Criteria for Estimating Likelihood of Difficulty of Endotracheal Intubation with the Macintosh Laryngoscope

Abstract

Many anatomical factors in difficult intubation at direct laryngoscopy have been evaluated. Lateral radiographs were taken of nineteen patients in whom tracheal intubation proved particularly difficult, and fourteen patients whose intubation was reasonably straightforward. Step wise discriminant analysis was used to select the best measurements for distinguishing between the difficult and straightforward groups. The variables which together are most reliable in predicting likely difficulty in intubation are reduced atlanto-occipital extension, reduced mandibular space, and lastly, increased antero-posterior thickness of the tongue. Aformula and graph have been derived to relate these variables with likelihood of difficulty, and a method has been described of applying this information at the bedside, without using X-ray examination, to estimate the likelihood of difficulty in intubating a new patient. Eighteen months' experience of the application of this clinical evaluation have so far found it reliable.

Difficult intubation in paediatrics

“…Reduced head extension, reduced mandibular space and increased anteroposterior tongue thickness, taken together, predicted difficult intubation with a high probability (4). These three variables also have predictive value in paediatric patients as they are compatible with some of the well known clinical features of difficult intubation.…”

“…Lateral neck radiograms or CAT scan may be helpful in delineating the anatomical changes in specific lesions (4,9,10).…”

Self-reported changes in attitude and behavior after attending a simulation-aided airway management course

“…For malignant hyperthermia, which has an incidence significantly lower than a cannot intubate-cannot ventilate situation (approximately 1:10 000 patients) [25][26][27][28], each anesthesia department in Germany must provide an adequate supply of dantrolene (Practice Guideline of the German Society for Anaesthesiology and Intensive Care Medicine, 2002). In contrast, a recent survey by Goldmann and Braun [29] showed that 36% of German university and university-affiliated teaching hospitals do not provide any difficult airway carts.…”

Laryngeal tube S II, ProSeal laryngeal mask, and EasyTube during elective surgery: a randomized controlled comparison with the endotracheal tube in nontrained professionals

“…Patients were excluded if they had morbid obesity (BMI >30 kg m À2 ), any disease of the neck, upper respiratory tract, or upper alimentary tract, if they were at increased risk of pulmonary aspiration of gastric contents, or if a difficult airway was previously known. Preoperatively, reclination of the head (according to Bellhouse and Dore [13]), the thyromental distance described by Patil et al [14], and the view of the oropharynx on mouth opening described by Mallampati et al [15] and modified by Samsoon and Young [16] were scored.…”