Direct Laryngoscopy Attempts Research Articles

Frenotomy Provides Improved Direct Laryngoscopy Exposure in Select Adult Patients With Ankyloglossia.

Objective: To analyze the effects of lingual frenotomy on adults with restrictive ankyloglossia and difficult direct laryngoscopy exposure. Methods: A case series study was conducted. Restriction of tongue protrusion due to ankyloglossia was identified in 2 patients who had a history of suboptimal true vocal fold (TVF) exposure on direct laryngoscopy for phonomicrosurgery. Inadequate exposure of the vocal folds was achieved on direct laryngoscopy attempts with manual tongue protrusion. Mandibular tori were not present in these patients. An intraoperative lingual frenotomy was performed in both patients. Results: After frenotomy and with manual tongue protrusion, direct laryngoscopy exposure was substantially improved allowing for considerably more visualization of the anterior TVFs. Conclusion: Lingual frenulum procedures with manual tongue protrusion should be considered in select adult patients with restrictive ankyloglossia affecting optimal direct laryngoscopy exposure.

Direct vs Video Laryngoscopy for Difficult Airway Patients in the Emergency Department: A National Emergency Airway Registry Study

IntroductionPrevious studies suggest improved intubation success using video laryngoscopy (VL) vs direct laryngoscopy (DL), yet recent randomized trials have not shown clear benefit of one method over the other. These studies, however, have generally excluded difficult airways and rapid sequence intubation. In this study we looked to compare first-pass success (FPS) rates between VL and DL in adult emergency department (ED) patients with difficult airways.MethodsWe conducted a secondary analysis of prospectively collected observational data in the National Emergency Airway Registry (NEAR) (January 2016–December 2018). Variables included demographics, indications, methods, medications, devices, difficult airway characteristics, success, and adverse events. We included adult ED patients intubated with VL or DL who had difficult airways identified by gestalt or anatomic predictors. We stratified VL by hyperangulated (HAVL) vs standard geometry VL (SGVL). The primary outcome was FPS, and the secondary outcome was comparison of adverse event rates between groups. Data analyses included descriptive statistics with cluster-adjusted 95% confidence intervals (CI).ResultsOf 18,123 total intubations, 12,853 had a predicted or identified anatomically difficult airway. The FPS for difficult airways was 89.1% (95% CI 85.9–92.3) with VL and 77.7% (95% CI 75.7–79.7) with DL (P <0.00001). The FPS rates were similar between VL subtypes for all difficult airway characteristics except airways with blood or vomit, where SGVL FPS (87.3%; 95% CI 85.8–88.8) was slightly better than HAVL FPS (82.4%; 95% CI, 80.3–84.4). Adverse event rates were similar except for esophageal intubations and vomiting, which were both less common in VL than DL. Esophageal intubations occurred in 0.4% (95% CI 0.1–0.7) of VL attempts and 1.5% (95% CI 1.1–1.9) of DL attempts. Vomiting occurred in 0.6% (95% CI 0.5–0.7) of VL attempts and 1.4% (95% CI 0.9–1.9) of DL attempts.ConclusionAnalysis of the NEAR database demonstrates higher first-pass success with VL compared to DL in patients with predicted or anatomically difficult airways, and reduced rate of esophageal intubations and vomiting.

Analysis of Laryngoscopy Attempts in Infants: Comment.

I read with great interest the retrospective cross-sectional cohort study by Galvez et al.,1 addressing the incidence of hypoxemia and bradycardia and the need for multiple direct laryngoscopy attempts in neonates and infants who were classified as American Society of Anesthesiologists (Schaumburg, Illinois; ASA) Physical Status I or II patients at the authors’ center. Their findings of the incidence of multiple direct laryngoscopy attempts (16%) and associated hypoxemia in patients younger than 12 months support other retrospective and observational studies2,3 suggesting that being an infant or neonate is an independent predictor of difficult direct laryngoscopy.ASA Physical Status, the most widely used preoperative risk stratification system, has been shown to be marred by high interoperator variability, including in pediatric patients.4,5 ASA Physical Status I patients are considered healthy individuals with no anticipated added risk to the low incidence of the inherent risks of anesthesia management. However, a high percentage of pediatric patients who had been initially assigned to that category were subsequently reclassified as ASA Physical Status II patients in a prospective analysis.5 A highly reliable and universally accepted preoperative stratification system for pediatric patients has not been routinely implemented in practice yet, and most of us still use the ASA Physical Status classification for that patient population. Although the classification considers age as unrelated to perioperative risks, based on the above data, age clearly does impact such risk for otherwise healthy infants and neonates.I believe that mounting evidence supports age as a predictor of difficult airway management in pediatric anesthesia. As long as we continue to use the preoperative ASA classification system in pediatric anesthesia, we could reduce some interobserver variability if we agreed that healthy children younger than 12 months of age are ASA Physical Status II patients based on the incidence of perioperative complications associated with their developmental status.The author declares no competing interests.

