General patient examination and differential diagnosis

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2 General patient examination and differential diagnosis

General examination of a patient

Many patients are apprehensive about being examined; the environment is unfamiliar, they may feel exposed and are likely to have anxieties about the findings. Be open about your status as a medical student or junior doctor. Reassure the patient that the extra length of time you take to complete your examination compared to someone more senior is because you are less experienced and that it does not necessarily imply the findings are worrying. Many students, early in their training, are anxious about touching and examining patients. Persevere, as with practice and experience, confidence will quickly come.

The examination should be conducted in a warm, private, quiet area. Daylight is preferable to artificial light, which may make the recognition of subtle changes in skin colour (e.g. mild jaundice) difficult. A cold room increases anxiety levels and shivering muscle generates strange noises on auscultation of the chest. In hospital, you may need to ask neighbouring patients to turn down the volume on their television or radio.

A thorough examination requires the patient to be adequately exposed. Patients should be asked to undress completely or at least to their underclothes and then to cover themselves with a sheet or an examination gown. If the patient keeps his underclothes on, do not forget to examine the covered areas (buttocks, breasts, genitalia, perineum). Ideally a chaperone should be present when a male doctor examines a female patient and is essential for intimate examinations such as rectal, vaginal and breast examinations. This is to reassure the patient and to protect the doctor from subsequent accusations of impropriety. Although the patient’s attendance at a consultation suggests he is happy to be examined, this may not be the case and it is always courteous to ask permission. Check he is able to prepare by disrobing and mounting an examination couch unaided. Do not embarrass him by waiting for him to fail and ask for help.

For most patients, start the examination on the right of the bed/couch with the patient semirecumbent (approximately 45°). Do not dent the confidence of an already anxious patient with heart failure or peritonitis by moving him unnecessarily from the position he finds most comfortable. From the right-hand side of the patient, it is easier to examine the jugular veins, apex beat and abdominal viscera, although left-handed students will take longer to master this approach. Try to expose only the area you are examining at the time. With practice, you will be become adept at using the gown or drape to cover the body part just examined as you proceed to the next. Regular attention to the patient’s comfort, such as adjustment/replacement of pillows, helps strengthen the professional bond and reassures him that you are concerned about his welfare.

Quickly make a global assessment of the severity of the patient’s illness. Ask yourself: ‘Does this person look well, mildly ill or severely ill?’ If the patient is severely ill then it is appropriate to postpone a detailed examination until the acute situation has been attended to. Do not put severely ill patients to inconvenience or distress that is not essential at that moment.

Physique and nutrition

The nutritional state of a patient may provide an important indicator of disease, and prompt correction of a deficient nutritional state may improve recovery. The more detailed methodologies available for nutritional assessment and management in the context of complex gastrointestinal disease are covered in Chapter 12. In the general survey, note if the patient is cachectic, slim, plump or obese. If obese, is it generalised or centrally distributed? Wasting of the temporalis muscle leads to a gaunt appearance and recent weight loss may result in prominence of the ribs. Other clues to poor nutrition include cracked skin, loss of scalp and body hair and poor wound healing. Malnutrition accompanying illness results in blood albumin being low leading to oedema, making overall body weight an unreliable marker of malnutrition. A smooth, often sore tongue without papillae (atrophic glossitis, Fig. 2.1) suggests important vitamin B deficiencies. Angular stomatitis (cheilosis, a softening of the skin at the angles of the mouth followed by cracking) may occur with a severe deficiency of iron or B vitamins (Fig. 2.1). Niacin deficiency, if profound, may cause the typical skin changes of pellagra (Fig. 2.2).

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Figure 2.1 Atrophic glossitis in a patient with severe vitamin B12 deficiency. There is also angular stomatitis from severe iron deficiency.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

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Figure 2.2 Pellagra as a result of niacin deficiency.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

Hands

Examine the hands carefully as diagnostic information from a variety of pathologies may be evident. The strength of the patient’s grip may be informative with regard to underlying neurological or musculoskeletal disorders. Characteristic patterns of muscular wasting may accompany various neuropathies and radiculopathies (see Ch. 14). Make note of any tremor, taking care to distinguish the fine tremor of thyrotoxicosis or recent beta-adrenergic therapy, from the rhythmical ‘pill rolling’ tremor of parkinsonism (see Ch. 14), and from the coarse jerky tremor of hepatic or uraemic failure (sufficiently slow to be referred to as a metabolic ‘flap’).

