Oral Endotracheal Intubation Research Articles

Tongue Necrosis: A Rare Complication of Oral Intubation

(1) Present a unique case of partial necrosis of the dorsal tongue caused by an endotracheal tube; (2) highlight the importance of verifying proper endotracheal tube positioning during cases requiring prolonged intubation. Case report and literature review. A 50 year-old man underwent total thyroidectomy and bilateral lymphadenectomies for papillary thyroid carcinoma. A nerve monitoring endotracheal tube was used during the case. Postoperatively, the patient reported tongue pain and examination revealed partial necrosis of his dorsal tongue. On follow up, the patient had improved tongue pain and well-healing dorsal tongue. We present the a case of tongue ischemia and partial necrosis due to oral endotracheal intubation, specifically with a nerve monitoring endotracheal tube, which has not previously been reported in the English literature. Tongue necrosis due to compression by an endotracheal tube during prolonged intubation is unusual, however surgeons, anesthesiologists and those involved in the care of intubated patients should consider the potential for this complication when orienting and securing endotracheal tubes. This unique case of tongue necrosis underscores the importance of proper endotracheal tube positioning during prolonged intubation.

Submental Intubation: An Alternative to Tracheostomy When Nasoendotracheal Intubation Is Unsuccessful – a Case Report

Submental intubation (SI) has been proposed as an alternative to nasoendotracheal intubation when oral endotracheal intubation is contraindicated. In patients who require intubation for maxillofacial reconstruction, this is an alternative to a traditional tracheostomy. The present case report presents an 18-year-old woman who suffered a comminuted mandibular fracture. Two days after her accident, she was taken to the operating room for open reduction with internal fixation of her mandible; however, the anesthesia staff was unable to nasally intubate the patient. A SI was performed. The procedure was completed without complications and the surgery accomplished with the SI. The patient was able to avoid a tracheostomy for an isolated operation. SI avoids the dangers of nasoendotracheal intubation in patients with midfacial fractures and avoids complications related to tracheostomy. Thus, SI may serve as an alternative to tracheostomy in patients without other medical conditions and indications for long-term intubation.

A Review of Intraoperative Airway Management for Midface Facial Bone Fracture Patients

In craniofacial trauma patients, oral route endotracheal intubation may thwart the accuracy of dental occlusion and nasotracheal intubation carries the risk of intracranial invasion in skull base fracture cases. Between November 2005 and June 2006, patients receiving facial bone fracture operations at Kaohsiung Medical University Hospital were enrolled in this study. Intraoperatively, the endotracheal tube was pushed to either the retromolar space or the missing tooth space and secured by two 4.0 silk stitches. Then, surgeons could perform the usual procedure to explore the fracture sites, check the occlusion and correct the deviated nose without limitation. Also, for better understanding the time needed for various intubation techniques, a time-measuring study was performed. Ninety-one patients were treated by this method. Most of them were satisfied with the result of occlusion and nasal contour. Only 2 patients received second surgery to correct nasal deformity. One hundred seventeen anesthesia procedures were checked. In average, an experienced anesthesiologist could successfully intubate a patient in less than 105 seconds. The advantages and reported complications of different intubation methods were discussed. This retromolar position and tooth fixation technique allowed surgeons to correct the dental occlusion and nasal deformity simultaneously. It has served well for zygoma fracture, maxilla fracture, and Le Fort II fracture patients. It is worthy of consideration in management of middle face trauma patients involving occlusion change and nasal deviation.

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.

