Evaluation of consciousness: the FOUR scale or the Glasgow coma scale? Review

Abstract

Assessing the level of consciousness is one of the key competencies of medical workers involved in the provision of emergency care. For 45 years, the Glasgow Coma Scale has been used for this, which has the highest level of interdisciplinary consistency and reproducibility, for which it was recognized as the gold standard for assessing consciousness when patients are admitted to the intensive care unit. But along with the advantage of simplicity and extensive experience in application, it has a number of significant drawbacks. In particular, the impossibility of verbal contact in intubated patients, the presence of motor aphasia and delirium deliberately reduces the score in the speech section, which is fraught with an underestimation of the overall assessment of the level of consciousness. It is also significant that GCS does not evaluate brain stem reflexes, eye movements, or complex motor reactions, which excludes the possibility of a reliable assessment of the condition of a patient with subtentorial damage and in a state of chronic impaired consciousness. As our own experience and preliminary analysis of the literature showed, these shortcomings are absent in the Full Outline of UnResponsiveness (FOUR) scale developed by FM Wijdicks at the Mayo Clinic in 2005. The spread of the FOUR scale in many countries and the growing need for effective monitoring of patients with acute cerebral injury motivated Federation of anesthesiologists of Russia (FAR) to initiate a multicenter study. The purpose of the study: validation, assessment of reproducibility and consistency of the results of using the Russian-language version of the FOUR scale for multidisciplinary use in patients with impaired consciousness. Prospective cohort nonrandomized study is completed at three centers that routinely use this scale in their practice for several years (“FOUR-Rus” NCT04018989 ClinicalTrials.gov).