Feel for Dupuytren’s contracture in both hands, the first sign of which is usually a thickening of tissue over the flexor tendon of the ring finger at the level of the distal palmar crease. With time, puckering of the skin in this area develops, together with a thick fibrous cord, leading to flexion contracture of the metacarpophalangeal and proximal interphalangeal joints. Flexion contracture of the other fingers may follow (Fig. 2.3).

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Figure 2.3 Dupuytren’s contracture.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

In clubbing of the fingers, the tissues at the base of the nail are thickened and the angle between the base of the nail and the adjacent skin of the finger is lost. The nail becomes convex both transversely and longitudinally and, in gross cases (usually due to severe cyanotic heart disease, bronchiectasis or empyema), the volume of the finger pulp increases (Fig. 2.4). Lesser degrees of clubbing may be seen in bronchial carcinoma, fibrosing alveolitis, inflammatory bowel disease and infective endocarditis. The last of these may also be associated with Osler’s nodes – transient, tender swellings due to dermal infarcts from septic cardiac vegetations (Fig. 2.5). Splinter haemorrhages (Fig. 2.6) and nail-fold infarctions (Fig. 2.7) may be signs of a vasculitic process, but may also be the result of trauma in normal individuals and are therefore rather non-specific.

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Figure 2.4 Clubbing of the fingers. This case is very marked.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

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Figure 2.5 Small dermal infarcts in infective endocarditis.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

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Figure 2.6 Splinter haemorrhages.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

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Figure 2.7 Nail-fold infarction.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

Trophic changes may be evident in the skin in certain neurological diseases and in peripheral circulatory disorders such as Raynaud’s syndrome, in which vasospasm of the digital arterioles causes the fingers to become white and numb, followed by blue/purple cyanosis and then redness due to arteriolar dilatation and reactive hyperaemia (Fig. 2.8).

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Figure 2.8 Raynaud’s syndrome in the acute phase with severe blanching of the tip of one finger.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

In koilonychia the nails are soft, thin, brittle and the normal convexity replaced by a spoon-shaped concavity (Fig. 2.9). It is usually due to longstanding iron-deficient anaemia. Leuconychia (opaque white nails) may occur in chronic liver disease and other conditions associated with hypoalbuminaemia (Fig. 2.10).

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Figure 2.9 Koilonychia.

(Reproduced with permission from Mir 2003 Atlas of Clinical Diagnosis, 2nd edn, Saunders, Edinburgh.)

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Figure 2.10 Leuconychia in a patient with chronic liver disease.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

Lymph glands and lymphadenopathy

Details pertaining to the examination of specific lymph node groups may be found in the relevant chapters (e.g. Ch. 20 for cervical lymphadenopathy). Here, the principles of palpating for lymphadenopathy will be covered. Lymph nodes are interposed along the course of lymphatic channels and their enlargement should always be noted. Lymph from the arm drains into the axillary nodes. These should be routinely examined, but particularly in conjunction with examination of the breast (see below). Lymph from the lower limbs drains via deep and superficial inguinal nodes, although only the latter can be palpated and, in turn, comprise a vertical and horizontal group. The vertical inguinal nodes lie close to the upper part of the long saphenous vein and drain the leg. The horizontal group lies above the inguinal ligament and drains the lower abdominal skin, anal canal, external genitalia (excluding the testes), buttocks and lower vagina.

Examination of lymph nodes involves inspection and palpation. Inflammation of the overlying skin and associated pain usually implies an infective aetiology, whereas malignant lymphadenopathy is usually non-tender. To palpate for lymphadenopathy, use the pulps of your fingers (usually the index and middle but, for large nodes, the ring as well) to move the skin overlying the potentially enlarged node(s). Determine the size, position, shape, consistency, mobility, tenderness and whether it is an isolated lymph node or whether several coalesce. For the head and neck nodes, it is often helpful to tilt the head slightly towards the side of examination in order to relax the overlying muscles. Feel for each of the groups shown in Figure 2.11 in whatever order you find most efficient and reliable. Muscles and arteries in the neck and groin may be mistaken for lymph nodes. If in doubt, try to move the structure in question in two directions (laterally and superior to inferior). It should be possible to move a lymph node in two directions, but not an artery or muscle.

