieving airway clearance in this setting.

Oesophageal injury after attempted oral tracheal intubation

Introduction: Iatrogenic oesophageal injury is a serious life threatening lesion and may occur during gastrointestinal fiberscopy, therapeutic procedure for oesophageal diseases, and very rarely, oral intubation by a tracheal tube. Few reports concerning oesophageal injuries after attempted tracheal intubation have been published. This case report presents a suspected case of oesophageal injury following attempted tracheal intubation in a patient with respiratory arrest. Case report: A 78-year-old female in an old peoples home with a history of cerebral infarction and senile depression complained of dyspnoea and presented with oxygen desaturation and tachypnoea.

Pediatric Laryngoscope Blade Size Selection Using Facial Landmarks

The study evaluates whether facial landmarks can be used to estimate an appropriate laryngoscope blade length for oral endotracheal intubation in children. We tested the hypothesis that the laryngoscope blade measuring 10 mm or less distal or proximal to the angle of the mandible (when the flat portion of the blade follows the facial contour from the upper incisor teeth to the angle of the mandible) will demonstrate greater success and ease of oral tracheal intubation. We performed an observational study that prospectively evaluated a convenience sample of children 8 years old or younger and who were undergoing direct laryngoscopy for oral endotracheal intubation in the operating room, outpatient surgery center, emergency department, or pediatric intensive care unit of a tertiary referral medical center. Ease and success of oral tracheal intubation were compared with distance measurements from the angle of the mandible to the tip of the laryngoscope blade. Blade lengths considered too short (blade lengths >10 mm proximal to the angle of the mandible) were more likely to be associated with more than 1 attempt at intubation. Only 57.1% (12/21; 95% confidence interval [CI], 36.5-75.5) of the intubations using the shorter blade were performed on the first attempt as compared with 89.7% (26/29; 95% CI, 73.6-96.4) of the intubations using the recommended length or 85.7% (6/7; 95% CI, 48.7-97.4) of the intubations using blades extending longer than 10 mm past the angle of the mandible. The distance from the upper incisor teeth to the angle of the jaw seems to be an excellent clinical landmark for laryngoscope blade length selection for pediatric intubations. When the blade (excluding the handle insertion block) is placed at the upper midline incisor teeth and the tip is located within 1 cm proximal or distal to the angle of the mandible, oral tracheal intubations are more consistently accomplished on the first attempt. Our observations suggest that facial landmarks can be used to estimate an appropriate laryngoscope blade length for oral endotracheal intubation in children.

An assessment of paramedic performance during invasive airway management

Objective. To assess the performance of paramedics, in a newly-initiated prehospital program, during invasive airway management. Methods. An audit of paramedic call reports for a 12-month period from January to December 1997 was performed. Call reports that documented invasive airway management were retrieved and relevant data were extracted using a preformulated data-entry form. Results. Paramedics attempted tracheal intubation in 453 patients and were successful in 408 (90.1%); 331 of the patients were in cardiopulmonary arrest with vital signs absent (VSA), 101 had medical emergencies, and 21 had trauma-related problems. In the VSA cohort, the tracheas of 96% of the patients were intubated successfully; 80.1% on the first attempt, 10.6% on the second, 4.5% on the third, and 0.9% after more than three attempts. In the medical cohort, the tracheas of 74.3% of the patients were intubated; 60.4% on the first attempt, 11.9% on the second, and 2.9% on the third. In the trauma cohort, 71.4% of the intubations were successful; 66.6% on the first attempt, 26.6% on the second, and 6.6% on the third. There was a difference (p < 0.001) in the incidence of successful intubations comparing the VSA cohort with the medical/trauma cohorts. There was also a difference (p < 0.001) between the success rate for nasal intubations (43 of 68, 63% of patients successfully intubated) and that for oral intubation (365 of 385, 94% of patients). Conclusion. This study demonstrated a difference in the paramedics' success rates for tracheal intubation in VSA patients compared with those with preserved airway reflexes and a lower success rate for nasal vs oral tracheal intubation. These differences may be due to inadequate training, technical difficulties experienced in the field, or lack of sufficient exposure to medical/trauma scenarios to gain management experience. Future training to address these issues, both in the initial training phase and in the continuing education program, may be beneficial in improving performance. PREHOSPITAL EMERGENCY CARE 2000;4:164-167