The elimination of silver from the body is accomplished very slowly. Heller and Orfila failed to detect silver in the urine of animals taking it; others, however, have detected it in the urine, and it is probable that it is eliminated, though very slowly and in small quantities, by the kidneys. Fraschetti denies that it is eliminated by either the kidneys or the intestines. When silver is taken for a long, continuous period certain changes take place in the skin and mucous mem brane which will be considered under CHRONIC POISONING BY SILVER _NI TRATE.
Poisoning by Silver Nitrate.—There are two forms of poisoning: that follow ing a large single dose (acute) and that following the long-continued use of small doses (chronic).
ACUTE POISONING.—The symptoms of acute poisoning by silver nitrate are partly gastro-intestinal and partly cere bro-spinal. Either series of phenomena may predominate in a case of acute poi soning.
Almost immediately after a poisonous dose of the drug is taken, violent ab dominal pain, with vomiting and purg ing, comes on. At the same time evi dences of wide-spread gastro-enteritis develop. The abdominal walls become hard and knotted, more rarely scaphoid. The face becomes flushed or livid, and is covered with sweat. The expression is one of anxiety. When vomiting occurs, the ejecta are brown cr blackish in color, sometimes white and curdy, especially after sodium chloride has been given. The lips; skin, and mouth are stained white, but rapidly change in color to brown and then black.
In some cases the nervous symptoms are severe: loss of power of co-ordina tion, paralysis, and convulsions with coma or delirium may occur. The con vulsions are severe, generally tetanic (II. C. Wood), and, according to Rouget, are plainly reflex and persist after the com plete abolition of voluntary movements. Curci (London Med. Record, p. 72, '77) affirms that they are due to excitation of the motor tract of the cord, and that this is preceded by a similar influence upon the sensory tracts.
Death ensues from asphyxia due to centric respiratory paralysis (Ronget), accompanied by a profuse exudation of liquid mucus into the bronchial tubes, pulmonary congestion and oedema being found on post-mortem examination. An other theory is that the asphyxia accom panied by the excessive secretion and pulmonary congestion is caused by an altered state of the blood induced by the poisonous action of the drug (Krahmer, Rabuteau, Mourier).
In a case reported by Beck (Beck's Med. Jurisprudence, i, 675, Phila., '63) the symptoms were insensibility, violent convulsions, and dilated pupils, with, on a partial return to consciousness, intense gastric pain; complete restoration of con sciousness did not return until eleven hours after administration, and the coma returned at intervals during several days.
At post-mortem the stomach and bow els are found corroded, often ecchymosed, and with patches of a white or grayish color. The lungs arc congested and the bronchial tubes filled with fluid mucus. Poisoning by this drug is not common. H. C. Wood recalls (1S94) but 3 fatal cases. The lethal dose is not certain; 30 grains have killed and recovery has fol lowed the ingestion of an ounce.
Treatment of Acute Poisoning.—The chemical antidote is common salt (so dium chloride), which should be admin istered in large amounts. Vomiting should then be induced at once, as the chloride of silver formed is soluble in solutions of sodium chloride and in the digestive fluids. Lavage of the stomach with a very soft stomach-tube may be carefully tried. If the stomach cannot be washed out, give large draughts of salt-water and produce vomiting alter nately. Opium and oils may be given to allay the irritation, and large draughts of milk, or of soap and wa'er, to dilute the poison and protect the mucous membrane of the stomach and oesophagus from the irritant action of the drug. The ex ternal bodily heat should be maintained.