Determining whether a lymph node is pathological can be difficult and requires practice and experience. In general, small, mobile, discrete lymph nodes are frequently found in normal individuals, particularly those who are slim and have little overlying adipose tissue. The finding of an enlarged lymph node should prompt the question ‘Is this consequent upon local pathology, for example infection or malignancy, or is it part of a more generalized abnormality of the reticuloendothelial system (including other lymph node groups, liver and spleen)?’ (Fig. 2.12).

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Figure 2.12 Gross enlargement of supraclavicular and cervical lymph nodes.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

Axillae

Most information from examination of the axillae comes from palpation for possible lymphadenopathy (Fig. 2.13), but inspection may reveal an absence/paucity of secondary sexual hair in either gender (most commonly in association with chronic liver disease, but also in certain endocrinopathies), abnormal skin colouring, such as the dark velvety appearance of acanthosis nigricans, or (very rarely and almost always in the presence of café au lait spots elsewhere) the characteristic freckling of von Recklinghausen’s disease.

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Figure 2.13 Gross (in this case, painless) axillary lymph node enlargement.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

Support the weight of the patient’s arm by holding his arm at the elbow with your non-examining hand, so that the patient’s pectoral muscles are relaxed. With the fingers of your right hand cupped together, probe the apex of the left axilla, then slide them downwards against the chest wall to feel for lymphadenopathy. Next, ‘sweep’ your fingers along the inside of the anterior and posterior axillary folds, feeling for enlargement of the pectoral and subscapular lymph nodes respectively. Use your left hand in the same way to examine the right axilla.

Skin

Examination of the skin with respect to specific dermatological diagnoses is covered in Chapter 15. In the context of the general examination, the most important features relate to temperature, hydration, pallor, colour/pigmentation and cyanosis. Use the back of your fingers to assess the temperature of the skin. This complements rather than replaces the formal measurement with a thermometer. There may be generalized warmth in febrile illness or thyrotoxicosis, or localized warmth if there is regional inflammation. Cold skin may be localized, such as when a limb is deprived of its blood supply, or generalized in states of circulatory failure, when the skin feels clammy and sweaty.

Lift a fold of skin and make note of its thickness, mobility and how easily it returns to its original position (turgor). The skin on the back of the hand is often thin and fragile in elderly patients, may show decreased mobility in scleroderma (Fig. 2.14) or in oedematous states, and have reduced turgor in the presence of dehydration. The skin of acromegalic patients is typically thick and greasy.

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Figure 2.14 Advanced scleroderma.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

An important determinant of skin colour is the relative amount of oxyhaemoglobin and deoxyhaemoglobin. Oxyhaemoglobin is a bright red pigment. An increase in its flow beneath thinned facial skin causes the characteristic plethora of Cushing’s syndrome (Fig. 2.15), whereas a decrease in flow causes pallor. As blood passes through the capillary bed, oxygen is given up to metabolizing tissues to produce deoxyhaemoglobin. This has a darker, less red, more bluish pigment and its presence in peripheral blood vessels in increased amounts causes the clinical sign of cyanosis. There are two physiological types of cyanosis: peripheral and central. Peripheral cyanosis is associated with increased extraction of oxygen from capillaries when peripheral blood flow is slowed, often due to vasospasm caused by cold, heart failure or anxiety. The cyanosed extremity is usually cold and the tongue is unaffected. Any condition causing slowing of the peripheral circulation may lead to peripheral cyanosis as there is more time for oxygen extraction. Central cyanosis is caused by inadequate oxygenation of blood, in turn due to heart failure, serious respiratory disease or mixing of venous and arterial blood across a right to left cardiac shunt. In the latter situation, blood passes directly from the right to the left side of the heart, without passing through the pulmonary circulation, thereby failing to become oxygenated. Central cyanosis is generalized and the peripheries are often warm. At least 5 g/dl of reduced haemoglobin is necessary to produce central cyanosis, and it is therefore less marked in anaemic patients. The cyanosis of heart failure is often due to both peripheral and central causes. The presence of central cyanosis is best appreciated at the lips, mucous membranes and conjunctivae, where the keratinized skin is thinnest (Fig. 2.16).

