UNIT 7 Medical Interventions What is medical intervention

UNIT 7 Medical Interventions

What is medical intervention? � Video clip – intro to OR � A medical intervention is something that is done to treat or prevent an illness or injury.

How are diseases prevented? � Hygiene � Sanitation � Isolation/Quarantine

What types of medical interventions are available to treat diseases? � Medication � Surgery � Physical/Occupational Therapy � Medical Devices (pacemakers, prosthetics)

Do all patients with a disease respond to the same treatment? � No, some people may have different diseases that only respond to certain treatments. ◦ There are different interventions that can help to treat the different diseases � Even patients with the same disease do not respond to the same treatment. ◦ Metabolic rates are different between people ◦ Allergic reactions differ between people

7. 1. 2 How Are Medicines Developed & Tested? � Medical interventions are developed and tested by performing clinical trails in which the scientist can observe the patients side affects after taking the medical intervention (drug) and see if it is safe to go out to the public. � It can take over 20 years to go from the initial testing or development of a medication until it is available to patients. ◦ Less than 1 of every 5, 000 potential medications actually becomes available to patients.

Patent � As soon as a likely compound is found, the company applies for a patent. � This is because it costs so much money to develop promising compounds. � The patent protects the company against other companies marketing the same compound. � The patent lasts for 20 years. However, because of the time taken to develop the product, it will only be protected for about 710 years after it is launched.

Research: early research � Understanding a disease and determining a way to treat it can take up to twenty years. � This research is going on all the time. Scientists will come up with a theory about what causes a disease. For example, the narrowing of airways that occurs during an asthma attack.

Research: target � They will then target a part of the biological process that causes the problem. � This might be a missing protein, a lack of a hormone or a defective gene. � In the case of asthma, scientists knew that adrenalin acted as a bronchodilator and, although not suitable itself, they reasoned that a similar substance might work.

Research: discovery � They will then look for or design suitable compounds which might prevent, treat or cure the disease. � Sometimes these compounds are based on substances already produced in the body, or are developed from plant sources. � Computers are very important in medical research because they are used to help design new compounds and to select those which look most promising. ◦ It can take several years to get a group of likely compounds, and up to 10 000 possible new chemicals might be investigated.

Selection �A potential drug will only be selected for further research if it meets certain requirements: ◦ ◦ It isn't poisonous it will be effective against the disease it won't break down too quickly in the body no major problems can be foreseen for making it on a large scale.

Testing � There are three stages of testing: ◦ ‘in vitro’ tests This stage uses techniques such as cell culture to look at biological activity and to eliminate all but a few of the original possible compounds. Compounds that have obvious toxic effects can be eliminated at this stage. In vitro means "in glass“. ◦ ‘in vivo’ tests These are tests using laboratory animals, and they are a vital safety check. Because the bodies of other mammals work in similar ways to the human body, tests on animals show the selected compounds are likely to react in the human body. The use of animals also gives important information about the dose level and how often to take a medicine. ◦ Human clinical trials comprise the 3 rd step and will be carried out later.

Human Clinical Trials The chosen compound is tested on humans to check that there are no adverse side effects and to ensure that it does treat the disease. � Phase I Small numbers (20 to 80) of healthy volunteers take a short course of the new medicine. This is to look for factors such as: � lowest and highest dose �how long each dose works �side effects.

Human Clinical Trials � Phase II Longer term studies in healthy volunteers. Also, there are short term studies in several hundred patients (who have the target disease) to see how well the compound works on the disease.

Human Clinical Trials � Phase III Large scale studies in several thousand patients to look for statistical evidence that the compound is effective, what dosages will be required and potential side effects.

Who develops and tests the effectiveness of an intervention to prevent or treat a disease? � The person who came up with the medical intervention is usually the person who develops and test the effectiveness. � The inventor usually tests it on other people or animals but is in charge of the clinical trial.