The HEAVEN criteria predict laryngoscopic view and intubation success for both direct and video laryngoscopy: a cohort analysis

BackgroundExisting difficult airway prediction tools are not practical for emergency intubation and do not incorporate physiological data. The HEAVEN criteria (Hypoxaemia, Extremes of size, Anatomic challenges, Vomit/blood/fluid, Exsanguination, Neck mobility) may be more relevant for emergency rapid sequence intubation (RSI).MethodsA retrospective analysis included air medical RSI patients. A checklist was used to assess HEAVEN criteria prior to RSI, and Cormack-Lehane (CL) laryngoscopic view was recorded for the first intubation attempt. The incidence of a difficult (CL III/IV) laryngoscopic view as well as failure to intubate on first attempt with and without oxygen desaturation were determined for each of the HEAVEN criteria and total number of HEAVEN criteria. In addition, the association between HEAVEN criteria and both laryngoscopic view and intubation performance were quantified using multivariate logistic regression for direct laryngoscopy (DL) and video laryngoscopy (VL) configured with a Macintosh #4 non-hyperangulated blade.ResultsA total of 5137 RSI patients over 24 months were included. Overall intubation success was 97%. A CL III/IV laryngoscopic view was reported in 25% of DL attempts and 15% of VL attempts. Each of the HEAVEN criteria and total number of HEAVEN criteria were associated with both CL III/IV laryngoscopic view and failure to intubate on the first attempt with and without oxygen desaturation for both DL and VL. These associations persisted after adjustment for multiple co-variables including the other HEAVEN criteria.ConclusionThe HEAVEN criteria may be useful to predict laryngoscopic view and intubation performance for DL and VL during emergency RSI.

Comparison of Miller laryngoscope and UEScope videolaryngoscope for endotracheal intubation in four pediatric airway scenarios: a randomized, crossover simulation trial

With different videolaryngoscopes for pediatric patients available, UEScope can be used in all age groups. The aim of this study was to compare the Miller laryngoscope and UEScope in pediatric intubation by paramedics in different scenarios. Overall, 93 paramedics with no experience in pediatric intubation or videolaryngoscopy performed endotracheal intubation in scenarios: (A) normal airway without chest compressions, (B) difficult airway without chest compressions, (C) normal airway with uninterrupted chest compressions, (D) difficult airway with uninterrupted chest compressions. Scenario A. Total intubation success with both laryngoscopes: 100%. First-attempt success: 100% for UEScope, 96.8% for Miller. Median intubation time for UEScope: 13 s [IQR, 12.5–17], statistically significantly lower than for Miller: 14 s [IQR, 12–19.5] (p = 0.044). Scenario B. Total efficacy: 81.7% for Miller, 100% for UEScope (p = 0.012). First-attempt success: 48.4% for Miller, 87.1% for UEScope (p = 0.001). Median intubation time: 27 s [IQR, 21–33] with Miller, 15 s [IQR, 14–21] with UEScope (p = 0.001). Scenario C. Total efficiency: 91.4% with Miller, 100% with UEScope (p = 0.018); first-attempt success: 67.7 vs. 90.3% (p = 0.003), respectively. Intubation time: 21 s [IQR, 18–28] for Miller, 15 s [IQR, 12–19.5] for UEScope. Scenario D. Total efficiency: 65.6% with Miller, 98.9% with UEScope (p < 0.001); first-attempt success: 29.1 vs. 72% (p = 0.001), respectively. Intubation time: 38 s [IQR, 23–46] for Miller, 21 s [IQR, 17–25.5] for UEScope.Conclusion: In pediatric normal airway without chest compressions, UEScope is comparable with Miller. In difficult pediatric airways without chest compressions, UEScope offers better first-attempt success, shorted median intubation time, and improved glottic visualization. With uninterrupted chest compressions in normal or difficult airway, UEScope provides a higher first-attempt success, a shorter median intubation time, and a better glottic visualization than Miller laryngoscope.What is Known:• Endotracheal intubation is the gold standard for adult and children airway management.• More than two direct laryngoscopy attempts in children with difficult airways are associated with a high failure rate and increased incidence of severe complications.What is New:• In difficult pediatric airways with or without chest compressions, UEScope in inexperienced providers in simulated settings provides better first-attempt efficiency, median intubation time, and glottic visualization.

