Cormack-Lehane Score Research Articles

Evaluation of three different airway predictive indices in obstetric patients using the modified cormack-lehane scoring system (MCLSC)

s and Programme: EUROANAESTHESIA 2011: The European Anaesthesiology Congress: Airway Management

Comparison of the Laryngeal View during Tracheal Intubation Using Airtraq and Macintosh Laryngoscopes by Unskillful Anesthesiology Residents: A Clinical Study

Background and Objective. The Airtraq laryngoscope (Prodol Meditec, Vizcaya, Spain) is a novel tracheal intubation device. Studies, performed until now, have compared the Airtraq with the Macintosh laryngoscope, concluding that it reduces the intubation times and increase the success rate at first intubation attempt, decreasing the Cormack-Lehane score. The aim of the study was to evaluate if, in unskillful anesthesiology residents during the laryngoscopy, the Airtraq compared with the Macintosh laryngoscope improves the laryngeal view, decreasing the Cormack-Lehane score. Methods. A prospective, randomized, crossed-over trial was carried out on 60 patients. Each one of the patients were intubated using both devices by unskillful (less than two hundred intubations with the Macintosh laryngoscope and 10 intubations using the Airtraq) anesthesiology residents. The Cormack-Lehane score, the success rate at first intubation attempt, and the laryngoscopy and intubation times were compared. Results. The Airtraq significantly decreased the Cormack-Lehane score (P = 0.04). On the other hand, there were no differences in times of laryngoscopy (P = 0.645; IC 95% 3.1, +4.8) and intubation (P = 0.62; C95% −6.1, +10.0) between the two devices. No relevant complications were found during the maneuvers of intubation using both devices. Conclusions. The Airtraq is a useful laryngoscope in unskillful anesthesiology residents improving the laryngeal view and, therefore, facilitating the tracheal intubation.

Prediction of difficult intubations using conventional indicators; Does rapid sequence intubation ease difficult intubations? A prospective randomised study in a tertiary care teaching hospital

Background:Endotracheal intubations performed in the Emergency Department.Aims:To assess whether conventional indicators of difficult airway can predict a difficult intubation in the Emergency Setting and to investigate the effect of rapid sequence intubation (RSI) on ease of intubation.Settings and Design:A prospective randomized study was designed involving 60 patients requiring intubation, over a period of 4 months.Materials and Methods:Demographic profile, details of methods used, airway assessment, ease of intubation, and Cormack and Lehane score were recorded. Airway assessment score and ease of intubation criteria were devised and assessed.Statistical Analysis:Descriptive statistical analysis was carried out. Chi-square/2 × 2, 2 × 3, 3 × 3, Fisher Exact test have been used to find the significance of study parameters on categorical scale between two or more groups.Results:Patients with a Mallampatti score of three or four were found to have worse laryngoscopic views (Cormack–Lehane score, 3 or 4). Of all airway indicators assessed, an increased Mallampatti score was found to have significant correlation with increased difficulty in intubation. The use of RSI was associated with better laryngoscopic views, and easier intubations.Conclusions:An airway assessment using the Mallampatti score is invaluable as a tool to predict a difficult airway and should be performed routinely if possible. RSI aids intubation ease. If not otherwise contraindicated, it should be performed routinely for all intubations in the ED.

Avaliação sistematizada da dificuldade de exposição das pregas vocais na microcirurgia da laringe

