Pediatric Appendicitis

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Background

Acute appendicitis is acute inflammation and infection of the vermiform appendix, which is most commonly referred to simply as the appendix. The appendix is a blind-ending structure arising from the cecum. Acute appendicitis is one of the most common causes of abdominal pain and is the most frequent condition leading to emergent abdominal surgery in children. The appendix may be involved in other infectious, inflammatory, or chronic processes that can lead to appendectomy; however, this article focuses on acute appendicitis. Appendicitis and acute appendicitis are used interchangeably. (See Anatomy, as well as Pathophysiology.)

Images of pediatric appendicitis are provided below.


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Ultrasonographic examination of the right lower quadrant reveals a greater than 6-mm noncompressible tubular structure shown in cross section. Discomf....


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CT scan depicting a distended tubular structure descending into the pelvis and containing a round calcification (ie, an appendicolith).

Common symptoms of acute appendicitis include abdominal pain, fever, and vomiting. The diagnosis of appendicitis can be difficult in children because the classic symptoms are often not present. (See Clinical Presentation.)

A delay in the diagnosis of appendicitis is associated with rupture and associated complications, especially in young children. Improvements in rupture rates have been made with advanced radiologic imaging. Appendicitis is a clinical diagnosis with imaging used to confirm equivocal cases. (See Workup.)

The definitive treatment for appendicitis is appendectomy. Initiation of antibiotics upon diagnosis is important to slow the infectious process and help prevent progression of a nonperforated appendix. Key to any evaluation and treatment plan are the following: relieve the patient's pain and discomfort early and consistently; communicate with the patient and family about the plans; repeat the examination often; adjust the differential diagnosis as appropriate; and keep the patient for observation if a firm diagnosis is not made. (See Treatment and Management.)

The most widely used antibiotic regimen is the combination of ampicillin, clindamycin (or metronidazole), and gentamicin. (See Medication.)

Patient education

For patient education information, see the Esophagus, Stomach, and Intestine Center, as well as Appendicitis and Abdominal Pain in Children.

Anatomy

The vermiform appendix is generally 5-10 cm in length. It arises from the cecum, which in most children is located in the right lower quadrant of the abdomen.

Although the base of the appendix is fixed to the cecum, the tip can be located in the pelvis, retrocecum, or extraperitoneum. Note that the anatomic position of the appendix determines the symptoms and the site of tenderness when the appendix becomes inflamed.

The appendix is lined by typical colonic epithelium. The submucosa contains lymphoid follicles, which are very few at birth. This number gradually increases to a peak of about 200 follicles at age 10-20 years and then subsequently declines. In persons older than 30 years, less than half that number is present, and the number continues to decrease throughout adulthood.

Pathophysiology

Once the appendix becomes obstructed, bacteria trapped within the appendiceal lumen begin to multiply, and the appendix becomes distended. The increased intraluminal pressure obstructs venous drainage, and the appendix becomes congested and ischemic.

The combination of bacterial infection and ischemia produce inflammation, which progresses to necrosis and gangrene. When the appendix becomes gangrenous, it may perforate. The progression from obstruction to perforation usually takes place over 72 hours.

One study noted that appendiceal perforation is more common in children, specifically younger children, than in adults. A substantial risk of perforation within 24 hours of onset was noted (7.7%) and was found to increase with duration of symptoms. While perforation was directly related to the duration of symptoms before surgery, the risk was associated more with prehospital delay than with in-hospital delay.[1]

During the initial stage of appendicitis, the patient may feel only periumbilical pain due to the T10 innervation of the appendix. As the inflammation worsens, an exudate forms on the appendiceal serosal surface. When the exudate touches the parietal peritoneum, a more intense and localized pain develops.

Perforation results in the release of inflammatory fluid and bacteria into the abdominal cavity. This further inflames the peritoneal surface, and peritonitis develops. The location and extent of peritonitis (diffuse or localized) depends on the degree to which the omentum and adjacent bowel loops can contain the spillage of luminal contents.

If the contents become walled off and form an abscess, the pain and tenderness may be localized to the abscess site. If the contents are not walled off and the fluid is able to travel throughout the peritoneum, the pain and tenderness become generalized.

Etiology

Acute appendicitis is due to obstruction of the blind ending appendix, resulting in a closed loop. In children, obstruction usually results from lymphoid hyperplasia of the submucosal follicles. The cause of this hyperplasia is controversial, but dehydration and viral infection have been proposed. Another common cause of obstruction of the appendix is a fecalith.

Rare causes include foreign bodies, parasitic infections (eg, nematodes), and inflammatory strictures.

Epidemiology

Appendicitis has an incidence of 70,000 pediatric cases per year in the United States. The incidence between birth and age 4 years is 1-2 cases per 10,000 children per year. The incidence increases to 25 cases per 10,000 children per year between 10 and 17 years of age. Overall, 7% of people in the United States have their appendix removed during their lifetime. The male-to-female ratio is approximately 2:1.

Appendicitis is much more common in developed countries. Although the reason for this discrepancy is unknown, potential risk factors include a diet low in fiber and high in sugar, family history, and infection.

Appendicitis occurs in all age groups but is rare in infants. Appendicitis is most common in the second decade of life (age 10-19 y), occurring at a rate of 23.3 cases per 10,000 per year. Thereafter, the incidence continues to decline, although appendicitis occurs in adulthood and into old age.

Prognosis

Generally, the prognosis is excellent. At the time of diagnosis, the rate of appendiceal perforation is 20-35%. The rate of perforation is 80-100% for children younger than 3 years, compared with 10-20% in children 10-17 years old. Children with ruptured appendicitis are at risk for intra-abdominal abscess formation and small bowel obstruction, and they can have a prolonged hospital stay (several weeks or more). The mortality rate for children with appendicitis is 0.1-1%.

Death from appendicitis is most common in neonates and infants for the following 2 reasons:

History

The classic history of anorexia and vague periumbilical pain, followed by migration of pain to the right lower quadrant (RLQ) and onset of fever and vomiting, is observed in fewer than 60% of patients.[2] If the appendix perforates, an interval of pain relief is followed by development of generalized abdominal pain and peritonitis. Although some patients progress in the classical fashion, some patients deviate from the classic model. Atypical presentations are common in neurologically impaired and immunocompromised patients, as well as in children who are already on antibiotics for another illness.