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Figure 2.15 The characteristic plethoric appearance of a patient with Cushing’s syndrome.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

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Figure 2.16 Central cyanosis in a patient with severe respiratory disease (left) compared to the tongue of a normal person.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

Pulses

Arterial pulses are detected by compressing the relevant vessel against a firm underlying structure, usually a bone. Details of the characteristic pulse abnormalities that help in the diagnosis of various cardiac disorders are described in Chapter 11, but palpation of all the peripheral pulses should form part of the general examination of all patients. Some may be difficult to feel and you may need to vary the degree of pressure in order to pick up the relevant pulsation. On occasion, you may confuse the patient’s pulse with your own. Count your own heart rate and compare it with the patient’s as they will usually be different.

The radial pulse is palpated by gentle pressure of the artery against the distal shaft of the radius, using the tips of the index and middle fingers. It provides information about rate and rhythm, although significant abnormalities in character may also be detected. If the rhythm is regular, it is safe to count the number of beats for 15 seconds and multiply by 4 for the rate. Irregular and very slow pulses require palpation for a full minute.

To palpate the femoral pulse, press deeply below the inguinal ligament, midway between the anterior superior iliac spine and the symphysis pubis. The pulse is usually easily felt against the underlying femur. In obese patients it may be useful to use two hands, one on top of the other.

The popliteal pulse is the most difficult to palpate. Flex the knee to approximately 120° and, with your thumbs on the patella, place your fingers in the popliteal fossa such that they meet in the midline. Occasionally, it may be necessary to lie the patient prone and, with the knee flexed to 90° and the leg resting against the shoulder or upper arm, press the thumbs deep into the popliteal fossa.

The dorsalis paedis (DP) pulse is palpated by pressing against the tarsal bones just lateral to the extensor tendon of the great toe although, in some patients, it may be necessary to explore the dorsum of the foot more widely. In general, it is most convenient to use the right hand to examine the left DP pulse; the right is often best felt with the right hand from the left side of the patient.

To feel the posterior tibial (PT) pulse, with the patient’s foot relaxed between plantar- and dorsiflexion, press your curved fingers against the distal part of the tibia, approximately 1 cm behind and below the medial malleolus. The PT pulse may be difficult to feel and require extra patience and pressure in obese or oedematous patients.

Legs and feet

Examination of the legs requires adequate exposure from the groins and buttocks to the toes. Note the colour and texture of the skin. Peripheral vascular disease often makes the skin shiny and hair does not grow on ischaemic legs or feet (Fig. 2.17). Pressure on the toes of ischaemic feet will cause blanching of the characteristic purple colour with subsequent slow return. Passive elevation of an ischaemic leg leads to marked pallor of the foot as perfusion against gravity falls. Painless trophic lesions, often with deep ulceration, may be seen in diabetic peripheral neuropathy. The posterior aspect of the heels is a particularly important area to inspect in elderly, emaciated or neurologically impaired patients, all of whom are vulnerable to pressure sores caused by obliteration of arteriolar and capillary blood flow to the skin.

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Figure 2.17 Peripheral vascular disease. There is pallor, loss of hair and early ulceration on the dorsum of three toes.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

Inspect the legs for obvious oedema and examine for pitting oedema. Press firmly but gently for around 5 seconds behind the medial malleolus, over the dorsum of the foot and on the shin. If oedema is present, a depression/concavity will form (Fig. 2.18).

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Figure 2.18 Pitting oedema in a patient with cardiac failure. A depression remains in the oedema for several minutes after firm fingertip pressure is applied.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

Varicose veins should be examined for with the patient standing (Fig. 2.19). Superficial varicosities are generally obvious in this position, whereas the efficiency of the valves of the long saphenous vein should be assessed by Trendelenburg’s test. With the patient lying, the saphenous vein is emptied by elevating the leg. Occlude the upper end of the vein by finger pressure on the saphenous vein opening (alternatively use a tourniquet) and ask the patient to stand while maintaining this pressure. If the valves are incompetent, the veins will rapidly fill from above when the pressure is released.

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Figure 2.19 Varicose veins.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

Venous thrombosis is rare in healthy mobile subjects, but frequently complicates enforced bed rest, particularly after surgery. The affected limb will be swollen. The circumference of the calf should be measured and compared with the unaffected leg, at the same distance below the tibial tuberosity. A discrepancy of more than 1 cm is significant. The affected leg is also tender and warmer than normal, with dilated superficial veins which do not collapse when the leg is elevated. Forceful dorsiflexion of the foot may cause pain in the calf (Homan’s sign). Sometimes extension of a deep vein thrombosis may extend up the thigh leading to a tender, hard, palpable femoral vein.

