Pneumatic Compression Aids Hip Replacement Patients

A major study of patients hospitalized because of life-threatening blood clots after hip replacement surgery has shown that pneumatic compression of the legs can dramatically lower the risk. The study, conducted by researchers at the University of California, Davis, Medical Center (USA) was published in the December 14 issue of The New England Journal of Medicine.

Only a small proportion of clots causes symptoms, and the rest disappear. Symptoms of deep vein thrombosis (DVT) include persistent swelling and pain. People who develop pulmonary emobli become short of breath, develop chest pain, and may cough up blood. The ultimate goal is to prevent sudden death from pulmonary embolism.

In the study, researchers compared patients who developed symptoms to patients who did not in the 91 days after surgery, comparing the past medical records of 297 patients rehospitalized for a blood clot to 592 who were not rehospitalized. The research team assessed a number of factors, including pneumatic compression, anticoagulant therapies, and obesity. The results showed that overweight patients were most at risk for developing blood clots that required hospitalization. Continuing anticoagulant drug therapy after discharge helped all patients, making them only 60% as likely to have symptoms as the controls.

Pneumatic compression greatly helped all patients who were not overweight. This therapy uses plastic thigh-high cuffs that inflate every few minutes, squeezing blood from ankle to thigh. This mechanical massage is thought to prevent blood from polling in the veins and clotting. In the study, normal-weight patients treated with pneumatic compression were only 30% as likely to have been rehospitalized for symptomatic clotting as patients who did not receive this therapy.