A 12 month retrospective study of airway management practices

Australian emergency nurses have a primary role in advanced airway management. Consequently, they need to be competent in, and have a systematic approach to, airway preparation, management and rescue. The aims of the study were to (i) identify all patients undergoing endotracheal intubations in the emergency department; (ii) describe patient characteristics, diagnosis and disposition; and, (iii) review the introduction of an advanced airway management algorithm and difficult airway equipment tray. A 12 month retrospective study was undertaken (1/1/2006 to 31/12/2006) of all patients requiring oral endotracheal intubation. A survey was conducted to determine nursing confidence and practice with intubation and the benefit of introducing an advanced airway management algorithm and a preassembled difficult airway equipment tray. Two hundred and fifty three patients required intubation during the study. The age ranged from neonates/infants to 98 years. Emergency nurses felt confident in assisting with endotracheal intubation and regularly encountered airway rescue situations. The pre-assembled difficult airway equipment and airway management algorithm led to improved confidence and practice. Endotracheal intubation is a regular ED intervention. Emergency nurses need to have knowledge of airway management and rescue. A developed airway management algorithm and difficult airway equipment tray improved nursing confidence, expertise and response time in advanced airway interventions.

Submental intubation: An alternative to tracheostomy when nasoendotracheal intubation is unsuccessful - A case report

Submental intubation (SI) has been proposed as an alternative to nasoendotracheal intubation when oral endotracheal intubation is contraindicated. In patients who require intubation for maxillofacial reconstruction, this is an alternative to a traditional tracheostomy. The present case report presents an 18-year-old woman who suffered a comminuted mandibular fracture. Two days after her accident, she was taken to the operating room for open reduction with internal fixation of her mandible; however, the anesthesia staff was unable to nasally intubate the patient. A SI was performed. The procedure was completed without complications and the surgery accomplished with the SI. The patient was able to avoid a tracheostomy for an isolated operation. SI avoids the dangers of nasoendotracheal intubation in patients with midfacial fractures and avoids complications related to tracheostomy. Thus, SI may serve as an alternative to tracheostomy in patients without other medical conditions and indications for long-term intubation.

How to Establish a Solitary and Localized VX2 Lung Cancer Rabbit Model? A Simple and Effective Intrapulmonary Tumor Implantation Technique

The purpose of this study is to establish a simple and effective technique for the generation of an intrapulmonary tumor model that yields solitary, localized intrapulmonary tumor, and to analyze the highlights of the technique. After being anesthetized by slow intravenous injection of pentobarbital without oral endotracheal intubation, a right intercostal incision was made between the fifth and sixth ribs or at the next intercostal space; the inferior lobe of the right lung was exposed. A 16-gauge needle contained a strip of tumor tissue in the distal portion which connected to a 1.0-mL syringe that contained 0.1 mL air inside, was inserted into the parenchyma at an estimated depth of 1.0 cm, and the air was injected quickly to eject the tumor tissue into the pulmonary parenchyma. The air was drawn from the chest cavity by a race track, and the chest was closed. Thirty animals (Group A) received intrapulmonary tumor implantation (IPTI) as described above, and 16 animals (Group B) received IPTI using a suspension of small tumor fragment. Eight animals in each group were monitored by computed tomography (CT) scanning (Group CTA and CTB) and were used to determine survival time. Twenty-two animals in Group A and 8 animals in Group B were sacrificed and dissected at 21 d post-IPTI, followed by histological examination. Tumor take rate (tumor developed anywhere in the chest) was 80% in Group A (24/30) and 75% in Group B (12/16); there was no significant difference (P = 0.987). The rate of total chest seeding was significantly higher in Group B (66.7%, 8/12) than in Group A (12.5%, 3/24; P = 0.002). At 3 wk post-IPTI, solitary, localized tumor foci developed at the implantation site in 70% of Group A (21/30); this rate was significantly higher than the 18.8% rate of tumor foci development in Group B animals (3/16; P = 0.001). Twelve of the 16 animals monitored by CT scanning developed tumors. Among them, 7 animals that developed localized intrapulmonary tumors at early time post-IPTI survived significantly longer than the remaining 5 animals that developed extrapulmonary chest seeding tumors (P = 0.001). Intrapulmonary nodules after IPTI may develop granulomas, which were identified by histological examination. Unidentified nodules were detected in CT images, which gradually decreased in size and eventually disappeared. We establish a simple and effective method for the generation of an intrapulmonary tumor model that yields solitary, localized intrapulmonary tumor. The highlights of this technique are tumor quality control and tumor dissemination control. Extrapulmonary chest seeding at early time post-IPTI contributes to short survival. It is necessary to characterize the intrapulmonary nodules using histological methods prior to the evaluation of therapy; this approach may lead to a more accurate determination of therapeutic outcomes.

