Explain why this statement is true, detailing the mechanisms of coagulation in your answer.Blood clotting involves three simultaneous and overlapping processes: the formation of a plug from platelets in the blood; binding the platelet plug to the site of injury to form a clot; and confining the clot to the area of injury. Normal platelets and normal clotting factors are needed for effective clotting. The older person is more prone to bleeding disorders than the younger person, and the causes for the disorders are different and more complex. A simple classification are conditions that reduce the number of platelets in the blood, platelets that do not function properly, and abnormalities in the clotting factors.
Statistically, the elderly seem to be at a much greater risk of developing blood clotting disorders. One of the reasons for this may be due to non-communicable diseases, such as diabetes, heart disease, and cancer that are increasing due to the increase in life expectancy and general improved economic status. Diabetes is of particular importance in the elderly and its incidence is increasing rapidly worldwide, again, in part due to the increase in life expectancy and due to poor diet and excess sugar intake. One characteristic of diabetes is impaired fibrinolysis, mainly due to increased concentrations of plasminogen activator inhibitor – type 1 in tissues and blood, (Sobol 2003).
This in turn drastically increases the risk of blood clot formation which increases the chance of illnesses such as myocardial infarction and stroke. Cancer is also an important risk factor. an example of how cancer can directly effect or cause coagulation problems is in the case of Leukaemia. In some forms of leaukaemia, marrow hypoplasia is seen, which eventually leads to thrombocytopenia. Thrombocytopenia is the most common cause of bleeding amongst the elderly. Other myeloproliferative disorders, multiple myeloma, cardiovascular disease (Schumacher et al 1981), liver disease (Owen et al 1981), and uremia (Remuzzi et al 1983), all also affect the elderly and may all be associated with coagulation abnormalities.
Another major illness that is common amongst the elderly and that directly affects blood coagulation is atherosclerosis. Atherosclerosis is the leading cause of occlusive arterial disease of the lower extremities and is the process in which lipids such as cholesterol build up in the inner lining of the artery causing it to narrow and thicken and these build-ups are known as plaques. Even though atherosclerosis is a slow, complex disease that typically starts in childhood (www.americanheart.org), it normally only manifests with symptoms in later life, particularly in the elderly.
There are also many other factors that can lead to atherosclerosis such as poor diet (excess intake of fats and cholesterol), cardiovascular problems and high blood pressure, which are all common in the elderly, smoking and diabetes. Atherosclerotic plaques can grow large enough to significantly reduce the blood flow through an artery. This in itself can cause coagulation problems in the extremities as blood flow is decreased to these parts, however, most of the damage occurs when these plaques become fragile and rupture. These plaques that rupture cause blood clots to form that can block blood flow to areas such as arms and legs causing pain, fatigue and eventually gangrene. The clot that is formed can also break off and travel to other parts of the body and thus has a potential for causing illnesses such as myocardial infarction or stroke.
Liver disease is also an illness that has a major impact on blood clotting and coagulation as the liver has an important role in the coagulation process and thus clotting abnormalities are a prominent feature of acute and chronic liver disease. Liver disease, in particular chronic liver disease is seen more in older patients, in particular the elderly. This can be due to many reason such as long term alcohol abuse, cardiac dysfunction, diabetes and hepatitis. The key point to note here is that even though younger individuals may suffer from these illnesses, it is the long-term effects of them that tend to cause major complication and they only normally tend to manifest after many years or in later life.
In patients with chronic liver disease, particularly the elderly, bleeding can reflect primarily anatomic or specific abnormalities of the coagulation system (Mancuso et al 2003). The outcome is often portal hypertension eventually leading to esophageal and gastric varices, hemorrhagic gastritis and volume overload in the portal system. These conditions may lead to severe gastrointestinal hemorrhage and bleeding due to quantitative and qualitative platelet and coagulation factor abnormalities, for example, normally 30% of the platelet pool is sequestered in the spleen, however, in the presence of portal hypertension this figure can rise to as much as 90% leading to a large reduction in the circulating platelet count.
Other factors that can lead to defective haemostasis in patients with liver disease include decreased synthesis of pro-coagulant and anti-coagulant proteins, impaired clearance of activated coagulation factors, synthesis of functionally abnormal fibrinogen, splenomegaly, qualitative platelet defects and in some cases bone marrow suppression of thrombopoiesis, each leading to impaired coagulation efficiency (John et al 2003). It is important to note that in general, the elderly normally have a decreased haemoglobin level and a decreased physical and mental ability to deal with any kind of trauma and thus any kind of hemorrhage will not only be traumatic but will also be life threatening.