Direct vs. Video Laryngoscopy in a Helicopter Emergency Medical Service (HEMS) Setting: A Retrospective Comparison

Introduction In the prehospital setting, when caring for critically ill patients, the ability to quickly and effectively secure a definitive airway can be a matter of life of death. As such, all helicopter emergency medical service (HEMS) providers must be able to safely perform this procedure with speed and efficacy. Video laryngoscopy (VL) was invented and introduced as an improved technique for performing orotracheal intubation, and its use has become widespread amongst pre-hospital and HEMS organizations. Despite this, little information is available regarding the efficacy of VL when compared to standard direct laryngoscopy (DL) in this pre-hospital setting. As such, there is sparse evidence to guide the HEMS provider's decision on which to use when attempting to secure the airway of a critically ill patient. Provider preference often comes into play in this situation. In a preliminary survey, Nolen and Pokorney found that while the majority of Wisconsin Flight For Life (FFL) HEMS providers choose VL, variation does exist between providers in regards to VL vs DL preference. Self-reported success rates by providers suggested 100% first pass success with DL and 87.5 success with VL. This survey relied on provider recall, and further review of records is required to evaluate the accuracy of these reports. Currently, there is no protocol regarding which laryngoscopy modality to employ in the HEMS setting. This research aims to improving the quality of care received by patients who require orotracheal intubation by HEMS providers. To do this, we investigate whether the use of VL or DL increases successful orotracheal intubations by HEMS providers. We hypothesized that the first pass and overall success would be greater with VL and the overall complications would be less with VL when compared to DL. Methods A retrospective chart review was performed of all intubated patients transported by HEMS providers from January 2015 to July 2017. Inclusion Criteria Adult patients transported by HEMS providers that required orotracheal intubation and underwent at least one attempt at orotracheal intubation. Results When comparing the survey results, we found similar rates of DL vs VL attempts (15/21 vs 104/120). First pass success rates were overestimated for both modalities (100%/90.5% vs 87.5%/84.8%). First Pass Success Rate No statistically significant difference was found in 1st pass success rate. The top reported reason for failed DL attempts was inability to pass tube, while the top reported reason for failed VL attempts include blood/secretions on camera, followed by inability to pass tube. Overall Success Rate No statistically significant difference was found between the two modalities. However, there was notably no difference between 1st pass and overall success rate in the DL group, while the overall success improved over fist pass in the VL group. While not statistically significant, this trend results from more attempts and alterations by those performing VL prior to resorting to a rescue airway. The most common alteration made was change in VL blade, followed by changing from VL to DL. Complications DL and VL groups had nearly identical complication rates. In both groups, the primary complication was hypoxia, so BVM ventilation was utilized. There was one cardiac arrest in the DL group. Influencing Factors Overwhelmingly, the method of intubation favored by HEMS providers is video laryngoscopy (VL). In the survey by Pokorney and Nolan, provider preference was the most common reason for choosing a modality. Of the patient characteristics observed, no significant differences were found. Initial GCS showed near statistical significance, with lower initial GCS trending to VL. Perhaps VL is more utilized when indication for intubation is apparent immediately upon arrival on scene. Unresponsiveness as reason for intubation, however, did not vary significantly. Respiratory failure alone demonstrated a statistically significant difference with proportionally more VL intubations in these patients. No definition for what constitutes respiratory failure was present in the charts and the reason for this variance between modality used is unknown. Conclusion In the data reviewed, no significant differences were found in first pass or overall success rates for direct and video laryngoscopy. Additionally no significant difference was observed in the complication rates and no factors were found that influenced the decision to perform DL vs VL.

