A lexicon for endoscopic adverse events: report of an ASGE workshop.

National High Blood Pressure Education Program.

This is a retrospective study of patients whose tracheas were impossible to intubate on a previous occasion. There is a correlation between the degree of difficulty and the anatomy of the oropharynx in the same patient. The study was initially on obstetric patients but was extended to nonobstetric surgical patients in order to increase the number of cases investigated. The incidence of failed intubations in the obstetric group over a 3-year period was seven out of 1980 cases, whereas in the surgical group the results were six out of 13,380 patients. Any screening test which adds to our ability to predict difficulty in intubation must be welcomed, as failure to intubate can potentially lead to fatality.

https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2044.1987.tb04039.x

Difficult tracheal intubation: a retrospective study

The objective of this study was to systematically determine the diagnostic accuracy of bedside tests for predicting difficult intubation in patients with no airway pathology. Thirty-five studies (50,760 patients) were selected from electronic databases. The overall incidence of difficult intubation was 5.8% (95% confidence interval, 4.5‐7.5%). Screening tests included the Mallampati oropharyngeal classification, thyromental distance, sternomental distance, mouth opening, and Wilson risk score. Each test yielded poor to moderate sensitivity (20‐62%) and moderate to fair specificity (82‐97%). The most useful bedside test for prediction was found to be a combination of the Mallampati classification and thyromental distance (positive likelihood ratio, 9.9; 95% confidence interval, 3.1‐31.9). Currently available screening tests for difficult intubation have only poor to moderate discriminative power when used alone. Combinations of tests add some incremental diagnostic value in comparison to the value of each test alone. The clinical value of bedside screening tests for predicting difficult intubation remains limited.

/pdf/predicting-difficult-intubation-in-apparently-normal-1kor8ihpxe.pdf

Predicting difficult intubation in apparently normal patients: a meta-analysis of bedside screening test performance.

Background:A quantitative scale of intubation difficulty would be useful for objectively comparing the complexity of endotracheal intubations. The authors have developed a quantitative score that can be used to evaluate intubating conditions and techniques with the aim of determining the relative va

The intubation difficulty scale (IDS): proposal and evaluation of a new score characterizing the complexity of endotracheal intubation.

It has been suggested that the size of the base of the tongue is an important factor determining the degree of difficulty of direct laryngoscopy. A relatively simple grading system which involves preoperative ability to visualize the faucial pillars, soft palate and base of uvula was designed as a means of predicting the degree of difficulty in laryngeal exposure. The system was evaluated in 210 patients. The degree of difficulty in visualizing these three structures was an accurate predictor of difficulty with direct laryngoscopy (p less than 0.001).

/pdf/a-clinical-sign-to-predict-difficult-tracheal-intubation-a-3shggw1jw9.pdf

Barbara Waraksa

Papers

A clinical sign to predict difficult tracheal intubation: a prospective study