Definition
A.Appendicitis is acute inflammation of the appendix caused by the obstruction of the appendiceal lumen. There is no single sign, symptom, or diagnostic test that accurately confirms the diagnosis of inflammation. Perforation is rare in the first 12 hours, but the rate of perforation increases after 72 hours. Prompt, early diagnosis and operative intervention is the goal of treatment. The differential diagnoses for appendicitis include all abdominal sources of pain.
Incidence
A.Acute appendicitis occurs at a rate of 233:100,000. It is most common between the ages of 10 and 19 with a male predominance. It is the most common condition in children (1%–8%) and during pregnancy (0.06%–0.1%) that requires emergency abdominal surgery. One in every 2,000 adults older than age 65 will develop appendicitis.
Pathogenesis
A.Foreign bodies, fecal material, tissue hypertrophy, strictures, or a bend or twist on the organ may cause obstruction of the appendix. The obstruction causes colicky pain. Bacterial invasion causes inflammation and leads to gangrene and perforation. The most common bacteria are Escherichia coli, Pseudomonas, Bacteroides fragilis, and Peptostreptococcus species.
Predisposing Factors
A.Pregnancy.
B.Torsion.
C.Abdominal trauma.
D.Male gender, age 10 to 30.
E.Recent gastrointestinal (GI) infection.
F.Low-fiber diet.
G.Positive family history.
Common Complaints
The classic history of anorexia and periumbilical pain followed by nausea, right lower quadrant (RLQ) pain, and vomiting occurs in only 50% of cases.
A.Adults:
1.Generalized or localized abdominal pain in the epigastric or periumbilical areas. Within 2 to 12 hours, pain localizes in RLQ at McBurney’s point, and intensity increases.
2.Pain typically develops before vomiting.
3.Nausea and/or vomiting (may be projectile).
4.Anorexia signals organic cause of abdominal pain.
5.Nonspecific symptoms including indigestion, flatulence, change in bowel habits, and malaise.
6.The location of the appendix is altered in pregnancy.
7.The location of pain can vary according to the position of the appendix and the region that is inflamed.
B.Elderly patients are less likely to present with anorexia, RLQ pain, fever, or leukocytosis.
Other Signs and Symptoms
A.Rigid abdomen.
B.Changes in pulse (tachycardia), breathing (tachypnea), or skin temperature.
C.Involuntary guarding.
D.Rebound tenderness.
Subjective Data
Evaluate for a surgical abdomen,
defined as a rapidly worsening prognosis in the absence of surgical intervention. Patients should not eat or drink while a diagnosis of a surgical abdomen remains under consideration. Once a surgical abdomen has been excluded, the remainder of the evaluation will be guided by the chronicity of symptoms along with the location of pain:
A.Review onset, duration, course, and quality of pain. Has pain ever occurred before? If so, what was the primary diagnosis? What was the previous treatment, and was it effective?
B.Qualify the duration of pain in minutes, hours, days, weeks, or months. Does it interfere with sleep? Is there a pattern to the pain?
C.Have the patient rate the pain on a 10-point pain scale, with 0 being no pain and 10 being the worst pain the patient has ever felt.
D.Review the pattern of pain:
1.Review aggravating factors.
2.Review alleviating factors.
3.Does the pain radiate?
4.Does the pain have any relationship to food?
E.Questions specific to females:
1.Determine the patient’s last menstrual period (LMP) to rule out pregnancy.
2.What type of contraception is used? Specifically evaluate for an intrauterine device (IUD).
3.Has she had a hysterectomy or tubal ligation?
4.Does she have a recent history of dyspareunia or dysmenorrhea that suggests pelvic pathology?
F.Review current medications and drug history, especially antibiotic and laxative use. Patients taking corticosteroids may have a significant masking of pain.
G.Rule out abdominal trauma, motor vehicle accidents, falls, and assault.
H.Discuss bowel habits, including any changes, such as constipation or diarrhea, anorexia, food intolerance, nausea and vomiting, bloating.
I.Ask the patient about urinary frequency, urgency, dysuria, flank pain, and back pain. In males, ask about hesitancy, difficulty starting the urine stream, nocturia, low urinary volume, or lower abdominal distension (urinary retention).
Physical Examination
A.Check temperature, pulse, respirations, and blood pressure (BP), including orthostatic BP. Often, temperature is greater than 101ºF.
B.Inspect:
1.Observe general appearance: Facial expressions (grimace during exam), walk, skin color and turgor, level of consciousness, and acuity level of pain.
