Answer
Mrs O'Leary has had radical right mastectomy with removal of right breast, axillary lymph nodes and lymphatic vessels draining her right arm.
Her right arm is swollen (edematous) because of accumulation of interstitial fluid (ISF) in the interstitial/tissue spaces (ISS).
The compression sleeve will increase pressure on the tissues in her right arm. Normally, fluid leaves the blood system from capillary at the arteriolar end because of a net filtration pressure(NFP) of about 10 mmHg. Usually, most of this fluid is returned to the blood circulation by the effect of a net negative pressure of about 8 mm Hg (- 8 mm Hg). This is not all the fluid that leaves the circulation at the arterial end , but the residue is returned by the lymphatic system drainage. Since Mrs O'Leary has lost the lymph drainage for her right arm, the interstitial fluid not returned by the veins is accumulating in the interstitial spaces .
The compression sleeve is a garment accessory with elastic fibers. If properly fitted, the sleeve will compress the tissue where applied, and increase the pressure on both tissue and blood in blood vessels. There will be two important consequences. First , the increased mechanical pressure will decrease overall ISS in the area; and second, the ISF hydrostatic pressure will increase. This combination of influences should decrease the out fitrafion of ISF at the arterial end to almost zero.
Work Step by Step
If the sleeve pressure is properly calibrated, it will have the effect of increasing the vasomotor tone in the relevant area of the arm-- just a little above normal, but not enough to increase NFP significantly; just enough to move the blood faster in the area. This effect would decrease filtration or leakage of fluid from the capillaries at the arterial end. In any case, the the Starling force affected by the compression sleeve is hydrostatic pressure( HPc or Pc). Colloid osmotic pressure ( OPc ) would not be affected