In patients with a retrocecal appendix, who constitute 15% of cases, signs and symptoms may not localize to the RLQ but instead to the psoas muscle, the flank or right upper quadrant. In other patients, the tip of the appendix is deep in the pelvis, and the signs and symptoms localize to the rectum or bladder resulting in pain with defecation or voiding.

Certain features of a child's presentation may suggest a perforated appendix. A child younger than 6 years with symptoms for more than 48 hours is much more likely to have a perforated appendix. The child may have generalized abdominal pain and may have a high heart rate and a temperature higher than 38°C.

A substantial risk of perforation within 24 hours of onset was noted (7.7%) in one study and was found to increase with duration of symptoms. While perforation was directly related to the duration of symptoms before surgery, the risk was associated more with prehospital delay than with in-hospital delay.[1]

Pain

All patients with appendicitis have abdominal pain, and many have anorexia; absence of both of these findings should place the diagnosis of appendicitis in question. A child who states that the ride to the hospital is painful when the vehicle hits bumps in the road suggests peritoneal irritation.

Acute onset of severe pain is not typical of acute appendicitis but is seen with acute ischemic conditions such as volvulus, testicular torsion, ovarian torsion, or intussusception. If the pain is initially located in the right lower quadrant, severe constipation should be considered. A high index of suspicion should be maintained when attributing pain to constipation, especially in a child who does not have a prior history of constipation. Many children do not report the early symptoms of appendicitis and only appreciate the pain when it localizes to the RLQ. In addition, children with a retrocecal appendicitis may have a delay in the appreciable pain, leading to a delay in presentation.

As appendicitis progresses, the pain migrates to the RLQ due to inflammation of the parietal peritoneum. This pain is more intense, continuous, and localized than the initial pain. This shift of pain rarely occurs in other abdominal conditions.

Atypical pain is common and occurs in 40-45% of patients. This includes children who initially have localized pain and those with no visceral symptoms. Pain on urination can be seen with pelvic appendicitis.

Nausea and vomiting

A unique feature of appendicitis is gradual onset of pain followed by vomiting. Vomiting first is more typical of gastroenteritis.

Generally, vomiting that occurs prior to pain is unusual. However, in patients with retrocecal appendices, particularly those that extend cephalad along the posterior surface of the right colon, inflammation of the appendix irritates the nearby duodenum, resulting in nausea and vomiting prior to the onset of RLQ pain.

Diarrhea

Significant diarrhea is atypical in appendicitis, and the physician should consider other diagnoses, while not ruling out appendicitis. In patients with an appendix in a pelvic location, inflammation of the appendix occasionally results in an irritative stimulation of the rectum. These patients often report diarrhea. However, upon closer questioning, such patients usually describe frequent, small-volume, soft stools rather than true diarrhea.

Fever

Most children with appendicitis are afebrile or have a low-grade fever and characteristic flushing of their cheeks. Severe fever is not a common presenting feature unless perforation has occurred, and even then it may still be rare. According to one study, vomiting and fever are more frequent findings in children with appendicitis than in children with other causes of abdominal pain.

Physical Examination

The physical examination findings in children may vary depending on age. Irritability may be the only sign of appendicitis in a neonate. Older children often seem uncomfortable or withdrawn. They may prefer to lie still because of peritoneal irritation. Teenaged patients often present in a classic or near-classic fashion.

Examination of the child requires skill, patience, and warm hands. Initial and continued observation of the child is of critical importance. An ill-appearing quiet child who is lying very still in bed, perhaps with the legs flexed, is much more a cause for concern than a child who is laughing, playing, and walking around the room.

The examination should be thorough and start with areas other than the abdomen. Because lower lobe pneumonias can cause abdominal findings, a history of such should be elicited and a thorough chest examination performed. It is also important to exclude urinary tract infection (UTI) as a cause of abdominal pain.

Children vary in their ability to cooperate with the physical examination. It is important to tailor the physical examination to the child's age and developmental stage.

General examination

Patients’ general state should be observed before interacting with them. The patient’s state of activity or withdrawal may lend information into their condition. The child's gait may be observed if they are well enough to ambulate. A patient in obvious distress with abdominal pain gives the impression of an infectious process; however, other causes must be ruled out.

Cardiac and pulmonary examination

The findings on evaluation of the heart and lungs typically reflect the patient’s overall state more than they may suggest appendicitis. Patients are often dehydrated or in pain and may be tachycardic or tachypneic. Pediatric patients have great physiological reserves and may not show any general symptoms until they are very ill.

Abdominal examination

Full exposure of the abdomen is key. Before examining the abdomen, ask the child to point with one finger to the site of maximal pain. Begin palpation of the abdomen at a site distant to this, with the most tender area examined last. If the child is particularly anxious, palpation may be performed with a stethoscope.

Distracting questions concerning school and family members may be helpful to relieve anxiety during the examination. Observing the child's facial expressions during this questioning and palpating is critical.

Palpation of the abdomen should be performed with a gentle and light touch, searching for involuntary guarding of the rectus or oblique muscles. In early appendicitis, children may not have significant guarding or peritoneal signs. Younger children are much more likely to present with diffuse abdominal pain and peritonitis, perhaps because their omentum is not well developed and cannot contain the perforation.

Typically, maximal tenderness can be found at the McBurney point in the RLQ. A mass may be palpable in the RLQ if the appendix is perforated.

However, the appendix may lie in many positions. Patients with a medially positioned appendix may present with suprapubic tenderness. Patients with a laterally positioned appendix often have flank tenderness. Patients with a retrocecal appendix may not have any tenderness until appendicitis is advanced or the appendix perforates.

Presence of the Rovsing sign (pain in the RLQ in response to left-sided palpation or percussion) strongly suggests peritoneal irritation.

To assess for the psoas sign, place the child on the left side and hyperextend the right leg at the hip. A positive response suggests an inflammatory mass overlying the psoas muscle (retrocecal appendicitis).

