|
But in spite of all good favorable opinions that have been expressed as to the value of basal metabolic determinations. “the most important thing is still a careful history and physical examination; the basal metabolism comes next, but should not be considered pathognomonic (definitely indicative of a cer¬tain disease).” The test fails to give the desired information in certain individual cases, and various factors govern it to such an extent that it must always be checked with symptoms and findings upon examination.
These basal metabolism tests are valuable chiefly because of their aid in the recognition of diseases in which the metabolic rates are increased or decreased and in the differential diag- nosis between abnormal conditions having similar manifestations yet regularly having different metabolic rates; also as a guide in treatment, and to determine the effectiveness of the treatment. Especially in the following conditions the tests are of value:
Enlarged thyroid gland with symptoms of hyperthyroid-ism; enlarged thyroid where symptoms resembling those of hyperthyroidism are due to other causes; enlarged thyroid with no symptoms; symptoms of hyperthyroidism with no enlargement of the thyroid; enlargement of the thyroid from tumors; enlarged thyroid with symptoms of hypothyroidism; symptoms of hypothyroidism with no change in the size of the thyroid.
In the case of goiter with disturbed health the tests will help determine whether the health impairment is due to the goiter or to other causes. Among conditions of disturbed thyroid activity in which the tests are of value may be men¬tioned nervous heart afflictions, nervousness, weakness, defec¬tive circulation, loss of weight and inability to gain weight, incipient tuberculosis and gastrointestinal disorders.
Usually in determining the basal metabolic rate comparison of the findings in a given case is made with tests already made on normal persons of both sexes and various ages. The rate of an individual subject is expressed in terms of per¬centage of the normal: a 25 per cent, increase being termed a basal metabolic rate of +25, and a 25 per cent, decrease being termed a basal metabolic rate of —25. There being a range in normal individuals of 15 per cent, above and below normal, only values above +15 or below —15 are considered abnormal.
Numerous conditions have been listed in which basal metabolic rate determination is of diagnostic value. Accord¬ing to one medical work, the value “is greatest in the group of cases with one or more of the symptoms caused by hyper¬thyroidism. Cardiac disturbances, as tachycardia, cardiac myasthenia (muscular weakness of the heart), and palpita¬tion; fine tremors, general debility, loss of weight, anemia, attacks of vomiting and diarrhea, psychic disturbance, as depressions and irritability, psychasthenia and sweats are symptoms in respect of which the exclusion of thyroid dis¬turbance or its acceptance as cause can be made by a determi¬nation of basal metabolism.” The test was further considered useful “in the differential diagnosis of hysteria, neurasthenia, tuberculosis (incipient), and neuroses simulating thyroid disease, and necessary in the diagnosis of effort syndrome.”
Various forms of apparatus have been devised and em¬ployed for determining the basal metabolism. Some simple devices have been produced that answer the purpose admir¬ably. The oxygen consumption of the patient may be studied in ten- or fifteen-minute jjeriods. It usually is more desirable to take three series of comparison tests on at least two differ- snt subjects having widely varying basal oxygen requirements. Research laboratories use expensive direct calorimetry appara¬tus; but in practice simple indirect calorimetry apparatus is used. As new apparatus is constantly being devised, those now used will have become antiquated within a small number of years.
The technique of determining the basal metabolic rate need not be considered here. While this determination is of much value in many abnormal conditions of the body, it should not be considered as of greater value than the patient’s history and symptoms and the findings under a careful physical examination.
Basal Metabolism is the rate of metabolism when the body is at complete’ rest and when, after a 12-hour fast, digestion is at its normal daily minimum. Normally there is a constant relation between the basal metabolism and the surface area, being represented by the total hourly heat production to the square meter (approximately a square yard) of body surface. It may be determined directly by measuring the actual heat given off by the individual in a stated time, or indirectly by measuring at the same time the amount of oxygen used and the carbon dioxide given off, the surface area being determined by the subject’s height and weight.
The figure obtained, in proportion to the body surface, is fairly constant for normal people of the same age and sex. but varies in some measure in disease. For instance, hyper-thyroidism, fever diseases and leukemia exhibit high rates, while hypothyroidism, inanition, asthenia, and deficiencies of glandular activity have a low rate, which is present also during rest in bed.
