THE INTUBATION DIFFICULTY SCALE (IDS) - PROPOSAL AND EVALUATION OF A NEW SCORE CHARACTERIZING THE COMPLEXITY OF ENDOTRACHEAL INTUBATION

Background: A quantitative scale of intubation difficulty would be use ful for objectively comparing the complexity of endotracheal intubatio ns. The authors have developed a quantitative score that can be used t o evaluate intubating conditions and techniques with the aim of determ ining the relative values of predictive factors of intubation difficul ty and of the techniques used to decrease such difficulties. Methods: An Intubation Difficulty Scale (IDS) was developed, based on parameter s known to be associated with difficult intubation. It was then evalua ted prospectively in a group of 311 consecutive prehospital intubation s and 315 intubations in an operating room, In the operating room, the IDS was compared with two other parameters: the time to completion of intubation and the visual analog scale (VAS). Time was measured by an independent observer. Operators in both groups completed a checklist regarding the conditions of intubation. Results: There is a food corre lation between the IDS scale and tile VAS assessment of difficulty and time to completion of intubation. VAS and time to completion have a s ignificant but lesser correlation to each other, Comparison of IDS wit h operator-assessed subjective categorical impression of difficulty by Kruskall-Wallis was statistically significant, Conclusions: The TDS c orrelates with but is less subjective than the VAS and categorical cla ssification. IDS correlates with time to intubation, but it offers det ails regarding the difficulty encountered that time alone does not. Th is score may not only aid in evaluation of factors linked to difficult intubations, but it may provide a uniform approach to comparing studi es related to this subject.