Harvesting Buccal Mucosa Graft Under Local Infiltration Analgesia—Mitigating Need for General Anesthesia

For buccal mucosal graft urethroplasty, nasal or oral endotracheal intubation anesthesia is used for harvesting the graft from the oral cavity. A technique of graft harvesting under local anesthesia using 2% lidocaine solution with adrenaline (1:200,000) is described. This method requires a cooperative patient but saves the morbidity of general anesthesia.

Prehospital Management of the Difficult Airway: A Prospective Cohort Study

The role of prehospital endotracheal intubation (ETI) remains controversial, with significant national variability in practice. The purpose of this project was to evaluate ETI management in a system of advanced life support (ALS) providers experienced in ETI and other advanced airway techniques, and describe management and outcomes of patients with a “difficult airway.” Data were collected prospectively for all ETIs performed by the fire department over a 4-year period (2001–2005), and included demographics, number of laryngoscopy attempts, airway procedures, complications, and outcomes. Of 80,501 ALS patient contacts, 4091 (5.1%) underwent attempted oral ETI, with a 96.8% success rate in four or fewer attempts. The difficult airway cohort included 130 patients (3.2%), whose airway management consisted of oral ETI after more than four attempts (46%), bag-valve-mask ventilation (33%), cricothyroidotomy (8%), retrograde ETI (5%), and digital ETI (1%). Procedural success rates ranged from 14% (digital ETI) to 91% (cricothyroidotomy). Nine patients (7%) had failed airway management, of whom 5 were found in cardiac arrest. The two most common reasons subjectively reported by ALS providers for airway difficulty were anterior trachea (39%) and small mouth (30%). Overall mortality for the difficult airway cohort was 44%. Prehospital ETI can be performed with a high success rate by experienced ALS providers, but may still require advanced airway techniques in a small subset of patients. Patient anatomy is a primary factor in failed ETI. Among the advanced procedures, cricothyroidotomy had the highest success rate and should not be delayed by other interventions.

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.

A Comparison of Hemodynamic Changes after Endotracheal Intubation by using the Bonfils Intubation Fibrescope and the Laryngoscope

Background: The hemodynamic changes associated with orotracheal intubation may result from direct laryngoscopy and the endotracheal intubation. This study evaluated and compared the cardiovascular changes after either Bonfils intubation fibrescope or conventional laryngoscopic endotracheal intubation. Methods: Sixty patients, aged 20 to 30 years, were randomly allocated into two groups, the Bonfils intubation fibrescope group (BF group, n = 30) and conventional intubation using a rigid laryngoscope (LS group, n = 30). Bonfils intubation fibrescope or laryngoscopic oral endotracheal intubation was performed after inducing anesthesia. The systolic and diastolic arterial pressures, heart rate, peripheral oxygen saturation and intubation time were recorded before and after orotracheal intubation. Results: In both groups, the systolic and diastolic arterial pressures increased significantly after endotracheal intubation. The heart rate increased significantly after the induction of anesthesia in both groups. However, the arterial blood pressure, heart rate and intubation time were similar in both groups. Conclusions: The use of a Bonfils intubation fibrescope does not modify the hemodynamic response associated with endotracheal intubation compared with conventional laryngoscopy.

Pediatric Laryngoscope Blade Size Selection Using Facial Landmarks

Study Objectives: The study evaluates whether or not facial landmarks can be used to estimate the most appropriate laryngoscope blade length for oral endotracheal intubation in children. We tested the hypothesis that the laryngoscope blade measuring no more than 10 mm 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.