Check for the obturator sign by internally rotating the flexed right thigh. A positive response suggests an inflammatory mass overlying the obturator space (pelvic appendicitis).

During the abdominal examination, try to avoid eliciting rebound tenderness. This is a painful practice and certainly destroys any trust that has been garnered during the examination. Peritonitis can be confirmed with gentle percussion over the right lower quadrant. Involuntary contraction of the abdominal wall musculature (involuntary guarding) and tenderness can be elicited with minimal stress or discomfort to the child.

Other methods can be used to establish that the patient has peritoneal irritation. Asking the patient to sit up in bed, cough, jump up and down, or bounce his or her pelvis off the bed while in the supine position may elicit pain in the presence of peritoneal irritation. Alternatively, other acceptable maneuvers are tapping the patient's soles and shaking the stretcher. A child with advanced appendicitis typically prefers to lie still due to peritoneal irritation.

Rectal examination

The digital rectal examination is often deferred but can be helpful in establishing the correct diagnosis, especially in sexually active adolescent girls. The patient should be told that the examination is uncomfortable but should not cause sharp pain. The caliber of the patient's anus should be taken into consideration, and smaller digits should be used for examining younger patients.

The rectal examination is particularly important in the child with a pelvic appendix, in whom the findings on the abdominal examination for appendicitis may be equivocal and indicative of peritoneal irritation.

Objective information to ascertain includes impacted stool or an inflammatory mass. Right-sided tenderness of the rectum is the classic finding in patients with pelvic appendicitis or in those with pus that pools in the pelvis from an inflamed appendix elsewhere in the abdomen.

Patients who are able to communicate should be asked if they have tenderness in different areas of the rectum. The rectal examination in a young child may have to be completely objective because they may not be able to communicate variations in tenderness or may have general discomfort from the examination.

Genitourinary examination

An external genitourinary (GU) examination is helpful to rule out testicular or scrotal tenderness in males and hematocolpos in pubertal girls.

Pelvic examination

A pelvic examination should be considered in sexually active adolescent girls to evaluate for tenderness (adnexal and/or cervical motion tenderness), masses, bleeding, or discharge.

Atypical findings

Becker et al found that 44% of patients diagnosed with appendicitis presented with 6 or more of the following atypical features[3] :

Approach Considerations

Making a timely diagnosis of appendicitis is a difficult challenge in children with abdominal pain. Laboratory findings may increase suspicion of appendicitis but are not diagnostic. The minimum laboratory workup for a patient with possible appendicitis includes a white blood cell (WBC) count with differential and urinalysis. Liver function tests and amylase and lipase assessments are helpful when the etiology is unclear. Baseline blood urea nitrogen and creatinine are needed prior to intravenous contrast CT scanning.

Other studies, such as interleukin 6 and C-reactive protein (CRP) assays, have been advocated by some in the diagnosis of appendicitis. However, in multiple clinical series, these studies have not been shown to be of clear benefit and, for the most part, only add to the cost of the evaluation.

CBC Count

The WBC count becomes elevated in approximately 70-90% of patients with acute appendicitis. However, the WBC count is elevated in many other abdominal conditions, as well. Furthermore, the WBC count is often within the reference range within the first 24 hours of symptoms. Elevation tends to occur only as the disease process progresses, and it is usually mild. Therefore, its predictive value is limited. Elevation of the neutrophil or band count can be seen without elevation of the total WBC count and may support the diagnosis of appendicitis.

If the WBCs exceed 15,000 cells/μL, the patient is more likely to have a perforation. However, one study found no difference in the WBC counts of children with simple appendicitis and those with perforated appendicitis. In the immunocompromised patient, a neutrophil count of less than 800 may suggest typhlitis.

Urinalysis

Urinalysis is useful for detecting urinary tract disease, including infection and renal stones. However, irritation of the bladder or ureter by an inflamed appendix may result in a few urinary WBCs. The presence of 20 or more WBCs per high-power field (hpf) suggests a urinary tract infection.

Hematuria may be caused by renal stones, urinary tract infection, Henoch-Schönlein purpura, or hemolytic-uremic syndrome. However, small numbers of red blood cells (RBCs) can be found in as many as 20% of patients with appendicitis when an overlying phlegmon or abscess lies adjacent to the ureter. Typically, urinary RBCs are fewer than 20/hpf.

Ketonuria is suggestive of dehydration and is more common with perforated appendicitis.

Normal urinalysis results have no diagnostic value for appendicitis. However, a grossly abnormal result may suggest an alternative cause of abdominal pain

Abdominal Radiography

Abdominal radiography findings are normal in many individuals with appendicitis. However, plain films may be helpful in the setting of severe constipation. A calcified appendiceal fecalith is present in less than 10% of persons with inflammation, but its presence suggests the diagnosis.

Radiographic signs suggestive of appendicitis include convex lumbar scoliosis, obliteration of the right psoas margin, right lower quadrant (RLQ) air-fluid levels, air in the appendix, and localized ileus. In rare incidents, a perforated appendix may produce pneumoperitoneum.

If no other imaging studies are to be performed, an abdominal series may be helpful.

For more information, see the Medscape Reference article Appendicitis Imaging.

Ultrasonography

Given the potential risks of radiation from CT scans, graded compression ultrasonography may be the preferred initial imaging modality in the evaluation of pediatric acute appendicitis. This technique involves locating the appendix and then attempting to compress its lumen.

For ultrasonography to be diagnostic of appendicitis, the operator must visualize the appendix. Even if the appendix is not visualized, however, appendicitis can be excluded more confidently if ultrasonography shows no secondary signs of appendicitis (eg, hyperechoic mesenteric fat, fluid collection, localized dilated small bowel loop).[4]

A positive finding is a noncompressible tubular structure 6 mm or wider in the RLQ (see the images below). This structure is tender during palpation with the ultrasonographic probe. Additional supportive findings include an appendicolith, fluid in the appendiceal lumen, focal tenderness over the inflamed appendix (sonographic McBurney point), and a transverse diameter of 6 mm or larger. In patients with a perforated appendix, ultrasonography may reveal a periappendiceal phlegmon or abscess formation.