Breasts

Examination of the breasts should form part of the routine clinical assessment, usually at the time of examination of the chest. It requires tact and sensitivity and should be conducted with a chaperone. With the patient disrobed to the waist, the arms should be in a relaxed position by the sides. By inspection, make note of the size, symmetry, contour (e.g. any dimpling) and colour of the breasts. Inflammatory breast cancer with oedema of the overlying skin may produce a characteristic look and texture termed peau d’orange (orange peel skin). Note any asymmetry or inversion of the nipples. Simple longstanding inversion is often a normal phenomenon, but associated retraction of the areola or recent nipple inversion are more sinister. Ask the patient to raise her arms above her head. This manoeuvre allows inspection of the inframammary fold and may expose subtle contour abnormalities. Now, with the patient supine, ask the patient to rest one arm above her head. This helps spread the breast tissue more evenly across the chest and makes palpation of any nodules easier. For ease of annotation, the breast is usually divided into four quadrants, with the upper outer quadrant extending into an axillary tail. Use the pads of your middle three fingers to palpate the breast, using rotatory movements gently to compress the tissue against the chest wall. Proceed systematically to examine all quadrants, the tail and areola. Sometimes it is useful to support the breast with the other hand in order to aid examination, especially when the breasts are large.

Breast tissue is variable between patients, ranging from smooth to granular, and may change in a given individual with the menstrual cycle. For any nodule, note its size, shape, consistency, tenderness, mobility and the presence of any tethering or skin ulceration. Ask the patient to press her hands against her hips. If the lump becomes less mobile, it is likely to be attached to the pectoral muscles. Fixation to skin may be assessed by moving the skin overlying the lump independently. If this is not possible then skin involvement is likely.

Swelling of male breast tissue is usually easily apparent (Fig. 2.20). Distinguishing true glandular enlargement from pectoral fat may be facilitated with the patient’s arms above his head. At some stage of puberty, most boys will have a palpable disc of tissue.

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Figure 2.20 Gynaecomastia in a male patient.

(From Forbes and Jackson 2002 Color Atlas and Text of Clinical Medicine, 3rd edn, Mosby, Edinburgh. Reproduced by kind permission.)

Putting it all together

The information given in this, and subsequent, chapters describes techniques of physical examination that may be helpful in elucidating the cause of a patient’s symptoms. It is not implicit that all of these examinations should be performed in all patients. For example, it is not appropriate to make a detailed assessment of the neurological system in someone in severe respiratory distress due to pulmonary oedema or in abdominal pain from peritonitis. Initially, both alone and during teaching, you will probably practise examining individual systems (e.g. the cardiovascular system). Soon, however, you will be ready to conduct a complete examination. The following is a suggested schema for the student to practise, and doctor to perform, in all hospitalized patients who are not acutely ill, in order to exclude major abnormality in the various bodily systems.

Documentation and communication

An accurate, concise record of a clinical episode is crucial for effective care. It serves as a tool for ordering the doctor’s thoughts as they review the findings before constructing a provisional differential diagnosis. It may identify errors or missing data (did I examine the reflexes?). It serves as a reminder of those thought processes at future consultations as the results of investigations become available and/or the condition evolves, and it allows colleagues to pick up the ‘thread’ of a case in the event of the initial assessing doctor being unavailable. Furthermore, as rising expectations and increasing availability of medical information via the Internet embolden more patients to question the quality of their care, accurate documentation is vital in order to provide the evidence for the quality of the decision-making and assessment in the event of a disagreement between patient and doctor. All medical note entries should be dated, timed and signed and each page should have the patient’s name and record number clearly written.

The style and extent of note-taking will vary according to circumstance. For example, a postoperative visit to a surgical outpatient clinic after a routine repair of a hernia is likely to focus exclusively on issues relating to pain and scar healing, with brief documentation. In contrast, the initial consultation at a falls clinic will involve the expert in elderly medicine gathering potentially relevant information about past medical history, current medication, social support and the history of the current problem, and will certainly require a comprehensive physical examination. A GP is likely already to know the details of the patient’s family, social, past medical and drug history, so in the limited time available will focus on the current problem. In all of these situations, however, the clinician should avoid being constantly engaged in writing notes or, increasingly in Western healthcare, looking at a computer screen. Maintain eye contact as the patient talks about his problems. The following suggestions refer to a new patient consultation in the outpatient clinic, or a non-acutely ill hospitalized patient. The goal is to write a complete yet concise record of the patient’s problem that can easily be followed as a logical narrative by the next doctor to see that patient.

