Avaliação do Escore de Wilson e do Teste de Mallampati modificado como preditores de difícil intubação orotraqueal: Estudo transversal / Evaluation of the Wilson risk-sum and the modified Mallampati Test as predictors of difficult orotracheal intubation: Cross-sectional study

INTRODUÇÃO: A consulta pré-anestésica é de extrema importância para o médico anestesiologista no planejamento do manejo das vias aéreas de pacientes sob o efeito de anestesia geral com intubação orotraqueal (IOT). OBJETIVO: Avaliar a sensibilidade, especificidade, valor preditivo positivo/negativo (VPP/VPN) de testes de predição de IOT difícil (Escore de Wilson - EW, e Teste de Mallampati modificado - TMM), em pacientes submetidos à anestesia geral, em hospital filantrópico do interior de Minas Gerais. MATERIAIS E MÉTODOS: Estudo descritivo transversal, por meio de fichas pré-anestésicas e transoperatórias, de pacientes submetidos à anestesia geral com IOT, entre os meses de janeiro (2019) e março (2020). RESULTADOS: Dos 440 pacientes, 56,1% necessitaram de IOT: média de idade de 49,9 anos (desvio padrão 18,6). A maioria foi classificada: TMM classe I e II; pontuação 0 a 2 no EW; distância esternomentoniana >12,5 cm, sugerindo IOT fácil. Apenas o TMM apresentou correlação com IOT difícil (p=0,045). Sensibilidade e especificidade dos testes respectivamente: TMM (54,6%;75,9%); EW (36,4% e 79,7%); baixo VPP (TMM: 9,5%; EW: 7,7%) e alto VPN (TMM: 97,3%; EW: 96,4%). Curva ROC: área sob a curva foi de TMM = 0,68; EW = 0,60. CONCLUSÃO: Apesar do TMM apresentar correlação significativa com a IOT difícil, não foi possível definir o melhor teste preditor. Ressaltamos que a sensibilidade e o VPP, de ambas as avaliações, ficaram abaixo daquilo que seria considerado adequado para um teste de rastreio e predição.

Introduction: A pre-anesthetic appointment is extremely important for the anesthesiologist when planning the management of the airways of patients under the effect of general anesthesia with orotracheal intubation (OTI). Objective: To evaluate the sensitivity, specificity, positive/ negative predictive value (PPV/NPV) of difficult OTI prediction tests (Wilson risk-sum ­ WRS, and Modified Mallampati Test - MMT) in patients undergoing general anesthesia in a philanthropic hospital in the countryside of the state of Minas Gerais. Materials and methods: Descriptive cross-sectional study using pre-anesthetic and transoperative records of patients submitted to general anesthesia with OTI between the months of January (2019) and March (2020). Results: Of the 440 patients, 56.1% required OTI: average age of 49.9 years (standard deviation 18.6). Most classified: MMT class I and II; score 0 to 2 on the WRS; sternomental distance greater than 12.5 cm, suggesting easy OTI. Only MMT showed statistical significance with difficult OTI (p=0.045). Sensitivity and specificity of the tests respectively: MMT (54.6%; 75.9%) WRS (36.4% and 79.7%) low PPV (MMT: 9.5%; WRS: 7.7%) and high NPV (MMT: 97.3%; WRS: 96.4%). ROC Curve: area under the curve was MMT = 0,68; WRS = 0,60. Conclusion: Although the MMT has a significant correlation with the difficult OTI, it was not possible to define the best predictor test. We emphasize that the sensitivity and PPV of both evaluations were below what would be considered adequate for a screening and prediction test.

Evaluation of difficult airway in paediatric population ranging from 5-12 years age group

Background: The aim of this study is to predict difficult airway on the basis of various airway assessment parameter in the paediatric population between 5-12 years age group. To assess the value of modified Mallampati test (MMT), upper-lip-bite test (ULBT), thyromental distance (TMD), ratio of height to thyromental distance (RHTMD) from which Cormack Lehane grade was derived to predict difficult airway i.e. difficult intubation in paediatric patients ranging from 5-12 years age. Material and Methods: 100 ASA grade I & II paediatric patients of either sex between the age group of 5-12 years posted for elective surgery under general anaesthesia requiring endotracheal intubation were included in the study. Modified Mallampati test, upper lip bite test, thyromental distance and ratio of height to thyromental distance of the patients were measured and recorded. All the distances were measured with the help of a flexible measuring tape so as to measure the distances accurately. Results: Modified Mallampati test has the highest sensitivity (75%) and specificity (92.05%) among all the other screening tests. It also has high positive predictive value (56.25%), negative predictive value (96.43%) and diagnostic accuracy (90%). Upper Lip Bite test has high specificity (79.55%) and negative predictive value (93.33%) with high diagnostic accuracy (77%). It has a sensitivity of 58.33% which is similar to the sensitivity of thyromental distance and ratio of height to thyromental distance. Thyromental distance has high specificity (65.90%) with high negative predictive value (92.06%). Conclusion: Modified Mallampati test is a useful bedside screening test for predicting difficult intubation in patients between 5-12 years age group. The Upper Lip bite test and thyromental distance has high specificity with high negative predictive value and diagnostic accuracy. The ratio of height to thyromental distance is least useful predictor of airway assessment.

