Answer to Question #327746 in Human Anatomy and Physiology for saleh Mubark

Question

▹Leona is 52 years old and smokes. She is also overweight and has atherosclerosis. When she was given a 2-week vacation from work, she packed up her bags and flew from Minnesota to Sydney, Australia, for the trip she always wanted to take. Unfortunately, just 3 days after she arrived, she was hospitalized when her left calf became inflamed, causing her considerable pain. The physician attending to her told her she developed a deep vein thrombosis. When Leona was in hospital, she received heparin therapy. 

▸Why the trip to Australia contributed to Leona’s DVT? Why was Leona already at risk for thrombus development?

▸Why heparin was taken to treat her DVT? Why was she not given heparin tablets to take back to the hotel with her?

Answer 1

• The trip to Australia contributed to Leona's DVT, because during a long air flight, she probably constantly sat in one place, not going out to walk around the aircraft cabin, and sitting with her legs bent at the knees led to a decrease in the blood flow in the veins of the legs. Leona was already at risk for thrombus development, because, firstly, she smokes, and the products of tobacco combustion bind hemoglobin, significantly reducing its transport capacity, and as compensation, the number of red blood cells increases in the blood, which leads to thickening of the blood and decreasing in the blood flow. Secondly, she is overweight, and extra pounds put pressure on the veins of the lower extremities, as a result of which blood flow slows down in them. Thirdly, she has atherosclerosis, and at the same time, atherosclerotic plaques clog the passage in the veins, and because of this, blood flow slows down. The simultaneous combination of these three cases leads to the development of thrombosis.
• Heparin was taken to treat Leona's DVT, because it thins the blood and reduces the occurrence of blood clots. There could be several reasons why Leona was not given heparin tablets to take back to the hotel with her. Firstly, in the hospital, heparin could be both in tablets and in injections, but heparin was administered using droppers, since the parenteral method of taking heparin is considered more effective due to its fast and long-lasting effect due to direct intake into bloodstream, bypassing the digestive system, where it takes a long time for heparin to reach the bloodstream, and where it can be converted into an inactive form by digestive enzymes. Secondly, instead of tablets, she could be offered to come to the hospital from time to time to be examined and take injections of heparin due to its higher efficiency. In any case, the attending physicians were sure that heparin in injections was considered more effective than in tablets.