Effect of Fire Suppression and Emergency Duties on Vascular Function

NCT ID: NCT01805063

Last Updated: 2024-05-01

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 30 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2012-01-09
• Study Completion Date: 2016-12-31

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.

Conditions

Vascular Function; Atherothrombosis

Study Design

• Observational Model Type: CASE_CROSSOVER
• Study Time Perspective: PROSPECTIVE

Study Groups

Fire suppression

Firefighters will attend for vascular assessments following a night shift where they have performed fire suppression

Forearm Vascular Study

Intervention Type: PROCEDURE

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).

Badimon Chamber

Intervention Type: PROCEDURE

Ex-vivo assessment of thrombus formation using the Badimon Chamber

Non-fire emergency duty

Firefighters will attend for vascular assessments following a night shift where they have had an emergency response without fire suppression eg. road traffic collision.

Forearm Vascular Study

Intervention Type: PROCEDURE

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).

Badimon Chamber

Intervention Type: PROCEDURE

Ex-vivo assessment of thrombus formation using the Badimon Chamber

Sedentary shift

Firefighters will attend for vascular assessments following a night shift where they have remained sedentary throughout the shift.

Forearm Vascular Study

Intervention Type: PROCEDURE

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).

Badimon Chamber

Intervention Type: PROCEDURE

Ex-vivo assessment of thrombus formation using the Badimon Chamber

Interventions

Forearm Vascular Study

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).

Intervention Type: PROCEDURE

Badimon Chamber

Ex-vivo assessment of thrombus formation using the Badimon Chamber

Intervention Type: PROCEDURE

Other Intervention Names

BK; SNP; ACh; VP

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 60 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Edinburgh

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

David E Newby, MD PhD

Role: STUDY_CHAIR

University of Edinburgh

Nicholas L Mills, MBChB PhD

Role: STUDY_DIRECTOR

University of Edinburgh

Amanda L Hunter, MBChB

Role: PRINCIPAL_INVESTIGATOR

University of Edinburgh

Locations

Royal Infirmary of Edinburgh Clinical Research Facility

Edinburgh, , United Kingdom

Countries

United Kingdom

Other Identifiers

PG/11/27/28842

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

11-SS-0049

Identifier Type: -

Identifier Source: org_study_id