Effect of Fire Suppression and Emergency Duties on Vascular Function

Completed

• Conditions: Atherothrombosis; Vascular Function
• Interventions: Procedure: Forearm Vascular Study; Procedure: Badimon Chamber

• Registration Number: NCT01805063
• Lead Sponsor: University of Edinburgh

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2012-01-09
• Status Verified: 2013-03
• Study First Submitted: 2013-03-04
• Study First Submitted QC: 2013-03-04
• Study First Posted: 2013-03-05
• Primary Completion: 2016-12-31
• Study Completion: 2016-12-31
• Last Update Submitted: 2024-04-30
• Last Update Posted: 2024-05-01

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 30

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

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Fire suppression	Badimon Chamber	Firefighters will attend for vascular assessments following a night shift where they have performed fire suppression
Non-fire emergency duty	Badimon Chamber	Firefighters will attend for vascular assessments following a night shift where they have had an emergency response without fire suppression eg. road traffic collision.
Sedentary shift	Badimon Chamber	Firefighters will attend for vascular assessments following a night shift where they have remained sedentary throughout the shift.
Fire suppression	Forearm Vascular Study	Firefighters will attend for vascular assessments following a night shift where they have performed fire suppression
Non-fire emergency duty	Forearm Vascular Study	Firefighters will attend for vascular assessments following a night shift where they have had an emergency response without fire suppression eg. road traffic collision.
Sedentary shift	Forearm Vascular Study	Firefighters will attend for vascular assessments following a night shift where they have remained sedentary throughout the shift.

Primary Outcome Measures

Name	Time	Method
Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators	up to 12 hours after exposure

Secondary Outcome Measures

Name	Time	Method
Plasma t-PA and PAI concentrations following infusion of bradykinin	During forearm study, up to 12 hours after exposure
Ex-vivo thrombus formation using the Badimon chamber	up to 12 hours after exposure

Trial Locations

Locations (1)

Royal Infirmary of Edinburgh Clinical Research Facility; 🇬🇧 Edinburgh, United Kingdom