Classically, appendicitis presents as an initial generalized or periumbilical abdominal pain that then localizes to the right lower quadrant. Initially, as the visceral afferent nerve fibers at T8 through T10 are stimulated, and this leads to vague centralized pain. As the appendix becomes more inflamed, and the adjacent parietal peritoneum is irritated, the pain becomes more localized to the right lower quadrant. Pain may or may not be accompanied by any of the following symptoms:

• Anorexia
• Nausea/vomiting
• Fever (40% of patients)
• Diarrhea
• Generalize malaise
• Urinary frequency or urgency

Uncommon presentation

Some patients may present with uncommon features. In these patients, the pain may have woken the patient up from sleep. In addition, the rare patient may complain of pain while walking or coughing.

Pain upon passive extension of the right leg with the patient in the left lateral decubitus position is known as psoas sign. This maneuver stretches the psoas major muscle, which can be irritated by an inflamed retrocecal appendix. Patients often flex the hip to shorten the psoas major muscle and relieve pain.

Physical exam findings are often subtle, especially in early appendicitis.

As inflammation progresses, signs of peritoneal inflammation develop. Signs include:

• Right lower quadrant guarding and rebound tenderness over McBurney's point (1.5 to 2 inches from the anterior superior iliac spine (ASIS) on a straight line from the ASIS to the umbilicus)
• Rovsing's sign (right lower quadrant pain elicited by palpation of the left lower quadrant)
• Dunphy's sign (increased abdominal pain with coughing)

Other associated signs such as psoas sign (pain on external rotation or passive extension of the right hip suggesting retrocecal appendicitis) or obturator sign (pain on internal rotation of the right hip suggesting pelvic appendicitis) are rare.

The time course of symptoms is variable but typically progresses from early appendicitis at 12 to 24 hours to perforation at greater than 48 hours. Seventy-five percent of patients present within 24 hours of the onset of symptoms.

The risk of rupture is variable but is about 2% at 36 hours and increases about 5% every 12 hours after that.

The emergency department physician must refrain from giving the patient any pain medication until the surgeon has seen the patient. The analgesics can mask the peritoneal signs and lead to a delay in diagnosis or even a ruptured appendix.

Lab Testing

Elevated white blood cells (WBC) with or without a left shift or bandemia is classically present, but up to one-third of patients with acute appendicitis will present with a normal WBC count. There are usually ketones found in the urine, and the C-reactive protein may be elevated.

Imaging

Appendicitis is traditionally a clinical diagnosis. However, CT scan has greater than 95% accuracy for the diagnosis of appendicitis and is used with increasing frequency.[7][8][9]

CT criteria for appendicitis include an enlarged appendix (greater than 6 mm in diameter), appendiceal wall thickening (greater than 2 mm), peri-appendiceal fat stranding, appendiceal wall enhancement, the presence of appendicolith (approximately 25% of patients). It is unusual to see air or contrast in the lumen with appendicitis due to luminal distention and possible blockage in most cases of appendicitis. Nonvisualization of the appendix does not rule out appendicitis.

Ultrasound is less sensitive and specific than CT but may be useful to avoid ionizing radiation in children and pregnant women. MRI may also be useful for the pregnant patient with suspected appendicitis and an indeterminate ultrasound.

Classically the best way to diagnose acute appendicitis is with a good history and detailed physical exam performed by an experienced surgeon; however, it is very easy to get a CT scan done in the emergency department. It has become common practice to rely mostly on the CT report to make the diagnosis of acute appendicitis. Occasionally appendicoliths are incidentally found on routine x-rays or CT scans. These patients are at a higher risk of developing appendicitis than the general population.

These patients should be considered for prophylactic appendectomies. Studies have also shown a 10% to 30% incidence of appendicoliths present in appendectomy specimens done for acute appendicitis.

While in the emergency department, the patient must be kept NPO and hydrated intravenously with crystalloid. Antibiotics should be administered intravenously as per the surgeon. The responsibility for the consent falls on the surgeon. 

The gold-standard treatment for acute appendicitis is to perform an appendectomy. Laparoscopic appendectomy is preferred over the open approach. Most uncomplicated appendectomies are performed laparoscopically. In cases where there is an abscess or advanced infection, the open approach may be needed. The laparoscopic approach affords less pain, quicker recovery, and the ability to explore most of the abdomen through small incisions. Situations, where there is a known abscess from a perforated appendix, may require a percutaneous drainage procedure usually done by an interventional radiologist. This stabilizes the patient and allows the inflammation to subside over time, enabling a less difficult laparoscopic appendectomy to be performed at a later date. Practitioners also start patients on broad-spectrum antibiotics. There is some disagreement regarding preoperative antibiotic administration for uncomplicated appendicitis. Some surgeons feel routine antibiotics in these cases are not warranted, while others give them routinely. There have also been several studies promoting the treatment of uncomplicated appendicitis solely with antibiotics and avoiding surgery altogether.[1][10]

In patients with an appendiceal abscess, some surgeons continue antibiotics for several weeks and then perform an elective appendectomy. When the appendix has ruptured, the procedure can still be done laparoscopically, but extensive irrigation of the abdomen and pelvis is necessary. In addition, the trocar sites may have to be left open.

