Friday 21 August 2015

What is a physical examination in medicine?


Indications and Procedures

Physical diagnosis—the principles, practices, and traditions that form the foundation of the modern physical examination—has rightly been called an art. Usually taught during the first two years of medical training, the basic skills of observation, auscultation, palpation, and percussion are later augmented by hands-on experience with actual patients. For many students, this acquisition of physical diagnostic skills marks the point when they begin to feel like “real” doctors. Observation techniques may be overt or subtle, as a patient may have difficulty maintaining usual behavior if consciously aware of scrutiny. An examiner may even find it necessary to distract the patient in order to allow accurate assessment.



Auscultation, from the Latin auscultare (to listen), is generally performed with the aid of a stethoscope. Normal bodily functions generate sounds, the presence or absence of which may provide clues to health or illness. Palpation, from the Latin palpare (to touch softly), involves the application of the examiner’s hands to the patient’s body. This touching conveys information about the size, texture, consistency, temperature, and tenderness of physical structures. This person-to-person contact can also exert an important calming or reassuring effect on the patient. Percussion, from the Latin percussio (striking), entails a gentle tapping of the examiner’s finger, which has been placed on the patient. A resonant return is noted over hollow, air-filled structures. In contrast, solid or fluid-filled structures produce a dull fullness. A simple demonstration of this technique can be performed by partially filling a bucket with water. By tapping on the outside and noting the variations in sound, it is possible to estimate the fluid level without looking inside the bucket.


To some extent, the widespread use of sophisticated diagnostic imaging technologies has decreased the emphasis on physical examination skills in actual practice. This trend is unfortunate, because it lessens face-to-face contact between the patient and physician and may thus prove unsatisfying for both. It would be misleading, though, to view technological discoveries as competing only with the physical examination. Over the years, the usefulness of physical diagnosis has been enhanced by the availability of simple tools and elegant instruments that augment the examiner’s biological senses. Common examples include the stethoscope, the oto-ophthalmoscope (a handheld halogen light source with interchangeable optics, used to view the inside of the eyes and ears), the reflex hammer, and the tuning fork. Indeed, the line separating physical diagnosis from other diagnostic procedures has been blurred as more portable devices find their way into the hands of the practicing physician.


During the physical examination, diagnostic techniques are applied in an interaction between the examiner and the patient at a unique moment in time. As such, the outcome depends on the skills of the individual examiner and on the patient’s manifest physical characteristics. Changes in physical state over time are common; variation in physical examination findings over time is not unexpected. For example,
heart murmurs, which are sounds generated by the heart, are graded on a scale from I/VI (one over six), designating a very faint murmur, to VI/VI (six over six), designating a murmur loud enough to be heard even without a stethoscope at a distance away from the patient. It is not uncommon for physicians, even cardiologists, who specialize in the heart, to disagree on the description of a murmur. In addition, a murmur itself can get louder or softer, or even disappear entirely with advancing age, exercise, pregnancy, or other factors. Physical diagnosis is an imprecise science. Medical educators have attempted to address this imprecision by modifying traditional instructional methods.


The physical examination should be considered within the larger context of medical information gathering. Customarily, it follows the collection of historical information about the patient’s immediate and past health statuses. Like a road map, the history guides the scope and focus of the subsequent examination. This marriage of history taking and physical examination is colloquially referred to as the “H and P.” Though not as often recommended as in the past, the annual complete (or head-to-foot) physical examination may come to mind when this topic is discussed. More commonly, a physical examination is directed and focused on particular regions or organ systems.


In the general

screening examination of an apparently healthy subject, a systematic survey is undertaken, following an assessment of structural and/or functional relationships. A structural division would involve examination of all the organ systems contained in or adjacent to a particular body part (for example, the foot), such as the bones, muscles, nerve supply, blood vessels, and skin. A functional examination of the cardiovascular organ system would include the heart, neck, lungs, abdomen, skin, and extremities, because manifestations of cardiovascular disease may be present in locations physically remote from the heart itself. A patient complaining of a specific problem undergoes a detailed examination of the organ systems or body structures most likely to be affected.


