Effect of Fire Suppression and Emergency Duties on Vascular Function

NCT01805063 | Completed DMC

• 2 other identifiers: 11-SS-0049PG/11/27/28842
• Study Type: observational
• Target: 30
• Locations: 1 country
• Sites: 1

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

Keywords

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

Outcome Measures

Primary Outcomes (1)

• Forearm blood flow measured by venous occlusion plethysmography in response to infused vasodilators

  up to 12 hours after exposure

Secondary Outcomes (2)

• Ex-vivo thrombus formation using the Badimon chamber

  up to 12 hours after exposure

• Plasma t-PA and PAI concentrations following infusion of bradykinin

  During forearm study, up to 12 hours after exposure

Study Arms (3)

Fire suppression

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

Procedure: Forearm Vascular Study; Procedure: 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; Procedure: 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; Procedure: Badimon Chamber

Interventions

Forearm Vascular Study 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).

Also known as: BK, SNP, ACh, VP

Fire suppression; Non-fire emergency duty; Sedentary shift

Badimon Chamber PROCEDURE

Ex-vivo assessment of thrombus formation using the Badimon Chamber

Fire suppression; Non-fire emergency duty; Sedentary shift

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Probability Sample

Study Population

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

You may qualify if:

• Non-smoking healthy firefighters

You may not qualify if:

• 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

Sponsors & Collaborators

• University of Edinburgh: lead

Study Sites (1)

Royal Infirmary of Edinburgh Clinical Research Facility

Edinburgh, EH16 4SA, United Kingdom

Location

Biospecimen

Retention: SAMPLES WITHOUT DNA

Plasma and urine samples

MeSH Terms

Conditions

Thrombosis; Myocardial Infarction

Condition Hierarchy (Ancestors)

Embolism and Thrombosis; Vascular Diseases; Cardiovascular Diseases; Myocardial Ischemia; Heart Diseases; Infarction; Ischemia; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Necrosis

Study Officials

• David E Newby, MD PhD

  University of Edinburgh

  STUDY CHAIR

• Nicholas L Mills, MBChB PhD

  University of Edinburgh

  STUDY DIRECTOR

• Amanda L Hunter, MBChB

  University of Edinburgh

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: CASE CROSSOVER
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 4, 2013
• First Posted: March 5, 2013
• Study Start: January 9, 2012
• Primary Completion: December 31, 2016
• Study Completion: December 31, 2016
• Last Updated: May 1, 2024

Record last verified: 2013-03

Locations

GB (1)