MEDICAL SPECIALITIES: January 2008

CLINICAL SKILLS

A complete medical evaluation includes a medical history, a systems enquiry, a physical examination, appropriate laboratory or imaging studies, analysis of data and medical decision making to obtain diagnoses, and a treatment plan.

The components of the medical history are:

Chief complaint (CC): the reason for the current medical visit. These are the 'symptoms.' They are in the patient's own words and are recorded along with the duration of each one. Also called 'presenting complaint.'
History of present illness / complaint (HPI): the chronological order of events of symptoms and further clarification of each symptom.
Current activity: occupation, hobbies, what the patient actually does.
Medications (DHx): what drugs the patient takes including prescribed, over-the-counter, and home remedies, as well as alternative and herbal medicines/herbal remedies such as St John's wort. Allergies are also recorded.
Past medical history (PMH/PMHx): concurrent medical problems, past hospitalizations and operations, injuries, past infectious diseases and/or vaccinations, history of known allergies.
Social history (SH): birthplace, residences, marital history, social and economic status, habits (including diet, medications, tobacco, alcohol).
Family history (FH): listing of diseases in the family that may impact the patient. A family tree is sometimes used.

Review of systems (ROS) or systems inquiry: a set of additional questions to ask which may be missed on HPI: a general enquiry (have you noticed any weight loss, fevers, lumps and bumps? etc), followed by questions on the body's main organ systems (heart, lungs, digestive tract, urinary tract, etc).

The physical examination is the examination of the patient looking for signs of disease ('Symptoms' are what the patient volunteers, 'Signs' are what the healthcare provider detects by examination). The healthcare provider uses the senses of sight, hearing, touch, and sometimes smell (taste has been made redundant by the availability of modern lab tests). Four chief methods are used: inspection, palpation (feel), percussion (tap to determine resonance characteristics), and auscultation (listen); smelling may be useful (e.g. infection, uremia, diabetic ketoacidosis). The clinical examination involves study of:

Vital signs including height, weight, body temperature, blood pressure, pulse, respiration rate, hemoglobin oxygen saturation
General appearance of the patient and specific indicators of disease (nutritional status, presence of jaundice, pallor or clubbing)
Skin
Head, eye, ear, nose, and throat (HEENT)
Cardiovascular (heart and blood vessels)
Respiratory (large airways and lungs)
Abdomen and rectum
Genitalia (and pregnancy if the patient is or could be pregnant)
Musculoskeletal (spine and extremities)
Neurological (consciousness, awareness, brain, cranial nerves, spinal cord and peripheral nerves)
Psychiatric (orientation, mental state, evidence of abnormal perception or thought)

Laboratory and imaging studies results may be obtained, if necessary.

The medical decision-making (MDM) process involves analysis and synthesis of all the above data to come up with a list of possible diagnoses (the differential diagnoses), along with an idea of what needs to be done to obtain a definitive diagnosis that would explain the patient's problem.

The treatment plan may include ordering additional laboratory tests and studies, starting therapy, referral to a specialist, or watchful observation. Follow-up may be advised.

This process is used by primary care providers as well as specialists. It may take only a few minutes if the problem is simple and straightforward. On the other hand, it may take weeks in a patient who has been hospitalized with bizarre symptoms or multi-system problems, with involvement by several specialists.

On subsequent visits, the process may be repeated in an abbreviated manner to obtain any new history, symptoms, physical findings, and lab or imaging results or specialist consultations.

PRACTICE OF MEDICINE

The practice of medicine combines both science as the evidence base and art in the application of this medical knowledge in combination with intuition and clinical judgment to determine the treatment plan for each patient.

Central to medicine is the patient-physician relationship established when a person with a health concern seeks a physician's help; the 'medical encounter'. Other health professionals similarly establish a relationship with a patient and may perform various interventions, e.g. nurses, radiographers and therapists.