Evaluation of emergency pediatric tracheal intubation by pediatric anesthesiologists on inpatient units and the emergency department.

There are limited data on pediatric emergency tracheal intubation on inpatient units and in the emergency department by anesthesiologists. This retrospective cohort study was designed to describe the frequency of difficult intubation and adverse events associated with emergency tracheal intubation performed by pediatric anesthesiologists in a large children's hospital. All emergency tracheal intubation on inpatient units and the emergency department performed by pediatric anesthesiologists over a 7-year period in children <18 years were identified by querying our perioperative clinical information system. Medical records were comprehensively reviewed to describe the emergency intubation process and outcomes. One hundred and thirty-two intubations from 120 children (median age 3.3 years) were eligible. The majority of emergency tracheal intubations were successful with 1-2 laryngoscopy attempts, while 14 (10.6%) were difficult. Despite grade 3 view in 3/14 cases, the airway was secured after multiple direct laryngoscopy attempts. Eleven required use of an alternative airway device to secure the airway. A preexisting airway abnormality or craniofacial abnormality was present in 57% of cases with difficult intubation including half with micrognathia or retrognathia. Major intubation-related adverse events such as aspiration, occurred in 5 (3.8%) emergency tracheal intubations. Mild-to-moderate intubation-related adverse events occurred in 23 (17.4%) emergency tracheal intubations including mainstem bronchus intubation (13.6%). A significant rate of difficult intubation and mild-to-moderate intubation-related adverse events were found in emergency tracheal intubations on inpatient units and the emergency department in children performed by a pediatric anesthesiology emergency airway team. Difficult intubation was observed frequently in children with preexisting airway and craniofacial abnormalities and often required the use of an alternative airway device to successfully secure the airway.

Airway management complications in children with difficult tracheal intubation from the Pediatric Difficult Intubation (PeDI) registry: a prospective cohort analysis

Despite the established vulnerability of children during airway management, remarkably little is known about complications in children with difficult tracheal intubation. To address this concern, we developed a multicentre registry (Pediatric Difficult Intubation [PeDI]) to characterise risk factors for difficult tracheal intubation, establish the success rates of various tracheal intubation techniques, catalogue the complications of children with difficult tracheal intubation, and establish the effect of more than two tracheal intubation attempts on complications. The PeDI registry consists of prospectively collected tracheal intubation data from 13 children's hospitals in the USA. We established standard data collection methods before implementing the secure web-based registry. After establishing standard definitions, we collected and analysed patient, clinician, and practice data and tracheal intubation outcomes. We categorised complications as severe or non-severe. Between August, 2012, and January, 2015, 1018 difficult paediatric tracheal intubation encounters were done. The most frequently attempted first tracheal intubation techniques were direct laryngoscopy (n=461, 46%), fibre-optic bronchoscopy (n=284 [28%]), and indirect video laryngoscopy (n=183 [18%]) with first attempt success rates of 16 (3%) of 461 with direct laryngoscopy, 153 (54%) of 284 with fibre-optic bronchoscopy, and 101 (55%) of 183 with indirect video laryngoscopy. Tracheal intubation failed in 19 (2%) of cases. 204 (20%) children had at least one complication; 30 (3%) of these were severe and 192 (19%) were non-severe. The most common severe complication was cardiac arrest, which occurred in 15 (2%) patients. The occurrence of complications was associated with more than two tracheal intubation attempts, a weight of less than 10 kg, short thyromental distance, and three direct laryngoscopy attempts before an indirect technique. Temporary hypoxaemia was the most frequent non-severe complication. More than two direct laryngoscopy attempts in children with difficult tracheal intubation are associated with a high failure rate and an increased incidence of severe complications. These results suggest that limiting the number of direct laryngoscopy attempts and quickly transitioning to an indirect technique when direct laryngoscopy fails would enhance patient safety. None.