How do medical personnel decide on the best treatment for a patient? � Medical personnel decide on the best treatment by ◦ studying the results of the clinical trials ◦ researching about the disease that the patient has ◦ finding the best options which will lead to the best treatment for the patient.

Do all patients have the same access to medical care and treatment? � No, some people can not pay for medical care and therefore have a difficult time paying for the treatment of their disease.

How have advances in technology affected the development and availability of medical interventions? � The advances have helped us come further in ways to treat patients with medical interventions. � We have such smart technology that is can design and create almost any model for cast, make any medcine, and fix almost any problem that a patient may come to the doctors for.

7. 1. 4 What Medical Interventions Might Have Helped � Remember Anna Garcia? ? ◦ You determined that the cause of death was a heart attack, but all the other health conditions also impacted her health and ultimately her ability to survive. ◦ She was diabetic and had further complications due to sickle cell disease, high cholesterol, and past bacterial infections. ◦ Because the body is a system and all the components work together, it is not uncommon for a patient to have multiple medical issues or complications.

7. 1. 4 What Medical Interventions Might Have Helped � According to the autopsy report, there was evidence of several medications in her blood including ◦ ◦ Thiazolidione Piolitizone acetylsalicylic acid hydroxyurea. � Were there other options available to treat her diseases?

Heart Disease/Coronary Artery Occlusion/Myocardial Infarction • Medication: acetylsalicylic acid � Function: has an antiplatelet effect by inhibiting production of thromboxane, which binds platelets together (Prevents heart attack and blood clots) � Side effect – gastrointestinal ulcers; inhibits kidneys from excreting uric acid � Other medications: anticoagulants warfarin, heparin; other NSAIDs (acetominophen and ibuprofen) � Lifestyle choices: healthy diet, moderate exercise, control blood pressure & cholesterol

Diabetes • Medication: Thiazolidione/Piolitizone � Function: works by decreasing insulin resistance and causing formation of new fat cells to decrease blood glucose levels; also inhibits growth of staphylococcus epidermis � Side effect – weight gain, peripheral edema, kidney damage � Other medications – sulfonylureas, meglitinides, alfa glucosidase inhibitors, biguanides � Lifestyle choices – healthy diet, moderate exercise, weight control

Sickle Cell Anemia • Medication: hydroxyurea � Function: makes the RBCs more flexible � Side effect: lowers white blood cells in blood, unusual bleeding, hair loss, increased risk of leukemia � Other medications: antibiotics, pain medications � Lifestyle choices: regular medical care

High Cholesterol � Medication: none indicated � Other medications: statins (lipitor), bile acid binding resins, zetia, vytorin � Function: statins block substances needed to make cholesterol, bile acid binding resons prevent reabsorption of bile (made from cholesterol) � Side effects: constipation, nausea, muscle pain � Lifestyle choices: healthy diet, moderate exercise

Past Bacterial Infections (valve damage due to rheumatic fever) � Medication: none detected � Other medications: antibiotics before dental procedures � Function: prevent further damage from bacteria entering the blood stream � Lifestyle Choices: immediate treatment of current bacterial infection, reduce strain on heart valves (lower blood pressure and cholesterol)

7. 1. 5 What Is Biomedical Engineering? � Biomedical engineers specifically work at the junction of the biomedical sciences and engineering. � They examine the structures and processes that occur in the human body. The human body performs a vast array of tasks including moving from place to place; transporting, distributing, and recycling of materials; building and repairing tissues; and obtaining energy.

7. 1. 5 What Is Biomedical Engineering? � The need for medical interventions drives the development, improvement, and application of technology. � The availability of technology drives the development, improvement, and application of medical interventions.