Start with the routine social data: name, address, marital status, occupation, dependent family members and children. The order in which the family, past medical and presenting complaint histories are documented is not rigidly set. For those patients who have enjoyed good health to the point of the current illness, the presenting complaint and history of the current problem fall naturally out of the context of the above background information. Medical notes for such a patient with (for example) a spontaneous pneumothorax might read as follows:

Mr JW, aged 32, manual labourer, married, 2 children.

Generally in excellent health and symptom free. Keen sportsman.

No relevant past medical history.

PC: Breathlessness.

HPC:

PMH:

An important differential diagnosis in a patient with pneumothorax is pulmonary embolism, sometimes with prior deep venous thrombosis. The ‘negative’ features of the history (no leg symptoms, no recent immobility) ‘steer’ the narrative and any subsequent reader of the history away from this diagnosis but serve as a focus for its consideration. If a rigid system were recommended of documenting all potentially relevant past medical and family history prior to the presenting problem, the same history might read:

Mr JW, aged 32, manual labourer, married, 2 children.

Generally in excellent health and symptom free. Keen sportsman.

No family history of deep vein thrombosis or pulmonary embolism. No family history of tall stature, lens dislocation, valvular heart disease (all features of Marfan’s syndrome, an important association with pneumothorax in young patients). Varicocoele surgery aged 25 with no history of postoperative deep vein thrombosis or pulmonary embolism.

PC: Breathlessness.

HPC:

Although used as an extreme example, such a style of documentation could ‘obstruct access’ to the presenting complaint. For many patients, however, it is appropriate to detail a pertinent family history and/or past medical history prior to the current problem, or as an ‘introduction/context’ to it. Good examples of this would include a middle-aged man with rectal bleeding and a strong family history of carcinoma of the colon, or a young person, breathless on exertion, who underwent corrective surgery for congenital heart disease as a child. For other patients, the current problem is the latest development of a longstanding illness, for example cough and breathlessness in a patient with chronic obstructive pulmonary disease. This skill of interweaving the past/family history with the current problem will develop with experience, so do not be disheartened if your notes initially seem disjointed.

Many patients have had medical and surgical episodes in their history that are essentially ‘closed events’, for example cataract removal, hernia repair or tonsillectomy as a child. Although they may seem irrelevant to the current problem, they may, subsequently, provide important useful information and it is important to document them meticulously. For example, knowing that a bilateral oophorectomy was performed at the time of a hysterectomy is helpful information in the assessment of a woman with ascites. The past medical history (if accurate) makes a diagnosis of carcinoma of the ovary highly improbable. Documentation of any surgical procedures, however minor, can provide reassuring or helpful anticipatory information in patients likely to undergo general anaesthesia. Recording of the history concludes with the full list of drugs, doses and dosing intervals, any adverse reactions to previously prescribed medicines and documentation of the review of systems (see Ch. 1).

Details of the physical examination should be documented in a clear, structured framework. Start with a general, non-judgemental comment about the patient’s overall appearance, such as ‘well man with moderate generalized adiposity’ or ‘drawn, anxious woman, breathless on undressing’. Record important positive and negative features on general examination, for example jaundice, clubbing, rash, fever, lymphadenopathy. The remainder of the examination should be documented under bodily systems: cardiovascular, respiratory, gastrointestinal (often referred to as abdominal), nervous system, skin, limbs and joints. Negative findings are often as pertinent as positive ones. Simple line drawings are often particularly effective. A concise summary of the findings in the cardiovascular system might read as in Box 2.1.

The case notes should conclude with a brief summary of the history and the major abnormalities found on examination, which leads in to the differential diagnosis.

Constructing a differential diagnosis

Together, the history and physical examination provide a combination of subjective and objective data with which to formulate an assessment of the patient’s problems. In some cases, the diagnosis will be clear, while in others, laboratory and/or radiological investigations may be required. For some patients, re-evaluation after a period of time may be diagnostically helpful.

