The Intubation Difficulty Scale (IDS)

Abstract

Difficult tracheal intubation can be a major source of morbidity and mortality in clinical practice, particularly in emergency situations. The complexity of intubation is often referred to in the literature, but unfortunately, no uniform method of description of the “difficult intubation” exists. Because of the lack of a standard definition of difficult intubation, the incidence and factors associated with difficult intubation vary drastically from one institution or time period to another and are virtually impossible to compare directly. [1–3 ] An objective scoring system might serve as reproducible quantitative means of overcoming some of these limitations. We thus propose an Intubation Difficulty Scale (IDS) score, which is a function of seven parameters, resulting in a progressive, quantitative determination of intubation complexity. This score may be calculated by the operator or an independent observer immediately after intubation. The score might then be used to compare difficulty of intubation under varying circumstances by isolating variables of interest. It was with this objective in mind that we undertook a prospective study to evaluate the IDS score in varying clinical situations, comparing it with previously described evaluation tools.