In the preparation made from a particle of faeces, emulsified in salt solution, we can note any excess of fatty acids or soap crystals and lack of normal digestion of meat fibres as well as presence of ova of intestinal parasites. Again such a preparation is necessary for noting amoeboid activity of amoebae as well as for the motility of flagellates and Strongyloides embryos. In the preparation mounted in Gram’s iodine solution we have distinctly brought out the nuclear division of encysted amoebae, our most practical means of differentiating between the pathogenic and nonpathogenic amoebae. This method also brings out flagellate characteristics. Again, any undigested starch grains show up distinctly by reason of their blue color. Blood cells and yeast cells stain a golden yellow.
In the examination of the urine it is well to take up with a pipette the entire sediment from a centrifuged tube of urine and deposit it on a slide.
Examination with diminished illumination and using the two-thirds objective quickly enables us to ascertain presence and character of casts. This same sediment is then treated with Gram’s iodine solution and a cover-glass applied. Such a preparation, using the one-sixth objective, brings out distinctly the differentiation of pus cells from renal epithelium as well as showing clearly golden-yellow red blood cells. While centrifuging one can test for albumin. A qualitative test for sugar takes only a few moments to make.
These simple quick tests of blood, faeces and urine suffice for the preliminary laboratory work in a case. Following the physical examination we can carry out more elaborate laboratory tests as indicated by the tentative diagnosis obtained from the physical examination and preliminary laboratory investigations.
Physical Examination.—As regards the physical examination it must be remembered that in the tropics glandular enlargements and skin eruptions are so essential in diagnosis that the rule generally adopted in skin clinics should be adhered to, that is an inspection of the entire body surface, either by stripping the patient or removing clothing from one part at a time.
The sphygmomanometer is of value in the diagnosis of tropical affections as well as those of temperate regions. Similarly, functional tests of the heart and kidneys, basal metabolism determinations, chemical examination of the blood, and tests for acid-base equilibrium may give definite information—in one climate as in another.
Palpation is peculiarly important in the diagnosis of the enlarged spleen, liver and glands of many tropical affections as well as for mapping out intestinal thickenings. Again in going over the patient for outlining heart, liver, etc., palpatory percussion is more satisfactory than the usual mediate percussion.
I find the use of the entire palmar surface of the middle finger, gently tapped over the surface, to give better results than any other method. In this way the percussion note is well elicited and the sense of resistance most satisfactorily obtained. The use of the tips of the index, middle and ring fingers, with a piano playing stroke, also should be employed.
One should always determine the character of the reflexes. Of these the most important are the patellar and biceps ones. This latter reflex is normally rarely obtained.