Consider which engineering fields were used in the development of some common medical devices Medical Devices � Prosthesis � Artificial heart valve � Insulin Pump � Pacemaker � Artificial Skin � Cochlear Implants � CT Scanner � Artificial blood � Artificial joints Engineering Fields General Engineering Fields: � Mechanical Engineering � Chemical Engineering � Materials Science � Electrical Engineering Bioengineering Fields: � Biomechanics � Biomaterials � Biochemical � Diagnostics

7. 1. 1 What Are Medical Interventions? �A medical intervention is something that is done to treat or prevent an illness or injury. � The focus in this activity is on medical interventions that are considered the foundation and history of Western medicine because the medical system in the United States has its roots in Western medicine. ◦ The roots of Eastern or Oriental medicine can be found in China, Japan, and other countries in the Orient. ◦ Other medical histories or traditions include the American Indian, Arabic, and Armenian.

Greek � Medical interventions: surgery, medication, bloodletting � Surgery: yes, carried out by “surgeons” � Instruments/facilities: Temples � Drugs/medications: yes � Theory of cause of disease: imbalance of the four humors � Technology: surgical tools

Roman � Medical interventions: hygiene, surgery, medication, bloodletting � Surgery: instruments used � Instruments/facilities: hospitals � Drugs/medications: herbs, painkillers, antiseptics � Theory of cause of disease: bad air, tiny creatures � Technology: surgical tools

Medieval � Medical interventions: surgery, medication, meditation � Surgery: yes, last resort � Instruments/facilities: no dedicated health centers � Drugs/medications: various plant, animal, & inorganic substances � Theory of cause of disease: bad odors, sins of the soul � Technology: surgical tools

Early 1700’s � Medical interventions: bloodletting � Surgery: performed by barbers � Instruments/facilities: no dedicated health centers � Drugs/medications: various plant, animal & inorganic substances � Theory of cause of disease: chemicals, natural causes � Technology: surgical tools, microscopes (late 1700’s)

American Civil War � Medical interventions: vaccinations (limited) � Surgery: amputations common, chloroform used � Instruments/facilities: tents, homes � Drugs/medications: various pant, animal & inorganic substances; purchased some from Europe � Theory of cause of disease: unknown � Technology: surgical tools, microscopes

World War 1 � Medical interventions: blood transfusions, artificial limbs � Surgery: emphasis on sterility/disinfection, facial reconstruction � Instruments/facilities: hospitals � Drugs/medications: produced/chemicaly engineered rather than herbs and natural substances � Theory of cause of disease: germs � Technology: x-rays, respirators

World War 2 � Medical interventions: plasma infusions, preventative measures against malaria, debridement � Surgery: advances in combat surgery � Instruments/facilities: hospitals � Drugs/medications: antibiotics widely used � Theory of cause of disease: germs � Technology: advanced surgical techniques

7. 1. 3 How can Pharmaceuticals Help? � Lactose – disaccharide found in milk � Glucose is metabolized for energy ◦ made of the monosaccharides glucose and galactose ◦ C 6 H 12 O 6 + 6 O 2 → 6 CO 2 + 6 H 2 O + energy � Lactose intolerance – lacks the enzyme (lactase) to break down lactose ◦ If it isn’t broken down, it can’t be metabolized for energy ◦ Bacterial in intestines metabolize it instead, causing gas and acid production leading to discomfort

7. 1. 3 How Can Pharmaceuticals Help? � People with lactose intolerance take a pharmaceutical that contains the enzyme lactase � Lactase enzyme breaks down the lactose sugar before it can reach the bacteria in the large intestine.

7. 1. 3 How Can Pharmaceuticals Help? � You will test the activity of a pharmaceutical that contains lactase and is sold to people with lactose intolerance using yeast. ◦ Yeast strains are single-celled eukaryotic organisms that are often confused with bacteria. Most yeast strains lack the lactase enzyme. Therefore, we can use yeast as a model of a lactose intolerant person. ◦ If the lactase is metabolized, then carbon dioxide gas will be released because the process of cellular respiration is the same in yeast cells as it is in human cells. ◦ We can measure the amount of carbon dioxide produced by yeast cells to indicate whether or not the sugar is being used for energy.