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Learning Center
Coagulation Corner
Sunday, January 31, 2010
COAGULATION: DID YOU KNOW THAT?
I admit it, I am a bit of a trivia nerd, I like knowing things, I am a pretty good jeopardy player (except for American Presidents and Greek mythology).
So it stands to reason, I am also a trivia nerd in coagulation- I like finding old textbooks that have different theories. I feel like if you know where things came from, you have a better understanding of where we are today. So, on the lighter side, this month, I will share with you some coagulation trivia, hey you never know when Alex Tribec might say our category tonight is Coagulation Trivia- you will be ready for the Daily Double!
Most people know that Hippocrates (460-377BC) was the Father of Medicine, (the Hippocratic Oath- which was not written by him, I might add) He made reference to animal blood congealing upon cooling and when shaken fibers would be removed, and the blood would return to fluid. Aristotle (384-322 BC) was known for his "cooling theory", that blood cooled when being removed from the body, He also noted that women's blood was thicker than males, old age blood was scanty and that deer had a coagulation deficiency and it was noted that blood fibers go astray, in contrast the blood of bulls congeal much quicker.
This theory was suggested many times doing the course of history, but it wasn't until 1770 that Hewson demonstrated that blood in a vein kept at body temperature would also clot. The theories that were promoted regarding blood coagulation were: cooling, rest, loss of vital force (dying) and air.
How does that translate into today, we know that cold reduces the amount of blood to an area, and the heat will increase it- we want good circulation and blood cells to be in motion, we know that consumption of cells, activators will cause the generation of thrombin and clotting, and air, well we all know what happens when you get a 'cut' and the role of platelets, etc- so there you have it., basic theories to us, but to evolve to these concepts took many centuries.
Platelets were not even described until 1842! This was done by the French histologist Donne, these small globules as being different from red globules or white globules. It was Bizzozero who gave us the term blood platelet (Blut Plattchen) and described the changes that platelets undergo when they are exposed to foreign surfaces as well as the formation of aggregates and white thrombi. In 1865 Schultze associated platelets with clotting and it wasn't really until the 1950's that platelet work really went into full swing - just a mere 60 years ago!
Did you know- factor facts?Hemophilia and royalty
The first written account of haemophilia occurred in the second century in the Babylonian Talmud. In it Rabbi Judah haNasi, redactor of the Mishneh, wrote: "If she circumcised her first child and he died, and a second one also died, she must not circumcise her third child." This passage refers to both the prolonged bleeding caused by circumcision and to the maternal inheritance of the disease. The first medical professional to describe a disease was Albucasis. In the tenth century he described families whose males died of bleeding after only minor traumas. While many other such descriptive and practical references to the disease appear throughout historical writings, scientific analysis does not begin until the start of the nineteenth century. The royal families Queen Victoria has a well established pedigree of disease that traveled through Europe. The Russian Romanov family also had a child that was a "bleeder". The term "haemophilia" is derived the term "haemorrhaphilia" which was used in a description of the condition written by Friedrich Hopff in 1828, while he was a student at the University of Zurich.
So what about Factor IX, or Hemophilia B- it was noted that when blood from a hemophiliac patient was mixed with another patient with severe bleeding, it corrected the patients defect, therefore one was deficient in VIII and the other in IX. This was called Christmas factor or Christmas disease, which was the surname of the person who had the disease. An article regarding this appeared during Christmas week, and was widely read by people who thought this was caused by Christmas overeating!
Did you know- coagulation therapy?
My grandmother believed that 3 things could cure almost anything:
1. Vicks vaporub- colds, pimples, headaches
2. Milk of magnesia - stomach, pimples, canker sores
3. Aspirin - turns out she was correct-
So we know that aspirin is from the tree of the willow bark, but did you know it was the first actual clinical trial conducted? Edward Stone, an English clergyman, reports to the Royal Society of London (world-renowned scientific group) of his successful experiments involving the use of willow bark to reduce fever in fifty of his patients.
Egyptians used lead and copper sulfates, antimony and verdigris to stop bleeding. The most popular treatment however was blood letting. This was done to remove the "plethora" which is blood that is thickened, serous, viscous or putrid. Interestingly, the saliva of the leech is used in the preparation of Hirudun, a direct thrombin inhibitor, or an anticoagulant.
