Association of Glasgow Coma Scale with Delayed Neuropsychiatric Sequelae in Carbon Monoxide Poisoning: A Systematic Review

Background: Delayed neurological sequelae (DNS) are a significant complication of acute carbon monoxide poisoning (COP). The Glasgow Coma Scale (GCS) is frequently used to assess neurological status, but its prognostic value for DNS is not universally established. Objectives: To evaluate the association between GCS at emergency department (ED) presentation and the development of DNS in COP patients Methods: A systematic review and meta-analysis was conducted on observational studies that reported on GCS and the subsequent occurrence of DNS. The search was performed from January 1980 to February 2024. We evaluated risk of bias with the QUIPS tool. We used a random-effects model. Sensitivity analyses were performed for studies at low risk of bias and with different GCS cut-off. Quality of evidence was evaluated according to an adapted GRADE framework. Results: After screening 1067 unique records, we included 24 studies, with 6153 patients, of whom 1002 (16.2%) developed DNS. Our primary analysis included 19 studies, revealing that patients developing DNS had significantly lower GCS scores at ED arrival, with a pooled mean difference (MD) of 4.06 points [95% CI, 3.09–5.02]. When considering GCS categorically with any cut-off, the pooled odds ratio (OR) for development of DNS was 3.00 [95% CI, 1.80–5.01]. Analysis with GCS as a continuous variable also confirmed GCS predictive value, with a pooled OR of 1.26 [95% CI, 1.19–1.32] for DNS per one-point decrease in GCS. Conclusions: GCS scores are a valuable prognostic tool for predicting DNS in COP patients.