Objective. To develop a model which can be used to elucidate the time
course and magnitude of changes in the fibrinolytic system associated
with application of intermittent pneumatic compression (IPC). Experime
ntal design. Intervention and response investigation with each subject
serving as his own control. Setting. Clinical research laboratory in
a large urban medical center. Patients. Healthy, non-smoking, male vol
unteers between 20 and 40 years of age. Intervention. Femoral venous c
atheter insertion. Blood samples were obtained via the catheter at fre
quent intervals for six hours to determine the effect of catheter inse
rtion on fibrinolytic parameters. Measures. Tissue plasminogen activat
or (tPA), plasminogen activator inhibitor type 1 (PAI-1), t-PA/PAI-1 c
omplex (t-PA/PAI-1) and euglobulin lysis time (ELT). Results. Placemen
t of femoral venous catheters led to early elevations in t-PA and PAI-
1, which returned to baseline within four hours of catheter insertion.
The complex, t-PA/PAI-1, revealed a biphasic response with elevations
at the beginning and end of the six-hour study period. Euglobulin lys
is time was unchanged. No catheter-related complications occurred in t
he study. Conclusions. We have developed a model which allows frequent
assessment of the components of the fibrinolytic system. Although cat
heter placement induces significant elevations of t-PA, PAI-1, and t-P
A/PAI-1, a new fibrinolytic baseline was established within four hours
of catheter placement. The new baseline will provide for subsequent d
etection of any changes in systemic fibrinolysis which result from IPC
.