JAUNDICE, ICTERUS, THE YELLOWS.
Symptomatic. Causes: Mechanical obstruction of bile duct, gall-stones, hydatids, distomata, extraneous bodies, inflammation, stricture, obliteration, absence, ulceration, spasm, tumor, enlarged lymph glands, gastric tumors, pancreatic, kidney or omental tumor, aneurism, fæcal accumulation, pregnancy, ovarian tumor: Without mechanical obstruction, ptomaines and toxins, animal venoms, mineral poisons, hepatic atrophy, fear, other emotions, cerebral concussion, imperfect oxidation, excess of bile, hepatic inflammation, constipation and reabsorption of bile, experimental jaundice, balance of tension in gall ducts and blood vessels, duodenitis, compression of aorta, hæmatoidin and bilirubin, destruction of blood globules by hydroæmia, taurocholate of soda, chloroform, ether, freezing, heat, electricity, alkalies, nitrites. Hæmoglobin: Its solubility in horse. Bile acids and blood pigment. Summary of causes. Gravity of icterus. Symptoms: Coloration, yellow, orange, brown, of tissues and secretions: Tests, staining white paper, Gmelin’s test, nitric and sulphuric acids, rainbow hues: Pettenkofer’s test for bile acids, syrup and sulphuric acid, dark violet: Stranburg’s test syrupy paper and sulphuric acid, dark violet; clay colored fœtid stools; gravity.
The terms icterus and jaundice are applied to a yellowness of the mucosæ, urine, skin and tissues caused by the presence in them of the coloring matters of bile. The condition is a symptom of many different affections rather than a disease per se, yet the phenomenon is so characteristic that it has been hitherto accorded a special place and article in systematic works.
Jaundice is either associated with mechanical obstruction of the bile duct or ducts, or it is independent of such obstruction. The following enumeration of its causes slightly modified from Murchison, is equally applicable to the lower animals as to man:
A. Jaundice From Mechanical Obstruction of the Bile Duct.
I. Obstruction by foreign bodies within the duct:
1. Gall stones and inspissated bile. 2. Hydatids and distomata. 3. Foreign bodies from the intestines.
II. Obstruction by inflammatory tumefaction of the duodenum or of the lining membrane of the bile duct with exudation into its interior.
III. Obstruction by stricture or obliteration of the duct.
1. Congenital deficiency of the duct. 2. Stricture from perihepatitis. 3. Closure of the orifice of the duct in consequence of ulcer of the duodenum. 4. Stricture from cicatrization of ulcers in the bile duct. 5. Spasmodic stricture.
IV. Obstruction by tumors closing the orifice of the duct or growing in its interior.
V. Obstruction by pressure on the duct from within, by:
1. Tumors projecting from the liver itself. 2. Enlarged glands in the fissure of the liver. 3. Tumor of the stomach. 4. Tumor of the pancreas. 5. Tumor of the kidney. 6. Post peritoneal or omental tumor. 7. An abdominal aneurism. 8. Accumulation of fæces in the bowels. 9. A pregnant uterus. 10. Ovarian and uterine tumors.
B. Jaundice Independent of Mechanical Obstruction of the Bile Ducts.
I. Poisons in the blood interfering with the normal metamorphosis of bile.
1. The poisons of the various specific fevers (Anthrax, Texas fever, Hog cholera, Swineplague, Petechial fever, Pyæmia, Septicæmia, etc.).
2. Animal poisons: snake poison.
3. Mineral poisons: phosphorus, mercury, copper, antimony, etc.
4. Chloroform, ether, etc.
5. Acute atrophy of the liver.
II. Impaired or deranged innervation interfering with the normal metamorphosis of bile.
1. Severe mental emotions: fright, anxiety, etc.
2. Concussion of the brain.
III. Deficient oxygenation of blood interfering with the normal metamorphosis of bile.
IV. Excessive secretion of bile, more of which is absorbed than can undergo the normal metamorphosis.
Congestion of the liver: a. Mechanical, b. Active, c. Passive.
V. Undue absorption of bile into the blood from habitual or protracted constipation.
Mechanical obstruction, by tying the bile ducts in a dog, caused in two hours yellow coloration of the contents of the hepatic lymphatics and thoracic duct, and also of the blood in the hepatic veins (Saunders). That this jaundice is due to reabsorption and not to suppressed secretion of bile, already present in the blood, may be fairly inferred, from the complete absence of icterus, where, from general disease of the liver, the secretion of bile has been entirely suspended, and in which the gall ducts and bladder contain only a little gray mucus (Haspell, Frerichs, Budd, Murchison), also from the fact that after complete extirpation of the liver in frogs not a trace of biliary acids nor pigment can be detected in the blood, urine, or muscular tissue (Müller, Runde, Lehmann, Moleschott). Bile acids and bile pigment are formed in the liver by disintegration of blood globules, and when present in excess in the blood it is by virtue of reabsorption.
This reabsorption will take place under the slightest favoring influence. The obstructions in the bile duct, above referred to, cause the tension in these ducts to exceed that of the blood in the capillaries of the liver and at once osmosis of bile into the blood vessels sets in. This may occur from so slight a cause as the congestion and swelling of the duodenal mucosa around the opening of the bile duct. Again reabsorption of bile may be determined by a lessening of the normal fullness and tension of the hepatic capillaries as when the aorta is mechanically compressed by abscess, neoplasm, ingesta, or otherwise, just behind the diaphragm (Heidenham, Brunton). The cause is the same in both cases, namely, the want of balance between the fullness and tension of the bile ducts, and the hepatic blood vessels. There is increased fullness of the hepatic biliary ducts, or decreased plenitude of the hepatic capillaries and lymphatics.