Processing of subjective and objective information takes place in the doctor’s mind against the background of their experience and acquired knowledge. Initially, it may seem impossible, without experience or extensive knowledge of pathological processes, to mould your data into a coherent differential diagnosis. Early in a student’s learning, reading about the clinical method may seem ‘abstract’ in the absence of an understanding of disease, and vice versa. Persevere, as with even a little experience, this will become easier and, most importantly, always trying to find out what happens to the patients you have seen allows the opportunity to learn from your own successes and errors.

In patients who are severely ill, the measured approach in which subjective and objective clinical information is moulded into a comprehensive differential diagnosis has to give way to a more direct, ‘functional’ approach in which the imperative is emergency correction of abnormal physiological parameters, for example hypotension, hypoxia or safeguarding an airway/cervical spine. This more urgent, focused style of clinical method is described in Chapter 8.

This section will refer to a situation in which the patient is being assessed in the outpatient clinic, a GP’s surgery or at the bedside of a non-acutely ill hospitalized patient.

Some helpful principles to follow include the following:

image Make a list of the patient’s major symptoms and the signs you have elicited on examination.

image Where possible, try to localize the clinical and anatomical findings. In some cases, this may be straightforward (e.g. a painful, swollen, hot, red knee) but in others this may be more diffuse (e.g. abdominal pain without abnormal examination findings) or not possible at all (e.g. weight loss and fatigue).

image Start with the most specific findings to formulate your clinical hypothesis. If a patient reports fatigue, abdominal pain, weight loss and you find an abdominal mass on examination, then focus your differential diagnosis around the mass rather than the fatigue which is a less specific feature.

image Think about possible pathological and/or physiological causes that might explain your patient’s symptoms. This will become easier as you read more about disease processes, but a helpful, frequently used ‘thinking framework’ is given in Box 2.2. Using this, try to correlate the combination of subjective and objective data with your list of possibilities. Certain features will help eliminate certain causes, e.g. the age of the patient and the time course of the illness, but at the start of your learning it is helpful to rehearse in your mind a wide range of possible causes.

image Try, at least initially, to account for the patient’s symptoms and findings by one disease process (the principle of Occam’s razor: entia non sunt multiplicanda praeter necessitatem; one should not increase, beyond what is necessary, the number of entities required to explain anything).

image Always try to explain the totality of the patient’s complaints. For example, the diagnosis of typical dyspeptic symptoms associated with use of over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs) may be straightforward, but why was it necessary to take the NSAIDs in the first place? In such a situation, a more complete diagnostic possibility would be ‘probable osteoarthritis, leading to excessive use of NSAIDs with consequent non-ulcer dyspepsia/peptic ulceration’.

image Always go through the mental discipline of challenging ‘established’ diagnoses before you ascribe the current problem to an evolution/complication of a previous one. For example, if a patient with a sternotomy and saphenous vein harvesting scars from previous coronary artery bypass grafting reports a familiar chest discomfort on exercise last experienced prior to surgery, such a scenario is eminently ‘logical’ and likely to need little further diagnostic enquiry. However, if a young patient, without obvious risk factors for ischaemic heart disease, reports that he has chest pain similar to several other ‘heart attacks’ but has a completely normal clinical examination and electrocardiogram, it may be that he has had a series of limited myocardial infarctions, but another possibility is that he has misunderstood or misremembered the outcome of previous episodes and that alternative explanations should be explored.

image Always consider the possibility that some, if not all, of the patient’s symptoms may relate to the side effects of prescribed or non-prescribed medications (particularly in the elderly).

image Always include in your list of possibilities potentially serious and treatable conditions, because the consequences of a delayed or missed diagnosis are severe for the patient, and sometimes for the doctor also (e.g. subarachnoid haemorrhage in a patient with acute severe headache).

The final differential diagnosis that you construct will be the result of an analysis of the ‘best match’ of the symptoms and signs to the list of pathological/physiological possibilities, but will also be influenced by the inherent probability of those diagnoses. For example, backache and haematuria is a classic presentation of renal cell cancer in a middle-aged or elderly patient, but this diagnosis is improbable in a 25 year old.

The above strategies should allow you to construct a provisional list of candidate explanations for the patient’s clinical presentation (the differential diagnosis). Further, diagnostically helpful information may come (alone or in combination) from revisiting the history, reviewing/expanding certain features of the examination and carefully selected investigations. Of note, a consultant seeing a patient on referral or for a second opinion will often spend more time retaking the history than re-examining the patient.

