An observational study in Decompression Sickness and Dysbarism, sponsored by University of Pennsylvania. Completed at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2016-08-22.
Sponsored by University of Pennsylvania · Observational
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).
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.
23 studies on the registry are indexed under Decompression Sickness; 7 are open to participants now.
This study's enrollment of 1 is below the median of 100 across 10 observational studies indexed under Decompression Sickness.
Browse Decompression Sickness studies →University of Pennsylvania is the lead sponsor of 1,664 studies on the registry; 236 are open to participants now.
Of its 156 completed or terminated interventional studies of FDA-regulated products, 107 (69%) have results posted.
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SCUBA divers over age 21 that present for evaluation of suspected decompression sickness
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Exclusion Criteria:
The sole group under study is SCUBA divers who have sustained decompression sickness
Microparticle elevations in injured divers
We will quantify microparticles in plasma by standard flow cytometry techniques.
Time frame: four years
Microparticle sub-types in injured divers
We will evaluate sub-types of microparticles to determine their cells of origin.
Time frame: four years
Neutrophil activation in injured divers
We will evaluate presence of neutrophil activation in injured divers.
Time frame: four years
The record gives a start of Aug 2011, a primary completion of Sep 2014 and a completion of Sep 2014. It does not say whether these dates are actual or estimated.
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This study is completed, as verified in Aug 2016. You cannot join it, but the record below documents what was studied.
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