J. Ahlqvist et al., HIGH HYDROSTATIC PRESSURES IN TRAUMATIC JOINTS REQUIRE ELEVATED SYNOVIAL CAPILLARY-PRESSURE PROBABLY ASSOCIATED WITH ARTERIOLAR VASODILATATION, Clinical physiology, 14(6), 1994, pp. 671-679
Three out of the four Starling pressures were determined at arthroscop
y of traumatic effusions of the knee. The range of the joint fluid hyd
rostatic pressure P-joint was 5-83 cmH(2)O (0.5-8.1 kPa, 4-61 mmHg), t
hat of the colloid osmotic pressure difference COPplasma-COPjoint 0-21
.7 cmH(2)O. In 11 of 15 cases the sum P-joint+COP difference exceeded
32.6 cmH(2)O (3.19 kPa, 24 mmHg), a high estimate of average capillary
pressure at the level of the heart. The number of 'exceeding' cases w
as 8/15 if only 80% of the COP difference was considered effective. P-
joint and the COP difference oppose filtration of fluid from plasma in
to joints, indicating that mean capillary pressure, the only Starling
pressure not determined, was elevated unless the effusions were being
resorbed back into the blood. The findings can be explained by tampona
de compensated by arteriolar vasodilatation, suspected to be metabolic
ally mediated.