Thus the basal metabolism rate differentiates diseases into three distinct groups: those with normal basal metabolic rates (normal heat production); those with increased rates; and those with decreased rates. There is a small variation nor¬mally, but not sufficient to disturb these three groups, for the increased and the decreased rates are respectively much above and below the normal range of variance.
Calories are used in expressing the metabolic rate; either the total in 24 hours or the number each hour to the square meter of surface area. However, in practice only the oxygen intake need be measured.
The metabolic rate is modified by various factors: It is greater in males than in females and greater in early life than later life; various foods modify the rate; muscular activity makes the test valueless; certain stimulating psychic reactions alter the rate; increase in temperature above normal increases the metabolic rate 7.2 per cent, for each degree Fahrenheit of temperature above normal.
Various diseases increase, while others decrease the rate. Children, as shown by basal metab¬olism determinations, require a larger proportion of food than do adults, the basal requirement in boys being 25 per cent, above that of adults of equal size. Before puberty the require-ment is especially high, but on the approach of full develop¬ment it becomes progressively lower. The same conditions pertain to girls, also, except that before and during the age of puberty there is not so pronounced an increase as there is in boys at the same period.
The figures in basal metabolism vary widely according to the rate of internal combustion and this latter is influenced by many internal and external causes.
Certain other conditions of the sputum may be mentionea. Scanty sputum appears in the first stage of spasmodic asthma, at the onset of acute bronchitis, in dry catarrh, first stage of diphtheritic laryngitis, hay-fever, chronic laryngitis, and the onset of acute pleurisy. Frothy sputum is characteristically present in cases of acute bronchitis, but also in emphysema, edema of the lungs, acute lobular pneumonia. Watery and abundant frothy sputum appears in bronchorrhea, and in gangrene of the lungs the upper layers are frothy.
The sputum is viscid or sticky in acute pneumonia especially, but also in bronchopneumonia, whooping cough and in millers and bakers (from inhaling flour). A mucopurulent sputum is found particularly in chronic bronchitis, but also after the end of a severe attack of asthma, in the third stage of whooping cough and tuberculosis and in acute pneumonia after the crisis.
Xummular or coin-shaped sputum comes visually from a tuberculous cavity in the lung, but also from bronchorrhea, bronchiectasis, and cirrhosis (fibrosis) of the lung. A puru¬lent sputum usually indicates an old chronic bronchitis, but may indicate an acute bronchitis bronchopneumonia, enlarged bronchial glands, or the bursting of an abscess into a bronchial tube. Blood-streaked sputum appears especially in chronic pharyngitis or plastic bronchitis (from violent coughing), cancer of the lung, or enlarged veins in the pharynx (pharyn-geal varix), but also from other inflammations and from growths in the throat or the bronchi and from pyorrhea or bleeding gums. Light streaks of blood often have no pro¬nounced significance.
Rusty sputum appears most often in acute pneumonia, prune-juice sputum usually from cancer of the lung. Casts appear in the sputum in diphtheria and plastic bronchitis. Black specks in the sputum are due to coal-dust, smoke, dust, -etc. Fetid sputum may be due to gangrene of the lung, large cavity” in pulmonary tuberculosis, actinomycosis, bronchi¬ectasis, abscess, or syphilitic laryngitis. The microscopic ex¬amination of the sputum cannot be taken up here.
The Sputum. The examination of the sputum is not rou¬tine by any physician or hospital or sanitarium except those concerned with treating tuberculous patients and those treat¬ing acute cases involving the lungs and bronchial tubes. The chief microscopical examination is for the tubercle bacillus.
The absence of tubercle bacilli from the sputum does not prove the absence of tuberculous involvement of the lung, for these bacilli rarely appear until the condition has become fairly well advanced—until the stage of softening has been reached. The test for these bacilli is definitely not for the layman, as it re¬quires chemicals and heat for staining and the microscope for studying the stained specimen.
Epithelial casts are hyaline casts with adhering cells that have been shed from the tubules, though sometimes these cells form hollow casts of themselves (true epithelial casts).. They are present in passive congestion, in jaundice, as the result of irritants, and especially in acute nephritis.
Fatty casts appear in pronounced degenerative changes in the epithelial cells of the kidney tubules, as in fatty de¬generation of the kidney and in chronic parenchymatous nephritis.