INTRODUÇÃO: Diversos estudos abordam fatores pré-operatórios que predizem dificuldade de intubação endotraqueal, graduada pelos anestesistas pela escala de Cormack-Lehane. Estes parâmetros foram pouco avaliados para a dificuldade de locação do laringoscópio nas microcirurgias da laringe. Não há uma escala padrão de dificuldade direcionada aos cirurgiões de laringe. OBJETIVO: Criar uma escala padrão de dificuldade de locação do laringoscópio durante microcirurgia da laringe, com foco na exposição das pregas vocais (PPVV); avaliar quais parâmetros clínicos predizem dificuldade de exposição das PPVV; verificar a melhora da exposição laríngea com o suspensor do laringoscópio. MÉTODO: Estudo prospectivo, randomizado, de 57 pacientes submetidos à microcirurgia de laringe. No pré-operatório foram avaliados: 3 dados epidemiológicos, 2 de anamnese e 13 de exame físico. No intra-operatório: o anestesista avaliava o escore de Cormack-Lehane e o cirurgião avaliava conforme a escala proposta, antes e após a colocação do suspensor. RESULTADOS E CONCLUSÃO:Vários parâmetros apresentaram sensibilidade, especificidade, valor preditivo positivo altos para exposição inadequada da laringe. Porém, apenas distância hiomentual <6,05cm (p=0,003) e classe 2 de Cormack-Lehane (p=0,04) com significância estatística e alta sensibilidade, 100% e 81% respectivamente. O uso do suspensor do laringoscópio melhorou a exposição laríngea de forma significativa (p=0,04). A escala proposta padroniza a vizualização e gradua a dificuldade de exposição das PPVV, facilitando comparações entre estudos e comunicação entre otorrinolaringologistas.

Characteristics and outcome of prehospital paediatric tracheal intubation attended by anaesthesia-trained emergency physicians

Aim To collect data regarding prehospital paediatric tracheal intubation by emergency physicians skilled in advanced airway management. Methods A prospective 8-year observational study of a single emergency physician-staffed emergency medical service. Self-reporting by emergency physicians of all children aged 0–14 years who had prehospital tracheal intubation and were attended by either anaesthesia-trained emergency physicians (group 1) or by a mixture of anaesthesia and non-anaesthesia-trained emergency physicians (group 2). Results Eighty-two out of 2040 children (4.0%) had prehospital tracheal intubation (58 in group 1). The most common diagnoses were trauma (50%; in school children, 73.0%), convulsions (13.4%) and SIDS (12.2%; in infants, 58.8%). The overall tracheal intubation success rate was 57 out of 58 attempts (98.3%). Compared to older children, infants had a higher number of Cormack–Lehane scores of 3 or 4, “difficult to intubate” status (both 3 out of 13; 23.1%) and a lower first attempt success rate for tracheal intubation ( p = 0.04). Among all 82 children 71 (86.6%) survived to hospital admission and 63 (76.8%) to discharge. Of the 63 survivors, 54 (85.7%) demonstrated a favourable or unchanged neurological outcome (PCPC 1–3). The survival and neurological outcomes of infants were inferior compared to older children ( p < 0.001). On average an emergency physician performed one prehospital tracheal intubation in 3 years in a child and one in 13 years in an infant. Conclusions Anaesthesia-trained emergency physicians working in our system report high success rates for prehospital tracheal intubation in children. Survival and neurological outcomes were considerably better than reported in previous studies.

Comparisons of the GlideScope and Macintosh Laryngoscope in Tracheal Intubation by Medical Students on Fresh Human Cadavers

Objective The GlideScope Video Laryngoscope (GS) is an intubating device that provides equal or better glottic views than conventional laryngoscopes, but correct tube placement is more time-consuming, even when performed by experienced operators. The aim of this study was to investigate the use of the GS compared with the more conventional Macintosh laryngoscope in easy and difficult tracheal intubation when performed by inexperienced medical students on fresh human cadavers Patients and Methods Forty-one medical students were assigned to perform tracheal intubation using the direct Macintosh laryngoscope (DL) and the GS. Each student was given four attempts, with a maximum of 180 seconds for each attempt, to successfully intubate the trachea with a 6.5-mm tracheal tube in each of two scenarios, one with an easy airway and the other with a difficult airway cadaver. Results The total time of intubation for the easy airway cadaver was significantly longer in the GS group (61.4 ± 4.8 seconds vs. 40.6 ± 5.3 seconds; p < 0.001) despite the modified Cormack-Lehane scores showing no difference between the two groups. In the difficult airway cadaver, total time of intubation was significant shorter in the GS group (64.3 ± 6.5 seconds vs. 98.7 ± 10.2 seconds; p < 0.001) Conclusion Most inexperienced operators found the GS to be more time-consuming for tracheal intubation than DL in the easy airway cadaver. However, an obvious advantage was demonstrated when the GS was used for the difficult airway.