The beginnings of a management plan

The word ‘management’ in this context refers to a clinical strategy that is a combination of monitoring, selection of further informative diagnostic tests and treatment. It may therefore be thought of as the clinical process whereby the patient is taken from the point of initial assessment through to final diagnosis and appropriate treatment, the outcome of which may vary from full recovery to death. In general practice or the outpatient clinic, the emphasis, initially, is likely to be on selecting informative investigations, although these may be accompanied at the same time by simple recommendations for treatment that will be applicable whatever the final diagnosis, such as lifestyle changes (weight loss, smoking cessation) or blood pressure control. In acutely ill patients, monitoring and emergency treatment are likely to feature more than investigations, at least until the situation is more stable. A good example of this is acute pulmonary oedema, in which measures to relieve breathlessness and monitoring for cardiac arrhythmias (sitting the patient up, provision of high-flow oxygen, intravenous opiates, connection to an ECG monitor) are needed urgently. Diagnostically informative echocardiography can usually follow in the subsequent hours or days. In general, Box 2.3 suggests an order of tasks to follow when constructing your provisional management plan. In some patients (particularly the elderly), it may also be appropriate to detail any additions/improvements to the social support network that exists, in preparation for the patient’s discharge.

Selecting appropriate investigations

As with history taking and physical examination, judicious selection of appropriate investigations to clarify a patient’s diagnosis is a skill that is developed through teaching, practice and a willingness to learn from mistakes. This is increasingly true as access to high-definition radiological imaging becomes more widespread and the vast majority of haematological and biochemical investigations are automated and provided as a ‘package’ rather than individually selected. Although it might instinctively be thought by the student that the easy availability of such data could only be beneficial to a patient (i.e. lead to the fortuitous diagnosis of unsuspected disease), in many cases it can lead to unnecessary expense and patient anxiety. This is because asymptomatic benign lesions identified on imaging or minor disturbances of haematological/biochemical parameters necessitate further investigation and surveillance.

Ask yourself the following questions when considering which investigations to request:

image Will this test confirm/complement the information derived from the history and examination?

image Will this test provide new information (such as a chest X-ray in a patient with a productive cough and weight loss but no physical findings on examination)?

image Could this test provide useful information over a period of time as a marker of disease progression (e.g. the inflammatory markers erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in a patient with infective endocarditis. Neither test is specific for the diagnosis but changes in both values may be useful markers of disease progression)?

image What are the possibilities of this test yielding clinically irrelevant/distracting information compared to a diagnostically informative result? A good example of this would be the indiscriminate use of cranial computed tomography (CT) scans in patients with ill-defined neurological symptoms (such as dizziness) before a detailed neurological examination has been performed. Meningiomas (benign tumours arising from the meninges) are not-infrequent findings in patients undergoing cranial imaging. In a patient with dizziness without other neurological symptoms or signs, such a finding is likely to be irrelevant and, because the meningioma will need routine surveillance, is likely to cause unnecessary anxiety. In contrast, the finding of a meningioma in a patient with a carefully taken history of focal seizures is likely to be highly relevant (and, in fact, a reassuring finding for many patients as the differential diagnosis includes many other, more aggressive, brain tumours with a bleak outlook).

image What are the potential risks and discomfort to the patient of the proposed test (including the risk of unnecessary anxiety generated by an irrelevant finding demanding further evaluation)? In the case of routine haematological and biochemical tests requiring straightforward venepuncture, the immediate risk (aside from minor discomfort) is low. In the case of coronary angiography, the risk of death is around 0.1% and of serious complication (myocardial infarction, stroke, arrhythmia, cardiac perforation) approximately 1.7%. Following a kidney biopsy, the risk of a haemorrhage sufficiently severe to require an emergency nephrectomy is around 0.0003% (1 in 3000). In these, and other, situations, the clinician must balance benefit and risk. The benefit can be diagnostic information leading to targeted treatment of a serious illness, or excluding problems for which the treatment has significant risk. The risk is that of the investigation itself, or of the anxiety or distress that it may provoke.

image What information does the laboratory and/or radiology department require to make this test maximally useful? A biopsy or surgical specimen sent to the pathology laboratory is likely to yield much more diagnostic information when accompanied by clinical details and a specific question than if delivered, speculatively, without either.

image If the diagnosis is not apparent after some effort at investigation, at some point clinicians should stop to ask themselves the questions listed in Box 2.4.