Clinical Trials Logo

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).


Clinical Trial 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. ;


Study Design

Observational Model: Case-Only, Time Perspective: Prospective


Related Conditions & MeSH terms


NCT number NCT01587209
Study type Observational
Source University of Pennsylvania
Contact
Status Completed
Phase N/A
Start date August 2011
Completion date September 2014

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