Comparative Effectiveness of the C-MAC Video Laryngoscope Versus Direct Laryngoscopy in the Setting of the Predicted Difficult Airway

Aziz, Michael F.*; Dillman, Dawn*; Fu, Rongwei†; Brambrink, Ansgar M.* Author Information

Performance of emergency physicians utilizing a video-assisted semi-rigid fiberoptic stylet for intubation of a difficult airway in a high-fidelity simulated patient: a pilot study

BackgroundThis study was designed to evaluate emergency physician success and satisfaction using a video-assisted semi-rigid fiberoptic stylet, the Clarus Video System (CVS), during a simulated difficult airway scenario.FindingsEmergency physicians (EPs) of all levels were first shown a brief slide show and three example videos, and then given 20 min to practice intubating a mannequin using both the CVS and standard direct laryngoscopy (DL). The mannequin was then placed in a c-collar and set to simulate an apneic patient with an edematous tongue and trismus. Each EP was given up to three timed attempts with each technique. They rated their satisfaction with the CVS, usefulness for their practice, and the effectiveness of the tutorial. Direct laryngoscopy had a 65% success rate on the first attempt, 20% on the second, and 15% required three or more. The CVS had a 100% success rate with a single attempt. Average time for independent DL attempts was 43.41 s (SD = ±26.82) and 38.71 s (SD = ±34.14) with CVS. Cumulative attempt times were analyzed and compared (DL = 74.55 ± 68.40 s and CVS = 38.71 ± 34.14 s; p = 0.028). EPs rated their satisfaction with, and usefulness of, the CVS as ≥6 out of 10.ConclusionEmergency physicians were able to successfully intubate a simulated difficult airway model on the first attempt 100% of the time. Emergency physicians were satisfied with the CVS and felt that it would be useful in their practice.

Comparative Effectiveness of the C-MAC Video Laryngoscope versus Direct Laryngoscopy in the Setting of the Predicted Difficult Airway

Video laryngoscopy may be useful in the setting of the difficult airway, but it remains unclear if intubation success is improved in routine difficult airway management. This study compared success rates for tracheal intubation with the C-MAC® video laryngoscope (Karl Storz, Tuttlingen, Germany) with conventional direct laryngoscopy in patients with predicted difficult airway. We conducted a two arm, single-blinded randomized controlled trial that involved 300 patients. Inclusion required at least one of four predictors of difficult intubation. The primary outcome was successful tracheal intubation on first attempt. The use of video laryngoscopy resulted in more successful intubations on first attempt (138/149; 93%) as compared with direct laryngoscopy (124/147; 84%), P = 0.026. Cormack-Lehane laryngeal view was graded I or II in 139/149 of C-MAC attempts versus 119/147 in direct laryngoscopy attempts (P < 0.01). Laryngoscopy time averaged 46 s (95% CI, 40-51) for the C-MAC group and was shorter in the direct laryngoscopy group, 33 s (95% CI, 29-36), P < 0.001. The use of a gum-elastic bougie and/or external laryngeal manipulation were required less often in the C-MAC intubations (24%, 33/138) compared with direct laryngoscopy (37%, 46/124, P = 0.020). The incidence of complications was not significantly different between the C-MAC (20%, 27/138) versus direct laryngoscopy (13%, 16/124, P = 0.146). A diverse group of anesthesia providers achieved a higher intubation success rate on first attempt with the C-MAC in a broad range of patients with predictors of difficult intubation. C-MAC laryngoscopy seems to be a useful technique for the initial approach to a potentially difficult airway.

Incidence of unanticipated difficult airway in obstetric patients in a teaching institution.

PURPOSE: Our aim was to determine the incidence of difficult intubation during pregnancy-related surgery at a high-risk, high-volume teaching institution. METHODS: Airway experience was analyzed among patients who had pregnancy-related surgery under general anesthesia from January 2001 through February 2006. A difficult airway was defined as needing three or more direct laryngoscopy (DL) attempts, use of the additional airway equipment after the DL attempts, or conversion to regional anesthesia due to inability to intubate. Airway characteristics were compared between patients with and without a difficult airway. In addition, pre- and postoperative airway evaluations were compared to identify factors closely related to changes from pregnancy. RESULTS: In a total of 30,766 operations, 2,158 (7%) were performed with general anesthesia. Among these, 1,026 (47.5%) were for emergency cesarean delivery (CD), 610 (28.3%) for nonemergency CD, and 522 (24.2%) for non-CD procedures. A total of 12 patients (0.56%) were identified as having a difficult airway. Four patients were intubated with further DL attempts; others required mask ventilation and other airway equipment. Two patients were ventilated through a laryngeal mask airway without further intubation attempts. Ten of the 12 difficult airway cases were encountered by residents during their first year of clinical anesthesia training. There were no maternal or fetal complications except one possible aspiration. CONCLUSION: Unanticipated difficult airways accounted for 0.56% of all pregnancy-related surgical patients. More than 99.9% of all obstetric patients could be intubated. A difficult airway is more likely to be encountered by anesthesia providers with <1year of experience. Proper use of airway equipment may help secure the obstetric airway or provide adequate ventilation. Emergency CD did not add an additional level of difficulty over nonemergency CD.