2.Inspect abdomen for surgical scars.
3.Observe for any bruising or other signs of domestic violence in the bathing suit
area: breasts, abdomen, or back that would be easily covered by clothes.
C.Auscultate:
1.Auscultate the abdomen for presence of bowel sounds and bruits.
2.Auscultate heart and lungs.
D.Palpate: Note guarding with exam:
1.Palpate the abdomen:
a.Ask the patient to bend his or her knees to help relax the abdominal wall musculature. Place arms at sides.
b.Note any rebound tenderness which indicates peritonitis. Perform at the end of the exam because positive response produces pain and muscle spasm that can interfere with subsequent exam.
c.Check for Murphy’s sign, which is inspiratory arrest in response to right upper quadrant (RUQ) palpation, seen with acute cholecystitis.
2.Palpate back; note cerebrovascular accident (CVA) tenderness.
3.Check for obturator sign, or abdominal pain in response to passive internal rotation of right hip from 90-degree angle hip–knee flexion position. A positive sign indicates pain secondary to irritation of obturator muscle with inflamed appendix.
4.Assess psoas sign or increased abdominal pain occurring when the patient attempts to raise his or her right thigh against the pressure of your hand placed over his or her right knee. Pain is caused by inflammation of the psoas muscle in acute appendicitis.
FIGURE 14.1The position of the appendix alters during pregnancy, and so must the site of incision to gain access.
5.Check for the Apley rule; the farther from the navel the pain, the more likely it is organic in origin.
6.Check for Rovsing’s sign, or referred pain to the RLQ with palpation of the left lower quadrant (LLQ).
7.The location of the appendix and pain is altered during pregnancy (see Figure 14.1).
E.Percuss abdomen.
F.Perform rectal exam. Although not demonstrated to show clear clinical benefit in cases of appendicitis, patients with a retrocecal appendicitis might experience more pain during a rectal examination.
Diagnostic Tests
A.Serum human chorionic gonadotropin (HCG): Pregnancy should be excluded in all women of childbearing age. Assume the woman is pregnant until proven otherwise.
B.Complete blood count (CBC) with differential—80% of appendicitis cases present with leukocytosis.
C.C-reactive protein (CRP).
D.Urinalysis, to rule out urinary disorders.
E.Abdominal ultrasonography; any person with trauma to abdomen should have abdominal ultrasound. A finding of appendiceal diameter greater than 6 mm is the most suggestive ultrasound finding.
F.CT scan with contrast; significant findings include appendiceal diameter of greater than 6 mm, appendiceal wall enhancement or thickening of greater than 2 mm, periappendiceal fat stranding.
G.MRI may be used as an alternative diagnostic test in pregnancy to avoid exposure to ionizing radiation. Appendiceal diameter of greater than 7 mm is considered significant.
H.Guaiac stool for occult blood.
Differential Diagnoses
The appendix has no fixed position. Duration of pain can help significantly in narrowing differential diagnosis. Nonspecific dysfunctional abdominal pain and psychogenic abdominal pain are diagnoses of exclusion:
A.Gastrointestinal:
1.Appendicitis.
2.Ruptured appendix—findings of white blood cell (WBC) greater than 15,000 and fever 103ºF or greater. Twenty percent of perforations occur in less than 24 hours from onset and 65% occur in greater than 48 hours.
3.Cecal diverticulitis—presents similar to appendicitis. Right-sided diverticulitis occurs in 1.5% of individuals from Western countries but is more frequent in the Asian population.
4.Meckel’s diverticulitis—occurs in younger patients but presentation is similar to acute appendicitis.
5.Regional enteritis or ileitis—associated with infection; presents with diarrhea.
6.Crohn’s disease (CD)/inflammatory bowel disease (IBD)—presents with more chronic symptoms along with fatigue.
7.Incarcerated groin hernia.
8.Abdominal wall hematoma.
9.Bowel obstruction.
10.Intestinal malrotation.
11.Intussusception.
12.Parasitic infection.
13.Constipation.
14.Leaking abdominal aneurysm.
B.Gynecological:
1.Pelvic abscess—secondary to pelvic inflammatory disease (PID) and usually occurs with vaginal discharge.
2.PID—worse with intercourse and usually occurs with vaginal discharge.
3.Ruptured ovarian cyst—usually worse with exertion and can cause bleeding.
4.Mittelschmerz—timing related to ovulation.
5.Ovarian tortion.