Evaluation of Modified Mallampati Score with Neck Circumference and Thyromental Distance to Predict Difficult Intubation in Non-obese Patients

Introduction: Preoperative diagnostic validity of airwayassessment help for prediction of difficult airway. Severalmodels were established for prediction of difficult intubation.In this study, we aim to predict difficult intubation in nonobese patients from various airway predictive indices suchas modified mallampati grade, neck movement (NM), neckcircumference (NC), thyrometal distance (TM), NC/TMD.Material and Methods: Total 121 patients with 18-72 yearsof age, ASA grade I or II, scheduled for elective surgerythat required general anaesthesia. Difficulty of intubationwas assessed using the IDS for each non-obese patient. Thestudy population was divided into two groups Easy (IDS <5)and Difficult intubation (IDS ≥5). Preoperative assessmentsincluded Mouth Opening (MO), modified mallampati grade,neck movement (NM), neck circumference (NC), thyrometaldistance (TM), NC/TMD. Multivariate analysis was usedto predict independent risk factors. Receiver OperatingCharacteristic Curve analysis (ROC analysis) was performedfor the airway assessment tests. The area under curve (AUC)was calculated.Results: The weight (59.74±7.76 kg and 65.00±5.92 kg)and BMI (21.51±1.79 and 23.8157±1.09) were significantlydifferent in between easy and difficult intubation. TheMouth Opening, NC, TMD, and NC/TMD were significantlyindependent risk factor for difficult intubation. NC/TMDwas showed higher sensitivity, specificity, positive predictivevalue (PPV) and a negative predictive value (NPV) with thirdlarge area under the curve (AUC) on the ROC curve.Conclusions: This study shows that the NC/TMD ratio canbe considered as a better predictor of difficult intubation innon-obese patients.

Difficult laryngoscopy and tracheal intubation: observational study / Dificuldade na laringoscopia e na intubação orotraqueal: estudo observacional

Abstract Introduction: Since anesthesia complications associated with unexpected difficult airway are potentially catastrophic, they should be avoided. The modified Mallampati test and jaw-thrust maneuver enable the identification of difficult airway. The aim of this study was to associate the modified Mallampati test and the jaw-thrust maneuver with laryngoscopy (Cormack-Lehane) in an attempt to identify a better predictor of difficult airway in an adult population undergoing elective surgery. Method: A cross-sectional study in which 133 adult patients undergoing elective surgery requiring tracheal intubation were analyzed. The accuracy and specificity of the modified Mallampati test and jaw-thrust maneuver were assessed by correlating them with difficult laryngoscopy (Cormack-Lehane Degrees 3 and 4). Results: In the 133 patients evaluated the difficult intubation rate found was 0.8%; there was association between the two predictive tests proposed (p = 0.012). The values of 94.5% for specificity and 95.4% for accuracy were found for the jaw-thrust maneuver and for the modified Mallampati test, the values found were 81.1% and 81.2%, respectively. Kappa agreement identified a result of 0.240 between jaw-thrust maneuver and Cormack-Lehane, which was considered reasonable. On the other hand, a poor agreement (κ = 0.06) was seen between modified Mallampati test and Cormack-Lehane test. Conclusion: The jaw-thrust maneuver presented superior accuracy and agreement than the modified Mallampati test, showing the ability to identify a difficult airway. It is necessary to emphasize the association of tests in the evaluation of patients, emphasizing their complementarity to minimize the negative consequences of repeated laryngoscopies.