Predicting Difficult Laryngoscopy in Acromegaly: A Comparison of Upper Lip Bite Test With Modified Mallampati Classification

Upper lip bite test (ULBT) is a simple test for predicting difficult intubation. However, it has not been evaluated in acromegalic patients. The primary aim of this study was to compare ULBT with modified Mallampati classification (MMPC) to predict difficult laryngoscopy in acromegalic patients. Over a 5-year period, 64 acromegalic and 63 nonacromegalic patients presenting for excision of pituitary tumor were enrolled. Preoperative airway assessment was done using MMPC and the ULBT. Under anesthesia, laryngoscopic view was assessed using Cormack-Lehane (CL) grading. MMPC III/IV and ULBT grade III were considered predictive of difficult laryngoscopy that was defined as Cormack-Lehane grades III or IV. Difficult intubation was defined as more than 2 direct laryngoscopy attempts involving change of blade or use of bougie/fiberoptic bronchoscope/intubating laryngeal mask airway. Sensitivity, specificity, positive and negative predictive values, and accuracy of both tests in predicting difficult laryngoscopy were calculated. Incidence of difficult laryngoscopy and intubation in acromegalics were 24% and 11%, respectively. MMPC and ULBT predicted difficulty in 61% and 14% acromegalics, respectively. However, only 26% and 44% of the laryngoscopies predicted to be difficult by MMMC and ULBT, respectively, were actually difficult. MMPC failed to predict 33% of difficult laryngoscopies whereas ULBT failed to predict 73%. Neither test predicted difficulty in 33% laryngoscopies that turned out to be difficult. Twenty-seven percent of the difficult laryngoscopies were correctly predicted by both tests. In acromegalic group, MMPC was more sensitive, whereas ULBT was more specific. Sensitivity and accuracy of both tests were less in acromegalic patients compared with nonacromegalic controls.

Paramedic Training for Proficient Prehospital Endotracheal Intubation

Background. Emergency airway management is an important component of resuscitation of critically ill patients. Multiple studies demonstrate variable endotracheal intubation (ETI) success by prehospital providers. Data describing how many ETI training experiences are required to achieve high success rates are sparse. Objectives. To describe the relationship between the number of prehospital ETI experiences and the likelihood of success on subsequent ETI and to specifically look at uncomplicated first-pass ETI in a university-based training program with substantial resources. Methods. We conducted a secondary analysis of a prospectively collected cohort of paramedic student prehospital intubation attempts. Data collected on prehospital ETIs included indication, induction agents, number of direct laryngoscopy attempts, and advanced airway procedures performed. We used multivariable generalized estimating equations (GEE) analysis to determine the effect of cumulative ETI experience on first-pass and overall ETI success rates. Results. Over a period of three years, 56 paramedic students attempted 576 prehospital ETIs. The odds of overall ETI success were associated with cumulative ETI experience (odds ratio [OR] 1.097 per encounter, 95% confidence interval [CI] = 1.026–1.173, p = 0.006). The odds of first-pass ETI success were associated with cumulative ETI experience (OR 1.061 per encounter, 95% CI = 1.014–1.109, p = 0.009). Conclusion. In a training program with substantial clinical opportunities and resources, increased ETI success rates were associated with increasing clinical exposure. However, first-pass placement of the ETT with a high success rate requires high numbers of ETI training experiences that may exceed the number available in many training programs.