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Ultrasonographic examination of the right lower quadrant reveals a greater than 6-mm noncompressible tubular structure shown in cross section. Discomf....


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Ultrasonographic examination of the right lower quadrant reveals a greater than 6-mm noncompressible tubular structure shown in cross section. Discomf....

Abdominal ultrasonography has proved to be valuable for diagnosing appendicitis in children, with most published reports indicating a sensitivity, specificity, and accuracy of at least 90-95%. Furthermore, some authors have found that ultrasonography is more sensitive and specific than clinical impression and increases diagnostic accuracy when used either alone or in conjunction with laboratory results.[5]

The advantages of ultrasonography include its noninvasiveness, lack of radiation, no contrast medium, and minimal pain. The downside of ultrasonography is that the examination is operator dependent and may not be available at some institutions. Factors that add difficulty to the examination include obesity and gaseous distention of the intestines overlying the appendix. However, results of one study determined that ultrasonography should continue to be the first diagnostic imaging study in suspected appendicitis, regardless of the child's body mass index (BMI).[6]

Ultrasonography is also useful in diagnosing alternative pathologies (eg, tubo-ovarian abscess, ovarian torsion, ovarian cyst, mesenteric adenitis).

A prospective study by Lowe et al comparing noncontrast CT scanning and ultrasonography revealed a sensitivity, specificity, and accuracy of 97%, 100%, and 98%, respectively, for unenhanced CT scanning, compared to 100%, 88%, and 91%, respectively, for ultrasonography.[7] Still others have shown that the perforation rate and negative appendectomy rate can be decreased by using both tests in tandem.

For more information, see the Medscape Reference article Appendicitis Imaging.

Computed Tomography

CT scanning is a useful modality for diagnosing appendicitis in children. Although radiation exposure is a concern, CT scans have been shown to have an accuracy of 97% in diagnosing appendicitis. Advantages of CT scan include the availability at most institutions, the ability to evaluate the entire abdomen and locate abscesses and phlegmon, the lack of dependence on operator skill, and physician familiarity with reading CT scans.

CT findings that are indicative of appendicitis include a thickened appendix, fat streaking around the appendix, or thickening of the cecal wall (see the images below).


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CT scan depicting a distended tubular structure descending into the pelvis and containing a round calcification (ie, an appendicolith).


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CT scan revealing an enhancing tubular structure descending into the pelvis. Periappendiceal inflammation and streaking, so-called dirty fat, is noted....

CT findings that suggest perforated appendicitis include periappendiceal or pericecal air, abscess, phlegmon, and extensive free fluid. Because the disease is due to obstruction of the appendix and the inflammation occurs distal to the obstruction, extravasation of contrast or extensive free air is rarely seen. If a patient is found to have free air throughout the abdomen or under the diaphragm, other diagnoses should be entertained.

CT scanning may be helpful in obese patients or those in whom a localized appendiceal abscess is clinically suspected. In patients with abscesses, CT scanning may also be helpful in the CT-guided drainage of the abscess.

CT scanning has been found to have sensitivity, specificity, and accuracy similar to those of ultrasonography.[7, 8] Disadvantages include the aforementioned radiation exposure, the need for oral and intravenous contrast and its related disadvantages, and the need for the patient to be still, which is often difficult for small children.

Because of the advantages of CT scans, 62% of surveyed North American pediatric surgeons preferred it for evaluation of appendicitis. Of note, less than 1% of pediatric surgeons favored CT scanning for every case of suspected appendicitis. Most preferred CT scanning on a selected basis, with 51-58% of patients with suspected appendicitis undergoing CT scanning.

However, despite now-widespread use of CT scanning for evaluation of appendicitis with its superior sensitivity and specificity, the negative appendectomy rate in children has not shown a statistically significant reduction.

Peck et al and Mullins et al have reported sensitivities of 92-97% and sensitivities of 99.6-99%, respectively, using noncontrast helical CT scanning.[8, 9] Callahan et al reported equivalent results using helical CT scanning and rectally administered contrast material.[10] They reported that this technique results in decreased total number of inpatient observation days, decreased number of negative laparotomies, and decreased per-patient cost.

Additional radiographic testing is clearly indicated in patients who present with equivocal signs and symptoms of appendicitis. Whether noncontrast CT scanning, rectally administered contrast-enhanced CT scanning, CT scanning with oral and intravenous contrast, or ultrasonography is used may be a function of the institution or time of day. The data clearly show that each has sensitivities and specificities over 90% and that each can be helpful in clinical decision-making.

For more information, see Appendicitis Imaging.

Chest Radiography

If the history, physical examination, laboratory tests, and imaging studies have failed to produce a satisfactory differential diagnosis, anteroposterior (AP) and lateral chest radiography should be performed to look for right lower lobe pneumonia.

Typically, histologic findings range from acute inflammatory infiltrate most apparent in the submucosal level in early appendicitis to transmural infarction in perforated appendicitis.

The finding of an apparently normal appendix at surgery requires careful follow-up of the histologic findings. Occasionally, early appendicitis is histologically identified and clinically correlates with the resolution of preoperative symptoms. Additionally, unsuspected findings of luminal nematodes should indicate further anthelmintic therapy (eg, mebendazole [Vermox]). Chronic inflammation or fibrosis of the tip of the appendix are occasionally seen and coincide with resolution of the symptoms.

Many surgeons now encounter patients with “early appendicitis” based on history, physical examination findings, and/or CT scans who had minimal changes found in the appendix in the operating room or only intraluminal inflammatory cells on histology. Most of these patients have complete resolution of their signs and symptoms after appendectomy. Whether this is because the appendectomy is performed at an earlier stage of appendicitis or is due to the placebo effect of the appendectomy is unknown.

For more information, see the Medscape Reference article Appendicitis Imaging.

Electrolyte levels

Electrolyte assessments and renal function tests are more helpful for management than diagnosis. Indications for these tests include a significant history of vomiting or clinical suspicion of significant dehydration.