It must be added, however, that the coloring matter of the bile is apparently produced, in the liver, from that of the blood, and that the pigment (hæmatoidin), found in old extravasations of blood, is probably identical with bilirubin, and that any agent or condition which causes liberation of the coloring matter of the red blood globules, will cause a staining of the tissues, like that of jaundice. The following agents are known to have this effect on the blood globules: water, in hydroæmic states of the blood (Hermann); taurocholate of soda from absorption of bile (Frerichs, Kuhne, Feltz, Ritter); chloroform (Chaumont); ether (Burdon-Sanderson); freezing (Rollet); a high temperature +60° C. (Schultze); frictional and induction currents of electricity (Burdon-Sanderson); the alkalies (ammonia, potash and soda) and nitrites when present in excess.
The injection of hæmoglobin into the veins of dogs has been followed by the appearance of bile pigment in the urine, but Naumyn, Wolff, Legg and Brunton failed to obtain the same result in rabbits.
It is noticeable that the hæmoglobin of horses’ blood is very soluble at all temperatures and that of dogs very slightly so (Burdon-Sanderson). This may serve to explain the great prevalence among solipeds of diseases, associated with dusky brown or yellow discoloration of the mucosæ, with petechiæ, and with the passage of blood pigments in the urine. It may further explain the usually benignant course of jaundice in the horse and its extreme gravity in the dog.
There is further reason to believe that the bile acids, when in excess, may be transformed into bile pigment in certain conditions of the blood, as occurs under the action of sulphuric acid out of the body (Stœdler, Meukomen, Folwarcyny, Röhrig). Moreover, in the healthy state, the greater part of the bile secreted, including acids and pigment, is re-absorbed from the intestinal canal, but is oxidized and decomposed in the blood so that it cannot be detected, in blood or urine. But let the transformation be interrupted, as in certain diseases of the lungs, with imperfect oxidation, and the bile circulates in the blood, stains tissues and urine, and in short causes jaundice.
To sum up: it may be said that icterus is probably never due to simple inactivity of the liver: it may, however, be caused by excessive secretion of bile which is re-absorbed from obstructed bile ducts or bowels:—it may result from imperfect transformation, in the blood, of the bile which is normally re-absorbed from the intestine: or it may possibly be caused by the formation of pigments in the blood from the abnormal transformation of bile acids, or by solution of the hæmoglobin of the blood corpuscles.
The gravity of jaundice varies as much as its causes. It is well known that the system may be saturated with bile, and the tissues and urine deeply stained without much constitutional disorder. The pigment alone is not an active poison. But there may be much attendant suffering from obstructed biliary ducts or bowels, from diseases of the lungs, or from disintegration of the blood globules and imperfect nutrition, or there may be profound nervous prostration and disorder from uræmia, or from the presence in the blood of an excess of effete and partially oxidized albuminoids (See Azotæmia). According to our present knowledge, constitutional disorder, prostration and suffering in cases of jaundice, are mainly due to the presence in the circulation of these albuminoids, and of taurocholic acid which latter has a most destructive effect on the blood corpuscles.
The symptoms, therefore, are not characteristic apart from the yellow coloration of the tissues and urine and the chemical reactions of the bile acids and bile pigments furnished by the latter.
The coloration of the tissues may be a simple tinge of yellow especially noticeable in the eye (conjunctiva), or it may amount to the darkest shades of orange and brown. It may or may not be complicated by the presence of spots or patches of blood-staining (ecchymosis) on the visible mucous membranes but especially in cases complicated by poisoning with taurocholic acid or effete nitrogenous products.
The urine may be similarly colored in all shades of yellow or orange brown, and may leave a correspondingly deep stain on white paper.
The test for bile pigments (Gmelin’s) is simple and beautiful. Pour a little nitric acid into a test tube held obliquely and then add a few drops of sulphuric acid, and finally a little urine, so slowly, that it will remain on the surface. Soon at the point of junction appear in succession the various colors of the rainbow: yellow, green, blue, violet, red and lastly a dirty yellow. It is open to this objection that the characteristic play of colors may be produced by alcohol in the absence of bile pigments. Indican also will produce the green and yellow with blue between but never the violet nor red, nor all in their regular order.
A second mode of applying this test is by spreading a few drops of the urine on a white plate and letting fall a drop of nitric acid in the centre. The play of colors is very characteristic.
The test for bile acids (Pettenkofer’s) is to place a portion of the urine in a test tube, and after adding a drop of syrup, to add cautiously, drop by drop, two-thirds of the amount of sulphuric acid. Shake the mixture and set aside for some minutes. If sufficient heat is not produced by the mixing of the acid and urine warm slightly. The mixture becomes of a dark violet color which is destroyed by a temperature a little above 140° Fah.
A convenient application of this test (Stranburg) is to add a little cane sugar to the urine, dip a piece of filtering paper in the mixture, dry it thoroughly, pour a drop of sulphuric acid on the paper and allow it to run partially off. In a quarter of a minute a beautiful violet color is produced, best seen by holding up the paper to the light and looking through it (Brunton).
In cases due to obstruction of the bile ducts the dung is destitute of bile, whitish, often clayey and fœtid, while in cases due to reabsorption without obstruction the fæces have their natural color and odor.
It is needless to enumerate all the concomitant symptoms of jaundice which will be better noticed under the different disorders which determine it, for a list of which see the causes.
The gravity of the affection will depend on the dangerous nature of these concurrent diseases, and the destructive changes in the liver and blood rather than on the depth of color in the textures.