Coma of vascular aetiology: evaluation and prognosis

Clinimetric study and review of the Reaction Level Scale

OBJECTIVES

Although the Reaction Level Scale (RLS) is still used for the assessment of the level of consciousness in distinct centers, its clinical characteristics and significance have been incompletely researched. In the current study, the clinimetric properties, the prognostic value, and the impact of the raters' background on the application of the RLS, in comparison with the Glasgow Coma Scale (GCS), are investigated.

MATERIALS AND METHODS

A systematic review on the available clinical evidence for the RLS was first carried out. Next, the RLS was translated into Greek, and patients with neurosurgical pathologies in need of consciousness monitoring were independently assessed with both RLS and GCS, by four raters (two consultants, one resident, and one nurse) within one hour. Interrater reliability, construct validity, and predictive value (mortality and poor outcome, at discharge and at 6 months) were evaluated.

RESULTS

Literature review retrieved 9 clinimetric studies related to the RLS, most of low quality, indicating that the scale has not been thoroughly studied. Both versions of the RLS (original and modified) showed high interrater reliability (κ_w >0.80 for all pairs of raters), construct validity (Spearman's p > .90 for all raters), and prognostic value (areas under the curve >0.85 for all raters and outcomes). However, except for broader patients' coverage, it failed to show any advantage over the GCS.

CONCLUSIONS

The RLS has not succeeded in showing any advantage over the GCS in terms of reliability and validity. Available evidence cannot justify its use in clinical practice as a substitute to the widely applied GCS.

Evaluation of coma: a critical appraisal of popular scoring systems

Numerous scoring scales have been proposed and validated to evaluate coma for rapid pre-hospital assessment and triage, disease severity, and prognosis for morbidity and mortality. These scoring systems have been predicated on core features that serve as a basis for this review and include ease of use, inter-rater reliability, reproducibility, and predictive value. Here we review the benefits and limitations of the most popular coma scoring systems. The methods include search of Medline, databases, and manual review of article bibliographies. Few of the many available coma scales have gained widespread approval and popularity. The best known and widely accepted scale is the Glasgow Coma Scale (GCS). The Reaction Level Scale (RLS85) has utility and proven benefit, but little acceptance outside of Scandinavia. The newer Full Outline of UnResponsiveness (FOUR) score provides an attractive replacement for all patients with fluctuating levels of consciousness and is gradually gaining wide acceptance.