Preoperative clinical prediction of difficult laryngeal exposure in suspension laryngoscopy

We investigated general and physical predictors of difficult laryngeal exposure in patients undergoing suspension laryngoscopy; 93 patients were included in this prospective study. The patients were classified as difficult laryngeal exposure group or non-difficult laryngeal exposure group based on the laryngeal view in suspension laryngoscopy. Twelve parameters (age, sex, body mass index, neck circumference, full mouth opening, modified mallampati index, hyoid-mental, thyroid-mental, horizontal thyroid-mental, vertical thyroid-mental, sternum-mental distance) that could predict difficult laryngeal exposure were evaluated. Of 93 patients, 22 had difficult laryngeal exposure. Cormack-Lehane score, neck circumference, body mass index, modified mallampati index, hyoid-mental, thyroid-mental, vertical thyroid-mental, and sternum-mental distance showed significant correlation with difficult laryngeal exposure. Based on the multivariate analysis, neck circumference superior to 40 cm, hyoid-mental and sternum-mental distance with respectively a value less than 6.05 and 13.9 cm were independently associated with difficult laryngeal exposure. Muscular neck, hyoid-mental and sterno-mental distance should be considered clinical predictors of difficult laryngeal exposure. Measurements of physical variables at full extension position of the neck are more useful and reliable predictors than neutral position for the risk of difficult laryngeal exposure.

Prediction of Difficult Laryngoscopy: Does Obesity Play a Role?

This study was intended to 1) identify preoperative predictors of difficult laryngoscopy and 2) determine the role of obesity in difficulty of obtaining adequate laryngeal exposure. A prospective study was undertaken of 63 patients who were undergoing elective direct laryngoscopy. Thirty-six patients met the obesity criteria (body mass index of at least 30 kg/m2). Measurements of height, weight, and neck circumference and Mallampati and Cormack-Lehane scores were obtained. The ease of laryngeal exposure was recorded by the attending surgeon on a visual analog scale (VAS; 1 to 10). Difficult laryngeal exposure (DLE) was defined as a VAS score of at least 3. The candidate morphological predictors were investigated. Obesity and Mallampati score were found to be predictors of DLE (p < .001). The VAS score was positively correlated with body mass index (p = .007), weight (p = .05), Mallampati score (p < .001), and Cormack-Lehane score (p < .001). Among obese patients, the VAS score was correlated with the Cormack-Lehane score (p = .01), whereas in nonobese patients the VAS score showed a significant association with both the Mallampati (p = .02) and Cormack-Lehane (p = .01) scores. Obese patients and those with a Mallampati score of at least 2 posed a significantly higher risk of DLE. Preoperative identification of a potentially difficult airway may aid surgical planning and allow more effective communication with a collaborating anesthesiologist.

Laryngoscopies in the Obese: Predicting Problems and Optimizing Visualization

This pilot study was designed to 1) identify predictors of difficult laryngeal exposure in obese patients, 2) develop strategies for efficient intubation and intraoperative visualization of the glottis, and 3) devise perioperative protocols for difficult laryngoscopies. We undertook a retrospective study over a 1-year period of 14 consecutive patients with a body mass index of more than 30 kg/M2 who underwent elective direct laryngoscopy under general anesthesia. Measurements of height, weight, neck circumference, Mallampati score, and Cormack-Lehane classification of the airway were recorded. Problems encountered during anesthesia induction and emergence were also noted. The laryngologist recorded on a visual analog scale the degree of difficulty encountered in obtaining a binocular stereoscopic view and magnification, illumination, and suspension. Anatomic challenges during difficult laryngoscopy included decreased neck extension, redundant folds of tissue in the oropharynx and hypopharynx, and upper airway collapsibility. Overall, there was an association between the incidence of difficult laryngeal exposure and the Cormack-Lehane score (r = .57; p = .03), but the Mallampati score was of limited utility to the laryngologist. Neck size in female patients correlated with the Cormack-Lehane score (p = .02). Neither weight nor body mass index were predictive of a difficult laryngeal exposure. Straight blade laryngoscopes with a distal flange allowed greater depth of insertion and provided the best visualization of the glottis. An appropriate clinical examination may help predict a difficult airway. However, further studies are warranted to fully characterize the anatomic predictors of a difficult laryngeal exposure.

