By G. Hanson. Sterling College, Vermont. 2018.
Although one may ﬁnd a study that shows a statistically signiﬁcant reduction of myocardial infarction generic extra super avana 260mg mastercard, if the result is only reported as a composite outcome along with other outcomes such as reduced incidence of angina and heart failure generic 260mg extra super avana visa, the result will not directly address your patient’s ques- tion. Since this type of presentation of data is used by authors when an individ- ual outcome is not itself statistically signiﬁcant, the combination of outcomes is used to achieve statistical signiﬁcance and get the study published. But, the composite is often made up of various outcomes not all of which have the same value to the patient. The goal of a discussion with the patient is to explain the results of each of the composite components so that she can make up her mind about which of the outcomes are important to her. Recommendations for understanding the patient’s experience and expectations The patient’s perspective on the problem as well as the available evidence deter- mines the true need to proceed with further steps to communicate evidence. It is possible that the patient’s questions relate only to background information, which is clearly deﬁned in the science of medicine and not dependent on your interpretation of the most recent research evidence for an answer. Then, if evi- dence is needed to answer a patient’s question, ﬁrst check to see whether it truly addresses the patients query about her desired outcomes rather than outcomes that are not important to the patient. Step 2: Build partnerships Taking time for this step is a way to build rapport with the patient. After dis- cussing the patient’s perspective, an impression will have developed of whether one generally agrees or disagrees with the patient. At this point in the discussion, Communicating evidence to patients 203 it should be clear what, if any, existing evidence may be of interest to the patient. The physician will also have a good understanding of whether to spend a major- ity of their time discussing basic or more advanced information. Using phrases such as “Let me summarize what you told me so far” or “It sounds like you are not sure what to do next” can help to build partnership that will allow a transition to the third step in the process of communicating evidence. In the example, the patient who is interested in aspirin for prevention of strokes and heart attacks is frustrated by her lack of reduction of weight or cholesterol after implementing some lifestyle changes. Expressing empathy for her struggles will likely help the patient see you as partner in her care. Step 3: Provide evidence As health-care providers, numbers are an important consideration in our decision-making process. While some may want the results this way, many patients do not want results to be that speciﬁc or in numerical form. As a general rule, patients tend to want few speciﬁc numbers, although patients’ preferences range from not wanting to know more than a brief statement or the “bottom line” of what the evidence shows to wanting to know as much as is available about the actual study results. Check the patient’s preference for information by ask- ing: “Do you want to hear speciﬁc numbers or only general information? Another way to start is by giving minimal information and allowing the patient to ask for more, or follow this basic information by asking the patient whether more speciﬁc infor- mation is desired. Previous experiences with the patient can also assist in deter- mining how much information to discuss. Presenting the information There are a number of ways to communicate information to patients and under- standing the patient’s desires can help determine the best way to do this. The ﬁrst approach is to use conceptual terms, such as “most patients” or “almost every patient” or “very few patients. A second approach is to use general numerical terms, such as “half the patients” or “1 in 100 patients. While these are the most common verbal approaches, both conceptual and numerical rep- resentations can be graphed, either with rough sketches or stick ﬁgures. In a few clinical situations, more reﬁned means of communicating evidence have been 204 Essential Evidence-Based Medicine developed, such as decision aid programs available for prostate cancer screen- ing. The patient answers questions at a computer about his preferences regard- ing prostate cancer screening and treatment. These preferences then determine a recommendation for that patient about prostate cancer screening using a decision tree similar to the ones that will be discussed in Chapter 30. Unfortu- nately, these types of programs are not yet widely developed for most decision making.
