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Clotting and fibrinolytic changes after firefighting activities.

Smith DL; Horn GP; Petruzzello SJ; Fahey G; Woods J; Fernhall BO
Med Sci Sports Exerc 2014 Mar; 46(3):448-454
Approximately 45%-50% of all duty-related deaths among firefighters are due to sudden cardiovascular events, and a disproportionate number of these fatalities occur after strenuous fire suppression activities. PURPOSE: The objective of this study is to evaluate the effect of strenuous firefighting activities on platelets, coagulation, and fibrinolytic activity and to document the extent to which these variables recovered 2 h after completion of the firefighting activity. METHODS: Firefighters performed 18 min of simulated firefighting activities in a training structure that contained live fires. After firefighting activities, firefighters were provided with fluid and allowed to cool down and then recovered for 2 h in an adjacent room. Blood samples were obtained prefirefighting, postfirefighting, and 2 h postfirefighting. RESULTS: Platelet number, platelet activity, and coagulatory potential increased immediately postfirefighting and many variables (platelet function, partial thromboplastin time, and factor VIII) reflected a procoagulatory state even after 2 h of recovery. Fibrinolysis, as reflected by tissue plasminogen activator, also was enhanced immediately postfirefighting but returned to baseline values by 2 h postfirefighting. In contrast, inhibition of fibrinolysis, as evidenced by a reduction in plasminogen activator inhibitor-1, was depressed at 2 h postfirefighting. CONCLUSIONS: Firefighting resulted in elevated coagulatory and fibrinolytic activity. However, 2 h postfirefighting, tissue plasminogen activator returned to baseline and coagulatory potential remained elevated. The procoagulatory state that exists after firefighting may provide a mechanistic link to the reports of sudden cardiac events after strenuous fire suppression activities.
Fire-fighters; Fire-fighting; Mortality-data; Morbidity-rates; Cardiovascular-system; Cardiovascular-system-disease; Cardiovascular-system-disorders; Cardiovascular-function; Cardiovascular-disease; Physical-exercise; Physical-reactions; Physiological-effects; Physiology; Blood-samples; Humans; Men; Age-groups; Author Keywords: Hemostasis; Coagulation; Fibrinolysis; Platelet Activity
Denise L. Smith, Ph.D., Department of Health and Exercise Sciences, Skidmore College, 815 N. Broadway, Saratoga Springs, NY 12866
Publication Date
Document Type
Journal Article
Email Address
Funding Type
Fiscal Year
Identifying No.
Grant-Number-R03-OH-009111; M102014
Issue of Publication
Source Name
Medicine and Science in Sports and Exercise
Performing Organization
University of Illinois at Urbana-Champaign
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division