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Appendicitis
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Related narratives: Appendectomy, Appendectomy (Video), Pelvic Abscess Following Appendectomy, From the time Melier identified the pathology of appendicitis in 1827 to the time Reginald Fitz named the entity in 1886, there was slow progress in the diagnosis and treatment of the condition. With the advent of anesthesia and McBurney (1889) and later Murphy's (1905) focus on the sequence of symptoms and findings, the modern diagnosis and treatment of appendicitis began. In the pre-antibiotic era, when the rate of intraperitoneal abscess was high, patients would be kept at bed rest in semi-Fowler's position to promote formation of a complicating abscess in the pelvis (rectovaginal pouch of Douglas) where it could be reached trans-rectally or transvaginally for drainage. The addition of antibiotics, starting with penicillin in the '40s, and the more recent advent of CT and US, the correct diagnosis and early treatment has reduced mortality below 1%, and the incidence of removing a normal appendix to well below the earlier expectation of 20%. Laparoscopic appendectomy offers additional advantages when the diagnosis is questionable, especially in women. It is currently unresolved whether there is a slightly higher incidence of intraabdominal abscess after laparoscopic appendectomy. The increasingly rare complication of intraabdominal abscess can be treated with CT or US-guided percutaneous drainage in most instances. Appendicitis is rare in the very young and in the elderly, with a peak incidence around 20 years. Obstruction of the appendiceal lumen, most often by submucosal lymphoid tissue hypertrophy (followed by fecolith and foreign body as causes) leads to bacterial overgrowth, inflammation, edema, lymphatic and vascular compromise and finally gangrene and perforation. If the process is rapid, or occurs in an immunocompromised individual, perforation leads to peritonitis. If slow, omentum and adjacent structures wall off the process and a localized abscess develops. The infecting organisms are colonic in nature, facultative aerobes and anaerobes. Bacterial translocation can be found in less than 50% of patients with early appendicitis, vs. 85% with gangrenous or perforated appendicitis. The potential lethality of appendicitis occurs in the latter category where peritoneal sepsis leads to multiple abscess, ongoing septicemia, systemic inflammatory response syndrome (SIRS), and ultimate death by multiple organ failure. Thus early diagnosis and treatment are critical. Signs and symptoms establish the diagnosis in most cases. In equivocal cases, double contrast CT can be helpful, diameter ( > 5-7 mm) and periappendiceal fat stranding (dirty fat) being the most important criteria. Ultrasound demonstrating compressibility, size, appendicolith, submucosal interruption and mass is highly operator dependent and less reliable. Rarely (1-2%) is there free air with perforation, and a true pain-free interval, from decompression on perforation, is rare. There is usually leukocytosis and shift. In children, gastroenteritis, Meckel's diverticulitis, intussusception and sickle cell crisis may mimic appendicitis. In the young, inflammatory bowel disease and genitourinary conditions can confuse the diagnosis, and malignancy, ulcer and biliary disease are added concerns in the adult and elderly population. Infectious complications are dependent on the stage of disease. With gangrenous or perforated appendicitis, it is prudent to continue antibiotics for 7-10 days, or until the patient is afebrile with a normal white count and normal bowel function. There is about a 15-25% wound infection rate if the skin is closed after removing a gangrenous or perforated appendix. Many would choose delayed primary closure on day 4-5 rather than having to reopen the wound in that 25%. About 2-5% of cases present with a mass representing either a phlegmon around the appendix or a localized abscess. If there is a well defined abscess cavity, image-guided (US or CT) drainage, leaving a pigtail catheter in place until the cavity is collapsed by repeat imaging, is the treatment of choice. To operate in the face of such inflammation risks aggravating the process and injuring friable adjacent bowel, creating serious complications. At the time of interval appendectomy (which is advocated in most instances) six weeks after the acute episode, the appendix often appears normal. Transient intestinal obstruction may be seen after appendectomy, especially in the pediatric population. It usually responds to non-operative management. Infertility is a risk in female children with perforated appendicitis. Appendicitis during pregnancy mandates operation regardless of the trimester, since complications are a far greater risk to the pregnancy than operation. The physiological leukocytosis and nausea of pregnancy may confuse the diagnosis. After the 5th month, the cecum and appendix are pushed up above the level of the iliac crest, and tenderness is the best indication of the condition and the location of the incision. References: Townsend: Sabiston Textbook of Surgery, 16th ed., 2001, WB Saunders Co. 919-926. Hartman, GE in Behrman: Nelson Textbook of Pediatrics, 17th ed, 2004, 1283-1285. Helmer, KS et al, Standardized patient care guidelines reduce infectious morbidity in appendectomy patients, Am J Surg, 183:6, June 2002. Related Critique: appendicitis quiz.
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