Some treatments were creative- for exhaustion from excessive blood loss opium and brandy in limited amounts were recommended. Chemically, I am not sure of the pathway, physically, with those drugs being administered, I would imagine you wouldn't care, you would be out cold! Hemophilia was treated with citron juice, opium, iron sulfate, magnesium sulfate and egg whites!
Okay, so that was then, this is now, and since all we hear is in these economic times, I thought this might interest you:
Did you know how much it costs to use heparin?
Drug costs for a six-day course of treatment for a patient weighing 176 pounds would be $712 for low molecular weight heparin Lovenox (enoxaparin) or Fragmin (dalteparin) versus $37 for unfractionated heparin, they reported in the Journal of the American Medical Association.
Seven days of prophylaxis with low-dose heparin cost $15.96 in Canada and $36.54 in the US. A week of enoxaparin cost $56.07 in Canada and $158.20 in the US.
Enoxaparin prophylaxis was associated with equal numbers of symptomatic [deep vein thrombosis] and [pulmonary embolism], 12 additional cases of major bleeding, and an additional cost of $86,050. (Canadian data) and $145,667. (US data) for every 1,000 patients treated.
Did you know how much a stroke costs?
Economic Cost of Stroke
- The total cost of stroke to the United States is estimated at $43 billion per year.
- The direct costs of medical care and therapy are estimated at $28 billion per year.
- Indirect costs from lost productivity and other factors are estimated at $15 million per year.
- The average cost of care for a patient up to 90 days after stroke is $15,000.
- For 10 percent of patients, the cost of care for the first 90 days after a stroke is $35,000.
- The percentage breakdown of the direct costs of care for the first 90 days after a stroke is:
Initial hospitalization - 43 percent
Rehabilitation - 16 percent
Physician costs - 14 percent
Hospital Readmission - 14 percent
Medications and other expenses - 13 percent
Did you know how much factor replacement costs:
The median cost for factor products among haemophilia patients with inhibitors was $55,853/year, $2,760 less than comparable haemophilia patients without inhibitors. The median number of hospitalizations per year was 1.0 for both inhibitor and non-inhibitor patients and the median number of days hospitalized was virtually the same. The largest component of the cost of care is that of factor concentrate, it becomes imperative in the current health care environment to better define the true costs and benefits of treatments designed to eradicate or manage inhibitors.
A review of an institution's experience revealed overdosing of coagulation factors in the majority of patients treated during a 12-month period, at a cost that approached$700,000. However and established mandatory
clinical pathology consultation before releasing such factors. In the subsequent 30 months, 32 adults received 64 courses of treatment. For patients with hemophiliaA, the mean cost per admission was reduced by
approximately 27% (total savings, $61,536). For patients with factor VIII inhibitor, there was an approximate 6% cost reduction (total savings, $47,292). The combined savings was $108,828. The mean plasma factor level achieved during the intervention period was 84% ± 55% compared with 117% ± 58% for the preintervention period (P = .008).Neither the number of treatment (factor transfusion) days nor the number of RBC transfusions changed
significantly. Our data support that pathology consultation yields consistent and appropriate therapy and improves resource utilization
Do you know what the risk of hemorrhage and thromboembolism is in patients on oral anticoagulation?
The risk of hemorrhage increased significantly at high international normalized ratios. Compared with the therapeutic ratio of 2-3, the relative risk (RR) of hemorrhage were 2.7 (1.8-3.9; p < 0.01) at a ratio of 3-5 and 21.8 (12.1-39.4; p < 0.01) at a ratio greater than 5. The risk of thromboemboli increased significantly at ratios less than 2, with a relative risk of 3.5. The risk of hemorrhagic or thromboembolic events was lower at ratios of 3-5 (RR 1.8) than at ratios of less than 2 (RR 2.4 p = 0.10). We found that a ratio of 2-3 had the lowest absolute risk (AR) of events (AR 4.3%/yr, 95% CI 3.0%-6.3%).
The risks of hemorrhage and thromboemboli are minimized at international normalized ratios of 2-3. Ratios that are moderately higher than this therapeutic range appear safe and more effective than subtherapeutic ratios.
Coagulation has not and never will be simple. It has been part of the history of the world from the Egyptians to Hippocrates, to the present day evening news. The historical study of how coagulation has been handled from early times has played an important role in history, and we have only just begun.
Donna Castellone
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About the Author
Donna Castellone,
MS, MT(ASCP)SH
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