INTRODUCTION
A 62-year-old man returns home from playing bingo, complaining of midline abdominal pain. He denies being hit or suffering any other trauma. Over the next few hours the pain does not remit but becomes more severe and is localized to the lower right quadrant. He also develops nausea and vomiting. He denies diarrhea and has not had similar episodes. The patient lies down in bed, and over the next 24 hours, the pain worsens and he develops fever and chills and is brought to the emergency center. On examination, he has a temperature of 102°F and appears ill. His abdomen is mildly distended and has hypoactive bowel sounds. The abdomen is diffusely tender to palpation, particularly in the right lower quadrant.
· What is the most likely
diagnosis?
· What additional tests
would help in making an accurate diagnosis?
Summary: A 62-year-old man complains of midline
abdominal pain. He denies being hit or suffering any other trauma. Over the next
few hours, the pain worsens and is localized to the lower right quadrant. He
also develops nausea and vomiting and, after 24 hours, develops fever and chills
and an acute abdomen.
· Most likely
diagnosis: Acute appendicitis.
· Additional diagnostic
tests: CT scan of the abdomen and pelvis.
CLINICAL
CORRELATION
Introduction
This older man has a typical picture of a ruptured
appendicitis with sepsis. He originally had mild right lower quadrant abdominal
pain, but it worsened, and after 24 hours he developed fever and chills. Perhaps
the most worrisome finding on physical examination is that he "appears ill." He
probably has sepsis, which is a systemic condition of infection-mediated
illness. The chills probably reflect bacteremia. The emergency physician should
expeditiously manage this situation, because delay could lead to morbidity or
mortality, particularly in a geriatric patient. The blood pressure is not
mentioned, but the patient could be in septic shock. Treatment should be
addressed in a systematic manner: airway, breathing, and circulation (ABC) with
oxygen administered, two large-bore intravenous lines (IVs), volume repletion
for the probable volume depletion and sepsis, blood cultures, urine culture, and
antibiotic therapy aimed at gram-negative bacilli and anaerobic bacteria. Blood
work to be obtained includes a complete blood count and a chemistry panel to
assess electrolytes and serum creatinine for kidney function. After
stabilization, the patient should be taken to the operating room. If the
diagnosis is unclear, a CT scan of the abdomen sometimes can help distinguish
other abdominal pathologies, such as diverticulitis.
Approach to
Appendicitis
Definitions
Appendicitis: Inflammation of the vermiform
appendix.
Diverticulitis: Inflammation of an outpouching
of the diverticulum.
Diverticulosis: A condition of outpouching of
the large bowel near the taeniae coli where the blood vessels penetrate.
Complications include hemorrhage (lower gastrointestinal bleeding) and
inflammation.
Approach to
Appendicitis and Diverticulitis
Discussion
Appendicitis
Acute appendicitis is a common disease in Western
countries and is uncommon in Africa and Asia. The incidence of the disease in
the United States has fallen considerably over the last 30 years; however, it
remains the most common abdominal emergency in childhood, adolescence, and
early adult life. Fewer than 5 percent of cases of acute appendicitis occur
in patients over age 60 years.
The pathologic process begins on the mucosal surface
of the appendix, and there is often an element of obstruction of the
appendicular lumen by a fecalith. This may lead to pressure necrosis of the
mucosa and invasion of the appendicular wall by bacteria. Common causes of
obstruction include elongation or kinking of the appendix, adhesions, and
neoplasias such as carcinoma and carcinoid tumors, both of which are rare. Some
cases spontaneously resolve, but more commonly, infection of the wall of the
appendix progresses, leading to impairment of its blood supply. When the
pathologic process has extended throughout the wall of the appendix to
involve the parietal peritoneum, the pain and tenderness are classically
over the McBurney point at the site of the appendix. The pathologic process
may continue and produce gangrene, perforation, and more generalized
peritonitis. Once perforation has occurred, the advancing bacteria may be
controlled by the ability of the omentum to wall off the inflammation;
alternatively, the peritonitis may become more widespread. In advanced
appendicitis, a mass may develop; alternatively, generalized peritonitis may
lead to the septic inflammatory response syndrome (SIRS), ultimately with
the development of multiple organ failure and death.