Pregnancy Testing

A beta–human chorionic gonadotropin (beta-HCG) test should be performed to rule out pregnancy or ectopic pregnancy in adolescent girls.

Scoring Systems

Evaluation rules and algorithms have been proposed to help the clinician make the correct diagnosis and treatment plan. Although these decision rules may help predict which children are at low risk for appendicitis, they are not used consistently

Kharbanda et al scoring system

The system proposed by Kharbanda et al assigns scores based on the following 6 findings[11] :

A score of 5 or less had a sensitivity of 96.3%, a negative predictive value of 95.6%, and a negative likelihood ratio of 0.102 in the validation set.

The Samuel score (pediatric appendicitis score)

This scoring system is based on 8 variables, as follows[12] :

Samuel recommended that patients with a score of 5 or lower should be observed, while those with a score of 6 or higher should undergo surgical consultation.

The Alvarado score (MANTRELS score)

The MANTRELS score is based on the following 8 variables:

Schneider et al found that an Alvarado score of 7 or higher yielded a sensitivity of 73% and a specificity of 80%.[13] Use of this scoring system is limited to risk stratification of suspected appendicitis in children.

Staging

The clinical staging of appendicitis has important implications in the postoperative treatment of the child. Although somewhat subjective at the time of surgery, appendicitis may be divided into 3 broad categories: acute (nongangrenous), suppurative or gangrenous (nonperforated), and perforated. Perforated appendicitis can be divided further into cases with diffuse or with localized peritonitis.

Acute (nongangrenous) appendicitis

This stage of appendicitis is referred to as early appendicitis. No mural gangrene or infarction is present. This type requires no further antibiotic therapy in most settings. The child may be discharged home as soon as diet and oral pain medications can be tolerated.

Suppurative or gangrenous (nonperforated) appendicitis

Patients with exudative appendicitis, particularly those with mural gangrene, have an increased rate of postoperative intra-abdominal and wound infections, even in the absence of demonstrable perforations. Often, microperforations are present and may be identified if cultures of the fluid are obtained. However, if the the child is clinically improved and Gram stain and culture findings, if available, are negative, the intravenous antibiotics can be stopped in approximately 24 hours, and the child may be discharged home as soon as diet and oral pain medications can be tolerated. A decision can be made by the surgeon to continue oral antibiotics at home.

Perforated appendicitis

Perforated appendicitis (diagnosed either by intraoperative findings or by positive intraoperative cultures) is associated with a postoperative infection rate of as high as 30%. Children with perforated appendicitis require antibiotic therapy for a minimum of 7-10 days. Often, intra-abdominal abscesses that require drainage may develop. A high index of suspicion for a postoperative abscess is required in the patient with perforated appendicitis who has fevers or ileus that last more than 5 days. A child who develops a postoperative abscess or a small bowel obstruction may need additional surgery and may have a prolonged hospital stay.

Approach Considerations

Given that patients with possible appendicitis may have an equivocal history and physical examination findings and inconclusive supporting test results, the following measures are key to any evaluation and treatment plan:

Algorithms, scoring systems, imaging studies, and consultation reports are part of the clinician's armamentarium. Documentation of medical decision making is important, as is knowledge of the current literature. Consultations with a pediatrician or general surgeon may be appropriate.

Because of the short time from obstruction of the appendix to perforation, 20-35% of patients who present with acute appendicitis have already perforated. In fact, estimates suggest that most patients perforate within 72 hours of symptom onset. A substantial risk of perforation within 24 hours of onset was noted (7.7%) in one study and was found to increase with duration of symptoms. While perforation was directly related to the duration of symptoms before surgery, the risk was associated more with prehospital delay than with in-hospital delay.[1]

If a patient presents beyond 72 hours from symptom onset, perforation is highly likely. However, if a patient presents with symptoms of appendicitis beyond 72 hours and has not perforated, diagnoses other than appendicitis must be entertained.

Avoid treating vague abdominal pain by administering parenteral opiates and then discharging the patient. Narcotics and potent nonsteroidal anti-inflammatory drugs may be needed for pain control. Large doses or ongoing use should be avoided until after surgical consultation.

Patients with a classic history require prompt surgical consultation. Maintain nothing-by-mouth status in patients with suspected appendicitis, and start intravenous fluids to restore intravascular volume. Antibiotics should be started upon diagnosis of appendicitis.

Emergency medical service (EMS) personnel are well trained and cognizant of how to assess and begin treatment of the febrile, vomiting child with abdominal pain. Intravenous fluid administration, pain management, and antiemetic medication should be administered based on local EMS protocols.

The insertion of nasogastric tubes (when necessary), intravenous lines, and urethral catheters (when necessary) and the administration of antibiotics, antiemetic drugs, antipyretic drugs, and analgesia should ideally be part of the emergency department protocol for preoperative management.

Fluid Resuscitation

Ensure adequate hydration for patients who present with suspected appendicitis. Even in early acute appendicitis, children frequently have not had sufficient oral intake and present with some degree of intravascular dehydration. Intravenous hydration often improves abdominal symptoms in children who do not have appendicitis.

Patients with appendicitis usually require fluid boluses prior to operation in order to counteract dehydration. However, these patients need continued fluid resuscitation appropriate to their fluid status and severity of appendicitis.

If fluid status is unclear, urine output is the most common measure. Urine output should be no lower than 0.5 mL/kg/h. If dehydration is suspected, Foley catheter placement, monitoring of urine output, and correct fluid replacement are indicated.

Postoperatively, the spectrum of fluid management ranges from patients with early appendicitis who are started on clear fluids postoperatively and can have intravenous (IV) fluids discontinued when advanced to a regular diet, to patients with perforated appendicitis who require postoperative fluid boluses.

Antibiotic Therapy

Antibiotic therapy is an important aspect of the treatment of ruptured appendicitis. Intravenous antibiotics should be started once the diagnosis of acute appendicitis is confirmed. Antibiotic therapy should be directed against gram-negative and anaerobic organisms such as Escherichia coli and Bacteroides species.

If the appendix is not gangrenous or perforated, no postoperative antibiotics are indicated. A gangrenous appendix warrants antibiotics for 24-72 hours, depending on clinical improvement and/or Gram stain, if one was obtained during surgery.