Blood casts appear when there has been some process, usu¬ally acute, which causes hemorrhage in the kidney, as in cancer, acute congestion, embolism or cystic disease of the kidney, kidney stone and acute nephritis. In case of hematuria (blood in the urine), blood casts establish the kidneys as the source of the blood.
Pus casts are not often seen, but may be found in abscess of the kidney and pyelonephritis.
Amy’oid or waxy casts, which may be of considerable size, are present in urine from kidneys chronically inflamed (chronic nephritis).
Cylindroids are thinner and often flatter than casts. Their main substance is mucus. They have no great significance, at most indicating irritation of the kidneys.
Numerous casts occur in abnormal urine, though, as a rule, a few isolated casts may be ignored. Sometimes they are absent when their presence is suspected, perhaps as a result of decomposition by bacterial action. Kidney diseases are diag¬nosed positively by means of the urine by the finding and the types of casts, which are moulds from the kidney tubules. A transudate from the cells of these kidney tubules that un¬dergoes coagulation, or a secretion that undergoes semi-hardening, forms the cast. There may be mixed with the casts or attached to them various substances, which may give rise to the name or type of the cast: tubular cells, pus-cells, red blood-cells, bacteria, granular matter or fat. The fatty, granular and epithelial casts have more significance than the others.
After trivial disturbances and after strenuous exercise and slight fevers, hyaline (glassy) or fibrinous casts are normally present in small numbers. Preceding an attack of diabetic coma they may appear in great numbers, though they may be numerous also in either acute or chronic nephritis. They are the most common casts found, yet are of least significance.
Granular casts receive their name from the attachment to plain hyaline casts of granular material from disintegrated kidney cells, blood-cells and other substances. They are pres¬ent in late chronic nephritis. The coarser and darker they are the greater their significance.
Glycosuria is urine containing sugar (glucose). It ap¬pears in any condition in which there is an appreciable increase in the blood-sugar over the normal one part in a thousand parts of blood. There is a transient glycosuria from an ex¬cessive intake of starch and sugar, after acute fevers in obese people and in some nervous diseases. When the oxygen sup¬ply is much lowered, as in suffocation and ether and chloro¬form anesthesia, there is a glycosuria. When sugar appears in the urine constantly and over long periods, however, it indicates diabetes mellitus (sugar diabetes). But in numer¬ous other conditions it may be found transiently, as in boils, alcoholism, cancer of the pancreas, concussion of the brain, exophthalmic goiter, whooping-cough, melancholia, neuras¬thenia, phosphorus-poisoning, and starvation.
Acetone normally is found in traces in the urine. When increased over this it may indicate malnutrition or chronic digestive disease, though it may be after chloroform anesthesia or in many fevers, also in cancer, gastric ulcer, malnutrition, nephritis, uremia, etc. If the carbohydrates in the diet are materially reduced below body requirements acetone may be greatly increased. In diabetes this is a danger sign, as it may indicate impending diabetic coma, especially if it con¬tinues to appear in the urine when treatment that should benefit the diabetic condition is given. This is a condition known as acetone acidosis. Sometimes, but not often, it de¬velops in fasting obese patients.
Diacetic acid usually is associated with acetone in diabetic urine and makes the prognosis of diabetes more grave. If it is present in large amounts a fatal acidosis is imminent. If oxybutyric acid is found in addition to acetone and diacetic acid the prognosis is still more grave regarding the acidosis. Diacetic acid also is found in moderate degree in fasting, fevers, exclusive meat diet and morphinism.
(more…)
Organic disease of the kidney does not always give an albuminuria. In even advanced cases of interstitial nephritis (contracted kidney.) no albumin may appear most of the time and only slight traces at the other examinations. In acute nephritis there is a large amount of albumin, part of which comes from the blood that is discharged with the urine. In chronic parenchymatous nephritis (large kidney) there may be a high percentage of albumin. In pyelitis (inflammation of the kidney pelvis) and abscess in or around the kidney there may be albuminuria.
Blood in the urine may be from one or more of various locations and causes which cannot be considered here. Vari¬ous inflammatory processes are the usual causes. The blood may appear as a few scattered cells, as a general red color, or as clots.
— Next Page »
|
|