Furthermore generic 260 mg extra super avana mastercard, the crystals can produce a pulse of electrical energy by mechanically exciting the crystal buy extra super avana 260mg on line. This ultrasound physics principle is called the piezoelectric effect (pressure electricity). Crystalline materials with piezoelectric properties are quartz crystals, piezoelectric ceramics such as barium titanate or lead zirconate titanate. A device that converts one form of energy into another is called a “transducer” – and they can be used for production and detection of diagnostic ultrasound. We are not going into more details about the equipment here, but it is possible to use ultrasound tech- nique to produce pictures of the inside of the body. Since ultrasound images are captured in real-time, they can show the structure and movement of the body’s internal organs, as well as blood fowing through the blood vessels. Ultrasound imaging is a noninvasive medical test that helps physicians diagnose and treat medical conditions. A short history The origin of the technology goes back to the Curies, who frst discovered the piezoelectric effect. Attempts to use ultrasound for medical purposes startet in the 1940s when they used a contineous ultrasonic emitter to obtain images from a patient`s brain. The use of Ultrasonics in the feld of medicine had nonetheless started initially with it’s applications in therapy rather than diagnosis, utilising it’s heating and disruptive effects on animal tissues. An excellent review of the history of ultrasound can be found in the following address: http://www. The transducer is coupeled to the body by a gel and the pulse of ultrasound goes into the soft tissuse (speed of about 1500 m per second). The transducer will then sense the refected, weaker pulses of ultrasound and transform them back into electrical signals. These echoes from different organs are amplifed and processed by the receiver and sent to the computer, which keeps track of the return times and amplitudes. You can see how arms and legs of a fetus move, or see the heart valve open and close. Computer Receiver A lot of technology is involved in the different parts Transducer of the ultrasound technique. Let us shortly mention that the transducer, that trans- mits and receives the ultrasound energy into and from the body is a key component. It is built up of hundreds of transducers in order to take a high reso- The main components of ultrasound lution real-time scan. The many transducers create a wavefront and the angle of the wavefront can be altered by fring the transducers one after another. By changing the angle of the wavefront, a three-dimensional image can be built up over a large area. Doppler ultrasound The velocity of the blood can be measured by the Doppler effect – i. Side effects Current evidence indicates that diagnostic ultrasound is safe even when used to visualize the embryo or fetus. In this connection we would like to mention that research in the beginning of 1980s showed that use of clinical ultrasound equipment could result in water radicals (H. Furthermore, in work with cells in culture exposed to ultrasound resulted in damage (simi- lar to those known from ionizing ra- diation). In the fgure to the right is given the world average use of radiation for medical imag- ing. New techniques and methods have been added with the result that the total dose (the collective dose) has increased. Since the 1950s it has been a goal to keep the doses for each examination as low as pos- sible – in order to prevent any deleterious ef- fects of radiation. Year The fgure shows the use of x-rays for imaging It may be of interest to attain some infor- since the start in 1895 mation about the radiation exposure from diagnostic medical examinations. The Committee concluded that medical applications are the largest man-made source of radiation exposure for the world’s population. The doses are in general small and are justifed by the benefts of accurate diagnosis of possible disease conditions. This implies that the effective doses to patients undergoing different types of medical diagnostic have been obtained.
Direct impacts on wildlife are not clear buy extra super avana 260 mg without prescription, although indirect long-term effects may include threats to the environment and aquatic biodiversity through discount extra super avana 260 mg fast delivery, for example, declining biomass and irreversible ecological disruption. Effect on Aquaculture High losses (up to 80-90% with bonamiosis) to oyster farmers through and Fisheries mortalities, and reduced growth/productivity. However, oysters could potentially pose a health concern for humans in cases where they contain high levels of Vibrio spp. Economic importance Oyster disease has the potential to financially decimate those who run oyster farming operations. Subsequently, oyster diseases can negatively affect the community and industries depending on the oyster trade. Risk assessment of Vibrio vulnificus in raw oysters: interpretative summary and technical report. Photos Oysters infected with Bonamia ostreae, illustrating classic symptoms of Bonamia ostreae infection, e. Although often characterised by high morbidity and mortality rates, pathogenicity can vary significantly, with clinical disease ranging from mild to severe. The outcome of infection may often be complicated by the involvement of pre-existing secondary pathogens. Species affected Small ruminants, predominantly sheep and goats, although many other species have been reported to be infected and develop clinical disease. The role of wildlife species in the transmission of the virus remains unclear although zoological collections in Saudi Arabia and various wildlife species across Africa have been shown to be susceptible (e. Arabian oryx Oryx leucoryx, Dorcas gazelle Gazella dorcas, Laristan sheep Ovis orientalis laristanica, gemsbok Oryx gazella, Nubian ibex Capra nubiana, Thomson’s gazelle Eudorcas thomsonii, grey duiker Sylvicapra grimmia, kobs Kobus kob and Bulbal hartebeest Alcelaphus buselaphus). Camels are also susceptible to infection and can display signs of clinical disease. However, the virus is known to be excreted in eye and nasal discharge as well as, to a lesser extent, in urine and faecal matter. Transmission via infected bedding, water, feed troughs and other inanimate objects (fomites) is possible but is thought to occur at a very low level. The variability in virulence between different isolates of the virus is currently poorly understood. However, animals can excrete and therefore spread the virus in the absence of clinical disease, often allowing the spread of virus to naïve populations