Comparison of direct and video-assisted views of the larynx during routine intubation

Objective To compare the direct and indirect (video monitor) views of the glottic opening using a new Macintosh blade that is modified to provide a video image of airway structures during laryngoscopy. Design Prospective multicenter trial. Setting 11 university-affiliated hospitals. Patients 867 adults undergoing elective surgery requiring general anesthesia and tracheal intubation. Interventions Patients received general anesthesia and were paralyzed. Direct laryngoscopy was supervised by one of the investigators at each institution. The best possible view was obtained with a Macintosh video laryngoscope during direct vision using standard techniques such as external laryngeal manipulation and backward, upward, and rightward pressure, if necessary. The laryngoscopist then looked at the video monitor and performed any necessary maneuvers to obtain the best view on the video monitor. Thus, 2 assessments were made during the same laryngoscopy (direct naked-eye view vs video monitor view). Tracheal intubation was then performed using the monitor view. Glottic views were rated according to the Cormack-Lehane scoring system, as modified by Yentis and Lee. A questionnaire was completed for each patient. Measurements and Main Results Data from 865 patients were suitable for analysis. Visualization was considered easy (Cormack-Lehane score < 3) in 737 patients and difficult (Cormack-Lehane score = 3 or 4) in 21 for both direct and video-assisted views. In 7 patients, the view was considered easy during direct visualization yet difficult on the video monitor view. On the other hand, the view was considered difficult in 100 patients during direct visualization yet easy on the video monitor view ( P < 0.001). Conclusions Video-assisted laryngoscopy provides an improved view of the larynx, as compared with direct visualization. This technique may be useful for cases of difficult intubation and reintubation as well as for teaching laryngoscopy and intubation.

Prediction of Difficult Laryngeal Exposure in Patients Undergoing Microlaryngosurgery

Although difficult laryngeal exposure (DLE) is a common problem encountered during microlaryngosurgery, reliable predictors of DLE and grading systems of laryngeal exposure have been scarcely suggested in the field of laryngology. We propose a new classification of laryngeal exposure focusing on the extent of glottic visualization. We investigated physical parameters that could predict DLE; 73 patients underwent a physical examination including 15 parameters. During endotracheal intubation and suspension laryngoscopy, Cormack-Lehane and laryngeal exposure scores were obtained for each patient and compared with the parameters. The patients' ages ranged from 23 to 77 years. The laryngeal exposure score was correlated with the Cormack-Lehane score (p < .001, r = 0.469). Of all parameters, body mass index, neck circumference, thyroid-mental distance, and horizontal thyroid-mental distance showed significant correlation with the laryngeal exposure score (p < .05). From analysis of the candidate parameters in 13 patients with DLE and the non-DLE group, we found that the cutoff values for predicting DLE were a body mass index of > 25.0 kg/m2, a neck circumference of > 39.5 cm, a thyroid-mental distance of < 5.5 cm, and a horizontal thyroid-mental distance of < 4.0 cm. According to the proposed classification of laryngeal exposure, patients with obesity, a muscular neck, or retrognathia are likely to present DLE, and preoperative measurement of the predictors may be useful in preparing for microlaryngosurgery.