Effects of anaesthesia using endotracheal intubation or the laryngeal mask airway, or spinal anaesthesia, on oral mucosal host defences during minor surgery

Oral mucosal host defences are altered after anaesthesia and surgery. The effects of endotracheal intubation (ET) and the use of the laryngeal mask airway (LMA) on oral mucosal host defences after minor surgery were compared. Immunological (immunoglobulin A (IgA), IgG and IgM) and non-immunological (myeloperoxidase, total peroxidase, thiocyanate) oral host defence factors, and amylase and protein concentrations, were measured from saliva pre-operatively and on the first post-operative day in 60 ASA I-II patients undergoing minor surgery. The patients underwent general anaesthesia using oral ET or LMA. Spinal anaesthesia (S) was used as control. Serum IgG, IgM and IgA concentrations were determined. Protein-related salivary secretion of amylase and salivary concentration of IgM showed the only statistically significant overall differences between the groups. By contrast, changes were observed within the ET group in the salivary flow rate, protein concentration, amylase activity and immunological host defence factors. Some changes were also observed in the LMA group, but none in the S group. Most non-immunological test values did not change within any of the groups. ET and LMA induced similar oral mucosal host defence responses. There were, however, observations in this study that indicated a stronger response during ET than when LMA was used.

Improving the facial skin and oral mucosa integrity of patients with oral endotracheal intubation

The problems of damage to facial skin and oral mucus affecting intubated patients have seldom been effectively improved. The purpose of this project was to reduce the incidence of defects in facial skin and oral mucosa integrity in patients with oral endotracheal intubation. The main factors identified by data collection were: 1. Inappropriate endotracheal tube securement. 2. Dry lip mucosa. 3. Pressure points caused by large bite-blocks. 4. Patient's frequent movement of mouth. 5. Allergic reaction caused by adhesive tape. Through the implementation of a new standard for oral endotracheal tube securement and the application of new bite-blocks to deal with the problems mentioned above, the incidence rate of defects in facial skin and oral mucosa integrity decreased from 67% to 25%. The results indicate that the new standard of securement and the new bite-block can help to solve these problems.

Condylar resorption of the temporomandibular joint following arthroscopy in a patient with essential thrombocythemia

Condylar resorption of the temporomandibular joint (TMJ) is a poorly understood phenomenon that is the subject of much controversy. The etiology, diagnosis, and management of this condition have yet to achieve consensus. This case report describes a unique case of condylar resorption of uncertain etiology. The patient was a 49-year-old white female with complaints of left temporomandibular joint pain and numbness associated with reduced opening (35 mm). Over the previous 5 months, following abdominal surgery with oral endotracheal intubation, she noted increasing difficulty opening her jaw and pain. On a visual analog scale she reported a constant sharp aching (7/10) pain of the left joint that increased with function and decreased with resting the jaw. Her past medical history was significant for essential thrombocythemia, hypertension, hypothyroidism, and depression. Her medications included anagrelide, aspirin, hydrochlorothiazide/spironolactone, levothyroxine, and sertraline. An MRI revealed left disc displacement without reduction as well as a sound bony condyle consistent with TMJ plain films. She was unresponsive to 10 weeks of treatment provided by her general dentist consisting of a biteguard and analgesics. Given the refractory nature of the patient's complaint to this treatment, she was given the options of further nonsurgical or surgical management. In consultation with an oral and maxillofacial surgeon, she elected to undergo arthroscopy of the left joint. Under general anaesthesia, arthroscopy was performed. During the procedure, excessive intra-articular hemorrhage was repeatedly encountered, resulting in obliteration of the entry lumen of the arthroscope and outflow port. Initially following surgery the patient was able to open 32 mm with stretch to 38 mm, but with deviation to the left and heavy anterior occlusion. Two months following the procedure, the patient continued to experience dysfunction and pain. A course of physical therapy with gentle mobilization of the left TMJ was prescribed. The patient was lost to follow-up owing to a family member's illness. Five months later, she presented to the office not having pursued physical therapy, but was completely pain free with normal mandibular opening (45 mm). She complained that her “bite was off” and had progressively worsened. Clinically, a right posterior openbite was present accompanied by marked facial asymmetry. She had no pain upon palpation or with function of the left TMJ but deviated to the left upon opening. TMJ plain films, tomograms, and CT scan revealed marked resorption and surface irregularities of the left condylar head. The patient declined further treatment and was followed for 3 years. She remained clinically stable with no further deterioration. It is hypothesized that the resorption of the left condyle may have been due to hemarthrosis with possible thrombosis of the microvasculature of the synovial tissues and/or condyle, precipitated by the arthroscopic procedure. Alternatively, the resorptive process may have been initiated with jaw manipulation during the abdominal surgery, and progressed during the observed time period. Based upon this experience, it would appear that surgical procedures involving the TMJ in a patient with thrombocythemia should be undertaken with caution. Conversely, maximal management of the underlying pathology may have given improved results.