Antibiotic therapy for ruptured appendicitis is continued for a minimum of 7-10 days, but a longer course may be needed. Intravenous antibiotics are used during the hospitalization. Oral antibiotics may be used to complete therapy if a child is well enough for discharge.

While appendectomy remains the definitive treatment for appendicitis, many patients with perforated appendicitis are now treated with intravenous antibiotics alone with drainage of the abscess if needed. Additionally, some advocate nonoperative treatment with antibiotics only for early appendicitis, especially when the diagnosis is vague.

Appendectomy

The definitive treatment for appendicitis is appendectomy. Historically, appendectomy had a 10-20% false-positive rate, but the widespread use of imaging studies has reduced this rate.

Patients with perforated appendicitis can be divided into 2 cohorts; those whose perforation is discovered in the operating room during appendectomy and those with preoperative evidence of perforation, most commonly seen on CT scans or ultrasounds. Increasingly, the approach in the latter group is conservative (nonoperative) management, with percutaneous drainage if possible and surgery after 8-12 weeks (ie, interval appendectomy).

Patients discovered to have perforated appendicitis during appendectomy should be treated in the same fashion as those with nonperforated appendicitis. The surgeon should complete the appendectomy in a normal fashion.

If a laparoscopic appendectomy is being performed, perforation alone is not a reason for conversion to open appendectomy. However, if an abscess is encountered and drained, placement of a drain in the abscess cavity should be considered. In addition, when an open appendectomy is being performed on a patient with a perforated appendix, the high incidence of wound infection should be considered in terms of skin closure.

In rare instances, the inflammation can be so severe that the appendix cannot be safely identified and removed. To avoid unnecessary morbidity, drainage procedures with subsequent interval appendectomy (see conservative [nonoperative] management) is acceptable.

To see complete information on Pediatric Appendectomy, please go to the main article.

Conservative (Nonoperative) Management

Historically, a patient with appendicitis, especially perforated appendicitis, was rushed to the operating room for appendectomy; however, this is no longer the case. Conservative management with interval appendectomy may be appropriate for perforated appendicitis. Whyte et al have suggested that interval appendectomy may be safely performed as an outpatient procedure.[14]

Conservative management begins with a trial of medical therapy. A patient found to have perforated appendicitis based on imaging study findings should be admitted to the hospital, should be placed on a nothing-by-mouth (NPO) diet, and should be given intravenous (IV) fluid resuscitation.

If the patient is hemodynamically unstable or if urine output cannot be measured, a Foley catheter should be placed. IV antibiotics should be started. Generally, antibiotics for this condition are targeted at enteric flora (eg, second-generation cephalosporin, gentamicin, metronidazole; see Medication). If the patient has an abscess that is accessible, percutaneous drainage is performed. Discharge from the hospital is based on lack of fever, tolerance of pain on oral medications, and adequate oral intake.

A patient who does not improve after admission and intravenous antibiotic therapy should undergo surgery for drainage of the infection and appendectomy, if technically feasible. Factors that suggest failure of conservative management include bandemia on admission CBC count, fever of more than 38.3° C after 24 hours of medical therapy, and multisector involvement on CT scan. Medical therapy is deemed to have failed at a median of 3 days. Medical therapy fails in as many as 38% of children with perforated appendicitis.

In children who recover with medical therapy, an alternative to interval appendectomy is to postpone surgery indefinitely. Most patients do well with this approach. Appendicitis recurrence rates range from 0-20%, with a pooled rate of 8.9% found by one large meta-analysis.[15]

A much higher recurrence rate (72%) is seen in pediatric patients with an appendicolith present during the initial acute episode. Consequently, many experts suggest that interval appendectomy may be needed only in patients with appendicolith.

Most patients who experience recurrence do so within the first 6 months after their initial episode of appendicitis; the longest follow-up to date is 13 years. However, it is not known whether pediatric patients who receive conservative treatment for appendicitis are at risk for recurrence during adulthood. Because of this uncertainty, many pediatric surgeons prefer to perform interval appendectomy.

Delaying definitive surgery is associated with significant resource use, including increased imaging, drainage procedures, and additional admissions. In addition, conservative management with laparoscopic appendectomy performed at a later date poses the risk of misdiagnosis. The major differential diagnoses for acute appendiceal abscess or mass include Crohn disease and malignancy.

The increased use of CT scanning or ultrasonography in the emergent setting has decreased this risk of misdiagnosis. These studies help to confirm the diagnosis of appendiceal mass and also guide drainage interventions. The increased use of technology, combined with improvements in antibiotics, makes conservative management a more attractive and less risky choice in terms of misdiagnosis or treatment failure.

Nonoperative management with antibiotics for early appendicitis is a new concept in the pediatric population and further studies are required prior to routine recommendation of this practice.

Percutaneous Drainage

Often, patients with gangrenous or perforated appendicitis develop intra-abdominal abscesses. These may be present at the time of presentation or may develop after surgery or during hospitalization if an interval appendectomy is planned. Commonly, a patient who has a prolonged ileus or fever for more than 5 days postoperatively has an intra-abdominal abscess.

The usual approach is to perform a CT scan of the abdomen and pelvis with oral and intravenous contrast to define the presence of an abscess. If this study confirms the presence and accessibility of an abscess, percutaneous drainage should be performed.

A drain is commonly left in the abscess cavity, and continued drainage is monitored. Once drainage decreases, the drain can be removed. Repeat imaging is not always needed.

Postoperative Pain Management

Patients who have undergone an appendectomy should be prescribed pain medication upon discharge. Liquid acetaminophen usually suffices in smaller children, with liquid acetaminophen plus codeine or hydrocodone administered for breakthrough pain. The same medication combination in a tablet form can be used in older patients, assuming they are able to swallow the tablets.

Patients who received inpatient narcotics or who are discharged on outpatient narcotics should be cautioned about the possibility of becoming constipated. These patients may need prescribed stool softeners.

Diet and Bowel Function

Patients with nonperforated appendicitis may be started on clear fluids postoperatively. Diet is advanced as tolerated.