The site of the pain in appendicitis may vary. When the
appendix is retrocecal in position, somatic pain may be perceived in the
flank and loin rather than in the right lower quadrant. Anorexia
is an almost invariable symptom in association with appendicitis. The presence
of hunger usually eliminates this diagnosis. In association with anorexia,
nausea is common and tends to proceed to vomiting. Diarrhea sometimes occurs and
may be a result of the appendix lying in a pelvic position.
Laboratory investigations commonly performed include
the peripheral white blood cell count, which may be elevated with a predominance
of polymorphonuclear leukocytes. The urinalysis is usually normal. A CT scan of
the abdomen may show thickening of the appendix with periappendicular
inflammation and the presence of intraperitoneal fluid.
The differential diagnosis includes acute
gastroenteritis, which typically has vomiting and diarrhea as prominent
symptoms and abdominal pain that is less well defined. Intestinal
obstruction must be considered and typically presents with vomiting and
abdominal distention. Mesenteric adenitis may mimic appendicitis closely
but is associated with a generalized viral illness and causes less severe pain.
Inflammation of Meckel diverticulum may produce symptoms remarkably
similar to those of appendicitis, and laparoscopy or laparotomy may be needed
for the diagnosis. Crohn disease may closely simulate appendicitis;
affected patients generally have intestinal obstruction, and usually
conservative management is the best therapy. Gynecologic disorders such as
pelvic inflammatory disease with cervical motion tenderness and adnexal
tenderness may present similarly to appendicitis. Ureteral colic is
associated with pain and tenderness of the flank area, radiating to the groin
region. Other conditions include acute diverticulitis, colonic carcinoma,
acute cholecystitis, and pancreatitis.
Appendicitis in the elderly may have a more
rapid course. Gangrene and perforation are more common in those over age 60
years, and this may be due to a delay in diagnosis. A classic picture of the
appendicitis may be lacking, and the pain may be a less prominent feature.
Overall, although there has been a decline in the incidence of peritonitis,
paradoxically, it has increased among the elderly. Thus, appendicitis should be
at the forefront of the differential diagnosis in males with right lower
quadrant pain and tenderness.
The treatment of uncomplicated appendicitis is
surgical, consisting of an appendectomy. The abdomen is opened, and if
the appendix is found to be normal in the absence of any other pathology, it
should be removed prophylactically. At the present time, most appendixes are
removed laparoscopically rather than in an open operation.
Diverticulitis
Diverticuli are blind pouches involving the
bowel. They result from herniation of the mucosa through the circular
muscle at the site of small penetrating blood vessels. Their walls consist
of an outer layer of serosa and an inner mucosa. There is no muscle in the
wall of the diverticulum. Diverticular disease is associated with increased
intraluminal pressure in the large intestine with hypertrophy of both circular
and longitudinal muscle layers. Diverticula can occur anywhere in the large
bowel and small bowel but are found most commonly in the sigmoid colon.
Muscle hypertrophy predates the development of diverticula and results in a
narrowing of the bowel and, consequently, an increase in the intraluminal
pressure.
Diverticular disease may produce central or left lower
quadrant abdominal pain together with an alteration in bowel habit with
occasional rectal bleeding. The diagnosis is confirmed by barium enema or
colonoscopy, which will show muscle thickening and multiple diverticula with
small orifices emerging through the colonic wall. Diverticular disease of the
colon is common in Western countries and rare in central Africa, the Middle
East, the Far East, and the Pacific islands. The incidence of the disease in
Japan is increasing, possibly because of the adoption of a more westernized
diet. African Americans residing in the United States now have an incidence of
the disease equal to that of the white population. Epidemiologic studies support
the concept that the disease is not racially determined but is related to
changes in the environment and to dietary factors. Postmortem studies in the
Western countries report an incidence of about 40 percent overall and one as
high as 60 percent in those over age 60 years.
Acute or chronic inflammation within a diverticulum is
designated diverticulitis. It is estimated that the approximately 20
percent of patients with diverticulosis will manifest diverticulitis. Localized
inflammation, or even perforation and peritonitis, may occur. Pneumaturia,
resulting from a colovesical fistula, may occur, and on occasion, fecal
material may be passed in the urine. CT imaging of the abdomen remains the
primary method of diagnosing the acute process, whereas barium enema and
endoscopic examinations are relatively contraindicated during acute
infection.
