Relationship Between Central Nervous System Dysfunction And Hyperthermia In Exertional Heat Stroke Patients

Despite evidence supporting best practice for recognition and management of exertional heat stroke (EHS), there is a lack of understanding regarding the central nervous system (CNS) dysfunction observed in the clinical presentation of EHS. PURPOSE: The purpose of this study was twofold: (1) to describe CNS function using the Glasgow Coma Scale (GCS) and signs and symptoms (S&Sx) in EHS patients, and (2) to determine the relationship between rectal temperature (Tre) and GCS in EHS patients. METHODS: A cross sectional research design was used by observing EHS patients (defined as >40 °C + CNS dysfunction) at an 11.3-km road race. Trained scribes recorded information on the patients’ medical records which were then de-identified for the research team. Primary outcome measures were GCS, Tre, and S&Sx. Parametric and non-parametric descriptive statistics were calculated. A Spearman’s rank or Pearson correlation was used (based on measurement type) to determine the relationship between variables. RESULTS: Runners diagnosed with EHS (male = 13, female = 10) were aged 30 ± 14y (range 15-58y), with an initial medical tent Tre of 41.0 ± 0.6 °C (40.0-42.1 °C) and GCS of 14 ± 3 (4-15). Across evaluation and treatment time points, maximum Tre for EHS patients ranged from 40.0 to 42.5 °C and GCS ranged from 0-15. There was a significant but weak correlation between Tre and GCS (rs(121) = -0.284, p = .002) and between Tre and the number of S&Sx present (r(121) = 0.288, p = 0 = .001) for all time points but no correlation between these measures when Tre was >40 °C (rs(60) = -0.209, p > 0.05). Initial recorded S&Sx included nausea (17.4% of observations), dizziness, irritability, aggressive, headache, and malaise (all 4.3%). Confusion (13%), difficulty remembering (8.7%), and irritability (8.7%) had the highest percent of observations during all time points. CONCLUSION: GCS scores in EHS patients varied widely, resulting in a weak relationship between GCS and Tre. There were several different S&Sx observations, with not one symptom representing most observations at any time point. Clinicians should be aware CNS dysfunction in EHS patients presents in a variety of ways. The presence or absence of CNS dysfunction should serve as a diagnostic measure for EHS but should not be used to determine treatment, cessation of cooling, or EHS severity. ACSM Clinical Sports Medicine Endowment; Mid-Atlantic Athletic Trainers' Assoc Grant