Patients who can tolerate regular diet may be discharged home. These patients have minimal delay in the return of bowel function and do not need to have a bowel movement prior to discharge.

Patients with perforated appendicitis who have immediate appendectomy should remain NPO until their bowel function returns. They should then be started on clear fluids, and the diet advanced as tolerated. Total parental nutrition may be needed in children with prolonged hospitalization from a ruptured appendicitis.

Complications

Complications may include the following:

Medication Summary

Administer 1 dose of preoperative antibiotics to children with suspected appendicitis. Antibiotics can be discontinued after surgery if no perforation is noted.

Antibiotics are selected to provide coverage for aerobic and anaerobic organisms. The most widely used regimen is the combination of ampicillin, clindamycin (or metronidazole), and gentamicin. Alternative regimens include the following:

Resistant organisms develop in 15% of patients with a ruptured appendix. Antibiotic substitutions are made for patient allergies, poor clinical improvement or deterioration on current regimen, or culture-proven antibiotic resistance.

Patients with appendicitis also require medication for pain control. Antiemetic and antipyretic agents may also be indicated.

Antibiotic regimens should cover the most commonly encountered organisms, including Escherichia coli and Bacteroides, Klebsiella, Enterococcus, and Pseudomonas species.

Ampicillin (Marcillin, Omnipen, Polycillin, Principen)

Clinical Context:  Ampicillin is a beta-lactam antibiotic with activity against some gram-positive and gram-negative organisms. It inhibits bacterial cell wall synthesis during active multiplication.

Ampicillin/sulbactam (Unasyn)

Clinical Context:  A combination of ampicillin with a beta-lactamase inhibitor, this agent has activity against some gram-positive organisms, gram-negative organisms (nonpseudomonal species), and anaerobic bacteria.

Piperacillin/tazobactam (Zosyn)

Clinical Context:  A combination of a beta-lactamase inhibitor with piperacillin, this agent has activity against some gram-positive organisms, gram-negative organisms, and anaerobic bacteria. It inhibits biosynthesis of bacterial cell wall mucopeptide and is effective during the stage of active multiplication.

Ticarcillin and clavulanate potassium (Timentin)

Clinical Context:  This combination of an antipseudomonal penicillin plus a beta-lactamase inhibitor provides coverage against most gram-positive and gram-negative organisms and most anaerobes. It inhibits biosynthesis of cell wall mucopeptide and is effective during the stage of active growth.

Imipenem and cilastatin (Primaxin)

Clinical Context:  This combination agent is indicated for treatment of multiple organism infections in which other agents do not have wide-spectrum coverage or are contraindicated because of potential for toxicity.

Class Summary

The penicillins are bactericidal antibiotics that work against sensitive organisms at adequate concentrations and inhibit the biosynthesis of cell wall mucopeptide. Examples of extended-spectrum penicillins include ticarcillin and clavulanate (Timentin) and ampicillin and sulbactam (Unasyn).

Gentamicin (Garamycin, Gentacidin)

Clinical Context:  Gentamicin is an aminoglycoside antibiotic with activity against gram-negative bacteria, including Pseudomonas species. It is synergistic with beta-lactams against enterococci. Gentamicin interferes with bacterial protein synthesis by binding to 30S and 50S ribosomal subunits. Dosing regimens are numerous; adjust the dose based on creatinine clearance and changes in volume of distribution. Gentamicin may be administered intravenously or intramuscularly.

Class Summary

Aminoglycosides are bactericidal antibiotics used to primarily treat gram-negative infections. They interfere with bacterial protein synthesis by binding to 30S and 50S ribosomal subunits.

Clindamycin (Cleocin)

Clinical Context:  Clindamycin is a lincosamide effective against gram-positive aerobic and anaerobic bacteria (except enterococci). It inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest.

Metronidazole (Flagyl)

Clinical Context:  Metronidazole is often used in combination with an aminoglycoside, such as gentamycin. It provides broad gram-negative and anaerobic coverage. It appears to be absorbed into cells, and the intermediate-metabolized compounds that are formed bind DNA and inhibit protein synthesis, causing cell death. Metronidazole is a synthetic, nitroimadazole-derivative antibacterial and antiprotozoal agent. Metronidazole may be administered intravenously or orally.

Class Summary

Anti-infectives such as metronidazole and clindamycin are effective against some types of bacteria that have become resistant to other antibiotics.

Cefoxitin (Mefoxin)

Clinical Context:  A second-generation cephalosporin, cefoxitin has activity against some gram-positive organisms, gram-negative organisms (nonpseudomonal species), and anaerobic bacteria. It inhibits bacterial cell wall synthesis during active multiplication by binding 1 or more penicillin-binding proteins.

Cefotetan (Cefotan)

Clinical Context:  Cefotetan is a second-generation cephalosporin indicated for infections caused by susceptible gram-positive cocci and gram-negative rods.

Class Summary

Cephalosporins are structurally and pharmacologically related to penicillins. They inhibit bacterial cell wall synthesis resulting in bactericidal activity.

Ketorolac (Toradol)

Clinical Context:  Ketorolac inhibits prostaglandin synthesis by decreasing the activity of cyclooxygenase, which results in decreased formation of prostaglandin precursors.

With proper dosing, it does not cause a significant decrease in hematocrit, increase in creatinine, or overall complications. Its use can decrease hospital stay and narcotic requirements in children who have undergone surgery.

Fentanyl citrate (Sublimaze)

Clinical Context:  Fentanyl is a synthetic opioid that is 75-200 times more potent and has a much shorter half-life than morphine sulfate. It has less hypotensive effects and is safer in patients with hyperactive airway disease than morphine because of minimal to no associated histamine release. By itself, it causes little cardiovascular compromise, although the addition of benzodiazepines or other sedatives may result in decreased cardiac output and blood pressure.

Consider continuous infusion of fentanyl because of its short half-life (30-60 min). Parenteral fentanyl is the drug of choice for conscious sedation analgesia. It is ideal for analgesia of short duration during anesthesia and the immediate postoperative period. It is readily titrated and is easily and quickly reversed by naloxone.