Known complications of diverticulitis include
bleeding, abscess formation, peritonitis, and fistula formation. Colonic
obstruction also can occur. The treatment of diverticulitis
includes broad-spectrum antibiotics, intravenous fluids, and nothing by
mouth until the condition settles. Frank peritonitis or abscess formation
usually requires surgical intervention, commonly involving excision of the
affected area, such as a sigmoid colectomy. Postoperatively, patients should be
instructed to eat a high-residue diet and drink plenty of
liquids.
COMPREHENSION
QUESTIONS
[7.1] A 20-year-old woman presents with the sudden
development of nausea, vomiting, and right lower abdominal pain. Physical
examination finds a mild fever, and laboratory evaluation finds an increased
peripheral leukocyte count. She is taken to surgery, where an appendectomy is
performed. Which one of the following histologic changes is most likely to be
present in her appendix?
A. Amorphic mucinous material within the
lumen
B. Caseating granulomas within the
periappendiceal fat
C. Hyperplastic lymphoid follicles within the
lamina propria
D. Multinucleated giant cells within the
epithelium
E. Numerous neutrophils within the muscular
wall
[7.2] A 61-year-old woman presents with nausea,
vomiting, and the sudden onset of left-sided abdominal pain. Physical
examination finds a low-grade fever, and laboratory evaluation finds increased
numbers of neutrophils in her peripheral blood. What is the most likely
diagnosis?
A. Appendicitis
B. Cholecystitis
C. Colitis
D. Diverticulitis
E. Pancreatitis
[7.3] Which one of the clinical findings listed below
is most likely to be present in an older individual with
diverticulosis?
A. Abdominal colic caused by intestinal
obstruction
B. Iron deficiency anemia caused by chronic
blood loss
C. Megaloblastic anemia caused by vitamin
B12 deficiency
D. Steatorrhea caused by malabsorption of
fat
E. Chronic diarrhea caused by decreased
absorption of protein
ANSWERS
[7.1] E. The histologic hallmark of acute
inflammation, such as that seen with acute appendicitis, is the presence of
numerous acute inflammatory cells, namely, neutrophils. Therefore, histologic
sections of an appendix surgically removed from an individual with acute
appendicitis will reveal numerous neutrophils within the muscular wall. The
inflammation can be so marked that it causes complete destruction of the
muscular wall, which can lead to perforation and peritonitis.
[7.2] D. Acute inflammation of diverticula
(diverticulitis) will produce the sudden onset of left-sided abdominal pain
accompanied by fever and peripheral leukocytosis (mainly neutrophils). These
clinical signs are essentially the same as those seen with acute appendicitis
except that the abdominal pain is on the left side rather than the right side.
As such, diverticulitis sometimes is referred to as left-sided
appendicitis.
[7.3] B. Diverticulosis refers to the presence
of numerous diverticula in the colon. The diverticula usually are located in the
sigmoid colon in older individuals. Although they may become inflamed and
produce signs of acute diverticulitis, more often they produce chronic blood
loss as a result of chronic bleeding, which will lead to heme-positive stools
and iron deficiency anemia.
PATHOLOGY
PEARLS
· Appendicitis usually is a
24-hour disease with periumbilical pain localizing to the right lower
quadrant.
· The primary treatment of
appendicitis is surgical.
· Appendicitis continues to
have high morbidity and mortality in older patients.
· Diverticula usually involve
the left colon, particularly the sigmoid colon.
· Diverticulitis presents as
left lower abdominal pain, fever, and nausea and vomiting.
· CT imaging is helpful in
diagnosing both acute appendicitis and diverticulitis.
REFERENCES
Liu C, Crawford JM. The gastrointestinal tract. In:
Kumar V, Assas AK, Fausto N, eds. Robbins and Cotran pathologic basis of
disease, 7th ed. Philadelphia: Elsevier Saunders, 2004:854-856,
870-872.
Silen AW. Acute appendicitis and peritonitis. In:
Kasper DL, Fauci AS, Longo DL, et al. Harrison's principles of internal
medicine, 16th ed. New York: McGraw-Hill, 2004:1805-1806.
Copyright © 2006 by the
McGraw-Hill Companies, Inc. All rights reserved.
