Clearance of serum solutes by hemofiltration in dogs with severe heat stroke

Classic and exertional heatstroke

In the past two decades, record-breaking heatwaves have caused an increasing number of heat-related deaths, including heatstroke, globally. Heatstroke is a heat illness characterized by the rapid rise of core body temperature above 40 °C and central nervous system dysfunction. It is categorized as classic when it results from passive exposure to extreme environmental heat and as exertional when it develops during strenuous exercise. Classic heatstroke occurs in epidemic form and contributes to 9-37% of heat-related fatalities during heatwaves. Exertional heatstroke sporadically affects predominantly young and healthy individuals. Under intensive care, mortality reaches 26.5% and 63.2% in exertional and classic heatstroke, respectively. Pathological studies disclose endothelial cell injury, inflammation, widespread thrombosis and bleeding in most organs. Survivors of heatstroke may experience long-term neurological and cardiovascular complications with a persistent risk of death. No specific therapy other than rapid cooling is available. Physiological and morphological factors contribute to the susceptibility to heatstroke. Future research should identify genetic factors that further describe individual heat illness risk and form the basis of precision-based public health response. Prioritizing research towards fundamental mechanism and diagnostic biomarker discovery is crucial for the design of specific management approaches.

Use of extracorporeal therapy in a dog with heatstroke

OBJECTIVE

To describe the use of extracorporeal therapy (ECT) in the management of a dog with complications stemming from heatstroke.

CASE REVIEW

A 3-year-old intact male Rhodesian Ridgeback was presented for heat-related illness following strenuous exercise. Despite intensive supportive care, the dog developed progressive and refractory hyperkalemia, hypoglycemia, neurologic dysfunction, acute kidney injury (AKI), and pulmonary dysfunction. Four ECT sessions were performed in this dog, consisting of 4 intermittent hemodialysis (HD) sessions, the first 2 of which concurrently utilized hemoperfusion with a cytokine adsorption filter. Interleukin-6 (IL-6), IL-8, IL-10, and monocyte chemoattractant protein-1 were detected in samples collected during the first ECT session. Despite an initial decrease in their concentration, the concentrations of these cytokines ultimately rose over the course of the ECT session. Rapid and sustained glycemic and electrolyte control were achieved after the first ECT session, although AKI and muscle injury persisted. The dog survived to discharge and was nonazotemic 3 months following initial management.

NEW OR UNIQUE INFORMATION PROVIDED

Heatstroke is a common, potentially catastrophic, occurrence in dogs. To the authors' knowledge, this represents the first clinical use of ECT consisting of HD and cytokine adsorption in the management of severe heat-related illness in a dog. The use of ECT for the management of complications from severe heatstroke in dogs warrants further investigation.