As part of the medical encounter, the healthcare provider needs to:

develop a relationship with the patient
gather data (medical history, systems enquiry, and physical examination, combined with laboratory or imaging studies (investigations))
analyze and synthesize that data (assessment and/or differential diagnoses), and then:
develop a treatment plan (further testing, therapy, watchful observation, referral and follow-up)
treat the patient accordingly
assess the progress of treatment and alter the plan as necessary (management).

The medical encounter is documented in a medical record, which is a legal document in many jurisdictions

HISTORY OF MEDICINE

Physician treating a patient. Louvre Museum, Paris, France.

The earliest type of medicine in most cultures was the use of empirical natural resources like plants (herbalism, animal parts and minerals. In all societies, even in Western ones, there were also religious, ritual and magical resources. In aboriginal societies, there is a large scope of medical systems related to religious thinking, cultural experience, and natural resources. The religious ones more known are : animism (the notion of inanimate objects having spirits); spiritualism (here meaning an appeal to gods or communion with ancestor spirits); shamanism (the vesting of an individual with mystic powers); and divination (the supposed obtaining of truth by magic means). The field of medical anthropology studies the various medical systems and their interaction with society.

The practice of medicine developed gradually in ancient Egypt, Babylonia, India, China, Greece, Persia, the Islamic world, medieval Europe, and elsewhere. Medicine as it is now practiced largely developed during the Middle Ages and early modern period in Persia (Rhazes and Avicenna), Spain (Abulcasis and Avenzoar), Syria/Egypt (Ibn al-Nafis, 13th century), England (William Harvey, 17th century), Germany (Rudolf Virchow, 19th century) and France (Jean-Martin Charcot, Claude Bernard and others). The new "scientific" or "experimental" medicine (where results are testable and repeatable) replaced early Western traditions of medicine, based on herbalism, the Greek "four humours" and other pre-modern theories.

The focal points of development of clinical medicine shifted to the United Kingdom and the USA by the early 1900s (Canadian-born) Sir William Osler, Harvey Cushing). Possibly the major shift in medical thinking was the gradual rejection, especially during the Black Death in the 14th and 15th centuries, of what may be called the 'traditional authority' approach to science and medicine. This was the notion that because some prominent person in the past said something must be so, then that was the way it was, and anything one observed to the contrary was an anomaly (which was paralleled by a similar shift in European society in general - see Copernicus's rejection of Ptolemy's theories on astronomy). Physicians like Ibn al-Nafis and Vesalius led the way in improving upon or indeed rejecting the theories of great authorities from the past (such as Hippocrates, Galen and Avicenna), many of whose theories were in time discredited. Such new attitudes were made possible in Europe by the weakening of the Roman Catholic church's power in society, especially in the Republic of Venice.

Evidence-based medicine is a recent movement to establish the most effective algorithms of practice (ways of doing things) through the use of the scientific method and modern global information science by collating all the evidence and developing standard protocols which are then disseminated to healthcare providers. One problem with this 'best practice' approach is that it could be seen to stifle novel approaches to treatment.

Drug ampoules

Genomics and knowledge of human genetics is already having some influence on medicine, as the causative genes of most monogenic genetic disorders have now been identified, and the development of techniques in molecular biology and genetics are influencing medical practice and decision-making.

Pharmacology has developed from herbalism and many drugs are still derived from plants (atropine, ephedrine, warfarin, aspirin, digoxin, vinca alkaloids, taxol, hyoscine, etc). The modern era began with Robert Koch's discoveries around 1880 of the transmission of disease by bacteria, and then the discovery of antibiotics shortly thereafter around 1900. The first of these was arsphenamine / Salvarsan discovered by Paul Ehrlich in 1908 after he observed that bacteria took up toxic dyes that human cells did not. The first major class of antibiotics was the sulfa drugs, derived by French chemists originally from azo dyes. Throughout the twentieth century, major advances in the treatment of infectious diseases were observable in (Western) societies. The medical establishment is now developing drugs targeted towards one particular disease process. Thus drugs are being developed to minimise the side effects of prescribed drugs, to treat cancer, geriatric problems, long-term problems (such as high cholesterol), chronic diseases type 2 diabetes, lifestyle and degenerative diseases such as arthritis and Alzheimer's disease.