Peritonitis, inflammation of the peritoneum. Systematic writers treat of acute, general, and partial peritonitis, of chronic peritonitis, and an epidemic form occurring in childbed fever called puerperal peritonitis, which will be treated under the title Puerperal Fever. - Acute general peritonitis may be caused by admission into the peritoneal cavity of the fluid and gaseous contents of the intestines, or of air or some foreign substance through a wound of the walls of the abdomen. It may result from perforation of the ileum following lesions of typhoid fever, and of the stomach in gastric ulcer; from the discharge of pus from hepatic ovarian or other abscesses; and from the admission of urine from rupture of the bladder. It may. also be developed in connection with acute articular rheumatism, or the morbid conditions of the kidney collectively called Bright's disease. Exposure to cold may cause it, and it is not very uncommon among workmen employed in winter and spring to repair water wheels which are damaged by ice. Acute peritonitis is sometimes developed gradually, but in most cases the attack is rapid. Pain of a lancinating or burning character is usually a marked symptom, commencing at a point and extending quickly over the whole abdomen.

It is often increased to exacerba tions so as to resemble the spasms of colic. The respiration is hurried, and is almost entirely carried on by the movement of the ribs, contraction of the diaphragm and abdominal muscles producing acute pain. There is great tenderness on pressure over the abdomen, continuing during the course of the disease. The patient generally lies upon the back with the knees raised, to relax the abdominal muscles and take off the weight of bed clothing. The abdomen is often greatly distended, the intestines containing considerable gas, and the peritoneal cavity serous effusion, which post-mortem examinations show to contain coagulated products of inflammation. Vomiting is a frequent and often a prominent symptom, attended by great pain. In the later stages regurgitation of the contents of the stomach is apt to take the place of active vomiting. The pulse is frequent, hard and wiry, beating from 120 to 150 per minute. There is great prostration, and the countenance is haggard and anxious. In some cases the upper lip is raised and tightly drawn across the teeth, and this when present is a characteristic symptom.

There is great difficulty in voiding the urine, partly owing to paralysis of the muscular coat of the bladder, and partly to the pain caused by any effort to contract the abdominal muscles, which induces the patient to postpone the act; the use of the catheter is therefore frequently necessary. The intellect is usually little disordered, but slight delirium is common toward the close of fatal cases. The disease is distinguished from acute enteritis by the greater degree of pain, especially on pressure, and of tympanitis, more frequent pulse, and as a rule the absence of diarrhoea, although this sometimes occurs. From colic it may be distinguished by the fact that although the pain may have exacerbations, yet it is continuous, and is always aggravated by pressure, while colic pains are often somewhat relieved by it. Acute general peritonitis is a grave disease, recovery depending more than in most simply inflammatory diseases on management. Judiciously treated cases of idiopathic peritonitis have a good prospect of recovery. When connected with gastric or intestinal ulceration or Bright's disease, the prognosis is always unfavorable, death often taking place in a few hours in cases of perforation, although recovery here sometimes occurs.

The average duration of fatal cases of peritonitis is from four to six days. In regard to treatment authorities are somewhat divided. Bloodletting was almost invariably resorted to by the older physicians, and is still used by some; but since about 1852 an important change has taken place, more particularly in the city of New York. Cathartics also used to be employed, but their action is now regarded as injurious. Arrest or retardation of the peristaltic movements of the intestine is one of the principal requirements, and is imperatively demanded in cases of perforation; and this is obtained, by full doses of morphine or some opiate. The use of opium in conjunction with other remedies was recommended by Armstrong more than 40, and by Watson more than 30 years ago; but what is known as the opium treatment, upon which almost exclusive reliance is now placed, is due to Prof. Alonzo Clark, who first called attention to it in connection with some cases of puerperal peritonitis in the lying-in wards of Bellevue hospital in 1851-'2. The dose is to be governed by the effect, which should be nearly perfect relief from pain and diminution of the pulse.

From half a grain to a grain of some salt of morphia may be given, when in the course of two or three hours the size of the repeated doses may be estimated. In addition to the opiate, warm fomentations over the abdomen, with application of rubefacients to the legs and feet, will be of service. The use of calomel in small doses was formerly practised, and by many is not yet discarded, although when given the doses are greatly reduced, not being more than from one eighth to a quarter of a grain every four hours. Its efficacy is doubtful. Peritonitis is decidedly an asthenic disease, and great caution should be exercised in guarding the patient against depressing agencies. Rice-water drinks and beef tea, in quantities as great as may be borne without increasing the nausea or loading the intestines, are advisable. Tonics and alcoholic stimulants are for the same reason recommended. - Partial peritonitis, or that which is limited to a circumscribed portion of the peritoneum, is the result of inflammation of parts lying beneath the membrane. In ulceration or abscess of some organ, as the liver, that portion of the peritoneum covering the part becomes inflamed, and the conservative tendency in the system is to cause the adjacent fold of the membrane to become attached to it by organized exudation.

In cases of wounds of the abdomen, a similar glueing together of the two layers of peritoneum tends to take place, either accompanied with a closing of the orifice or its remaining open. The treatment should be palliative. - Chronic peritonitis is rarely the result of acute, the latter affection generally passing away completely. It is commonly developed as an accompaniment of tuberculosis, when it is known as tuberculous peritonitis. Tuberculous deposits in the mesenteric and intestinal mucous glands are generally present, but the peritonitis may occur without such lesions, or other affection than the tuberculous cachexia. In some cases chronic peritonitis occurs in connection with carcinoma, either seated in the membrane or originating in adjacent structures, and is called cancerous peritonitis. The prognosis in all cases of chronic peritonitis is unfavorable. A fatal termination, even when the affection is not connected with either tubercle or cancer, is the rule; but in this case the duration of the disease may be extended several years. When it is tuberculous or cancerous, the period is confined to a few months or a year or more. The treatment therefore has no reference to recovery, and consists in supporting the strength and relieving local symptoms.

Occasionally the accumulation of fluid in the peritoneal sac is sufficient to warrant its removal by tapping.