The sequential performance of a physical examination incorporates both structural and functional strategies. Though most examiners follow a similar framework, individual differences in physicians and patients result in a wide variety of acceptable patterns. Ideally, the process begins when the patient first arrives. Clues to a patient’s overall level of independent function, such as mobility, dexterity, and speech patterns, may be noted. As the medical history is taken, the patient’s level of alertness, as well as orientation to time, place, and self, often becomes apparent. The complete examination generally begins with the head, including the face and scalp. A survey of the skin surfaces may be accomplished with the patient completely naked, or it may be divided into discrete segments to be checked as the examination proceeds. Inspection of the eyes, ears, nose, and throat follow. Next, the neck, chest, and back are surveyed. A breast examination may be done at this time. After evaluation of the heart and lungs, the patient is asked to lie down for the abdominal examination. Genital organs may be checked at this time or may be deferred until a later part of the session. The neurologic inspection usually follows and entails the integration of findings
from earlier parts of the examination with maneuvers specific to the neurological examination. In the mental status portion of the neurologic examination, formal evaluation of memory, orientation, speech patterns, and thought processes takes place. The musculoskeletal examination likewise integrates earlier findings with a detailed focus on bone and joint development and function. Finally, the extremities are checked. Upon completion of the history and physical, the diagnosis may be readily apparent or further evaluation may be needed.


Pertinent findings, whether normal or abnormal, are documented in the medical record and may be supplemented by diagrams or photographs if necessary. Depending on the purpose of the examination, these may be entered on a separate preprinted form with check-off spaces or simply noted in the chart. Computer technology allows the storage and retrieval of this information in a patient database file.




Uses and Complications

The application of physical examination techniques may be illustrated by considering three distinct cases: a child’s school physical, a routine gynecologic examination with a Papanicolaou (Pap) test, and the evaluation of a sprained ankle. Each has a unique purpose dictating the breadth and detail of the techniques employed. In the school physical, the purpose of the examination is to screen a symptom-free individual for signs of previously unrecognized medical conditions; thus, the survey is broad. The annual gynecologic examination with a Pap testing is more focused—screening for cervical cancer and other gynecologic illness, including sexually transmitted diseases—and will focus on the reproductive system. The evaluation of the sprained ankle is done to assess damage to an identified body part following a specific injury, and it will entail a detailed inspection of the affected area. How these underlying considerations influence the methods employed are apparent as each case is considered.


A child’s school physical examination is preceded by a broad historical investigation of the individual’s birth details, immunization status, social interactions, growth and development, and daily activity. Height and weight are measured and plotted on a growth chart to facilitate comparison with expected normal values for children of the same age and sex. In many cases, the actual numbers are of less importance than the trend relating repeated measurements. Vision and hearing
screening are employed to identify defects that could interfere with school performance.


Vital signs—temperature, pulse, blood pressure, and breathing—are determined. Temperature is usually determined orally, though rectal or axillary (armpit) locations may be used. Although 37 degrees Celsius (98.6 degrees Fahrenheit) is often quoted as normal, a range of body temperatures can be found in healthy patients.
Pulse rate is measured by palpation of the radial artery in the wrist. Circumstances may dictate performing this measurement in other locations, such as the carotid artery in the neck or the femoral artery in the groin. Most patients will have a pulse between sixty and one hundred beats per minute. Higher or lower numbers are common and may be related to athletic conditioning, medications, or illness.


Blood pressure is determined with the aid of a stethoscope and a sphygmomanometer (blood pressure cuff) and is expressed in millimeters of mercury. After pumping the cuff to a high pressure, the examiner slowly deflates the cuff while listening for the sounds of blood flow, usually in the brachial artery above the elbow. The onset and end of these sounds indicate the systolic and diastolic blood pressure measurements. A measurement of 120/80 (systolic over diastolic) is often considered normal, but acceptable blood pressures will vary among individuals. In this case, the normal blood pressure for a child is lower than for an adult. Breathing rate is checked by observation and varies, depending on age and medical conditions, from approximately twelve to forty breaths per minute. Infants and children have higher rates than adults.


