Microparticles in Scuba Divers With Decompression Sickness

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.

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