Clinical Trials Logo

Clinical Trial Details — Status: Completed

Administrative data

NCT number NCT01587209
Other study ID # 814139
Secondary ID
Status Completed
Phase N/A
First received April 23, 2012
Last updated August 18, 2016
Start date August 2011
Est. completion date September 2014

Study information

Verified date August 2016
Source University of Pennsylvania
Contact n/a
Is FDA regulated No
Health authority United States: Federal Government
Study type Observational

Clinical Trial Summary

The investigators hypothesize that membrane microparticles (MPs) are liberated into the blood stream in response to decompression stress and that certain MPs characteristics initiate inflammatory responses that contribute to the clinical syndrome the investigators call decompression sickness. The research goal is to evaluate the number, type and time-course for elevations in MPs in sport SCUBA divers who present for treatment of decompression sickness. Blood samples are to be taken from consenting patients before and after they undergo treatment for decompression sickness and at a follow-up clinic visit from 1 to 3 weeks later (three samples total).


Description:

Microparticles (MPs) are small membrane bound vesicles shed from the surface of a variety of cells by what appear to be well regulated processes. They are elevated in many physiological and disease states and in some instances have been associated with organ injury. Shear stress - as can be caused by intravascular bubbles - is one of the stimuli known to cause cells to release microparticles. Most sport SCUBA dives have been shown to generate intravascular bubbles - even safe dives well within limits established by the US Navy and sports authorities. The investigators have reported elevations in several sub-types of MPs in a group of individuals undergoing a well monitored series of open-water SCUBA dives. There is no information of the occurrence of MPs in injured divers. The investigators have published results using a murine model which demonstrated that mice subjected to varying decompression stresses exhibit progressive elevations in circulating MPs derived from leukocytes, erythrocytes, platelets and endothelial cells. Using novel interventions the investigators demonstrated that MPs cause intravascular neutrophil activation and inflammatory perivascular injuries. Therefore, there is pathophysiological information to suggest that one or more element of MPs (number and/or pro-inflammatory subtype) may be proximal elements that precipitate the clinical syndrome the investigators call decompression sickness.


Recruitment information / eligibility

Status Completed
Enrollment 1
Est. completion date September 2014
Est. primary completion date September 2014
Accepts healthy volunteers No
Gender Both
Age group 18 Years and older
Eligibility Inclusion Criteria:

- Patients who are given the diagnosis of decompression sickness will be offered entry into this study

Exclusion Criteria:

- Inability to provide informed consent

Study Design

Observational Model: Case-Only, Time Perspective: Prospective


Related Conditions & MeSH terms


Locations

Country Name City State
United States University of Pennsylvania Philadelphia Pennsylvania

Sponsors (3)

Lead Sponsor Collaborator
University of Pennsylvania Office of Naval Research (ONR), University of Maryland

Country where clinical trial is conducted

United States, 

References & Publications (3)

Thom SR, Milovanova TN, Bogush M, Bhopale VM, Yang M, Bushmann K, Pollock NW, Ljubkovic M, Denoble P, Dujic Z. Microparticle production, neutrophil activation, and intravascular bubbles following open-water SCUBA diving. J Appl Physiol (1985). 2012 Apr;112(8):1268-78. doi: 10.1152/japplphysiol.01305.2011. Epub 2012 Feb 9. — View Citation

Thom SR, Yang M, Bhopale VM, Huang S, Milovanova TN. Microparticles initiate decompression-induced neutrophil activation and subsequent vascular injuries. J Appl Physiol (1985). 2011 Feb;110(2):340-51. doi: 10.1152/japplphysiol.00811.2010. Epub 2010 Oct 21. — View Citation

Yang M, Milovanova TN, Bogush M, Uzun G, Bhopale VM, Thom SR. Microparticle enlargement and altered surface proteins after air decompression are associated with inflammatory vascular injuries. J Appl Physiol (1985). 2012 Jan;112(1):204-11. doi: 10.1152/japplphysiol.00953.2011. Epub 2011 Sep 29. — View Citation

Outcome

Type Measure Description Time frame Safety issue
Primary Microparticle elevations in injured divers We will quantify microparticles in plasma by standard flow cytometry techniques. four years No
Secondary Microparticle sub-types in injured divers We will evaluate sub-types of microparticles to determine their cells of origin. four years No
Secondary Neutrophil activation in injured divers We will evaluate presence of neutrophil activation in injured divers. four years No
See also
  Status Clinical Trial Phase
Completed NCT02118207 - Exercise and Repetitive Diving N/A
Completed NCT02468752 - Reduction of Venous Emboli Load After Breathing Normobaric Oxygen Compared to Air Phase 2/Phase 3
Completed NCT02432131 - Decompression Sickness in Divers With or Without Patent Foramen Ovale
Recruiting NCT03192956 - Markers of Central Nervous System Injury in Decompression Sickness
Recruiting NCT04791488 - Impact of Hyperoxia and Involvement of the Immune System in Diving Accident N/A
Completed NCT02736006 - Decreases in Diffusing Lung Capacity for Carbon Monoxide (DLCO) in Occupational Divers and Their Impact on Decompression Sickness Risks N/A
Not yet recruiting NCT06370897 - Prediction & Mechanisms of Recovery Following IEDS
Not yet recruiting NCT06216366 - Rhu-pGSN to Mitigate Proinflammatory Responses to Decompression in Healthy SCUBA Divers Phase 2
Enrolling by invitation NCT02483650 - Hyperbaric Oxygen Therapy Registry
Completed NCT02064361 - High Intensity Cycling Before SCUBA Diving Reduces Post-decompression Microparticle Production and Neutrophil Activation N/A
Completed NCT03390335 - Decompression Tables for Diving at Altitude N/A