Populations at Risk for Intubation Nonattempt andFailure in the Prehospital Setting

Objectives. Pediatric cardiac arrest patients andadult traumatic arrest patients are perceived as more difficult to endotracheally intubate than adult cardiac arrest patients. The study hypothesis was that these populations were at higher risk of endotracheal intubation failure compared with adult cardiac arrest patients andthat paramedics would more frequently defer attempts to intubate these patients. Methods. This was a retrospective, observational study analyzing oral endotracheal intubations on pediatric cardiac arrest, adult traumatic arrest, andadult cardiac arrest patients over 66 months. Homogeneity of intubation nonattempt andendotracheal intubation failure was studied with chi-square analysis. Relative risks (RRs) with 95% confidence intervals (CIs) were used to compare pediatric cardiac arrest with adult traumatic arrest with adult cardiac arrest nonattempt rates andendotracheal intubation failure rates. Results. 2,669 oral endotracheal intubations were included. There was a significant difference in intubation nonattempts andintubation failure between the combined pediatric cardiac arrest andadult traumatic arrest groups andthe adult cardiac arrest cohort (RR 7.24, 95% CI 5.73, 9.16 for nonattempt; RR = 2.33, 95% CI 1.93, 2.83 for intubation failure). Both groups individually showed significant risk for intubation nonattempt andendotracheal intubation failure compared with adult cardiac arrest, with the pediatric cohort at higher risk for failure andthe adult traumatic arrest cohort at higher risk for nonattempt. Conclusions. There was significant risk of intubation nonattempt andintubation failure in the pediatric cardiac arrest andadult traumatic arrest cohorts compared with the adult cardiac arrest population, with the pediatric cohort being at particularly high risk for intubation failure andthe adult traumatic arrest cohort at higher risk for nonattempt.

The use of the laryngeal mask in surgical tracheostomy

The laryngeal mask may be used as an airway during surgical tracheostomy. This techniques has several advantages over conventional oral endotracheal intubation.

The laryngeal mask airway for general anesthesia: the case for its use

About 6 years ago, I began performing general anesthesia in the office because of restrictions in patient access to my local hospital brought about by managed care. We selected ASA I and II patients ranging in age from 4 to about 60. For the first several years, we used oral endotracheal (ET) intubation. For induction of our typical adult patient, we administered propofol (1.5 to 2 mg/kg) with fentanyl (50 to 75 μg) as a coinduction agent. We used mivacurium or rocuronium as a muscle relaxant. Either isoflurane or sevoflurane was then used to maintain the anesthetic. I also typically administered metoclopramide 5 to 10 mg as emesis prophylaxis. Our typical procedure lasted 40 minutes and recovery time was similar. Despite using short-acting muscle relaxants, we frequently found the need to reverse the effects of the muscle relaxant. Coughing and bucking in response to the ET tube were also a problem for some patients, especially smokers.