Resumo Introdução: As complicações anestésicas associadas às vias aéreas difíceis inesperadas por serem potencialmente catastróficas devem ser evitadas. O teste de Mallampati modificado e a manobra de protrusão mandibular possibilitam a identificação da via aérea difícil. O objetivo deste estudo foi associar o teste de Mallampati modificado e a manobra de protrusão mandibular com a laringoscopia (Cormack-Lehane) e tentar identificar um melhor preditor de via aérea difícil na população adulta submetida à cirurgia eletiva. Método: Estudo corte transversal, foram analisados 133 pacientes adultos submetidos a cirurgias eletivas que necessitavam de intubação orotraqueal. Avaliaram-se a acurácia e especificidade do teste de Mallampati modificado e da manobra de protrusão mandibular, correlacionados com laringoscopia difícil (Cormack-Lehane Graus 3 e 4). Resultados: Entre os 133 pacientes avaliados, a taxa de intubação difícil encontrada foi 0,8%, houve associação entre os dois testes preditores propostos (p = 0,012). Foram encontrados os seguintes valores para a especificidade 94,5% e a acurácia 95,4% na manobra de protrusão mandibular. Já para o teste de Mallampati modificado valores de 81,1% e de 81,2% respectivamente. A análise de concordância Kappa identificou entre manobra de protrusão mandibular e Cormarck-Lehane um resultado de 0,240; considerado razoável. Por outro lado, observou-se uma fraca (κ = 0,06) concordância entre o teste de Mallampati modificado e o Cormarck-Lehane. Conclusão: A manobra de protrusão mandibular apresentou acurácia e concordância superiores ao teste de Mallampati modificado, mostrou a capacidade de identificar uma via aérea difícil. Faz-se necessário enfatizar a associação dos testes na avaliação do paciente, destacar a complementariedade deles, minimizar as consequências negativas de laringoscopias repetidas.

Comparison and evaluation of various bedside tests to predict difficult endotracheal intubation.

Introduction: As difficult laryngoscopy is a multifactorial problem, therefore any preoperative assessment of difficult tracheal intubation should have high sensitivity and specificity and result in minimal false positive and false negative values. This study was conducted in an attempt to devise a method of predicting difficult intubation and to assess the reliability of six simple bedside tests to predict difficult intubation. Material and Methods: This double blind prospective study involved 100 adult patients posted for elective surgery under general anesthesia. The airways were assessed for modified Mallampati test, Thyromental Distance, Sternomental Distance, Inter incisor gap; Atlanto-Occipital joint extension and Upper Lip bite Test. The laryngoscopic view and difficulty of intubation were noted. The sensitivity, specificity, positive and negative predictive values were calculated. Results: No method either individual or in combination with others had 100% sensitivity. The Modified Mallampati test had 76% sensitivity. Upper Lip bite Test had 98.66% specificity. The combination of Modified Mallampati test and Inter incisor gap had 52% sensitivity and 86.66% specificity. Conclusion: The “composite intubation difficulty score” is an easy and reliable method of predicting difficult intubation.

Modified Mallampati Test, Thyromental Distance and Hyomental Distance for Accurately Predicting Difficult Visualization of the Larynx.

Background: This study has been done to compare Hyomental distance with the modified Mallampati test, Thyromental distance for accurately predicting difficult visualization of the larynx in apparently normal patients’. Methods: 198 apparently normal patients of > 18 years of age, with ASA 1 and 2, undergoing general anaesthesia with tracheal intubation were evaluated. A hard-plastic bond ruler is used to measure the distance. After induction and paralysis using glottic visualisation was assessed by using modified Cormach and Lehane classification with no external laryngeal manipulation. Results: The highest sensitivity of 44.44 % was observed in predicting difficult visualization of the larynx with modified Mallampati followed by TMD 11.11 % and HMD 11.11 % (2/18). Conclusion: An optimal combination of tests that includes the HMD,MMT,TMD and other predictors and performing the tests in combination for predicting Difficult Laryngoscopy, rather than using it alone.

Prediction of Difficulty in Endotracheal Intubation in Patients with Obstructive Sleep Apnea: Comparison of Modified Mallampati Test and Upper Lip Bite Test / 대한마취과학회지

BACKGROUND: Patients with obstructive sleep apnea (OSA) may exhibit difficult endotracheal intubation and mask ventilation because of anatomical abnormalities of their upper airway. Many anesthesiologists try to predict difficult endotracheal intubation using simple bedside screening tests. Among these tests, modified Mallampati test (MMT) is the most popular one, but a newer method, called upper lip bite test (ULBT) has been investigated. We compared the clinical accuracy of modified Mallampati test and upper lip bite test for patients with OSA. METHODS: 65 patients with OSA were included in the study. Preoperatively, anestheiologist not involved in endotracheal intubation evaluated patient's airway with MMT and ULBT. Another anesthesiologist assessed the direct laryngoscopic grade. Using Fisher's exact test, we analyzed the correlation of MMT and ULBT with direct laryngoscopic grade and calculated the sensitivity, specificity, positive predictive value and negative predictive value. Furthermore, AUC of ROC (area under a receiver operating characteristic) curve were used to estimate the predictive accuracy of each tests. RESULTS: MMT grade III, IV and ULBT class III was significantly correlated with Cormack-Lehane grade III, IV (P < 0.05). The ULBT showed higher specificity and positive predictive value, but sensitivity and negative predictive value were higher in MMT. AUC of ROC curve was poor for MMT (0.656) and ULBT (0.617). CONCLUSIONS: These results suggest that MMT and ULBT has a poor diagnostic accuracy for predicting difficult intubation in OSA patients as a single bedside screening test.