Effect of Fire Suppression and Emergency Duties on Vascular Function

This study is currently recruiting participants. (see Contacts and Locations)
Verified March 2013 by University of Edinburgh
Sponsor:
Information provided by (Responsible Party):
University of Edinburgh
ClinicalTrials.gov Identifier:
NCT01805063
First received: March 4, 2013
Last updated: NA
Last verified: March 2013
History: No changes posted
  Purpose

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.


Condition Intervention
Vascular Function
Atherothrombosis
Procedure: Forearm Vascular Study
Procedure: Badimon Chamber

Study Type: Observational
Study Design: Observational Model: Case-Crossover
Time Perspective: Prospective
Official Title: Effect of Fire Suppression and Emergency Duties on Vascular Function in Firefighters

Resource links provided by NLM:


Further study details as provided by University of Edinburgh:

Primary Outcome Measures:
  • Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators [ Time Frame: up to 12 hours after exposure ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Ex-vivo thrombus formation using the Badimon chamber [ Time Frame: up to 12 hours after exposure ] [ Designated as safety issue: No ]
  • Plasma t-PA and PAI concentrations following infusion of bradykinin [ Time Frame: During forearm study, up to 12 hours after exposure ] [ Designated as safety issue: No ]

Biospecimen Retention:   Samples Without DNA

Plasma and urine samples


Estimated Enrollment: 30
Study Start Date: February 2012
Estimated Primary Completion Date: August 2014 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
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

  Eligibility

Ages Eligible for Study:   18 Years to 60 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Sampling Method:   Probability Sample
Study Population

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

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
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01805063

Contacts
Contact: Amanda L Hunter, MBChB +441312426437 amanda.hunter@ed.ac.uk
Contact: Nicholas L Mills, MBChB PhD +441312426437 nick.mills@ed.ac.uk

Locations
United Kingdom
Royal Infirmary of Edinburgh Clinical Research Facility Recruiting
Edinburgh, United Kingdom, EH16 4SA
Contact: Amanda L Hunter, MBChB    +441312426437    amanda.hunter@ed.ac.uk   
Contact: Nicholas L Mills, MBChB PhD    +441312426437    nick.mills@ed.ac.uk   
Principal Investigator: Amanda L Hunter, MBChB         
Sponsors and Collaborators
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
  More Information

No publications provided

Responsible Party: University of Edinburgh
ClinicalTrials.gov Identifier: NCT01805063     History of Changes
Other Study ID Numbers: 11-SS-0049, PG/11/27/28842
Study First Received: March 4, 2013
Last Updated: March 4, 2013
Health Authority: United Kingdom: National Health Service

Keywords provided by University of Edinburgh:
firefighters
myocardial infarction
endothelial function
thrombosis
fire suppression
non-fire emergency duty
sedentary shift

Additional relevant MeSH terms:
Emergencies
Disease Attributes
Pathologic Processes

ClinicalTrials.gov processed this record on September 22, 2014