Effect of Fire Suppression and Emergency Duties on Vascular Function

March 4, 2013 updated by: University of Edinburgh

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

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.

Study Overview

Status

Unknown

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Anticipated)

30

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United Kingdom
      • Edinburgh, United Kingdom, EH16 4SA
        • Recruiting
        • Royal Infirmary of Edinburgh Clinical Research Facility
        • Contact:
        • Contact:
        • Principal Investigator:
          • Amanda L Hunter, MBChB

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 60 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

Subjects will be healthy, non-smoking, whole-time firefighters working within Lothian and Borders Fire and Rescue Service

Description

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 Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Case-Crossover
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Fire suppression
Firefighters will attend for vascular assessments following a night shift where they have performed fire suppression
Procedure: 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).
Other Names:
  • BK
  • SNP
  • ACh
  • VP
Procedure: Badimon Chamber
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.
Procedure: 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).
Other Names:
  • BK
  • SNP
  • ACh
  • VP
Procedure: Badimon Chamber
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.
Procedure: 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).
Other Names:
  • BK
  • SNP
  • ACh
  • VP
Procedure: Badimon Chamber
Ex-vivo assessment of thrombus formation using the Badimon Chamber

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators
Time Frame: up to 12 hours after exposure
up to 12 hours after exposure

Secondary Outcome Measures

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

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Edinburgh

Investigators

  • Study Chair: David E Newby, MD PhD, University of Edinburgh
  • Study Director: Nicholas L Mills, MBChB PhD, University of Edinburgh
  • Principal Investigator: Amanda L Hunter, MBChB, University of Edinburgh

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

February 1, 2012

Primary Completion (Anticipated)

August 1, 2014

Study Registration Dates

First Submitted

March 4, 2013

First Submitted That Met QC Criteria

March 4, 2013

First Posted (Estimate)

March 5, 2013

Study Record Updates

Last Update Posted (Estimate)

March 5, 2013

Last Update Submitted That Met QC Criteria

March 4, 2013

Last Verified

March 1, 2013

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 11-SS-0049
  • PG/11/27/28842 (Other Grant/Funding Number: British Heart Foundation)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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