Risk Factors Assessment of the Difficult Airway: An Italian Survey of 1956 Patients

Over the last decade, there has been a heightened awareness and an increase in the amount of literature being published on recognition and prediction of the difficult airway. During the preoperative evaluation of the airway, a thorough history and physical specifically related to the airway should be performed. Various measurements of anatomic features and noninvasive clinical tests can be performed to enhance this assessment. In this study we correlated the Mallampati modified score and several other indexes with the laryngoscopic view to identify anatomical and clinical risk factors related to the difficult airway. We prospectively collected data on 1956 consecutive patients scheduled to receive general anesthesia requiring endotracheal intubation for elective surgery. The Mallampati classification versus the Cormack-Lehane (C-L) linear correlation index was 0.904. A Mallampati Class 3 correlated with a C-L Grade 2 (0.94), whereas a Mallampati Class 4 correlated with a C-L Grade 3 (0.85) and a C-L Grade 4 (0.80). Operator evaluation, performed by a simplified tracheal intubation difficulty scale, showed a linear correlation of 0.96 compared with the C-L groups. Although there is a correlation between oropharyngeal volume and difficult intubation, the Mallampati score by itself is insufficient for predicting difficult endotracheal intubation.

The modified Cormack-Lehane score for the grading of direct laryngoscopy: evaluation in the Asian population.

The use of a modified Cormack-Lehane scoring system (MCLS) of laryngoscopic views, as previously introduced in the Western population, was investigated during direct laryngoscopy in the Asian population. We studied the distribution of the different grades of MCLS, the predictive factors and rate of difficult laryngoscopy, and the association with difficult intubation. Six hundred and five patients requiring tracheal intubation during general anaesthesia were prospectively studied. The optimal views during direct laryngoscopy were scored using the 5-grade MCLS system. The distribution of the laryngoscopy scores was 73.9% Grade 1 (full view of the vocal cords), 21.0% Grade 2A (partial view of the vocal cords), 3.3% Grade 2B (only the arytenoids and epiglottis seen), 1.6% Grade 3 (only epiglottis visible) and 0.2% Grade 4 (neither the epiglottis nor glottis seen). External laryngeal pressure was necessary in 45.3% of cases to optimize laryngoscopic views. Grade 2B was associated with significantly higher incidence of difficult intubation compared with Grade 2A (65% vs 13.4%). The rates of difficult laryngoscopy and intubation were 5.1% and 6.9% respectively. The Mallampati classification and thyromental distance were associated with low predictive value for difficult laryngoscopy. The MCLS better delineates the difficulty experienced during laryngoscopy than the original Cormack-Lehane grading

IS ULTRASONIC INVESTIGATION REASONABLE FOR EVALUATION OF DIFFICULT AIRWAY IN PREGNANT WOMEN

Objective: The aim of this study was to compare clinical screening tests (modified Mallampati score, Cormack-Lehane score, thyromental distance, and sternomental distance) with ultrasonic measurements of the upper airway in predicting difficult intubation in pregnant women whose Body Mass Index (BMI) is higher and lower than 30 kg m-2. Methods: This study was designed as a prospective observational trial, and consisted of 40 pregnant women of American Society of Anesthesiologists (ASA) 1-2 groups. Patients with a BMI lower than 30 kg m-2 were included in Group 1 (n=20), and patients with a BMI higher than 30 kg m-2 were included in Group 2 (n=20). In the supine position with head in mild extension, the diameter of the transverse tracheal air shadow in the subglottic area of the front neck was measured using ultrasonography. Modified Mallampati score, Cormack-Lehane score, thyromental distance and sternomental distance measurements were recorded. Results: No statistically significant difference was detected between groups regarding mean age, mean number of pregnancy, ASA scores and comorbid disease. Mean body weight (p=0.0001) and mean pre-pregnancy weight (p=0.0001) were significantly higher in Group 2. There was no statistically significant difference between groups regarding mean modified Mallampati score, thyromental distance, sternomental distance measurements, Cormack-Lehane score, and mean ultrasonic measurements. Conclusion: It was found that BMI higher or lower than 30 kg m-2 has no effect on ultrasonic measurements and clinical airway tests. We thought that ultrasonic measurement could not give us valuable information in obese or non-obese pregnant women.