Factors associated with the use of pharmacologic agents to facilitate out-of-hospital endotracheal intubation

Objective To identify a set of clinical factors most strongly associated with the use of drug-facilitated intubation (DFI) in the out-of-hospital setting. Method The authors used data from a prospective, multicentered endotracheal intubation (ETI) observational cohort trial, including patients from 45 emergency medical services in Pennsylvania. Providers reported clinical, physiologic, and anatomic factors associated with each ETI effort. The authors included only data from the 23 services using DFI. They identified all non-arrest (presence of a pulse) adult patients. They included both successful and failed ETIs. They defined DFI cases as patients who received a sedative or neuromuscular-blocking agent to facilitate ETI. The authors also classified patients who underwent nasotracheal intubation as DFI. They defined control subjects as patients undergoing conventional oral ETI. They performed multivariate logistic regression to identify the clinical, physiologic, and anatomic factors characteristic of DFI. They examined alternate forms of the final prediction model. Results The authors analyzed data from 208 nonarrest patients, including 92 DFIs and 116 control subjects. Of 34 factors potentially related to DFI, 17 were excluded on univariate analysis (likelihood ratio p > 0.25). Multivariate logistic regression revealed the following as positively associated with DFI: presence of clenched jaw/trismus (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.10–4.95; p = 0.026); increased verbal Glasgow Coma Scale score (OR, 1.71; 95% CI, 1.29–2.26; p<0.001); use of cervical spine precautions (OR, 2.30; 95% CI, 1.15–4.62; p = 0.018). Anterior vocal cords (OR, 0.27; 95% CI, 0.10–0.71; p = 0.004) and laryngospasm (OR, 0.14; 95% CI, 0.02-1.17; p = 0.025) were negatively associated with DFI. The model showed good fit (Hosmer-Lemeshow p = 0.75) and discrimination (area under the curve = 0.76). Conclusions The authors identified a set of predictors strongly associated with DFI. These data offer insight into the current use of DFI and support the development of consensus-based guidelines for this procedure.

FACTORS ASSOCIATED WITH THE USE OF PHARMACOLOGIC AGENTS TO FACILITATE OUT-OF-HOSPITAL ENDOTRACHEAL INTUBATION

Objective. To identify a set of clinical factors most strongly associated with the use of drug-facilitated intubation (DFI) in the out-of-hospital setting. Method. The authors used data from a prospective, multicentered endotracheal intubation (ETI) observational cohort trial, including patients from 45 emergency medical services in Pennsylvania. Providers reported clinical, physiologic, and anatomic factors associated with each ETI effort. The authors included only data from the 23 services using DFI. They identified all non-arrest (presence of a pulse) adult patients. They included both successful and failed ETIs. They defined DFI cases as patients who received a sedative or neuromuscular-blocking agent to facilitate ETI. The authors also classified patients who underwent nasotracheal intubation as DFI. They defined control subjects as patients undergoing conventional oral ETI. They performed multivariate logistic regression to identify the clinical, physiologic, and anatomic factors characteristic of DFI. They examined alternate forms of the final prediction model. Results. The authors analyzed data from 208 nonarrest patients, including 92 DFIs and 116 control subjects. Of 34 factors potentially related to DFI, 17 were excluded on univariate analysis (likelihood ratio p > 0.25). Multivariate logistic regression revealed the following as positively associated with DFI: presence of clenched jaw/trismus (odds ratio [OR], 2.33; 95% confidence interval [CI], 1.10–4.95; p=0.026); increased verbal Glasgow Coma Scale score (OR, 1.71; 95% CI, 1.29–2.26; p < 0.001); use of cervical spine precautions (OR, 2.30; 95% CI, 1.15–4.62; p = 0.018). Anterior vocal cords (OR, 0.27; 95% CI, 0.10–0.71; p = 0.004) and laryngospasm (OR, 0.14; 95% CI, 0.02-1.17; p = 0.025) were negatively associated with DFI. The model showed good fit (Hosmer-Lemeshow p = 0.75) and discrimination (area under the curve = 0.76). Conclusions. The authors identified a set of predictors strongly associated with DFI. These data offer insight into the current use of DFI and support the development of consensus-based guidelines for this procedure.