Appendicitis is a condition in which the appendix, a finger-shaped projection connected to the large intestine, becomes inflamed and its opening blocked. It is a medical emergency.
Appendicitis develops when the opening of the appendix is blocked. This blockage can be caused by a number of different objects ranging from intestinal parasites to fecal matter, or by an infection. As the blockage progresses, the appendix begins to die from lack of blood flow. It is then invaded by bacteria and forms pus. If the condition is not treated, the appendix swells and eventually bursts, spreading the infection throughout the abdomen. This spread of infection and inflammation to the tissues lining the abdomen is called peritonitis and is a very dangerous condition. The pain of appendicitis usually starts two to three days before the appendix gets to the point of bursting. The person typically notices a vague discomfort in the area underneath the navel. Over the next day the pain gets worse and moves downward toward the lower right portion of the abdomen, near the right hip. The “classic” symptoms of appendicitis at this point are nausea, vomiting, low-grade fever, and loss of appetite. Fewer than 50 percent of patients with appendicitis, however, have the full set of classic symptoms. Children and the elderly are often misdiag-nosed because they have fewer of these symptoms. As a result, their treatment can be delayed. The appendix ruptures before surgery in about 270 out of every 1,000 cases, and the rate of rupture is higher in children, pregnant women, and older adults.
The National Institutes of Health (NIH) estimates that about 7 percent of the general population in the United States will develop appendicitis at some point in life. There are about 1.1 cases per 1,000 people each year. The disorder is most common in people between the ages of ten and thirty, but it can develop at any age. In a few cases, appendicitis has been
diagnosed in newborn babies. Appendicitis is equally common in persons of all races and ethnic groups. It is slightly more common in men than in women, however. Although appendicitis is not hereditary, it does appear to be more common in some families.
The basic cause of appendicitis is inflammation of the appendix resulting from an obstruction of some kind or an infection. The appendix can be blocked by an overgrowth of lymphoid tissue, food wastes, small pieces of hardened stool, worms or other parasites, foreign objects, or a cancerous tumor. It may also become inflamed as a result of trauma or infection, or as a complication of Crohn disease. The blocked appendix swells up with mucus, shutting down the blood vessels that supply it with blood. As its tissues die, bacteria from the intestine grow rapidly within it. If the infection is not stopped by surgical removal of the organ, the appendix will eventually burst and the bacteria inside it will spread to other parts of the abdomen. There is no single symptom that is unique to appendicitis, nor is there a “typical” group of symptoms that all
patients experience. The following are the most common symptoms and the percentages of patients who report having them:
- Pain in the abdomen moving from the navel to the right lower part of the abdomen: 80 percent.
- Nausea: 85 percent.
- Fever: 60 percent.
- Loss of appetite: 74 percent.
- Diarrhea or constipation: 18 percent.
- Symptoms lasting less than 48 hours: 80 percent. About 2 percent of patients, however, report pain in the abdomen lasting as long as two weeks.
- A previous history of pain in the abdomen: 23 percent.
Diagnosis of appendicitis is tricky and complicated, partly because there are many diseases and disorders—particularly complications of pregnancy and Crohn disease—that cause abdominal pain, fever, and vomiting; and partly because at least half of all patients who have appendicitis do not have the classic symptoms of the condition. In addition, the size and location of the appendix varies somewhat. In some patients the appendix is located on the left side of the body rather than the right, and in others the appendix is unusually long and extends from the right side toward the left side. Diagnosis of appendicitis is based on information from several different types of examinations and tests.
Wartime Appendectomy on a Submarine
A remarkable story of battlefield medicine during World War II is an emergency appendectomy performed on a 19-year-old sailor aboard a submerged submarine, the USS Seadragon, in September 1942. There was no time or opportunity to take the sick sailor to a hospital on land and no qualified surgeons on the submarine. As the sailor got worse, the commanding officer explained that a pharmacist's mate might be able to perform an appendectomy. The sailor said that whatever the pharmacist's mate could do to help him was fine. The operation was performed on a table in the dining area with ether as the anesthetic and improvised instruments sterilized in boiling water. The pharmacist's mate removed the appendix, cleansed the stump with alcohol from a torpedo, and used crushed sulfa tablets to prevent infection, as no penicillin was available in 1942. Luckily, the sailor's 3-inch (7.6-centimeter) incision healed easily; he was back on duty in a few days. Speaking to a historian in 1999, the pharmacist's mate recalled the operation: “What was important was that I did my job…. It was my job to do anything I could to preserve life and, really, I didn't deserve special credit or recognition for doing that….”
- Physical examination: The doctor will take the patient's history, record their temperature, and perform an examination of the abdomen. Patients with appendicitis typically feel what is called rebound tenderness (soreness) when the doctor first presses on the abdomen and then releases the pressure. The patient may also stiffen the muscles of the abdomen in response to pressure; this reaction is called guarding. In addition, the doctor may be able to feel that the abdomen itself is rigid. Last, the doctor may move or rotate the patient's right leg or hip in order to test for pain during these maneuvers.