Use of the intubating laryngeal mask airway in emergency pre-hospital difficult intubation

While several techniques are used for the management of difficult intubation (DI) in planned conditions in the operating theatre, they are not always suitable or usable in pre-hospital emergencies. We decided to assess the intubating laryngeal mask airway (ILMA) after failure of tracheal intubation (TI) under direct laryngoscopy. After emergency physicians of the mobile intensive care unit were trained (theory and training on manikin) in using the ILMA (Fastrach), prospective data were collected after each use from March 2002 to December 2005. Data included patient's age, clinical status, number of direct laryngoscopies before using ILMA, Cormack and Lehane grade, subjective and objective evaluation of ease of ILMA insertion and TI (analogue scale from 1 to 10, attempts required, failure rate). Over 46 months, the ILMA was used 45 times (24: cardio-respiratory arrest, 21: anaesthesia with rapid sequence induction). Median age was 59 years [range 20-86]. The number of direct laryngoscopy attempts was 3 [0-4] (76% Cormack 4). The success of ILMA insertion and TI were 96 and 91%, respectively. Emergency physicians were satisfied with using the ILMA. It allowed TI in 91% of cases of DI. The ILMA can be recommended to be included in the algorithm of DI in pre-hospital emergencies after initial training.

Anterior Tonsillar Pillar Perforation During Glidescope® Video Laryngoscopy

To the Editor: The Glidescope® video laryngoscope is an effective and well-established device for facilitating tracheal tube placement (1,2) Here we report an unusual complication of Glidescope® assisted intubation. A 72-yr-old man presented for resection of a thoracic spinal cord arteriovenous malformation. The patient had a past medical history significant for myotonia congenita and hiatal hernia with mild acid reflux. On physical examination he was found to have a Mallampati Class II view of the oropharynx with mouth opening slightly <4 cm and normal range of motion of the cervical spine. In addition, review of his previous records revealed that during a prior anesthetic he had a Cormack–Lehane Grade 3 laryngeal view necessitating three direct laryngoscopy attempts and the use of an intubating stylet to secure the airway. Anesthesia was induced with lidocaine, fentanyl, propofol, and cisatracurium. After 3 min of ventilation via mask, we easily inserted a Glidescope® video laryngoscopy blade and obtained a Grade I view of the vocal cords. An 8.0 mm internal diameter tracheal tube with the manufacturer recommended Rigid Stylet™ was passed through the vocal cords under Glidescope® visualization. The cuff was inflated and positive pressure ventilation through the tube produced a normal end tidal CO2 tracing and bilateral breath sounds. At this point a small amount of blood was noted in the retropharynx on the Glidescope® monitor. Upon withdrawal of the Glidescope® blade the tracheal tube was seen perforating the right anterior tonsillar pillar. After consulting with an otolaryngologist, we removed the tracheal tube and reintubated the trachea using a fiberoptic laryngoscope without difficulty. The trachea was extubated in the operating room following the procedure, and minimal throat soreness was reported on postoperative day one. We postulate several mechanisms for this unusual complication: After obtaining an adequate view of the vocal cords with the Glidescope®, we blindly passed the tracheal tube through the oropharynx until visualizing the tip of the tube adjacent to the glottic opening on the Glidescope® monitor. It was during this blind pass of the tube that the anterior tonsillar pillar was perforated. We used a standard tracheal tube and the manufacturer recommended Rigid Stylet™. The combination of the stylet and the sharp edge of the tracheal tube may have contributed to perforation of the anterior tonsillar pillar. Patients with myotonia congenita can be resistant to the effects of nondepolarizing muscle relaxants in the setting of direct stimulation (3). Inadequate relaxation of the palatoglosseus muscle may predispose to anterior tonsillar pillar perforation. The already thin tonsillar pillar membrane may have been pulled taut by palatoglosseus muscle contraction, making it more susceptible to perforation. To avoid similar complications when using the Glidescope® video laryngoscope we suggest the following: Use of a soft-edged endotracheal tube (such as the Parker Flex-Tip™) to avoid damage to pharyngeal structures, especially in conjunction with the Rigid Stylet™. Verathon Medical has recently introduced such a tube for use with the Glidescope® system (GVL® GlideRite™). Directly visualize the tracheal tube as it is inserted into the mouth along the curvature of the Glidescope® laryngoscope blade. Only after the tip of the tube has passed out of view should the Glidescope® video monitor be viewed. Asif M. Malik, MD Jonathan K. Frogel, MD Department of Anesthesiology Henry Ford Hospital 2799 West Grand Blvd. Detroit, MI 48202 [email protected]