when groups of animals are moved. Clinical disease is often preceded by a 4-5 day incubation period where animals must be considered to be contagious. Factors affecting the outcome of infection include breed, age, immunological competence, general health, and the presence of secondary infections. Subsequent and additional measures: quarantine affected area and restrict movement of animals avoid introduction of healthy animals collect samples (where appropriate and as directed) dispose of carcases (burning or burying as directed) disinfect in-contact fomites; most common disinfectants can be used. Diagnosis A tentative diagnosis can be made based on the clinical signs described above. The virus may survive for short periods in carcases and in refrigerated meat, and may survive for several months in salted or frozen meat. Livestock Livestock stakeholders are advised to monitor susceptible animals closely and frequently for any signs of disease or developing illness. Where possible, any newly acquired small ruminants should be quarantined for a minimum of 21 days and monitored, before being released. Infected animal carcases should be burned or buried deep, along with their contact fomites (bedding, feed etc). Disinfection and cleaning Thoroughly clean and disinfect all contaminated areas and items (including holding pens, physical perimeters, clothing and equipment) with lipid solvent solutions of high or low pH and disinfectants. Vaccination Consider and seek advice on the best use of vaccine; strategically ‘ring’ vaccinate and/or vaccinate high-risk populations. This involves vaccinating susceptible animals in a given zone, forming a buffer of immune individuals that then limit disease spread. Vaccination of high-risk populations in high-risk areas (prophylactic immunisation).
This may not always be possible since studies done with dif- ferent populations may result in different results of test characteristics generic extra super avana 260 mg without a prescription, a result which cannot be predicted cheap extra super avana 260 mg amex. In the ideal situation, the patients enrolled in the study are then all given the diagnostic test and the gold-standard tests without the researchers or the patient knowing the results of either test. As with any clinical study, there will be sources of bias in studies of diagnos- tic tests. Some of these are similar to biases that were presented in Chapter 8 on sources of bias in research, but others are unique to studies of diagnostic tests. You ought to look for three broad categories of bias when evaluating stud- ies of diagnostic tests. Selection bias Filter bias If the patients studied for a particular diagnostic test are selected because they possess a particular characteristic, the resulting operating characteristics found by this study can be skewed. The process of patient selection should be explicit in the study methods but it is often omitted. Part of the actual clinical diagnostic process is the clinician selecting or ﬁltering out those patients who should get a particular diagnostic test done and those who don’t need it. A clinician who believes that a particular patient does not have the target disorder would not order the test for that disease. Suspect this form of bias when only a portion of eligible patients are given the test or entered into the study. The process by which patients are screened for having the testing should be explicitly stated in any study of a diagnostic test allowing the reader to determine the external validity of the study. Decide for yourself if a particular patient in actuality is similar enough to the patients in the study to have the test ordered and to expect results to be similar to those found in the study. If there is no clear-cut and reproducible way to deterimine how they were selected it would be difﬁcult, if not impossible, to determine how to select patients to have the test done on them. It is possible that an unknown ﬁlter was applied to the process of patient selection for the study. Although this ﬁlter could be applied in an equitable and non-differential manner, it can still cause bias since its effect may be different in those patients with and without the target disease. This selec- tion process usually makes the test work better than it would in the community situation. The community doctor, not knowing what that ﬁlter was, would not know which patients to select for the suggested test and would tend to be less selective of those patients to whom the test would be applied. Spectrum and subgroup bias (case-mix bias) A test may be more accurate when given to patients with classical forms of a disease. The test may be more likely to identify patients with the disease that is more severe or “well-developed” and less likely to accurately identify the disease in those patients who present earlier in the course of the disease or in whom the disease is occult or not obvious. Most diagnostic tests have very little utility in the general and asymp- tomatic population, while being very useful in speciﬁc clinical situations. Most of that problem is due to a large percentage of false positives when the very low prevalence population is tested. There are also cases for which the test characteristics, sensitivity and speci- ﬁcity, also increase as the severity of disease increases. If only a small leak is present, the patient is more likely to present with a severe headache and no neu- rological deﬁcits. In the 1950s and 1960s, the yearly “executive physical examination,” which included many laboratory, x-ray, and other tests was very popular, especially among corporate executives. In fact the results were most often normal and, when abnormal, were usually falsely positive. They are touted as being able to spot asymptomatic disease in early and curable stages with testimonials given on their usefulness. But, sometimes those who have negative tests won’t all have the gold-standard test done and have some other method for evaluating the presence or absence of disease in them. This will usually make the test perform better than it would if the gold standard were done on all patients who would be considered for the test in a real clinical situation. Frequently, patients with negative tests are followed clinically for a certain period of time instead of having the gold-standard test performed on them. This may be appro- priate if no patients are lost to follow-up and if the presence of disease results in some measurable change in the patient over the time of follow-up. You cannot do this with silent diseases that become apparent only many years later unless you follow all of the patients in the study for many years.