- Blood test: A high white blood cell count indicates the presence of infection.
- Imaging tests: These may include x rays, ultrasound, or computed tomography (CT) scans. The CT scan is the most commonly used imaging test to diagnose appendicitis, but x-ray studies can be useful for detecting foreign bodies or hardened stools that may be blocking the appendix.
- Urine test: This test may be done to rule out kidney stones or a urinary tract infection, but can be abnormal if the appendix inflammation is close to the urinary tract.
In a few cases involving women who may have a disorder of the ovaries or the fallopian tubes, the doctor may need to perform an exploratory type of surgery called a laparoscopy to see which organ is causing the patient's symptoms.
In a few cases, if the doctor is not certain of the diagnosis, he or she may prescribe a course of antibiotics to see whether the patient's symptoms are caused by something other than an inflamed appendix and may not require surgery. For most patients, however, surgery is the only cure for appendicitis. The surgeon can perform an appendectomy (surgical removal of the appendix) in several different ways. The oldest procedure is called an open appendectomy. The surgeon makes an incision (cut) between 2 and 4 inches (5.1 and 10.2 centimeters) and in length on the lower right side of the abdomen. The appendix is removed from its location and the area is rinsed with sterile fluid to prevent further infection. A newer and more commonly used technique is called a laparoscopic appendectomy. It requires much smaller incisions, only an inch (2.5 centimeters) or so long. The surgeon inserts a laparoscope, which is an instrument that allows the surgeon to see inside the abdomen, through one incision, and surgical instruments to remove the appendix through another small incision. If the surgeon finds that the infection has spread or that there are other complications, the operation may have to be completed as an open appendectomy. In March 2008, surgeons at a medical
center in California removed a woman's appendix through her vagina. The procedure is still considered experimental but may allow female patients to recover more rapidly.
Most people do very well after an appendectomy if their appendix was removed before it ruptured. The average hospital stay is between one and three days after surgery, but full recovery at home may take a few weeks before the patient can return to vigorous exercise or lifting heavy objects. The mortality rate for appendicitis in the United States is very low, between 0.2 and 0.8 percent of patients; most of these deaths are caused by complications of peritonitis rather than by the appendectomy itself. The rate of complications in appendicitis increases tenfold if the appendix bursts before surgery.
There is some evidence that people from cultures whose diets have a high level of fiber (the part of plants that is not digested) are less likely to develop appendicitis than those whose diets are low in fiber. It is thought that higher levels of fiber in the diet help the intestines push food along more efficiently, thus lowering the likelihood that the appendix will become blocked by fecal matter. Apart from increasing the amount of fiber in one's diet, however, there is no way to predict or prevent appendicitis.
WORDS TO KNOW
Appendectomy: Surgical removal of the appendix.
Guarding: Stiffening of the muscles in response to a doctor's touch.
Laparoscope: A fiberoptic instrument resembling a telescope that can be inserted through a small incision to allow a doctor to see the inside of the abdomen during surgery.
Peritonitis: Inflammation of the membrane that lines the abdominal cavity and covers some of the internal organs.
Pus: A whitish-yellow material produced by the body in response to a bacterial infection. It consists of tissue fluid and dead white blood cells.
Rebound tenderness: Pain experienced when the doctor releases pressure on the abdomen.
As of 2008, about 10 percent of patients with appendicitis were not correctly diagnosed on their first visit to the doctor. Ongoing research may
help doctors lower the rate of missed diagnoses of appendicitis as well as develop improved surgical instruments and techniques.
SEE ALSO Crohn disease
King, John, ed. Mayo Clinic on Digestive Health, 2nd ed. Rochester, MN: Mayo Clinic, 2004.
“Appendix Removed through Vagina: U.S. First.” Science News Daily, March 30, 2008. Available online at http://www.sciencedaily.com/releases/2008/03/080328135738.htm (accessed May 15, 2008).
American College of Surgeons (ACS). “Appendectomy: Surgical Removal of the Appendix.” Available online in PDF format at http://www.facs.org/public_info/operation/brochures/app.pdf (accessed May 16, 2008). This is a nine--page illustrated patient brochure that tells patients about surgical removal of the appendix, how to prepare for surgery, possible complications, and home care during recovery.
Mayo Clinic. “Appendicitis.” Available online at http://www.mayoclinic.com/health/appendicitis/DS00274 (updated August 15, 2007; accessed May 15, 2008).
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). “Appendicitis.” Available online at http://www.digestive.niddk.nih.gov/ddiseases/pubs/appendicitis/index.htm (updated May 2004; accessed May 15, 2008).
TeensHealth. “Appendicitis.” Available online at http://www.kidshealth.org/teen/infections/intestinal/appendicitis.html (updated May 2007; accessed May 15, 2008).