Following the determination of vital signs, a general physical survey is performed. The head is inspected to confirm normal shape and absence of injury. Eye movements and response to light are noted, along with any inflammation. The ears, nose, and throat are checked for signs of inflammation or scarring. A puff of air may be used to test the mobility of the eardrum. Palpation of the neck may reveal enlargement of the thyroid gland or lymph nodes. The chest is observed for abnormalities, and auscultation of the lungs is performed to monitor air flow during breathing. The cardiac examination will focus on possible murmurs, sounds generated by turbulent blood flow. Since many murmurs are harmless, and many children will have a murmur noted at some point, careful auscultation is needed to define the nature of heart sounds. If a murmur is heard, the patient may be asked to perform certain maneuvers, such as standing up quickly or taking a deep breath and straining. These actions may cause the murmur
to change in a way that allows recognition of its underlying cause.


Next, the abdomen is observed for symmetry and distension. By palpation, the examiner may discover enlargement of the liver or spleen. Percussion over the liver area may confirm enlargement of that organ. Auscultation of the sounds produced by the bowels may provide clues to increased or decreased intestinal function. An external genital examination is appropriate for boys and girls. Proper descent of the testicles into the scrotum should be ascertained for boys, while menstrual complaints may dictate an internal examination for girls. Scoliosis (curvature of the spine) or other abnormalities in neurological or musculoskeletal development may be found. Examination of the skin surface is especially important in children; in addition to birthmarks, signs of child abuse may be visible and require evaluation. The length of time needed for the entire screening process will vary. If the child is already known to the examiner and has been seen recently for other reasons, the examination itself may be brief. The presence of abnormal findings may require a lengthy, detailed evaluation.


An annual gynecologic
examination and Pap testing is preceded by a directed gathering of the patient’s medical and family history, focusing on the reproductive system. This completed, the patient is asked to lie on her back, with her feet apart in foot rests that extend from the table. Examination of the female genital tract begins with a survey of the external structures, the clitoris, labia, and vaginal opening. A discharge or surface lesions such as sores or warts may arouse suspicion of sexually transmitted disease. Since many women have some discharge normally, however, laboratory tests are often needed to establish the diagnosis of infection. To examine the internal structures of the vagina, the examiner uses a speculum, a metal or plastic instrument about five inches long and shaped like a duck’s bill. A hinge in the back allows it to be opened after insertion into the vagina, permitting inspection of the cervix and the vaginal walls with the help of a bright light. At this time, the sample is taken from the cervix, usually with a small brush and wooden spatula. After removal of the speculum, the bimanual (literally, “two hands”) examination is done. Gloved, lubricated fingers are inserted into the vagina, while the other hand presses down from the outside of the abdomen. For many women, this is the most uncomfortable part of the examination, though sensitivity by the examiner can lessen the discomfort. The cervix, uterus, Fallopian tubes, ovaries, and bladder may be palpated. A rectovaginal examination is performed by placing one finger in the vagina and another finger of the same hand in the rectum. This allows palpation of the space between the vagina and the rectum, as well as of the rectum itself. A breast examination may be performed during the office visit. Although most women focus on lumps, other
potential signs of breast cancer, such as bleeding from the nipple, a persistent rash around the nipple, skin dimpling, or retraction (turning in) of the nipple, are noted. Because breast cancer is most common in upper and outer quadrants of the breasts and may spread to lymph nodes in the armpit, palpation of these areas is prudent.


In the
examination of an apparent ankle sprain, the presence of an abnormality is a given, and the evaluation is geared to the documentation of the extent of the injury to the ankle itself and to adjacent structures. Initial observation may reveal that the patient has obvious pain while walking into the examining area. Swelling and redness may be prominent. Palpation of the leg and ankle will likely elicit tenderness over the damaged ligaments, especially with movement. Intact circulation can be confirmed by placing the fingers over the arteries of the foot and noting strong pulses. Instability of the joint itself may be discovered by applying pressure in various directions. The possibility of nerve damage is assessed by testing sensation and the strength in the foot. Though this examination is directed toward a relatively limited area of the body, it may require considerable time because of the depth of detail involved.




