Skip to content

Effect of Fire Suppression and Emergency Duties on Vascular Function

Effect of Fire Suppression and Emergency Duties on Vascular Function in Firefighters

Status
Completed
Phases
Unknown
Study type
Observational
Source
ClinicalTrials.gov
Registry ID
NCT01805063
Enrollment
30
Registered
2013-03-05
Start date
2012-01-09
Completion date
2016-12-31
Last updated
2024-05-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Atherothrombosis, Vascular Function

Keywords

firefighters, myocardial infarction, endothelial function, thrombosis, fire suppression, non-fire emergency duty, sedentary shift

Brief summary

Firefighters are at increased risk of death from heart attacks when compared to other emergencyy service professionals whose jobs involve similar components such as emergency call-outs and shift work. In the largest analysis of cause of death amongst on-duty firefighters, firefighter deaths were classified according to the duty performed during the onset of symptoms or immediately prior to any sudden death. The majority of deaths due to a cardiovascular cause (i.e. heart attack) occurred during fire suppression whilst this activity represented a relatively small amount of a firefighters professional time. There was also a risk of death associated with other duties such as emergency non-fire response and physical exertion. The investigators hypothesize that participation in active fire-fighting duties impairs blood vessel function and increases blood clot formation when compared with non-fire-fighting activities. In this study, healthy career firefighters will be assessed after three periods of duty: fire-suppression, emergency response without fire suppression and following a sedentary shift. The investigators will take blood samples to measure platelet activity (platelets are the particles in blood that help blood clot) and will examine how blood clots outside of the body. The investigators will then perform studies placing small needles in the arm to assess blood vessel function following these duties. By undertaking this comprehensive assessment of blood, blood vessel and heart function the investigators hope to understand the mechanisms whereby the risk of a heart attack, fatal or otherwise, is posed throughout these distinct duties that firefighters undertake on a daily basis.

Interventions

Forearm venous occlusion plethysmography to measure forearm blood flow during intra-arterial infusion of the vasodilators Verapamil (10-100 µg/min), bradykinin (100-1000 pmol/min), sodium nitroprusside (2-8 µg/min) and Acetylcholine (5-20 µg/min).

Ex-vivo assessment of thrombus formation using the Badimon Chamber

Sponsors

University of Edinburgh
Lead SponsorOTHER

Study design

Observational model
CASE_CROSSOVER
Time perspective
PROSPECTIVE

Eligibility

Sex/Gender
ALL
Age
18 Years to 60 Years
Healthy volunteers
Yes

Inclusion criteria

* Non-smoking healthy firefighters

Exclusion criteria

* Current smoker * History of lung or ischaemic heart disease * Malignant arrhythmia * Systolic blood pressure \>190mmHg or \<100mmHg * Renal or hepatic dysfunction * Previous history of blood dyscrasia * Unable to tolerate the supine position * Blood donation within the last 3 months * Recent respiratory tract infection within the past 4 weeks * Routine medication including aspirin and NSAIDs

Design outcomes

Primary

MeasureTime frame
Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilatorsup to 12 hours after exposure

Secondary

MeasureTime frame
Ex-vivo thrombus formation using the Badimon chamberup to 12 hours after exposure
Plasma t-PA and PAI concentrations following infusion of bradykininDuring forearm study, up to 12 hours after exposure

Countries

United Kingdom

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026