如何预测困难气管插管

如何预测困难气管插管?How to Predict Difficult Intubation,四川大学华西医院麻醉科,Trouble with Airway Definition,Tests to determine difficult intubation are for laryngoscopy and may not apply to all devicesDifficult intubation vs Difficult laryngoscopyMay not see cords yet be able to intubationMay see cords and not be able to intubation,Cormack & Lehane 喉镜暴露分级,未预计的困难气管插管对麻醉医生是一种挑战。 是否可以通过简单的床旁体检来预测困难气管插管？,LEMON 法则 Look externally. Evaluate the 3-3-2 rule. Mallampati. Obstruction? Neck mobility.,Look Externally（外观检查）,肥胖（Obesity）颈短粗（Short bull neck）高腭弓（High arching palate）上门牙突出（Prominent Upper Incisors，Buck Teeth）小下颌（Receding mandible，Dentures）无牙（Edentulous mouth）面部畸形（Abnormal facial shape）面部创伤（Facial trauma）,Evaluate the 3-3-2 rule（3-3-2法则）,3 fingers between the patients teeth (patients mouth should open adequately to permit three fingers to be placed between the upper and lower teeth)3 fingers between the tip of the jaw and the beginning of the neck (under the chin)2 fingers between the thyroid notch and the floor of the mandible (top of the neck),改良Mallampati分级,Obstruction?（是否存在梗阻因素）,肿瘤脓肿血肿会厌炎甲状腺肿大,Neck Mobility（颈椎活动度）,气道评估指标,Anesthesiology 2003;98:1269-77.,Wilson Index（Wilson 指数）,Br J Anaesth 1988;61:211-6.,两个距离指标,甲-颏距离 6 cm胸-甲距离 12.5 cm,困难气管插管的解剖机制,Eur J Anaesthesiol 2001;18:3-12.,如何评估困难气管插管预测指标,Upper Lip Bite Test（咬上嘴唇试验）,A, Class I; lower incisors reflecting a bite of the upper lip, making its mucosa entirely invisible. B, Class II; lower incisors half-biting the upper lip, making the mucosa partially invisible. C, Class III; lower incisors attempting a bite but totally failing to catch the upper lip.,Anesth Analg 2003;96:595-9.,Anesth Analg 2003;96:595-9.,The upper lip bite test is an acceptable option for predicting difficult intubation as a simple, single test.,Anesth Analg 2005;101:284-9.,Both tests are poor predictors as single screening tests.,The specificity and accuracy of the ULBT is significantly higher than the other tests and is more accurate in airway assessment.However, the ULBT in conjunction with the other tests could more reliably predict easy laryngoscopy or intubation.,Comparison of two methods for predicting difficult intubation in obstetric patients,Comparing modified Mallampati test with Wilson risk sum score in 372 obstetric patientsMallampati class III or IV predicted 15 of the 23 patients while Wilson risk sum score or = 2 predicted 9 of the 14 patients in whom tracheal intubation was difficult.,Middle East J Anesthesiol. 2003 Jun;17(2):275-85.,Protrusion of the Mandible（下颌前突）,Predictive value for Mallampati score, thyromental distance, sternomental distance and protrusion of the mandible as predictors of difficult intubation,Br J Anaesth 1994;73:149-53.,Test Sensitivity(%) Specificity(%) Positive predictive value(%) Mallampati score 64.7 66.1 8.9 (grade III or IV) (38.3-85.6) (61.0-71.2) (3.9-13.9)Thyromental distance 64.7 81.4 15.1 (6.5 cm) (38.3-85.6) (77.2-85.6) (7.8-25.4)Sternomental distance 82.4 88.6 26.9 (12.5 cm) (56.6-96.2) (85.2-92.0) (15.6-41.0)Protrusion of mandible 29.4 85.0 9.1 (position B or C) (10.3-56.0) (81.2-88.8) (3.0-20.0),Can J Anesth 2005;52(3): 291296.,Forty-two studies enrolling 34,513 patients were included. For predicting difficult laryngoscopy, both versions of the Mallampati test had good accuracy. For predicting difficult intubation, the modified Mallampati test had good accuracy. Used alone, the Mallampati tests have limited accuracy for predicting the difficult airway and thus are not useful screening tests.,Anesth Analg. 2006;102(6):1867-78.,Thirty-five studies (50,760 patients) The most useful be