The differential diagnosis includes Crohn ileitis, mesenteric adenitis, mittelschmerz, salpingitis, ruptured ovarian cyst, ectopic pregnancy, tubal-ovarian abscess, musculoskeletal disorders, endometriosis, pelvic inflammatory disease, gastroenteritis, right-sided colitis, renal colic, kidney stones, irritable bowel disease, testicular torsion, ovarian torsion, round ligament syndrome, epididymitis, and other nondescript gastroenterological issues.

If diagnosed and treated early, within 24 to 48 hours, the recovery and prognosis should be very good. Cases that present with advanced abscesses, sepsis, and peritonitis may have a more prolonged and complicated course, possibly requiring additional surgery or other interventions.

Postoperative abscesses, hematomas, and wound complications are all complications that can be seen after appendectomies. If the wound does get infected, one may grow Bacteroides. "Recurrent" appendicitis can occur if too much of the appendiceal stump is left after an appendectomy. This acts just like an appendix and can become occluded and infected just as with the initial episode. Therefore, it is important to ensure that there be very minimal and preferably no residual appendiceal stump after an appendectomy. If left untreated, appendicitis can lead to abscess formation with the development of an enterocutaneous fistula. Diffuse peritonitis and sepsis can also develop, which may progress to significant morbidity and possible death.

Special consideration should be given to the treatment of patients with perforated appendicitis with an abscess. Those who present with an abscess and do not exhibit peritonitis may benefit from CT or ultrasound-guided percutaneous drain placement as well as antibiotics. Interval appendectomy is classically performed 6 to 10 weeks after recovery. Historically, 20% to 40 % of patients treated medically for perforated appendicitis with an abscess had recurrent appendicitis in historical literature. More recent studies suggest these rates be much lower.

Complications of appendicitis and appendectomy include surgical site infections, intra-abdominal abscess formation (3% to 4% in open appendectomy and 9% to 24% in laparoscopic appendectomy), prolonged ileus, enterocutaneous fistula, and small bowel obstruction.

Occasionally the incorrect diagnosis of acute appendicitis is made when, in reality, the correct diagnosis is Crohn disease of the cecum or terminal ileum. It is important to know that is this occurs that the appendix should be left in place if there is involvement at its base. The removal of the appendix in this situation has a high leak and fistula rate formation. On the other hand, if the base of the appendix is spared, then the appendix should be removed, even if it appears normal. This eliminates the future confusion of diagnosing acute Crohn disease versus acute appendicitis.

In the past, it was commonplace to routinely remove the appendix at the time of other nonrelated surgeries to avoid developing appendicitis in the future. Today, however, most surgeons do not routinely remove a normal appendix at the time of other scheduled procedures. If a patient does go into surgery for an incorrect diagnosis of acute appendicitis, then it is advised to remove the appendix to avoid any future diagnostic issues.

Patients with appendicitis usually first present to the emergency department with abdominal pain. The triage nurse should be familiar with the signs and symptoms of appendicitis because these patients need urgent admission and treatment to prevent perforation. However, making a diagnosis of appendicitis is not always easy.

Several guidelines exist that can help healthcare workers make a diagnosis of appendicitis. While most physicians, nurse practitioners, and physician assistants rely on the physical exam, others may obtain an ultrasound. For questionable cases, a CT scan of the abdomen may be helpful. The American College of Radiology recommends an ultrasound in pregnant women and an MRI in inconclusive cases in the same patient population.[11][12]

While the patient is undergoing investigation, the nurse should start an IV, administer fluids as ordered. In women, a pregnancy test must be done to rule out an ectopic. The surgeon should be notified. Pain medications should typically only be administered after the surgeon has seen the patient. The nurse should monitor the patient for acute changes in pain or vital signs and report to the interprofessional team. Before surgery, the pharmacist should evaluate for potential drug-drug interactions and potential drug allergies, reporting to the team any potential concerns.

Controversy also exists on how to best manage an appendiceal mass or phlegmon and when to undertake surgery. There is no longer any question that laparoscopic appendectomy is associated with minimal pain and faster recovery, but it is costly. Other studies indicate that a single small incision provides comparable results to a laparoscopic appendectomy and is cost-effective. Given these controversies, an interprofessional team approach to diagnosis and management of appendicitis needs to be established in each institution to ensure that the patient has no morbidity, and the management is cost-effective. [13](Level 3)

Outcomes

Many large series show that simple appendicitis treated either with an open or laparoscopic procedure has excellent outcomes. (Level 3)  However, more severe and complicated appendicitis is known to be associated with worse outcomes and greater utilization of resources. Further, the atypical presentation of appendicitis in pregnancy and the elderly may also make diagnosis difficult and lead to a higher incidence of complications.  [14][15](Level 3) In an era of managed care where quality care indices are monitored, it behooves healthcare workers to know the current standards of diagnosis and management of appendicitis or face denial of reimbursement.