Copyright © European Society of Anaesthesiology. Unauthorized reproduction of this article is prohibited. The Simplified Predictive Intubation Difficulty Score: a new weighted score for difficult airway assessment Joe ¨ l L’Hermite a,b , Emmanuel Nouvellon a,b , Philippe Cuvillon a,b , Pascale Fabbro-Peray a,c , Olivier Langeron d and Jacques Ripart a,b Background and objective Using the Intubation Difficulty Scale (IDS) more than 5 as a standardized definition of difficult intubation, we propose a new score to predict difficult intubation: the Simplified Predictive Intubation Difficulty Score (SPIDS). Methods We prospectively studied 1024 patients scheduled for elective surgery under general anaesthesia. Using bivariate and multivariable analysis, we established risk factors of difficult intubation. Then, we assigned point values to each of the adjusted risk factors, their sum composing the SPIDS. We assessed its predictive accuracy using sensitivity, specificity, positive (PPV) and negative predictive values (NPV), and the area under the receiver operating characteristic (ROC) curve (AUC), and compared it with the corresponding nonweighted score. The optimal predictive level of the SPIDS was determined using ROC curve analysis. Results We found five adjusted risk factors for IDS more than 5: pathological conditions associated with difficult intubation (malformation of the face, acromegaly, cervical rheumatism, tumours of the airway, and diabetes mellitus), mouth opening less than 3.5 cm, a ratio of patient’s height to thyromental distance 25 at least, head and neck movement less than 80-, and Mallampati 2 at least. Sensitivity, specificity, PPV and NPV of the SPIDS were 65, 76, 14 and 97%, respectively. AUC of the SPIDS and the nonweighted score (obtained previously using a stepwise logistic regression) were respectively 0.78 [95% confidence interval (CI) 0.72–0.84] and 0.69 (95% CI 0.64–0.73). The threshold for an optimal predictive level of the SPIDS was above 10 of 55. Conclusion The SPIDS seems easy to perform, and by weighting risk factors of difficult intubation, it could help anaesthesiologists to plan a difficult airway management strategy. A value of SPIDS strictly above 10 could encourage the anaesthesiologists to plan for the beginning of the anaesthetic induction with ‘alternative’ airway devices ready in the operating theatre. Eur J Anaesthesiol 26:1003–1009 Q 2009 European Society of Anaesthesiology. European Journal of Anaesthesiology 2009, 26:1003–1009 Keywords: anaesthesia, assessment, difficult airway, general, intubation, preanaesthetic a Faculte ´ de Me ´ decine, Universite ´ Montpellier I, Montpellier, b Division Anesthe ´ sie Re ´ animation Douleur Urgences, Groupe Hospitalo-Universitaire Caremeau, Nı ˆmes, c Biostatistique Epide ´ miologie Clinique Sante ´ Publique et Information Me ´ dicale (BESPIM), Groupe Hospitalo-Universitaire Caremeau, Nı ˆmes and d De ´ partement d’Anesthe ´ sie Re ´ animation, Centre Hospitalier Universitaire Pitie ´- Salpe ˆ trie ` re, Assistance Publique-Ho ˆ pitaux de Paris, Universite ´ Pierre et Marie Curie, Paris, France Correspondence to Dr Joe ¨ l L’Hermite, MD, Division Anesthe ´ sie Re ´ animation Douleur Urgences, Groupe Hospitalo-Universitaire Caremeau, Place du professeur Debre ´ , 30029 Nı ˆmes, Cedex 09, France Tel: +33 4 66 68 30 50; fax: +33 4 66 68 38 51; e-mail: joel.lhermite@chu-nimes.fr Received 26 January 2009 Revised 18 May 2009 Accepted 19 May 2009 Introduction Difficult tracheal intubation remains a relatively constant and significant source of morbidity and mortality in anaesthetic practice [1,2]. Airway management must still remain a matter of great concern for the anaesthesiologist [3]. During the preanaesthesia visit, anaesthesiologists have to estimate the risk of difficult intubation, to finally anticipate a difficult airway management strategy includ- ing ‘alternative’ airway devices [4,5]. Preoperative detec- tion of patients at risk for difficult intubation is, therefore, the first step in airway management. Many risk factors have already been identified, some models validated [6– 9], and associated guidelines have been established [4,5]. Despite these recommendations, insufficient or lack of airway assessment in the preoperative period continues to be a major cause of unanticipated difficult intubation [10]. Some explanations can be proposed preoperative airway evaluation is not always regarded as standard procedure [10,11], and the current predictive index is probably too complex to implement because the risk index is impossible to calculate without a pocket calcu- lator [8,9]. Practice guidelines for management of the difficult airway reported by the American Society of Anaesthesiologists advise that ‘multiple airway features should be assessed’ [4]. Nevertheless, the respective weight of each risk factor is unclear and has been rarely studied [9]. So, even keeping to guideline recommen- dations, it is not always easy for a practitioner, not expert on airway management, to anticipate judiciously a strategy, namely: when must the practitioner go into the operating theatre with, or without, a portable storage unit for difficult airway management? Original article 1003 0265-0215 ß 2009 Copyright European Society of Anaesthesiology DOI:10.1097/EJA.0b013e32832efc71