Perspective and Prospects

The modern physical examination is the product of a gradual evolution rather than of a single discovery or invention. Though certain individuals are credited with the adoption of particular physical diagnostic techniques, the interpretation of bodily characteristics as indicators of health status has ancient roots that predate Hippocrates, who was born in 460 BCE on the island of Cos in Greece. From the Middle Ages until the eighteenth century, physical examination focused on the pulse, which was accorded much diagnostic significance, and the feces. The scientific foundations of current practices were uncovered in Europe during the late eighteenth century and early nineteenth century. René Laënnec (1781–1826), a French physician, is generally acknowledged as the originator of the stethoscope, which greatly enhanced the power of auscultation. Compared to modern instruments, it was crude, consisting of a straight rigid tube which was placed between the patient’s body and the physician’s ear. The use of percussion as a diagnostic technique is credited to Leopold Auenbrugger and Jean-Nicolas Corvisart des Marets, contemporaries of Laënnec. Since that time, many physicians have contributed to the body of knowledge that supports physical diagnosis, and texts on the subject are filled with descriptions of maneuvers and findings that bear their names: Sir William Osler, Moritz H. Romberg, Joseph F. Babinski, William Heberden, Antonio M. Valsalva, Franz Chvostek, and so on.


Though the patient’s history and physical examination have excellent diagnostic power, the adoption of advanced imaging techniques may lead to less reliance on physical diagnostic techniques. Thus, traditional hands-on examination risks falling by the wayside. Reasons for adopting new medical technologies in its place are many and controversial. Like other skills, physical diagnosis requires ongoing use if the practitioner is to remain sharp. Physical examinations can be imprecise, with disagreement among competent examiners regarding the presence or absence of findings. In contrast, electromechanical systems may provide more consistent information, though the interpretation of this information is still subjective. It is easy to forget that laboratory or radiological findings by themselves have very limited usefulness. It is not unusual for test reports to note, “Clinical correlation is advised.” In other words, test results must be interpreted in the light of the information that has been gathered about the patient through the history and the physical examination. The performance of a detailed evaluation can be time-consuming for the physician and the patient, especially when
compared to requesting a test. Pressured by patient expectations or liability concerns, physicians may be reluctant to rely on the physical examination alone in lieu of a battery of confirmatory or exploratory scans or blood tests.


The consequences of this shift are likely to change the way in which the patient views the physician and the way in which the physician approaches the patient. Traditionally, the healing role has been intimately associated with the face-to-face meeting of doctor and patient, exemplified by the laying on of hands. From the patient’s perspective, the concept of the personal physician, the familiar voice and touch of the healer who displays ongoing concern and compassion, should not be discounted. This therapeutic relationship will be compromised if physicians become mere brokers for imaging and testing services. With such an arrangement, there would be no reason for the doctor and patient even to see each other. Additionally, important diagnostic information may present itself in a manner that cannot be detected by a scan, such as a subtle clue in the patient’s mannerisms or body language. Even a human examiner may have difficulty analyzing such vague information, but impressions can nevertheless contribute to the clinical evaluation. This suggests that the physical examination will continue to hold an important place in the physician’s array of diagnostic tools.




Bibliography


Goldman, Lee, and Dennis Ausiello, eds. Cecil Textbook of Medicine. 23d ed. Philadelphia: Saunders/Elsevier, 2007.



Jarvis, Carolyn. Physical Examination and Health Assessment. 6th ed. St. Louis, Mo.: Saunders/Elsevier, 2012.



Pagana, Kathleen Deska, and Timothy J. Pagana. Mosby’s Diagnostic and Laboratory Test Reference. 11th ed. St. Louis, Mo.: Mosby/Elsevier, 2013.



Shorter, Edward. Bedside Manners. New York: Simon & Schuster, 1985.



Siraisi, Nancy G. Medieval and Early Renaissance Medicine. 2d ed. Chicago: University of Chicago Press, 2009.



Swartz, Mark H. Textbook of Physical Diagnosis: History and Examination. 6th ed. Philadelphia: Saunders/Elsevier, 2010.



Tierney, Lawrence M., Stephen J. McPhee, and Maxine A. Papadakis, eds. Current Medical Diagnosis and Treatment 2007. New York: McGraw-Hill Medical, 2006.



Vorvick, Linda J. "Physical Examination." MedlinePlus, January 1, 2013.

1 comment:

How can a 0.5 molal solution be less concentrated than a 0.5 molar solution?

The answer lies in the units being used. "Molar" refers to molarity, a unit of measurement that describes how many moles of a solu...