The feasibility of point-of-care testing for initial urinary liver fatty acid-binding protein to estimate severity in severe heatstroke

Rapid assessment of severity is crucial for timely intervention and improved patient outcomes in heatstroke (HS). However, existing biomarkers are limited in their accuracy and accessibility in ER settings. A prospective pilot study was conducted to assess urinary liver fatty acid-binding protein (L-FABP) levels using a point-of-care testing (POCT) upon HS. Severity was estimated using initial Sequential Organ Failure Assessment (SOFA) scores, and outcomes were measured using modified Rankin Scale (mRS) scores. In 78 severe HS patients, semi-quantitative L-FABP measurements were performed in ER and patients were divided as P-group (positive group, L-FABP ≧ 12.5 ng/mL on POCT) and N-group (negative group: L-FABP < 12.5ng/mL, on POCT). urinary L-FABP concentrations were also measured on admission, with a median concentration of 48.3 ng/mL. The positive correlation was observed between urinary L-FABP concentration and pulse rate (r = 0.300, P < 0.01) and lactate (r = 0.259, P < 0.01). The POCT of L-FABP showed promise in predicting severity, as indicated by higher concentrations in patients with higher initial SOFA scores. Furthermore, the comparison between semi-quantitative POCT measurements and urine concentrations of L-FABP measured by enzyme-linked immunosorbent assay (ELISA) revealed significant differences among three POCT groups (POC Range < 12.5 ng/ml, 12.6–100 ng/ml, and 55 > 100 ng/ml, P = 0.001). Additionally, patients in the POCT positive group had significantly worse outcomes at discharge compared to the negative group, although this difference diminished over time. The study demonstrates the feasibility and potential utility of POCT for initial L-FABP in estimating severity in HS patients. This rapid and accessible testing method may aid in early field triage and intervention, ultimately improving patient outcomes in the management of HS.