Much of this information is offered to give you perspective of what may be possible in a long term catastrophic disaster or when working in an austere or remote environment without access to organised or trained medical care – we in no way endorse practicing these techniques except in such a situation extra super avana 260 mg sale. This information is offered as personal opinions and should not be taken to represent a professional opinion or to reflect any views widely held within the medical community 260 mg extra super avana amex. Appropriate additional references should be consulted to confirm and validate the information contained in this book. It was written in response to recurring posts asking the same questions and the fact that many answers were often wrong and occasionally dangerous. While the original content remains valid we thought it was time it underwent an update. This is a significant revision – most sections have been re-written and a number of new sections added. It is offered in good faith but the content should be validated and confirmed from other sources before being relied on even in an emergency situation. There are very few books aimed at the “Practicing Medicine after the End of the World As We Know It” market – which is hardly surprising! We also hope it will be useful for those people delivering health care in remote or austere environments. It is designed to provide some answers to commonly asked questions relating to survival/preparedness medicine and to provide relevant information not commonly found in traditional texts or direct you to that information. We have tried to minimise technical language, but at times this has not been possible, if you come across unfamiliar terms – please consult a medical dictionary. The authors and editors are passionately committed to helping people develop their medical knowledge and skills for major disasters. Web Site: For questions and comments the authors can all be contacted via posting at the following website: “The Remote, Austere, Wilderness and Third world Medicine Forum” http://medtech. Poor hygiene and disrupted water supplies would lead to an increase in diseases such as typhoid and cholera. Without vaccines there would be a progressive return in infectious diseases such as polio, tetanus, whooping cough, diphtheria, mumps, etc. People suffering from chronic illnesses such as asthma, diabetes, or epilepsy would be severely affected with many dying (especially insulin-dependent diabetics). There would be no anaesthetic agents resulting in return to tortuous surgical procedures with the patient awake or if they were lucky drunk or stoned. The same would apply to painkillers; a broken leg would be agony, and dying of cancer would be distressing for the patient and their family. Without reliable oral contraceptives or condoms the pregnancy rate would rise and with it the maternal and neonatal death rates, women would die during pregnancy and delivery again, and premature babies would die. Women would still seek abortions, and without proper instruments or antibiotics death from septic abortion would be common again. In the absence of proper dental care teeth would rot, and painful extractions would have to be performed. Our definition is: "The practice of medicine in an environment or situation where standard medical care and facilities are unavailable, often by persons with no formal medical training". This includes medical care while trekking in third world countries, deep-water ocean sailing, isolated tramping and trekking, and following a large natural disaster or other catastrophe. The basic assumption is that trained doctors and hospital care will be unavailable for a prolonged period of time, and that in addition to providing first aid - definitive medical care and rehabilitation (if required) will need to be provided. Austere medicine is the provision of medical care without access to modern investigations or technology. As is the case with any aspects of preparedness you need to decide what you are preparing for and plan accordingly. For some it will only be a 72-hour crisis, for others it will be a major long-term event, and for yet others a multiple generation scenario. Your medical preparations will need to reflect your own risk assessments in terms of what knowledge and skills you develop and what supplies/equipment/medicines you store. This book is more slanted towards preparation for medium to longer term disasters. A recent Internet survey asking about medical risk assessments in a major disaster came up with the following results: “What do you see as the most likely common source of medical problems?
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