After the initial parenteral dose, subsequent parenteral doses should not be titrated more frequently than every 3 or 6 hours. Fentanyl is highly lipophilic and protein bound. Prolonged exposure leads to accumulation in fat and delays the weaning process.

Morphine

Clinical Context:  Morphine sulfate has the advantages of reliable and predictable effects, a favorable safety profile, and ease of reversibility with naloxone. Various IV doses are used; it is commonly titrated until the desired effect is obtained.

The Joint Commission on the Accreditation of Healthcare Organizations has placed "MSO4" on the banned abbreviation list, because it can be mistaken for magnesium sulfate. Therefore, in writing the prescription, spell out "morphine sulfate" in full, legibly and clearly.

Class Summary

Pain management is a contentious topic for some emergency physicians and surgeons. Several classes of analgesic medications have proven to be safe and efficacious in the preoperative pediatric patient.

It is ethical and prudent for emergency physicians, surgeons, anesthesiologists, pediatricians, and pharmacists to agree on a plan for providing pain relief to the pediatric patient. Topics to be agreed upon include type, route, dose, and frequency of administration of analgesic drugs.

Author

Robert K Minkes, MD, PhD, Professor of Surgery, University of Texas Southwestern Medical Center at Dallas, Southwestern Medical School; Medical Director and Chief of Surgical Services, Children's Medical Center of Dallas-Legacy Campus

Disclosure: Nothing to disclose.

Coauthor(s)

Adam C Alder, MD, Assistant Professor, Department of Surgery, Division of Pediatric Surgery, Children's Medical Center, University of Texas Southwestern Medical Center at Dallas, Southwestern Medical School

Disclosure: Nothing to disclose.

Chief Editor

Carmen Cuffari, MD, Associate Professor, Department of Pediatrics, Division of Gastroenterology/Nutrition, Johns Hopkins University School of Medicine

Disclosure: Prometheus Laboratories Honoraria Speaking and teaching; Abbott Nutritionals Honoraria Speaking and teaching

Additional Contributors

Kirsten A Bechtel, MD Associate Professor, Department of Pediatrics, Yale University School of Medicine; Attending Physician, Department of Pediatric Emergency Medicine, Yale-New Haven Children's Hospital

Kirsten A Bechtel, MD is a member of the following medical societies: American Academy of Pediatrics

Disclosure: Nothing to disclose.

Deborah F Billmire, MD Associate Professor, Department of Surgery, Indiana University Medical Center

Deborah F Billmire, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American College of Surgeons, American Pediatric Surgical Association, Phi Beta Kappa, and Society of Critical Care Medicine

Disclosure: Nothing to disclose.

Jeffrey J DuBois, MD Chief of Children's Surgical Services, Division of Pediatric Surgery, Kaiser Permanente, Women and Children's Center, Roseville Medical Center

Jeffrey J DuBois, MD, is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American College of Surgeons, American Pediatric Surgical Association, and California Medical Association

Disclosure: Nothing to disclose.

Michael Stephen Freitas, MS State University of New York at Buffalo School of Medicine and Biomedical Sciences

Michael Stephen Freitas, MS is a member of the following medical societies: American College of Surgeons, American Medical Association, American Physical Therapy Association, and Medical Society of the State of New York

Disclosure: Nothing to disclose.

Philip Glick, MD, MBA Professor, Departments of Surgery, Pediatrics, and Gynecology and Obstetrics, Vice-Chairperson for Finance and Development, Department of Surgery, State University of New York at Buffalo

Philip Glick, MD, MBA is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American College of Surgeons, American Medical Association, American Pediatric Surgical Association, American Thoracic Society, Association for Academic Surgery, Association for Surgical Education, Central Surgical Association, Federation of American Societies for Experimental Biology, Medical Society of the State of New York, Phi Beta Kappa, Physicians for Social Responsibility, Royal College of Surgeons of England, Sigma Xi, Society for Pediatric Research, Society for Surgery of the Alimentary Tract, Society of Critical Care Medicine, and Society of University Surgeons

Disclosure: Nothing to disclose.

Kara E Hennelly, MD Fellow, Department of Pediatric Emergency Medicine, Children's Hospital Boston

Kara E Hennelly, MD is a member of the following medical societies: American Academy of Pediatrics

Disclosure: Nothing to disclose.

Michael S Katz, MD Research Fellow, Department of Pediatric Surgery, St Christopher's Hospital for Children

Michael S Katz, MD is a member of the following medical societies: American College of Surgeons, American Medical Association, and American Medical Student Association/Foundation

Disclosure: Nothing to disclose.

Robert Kelly, MD Chairman, Department of Surgery, Departments of Surgery and Pediatrics, Children's Hospital of the King's Daughters; Associate Professor, Eastern Virginia Medical School

Robert Kelly, MD is a member of the following medical societies: American Academy of Pediatrics, American College of Surgeons, American Medical Association, American Pediatric Surgical Association, American Society of Abdominal Surgeons, Medical Society of Virginia, Norfolk Academy of Medicine, and Southern Medical Association

Disclosure: Nothing to disclose.

David A Piccoli, MD Chief of Pediatric Gastroenterology, Hepatology and Nutrition, The Children's Hospital of Philadelphia; Professor, University of Pennsylvania School of Medicine

David A Piccoli, MD is a member of the following medical societies: American Association for the Study of Liver Diseases, American Gastroenterological Association, and North American Society for Pediatric Gastroenterology and Nutrition

Disclosure: Nothing to disclose.

Jeffrey R Tucker, MD Assistant Professor, Department of Pediatrics, Division of Emergency Medicine, University of Connecticut School of Medicine, Connecticut Children's Medical Center

Disclosure: Merck Salary Employment

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Wayne Wolfram, MD, MPH Associate Professor, Department of Emergency Medicine, Mercy St Vincent Medical Center

Wayne Wolfram, MD, MPH is a member of the following medical societies: American Academy of Emergency Medicine, American Academy of Pediatrics, and Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

References

  1. Narsule CK, Kahle EJ, Kim DS, Anderson AC, Luks FI. Effect of delay in presentation on rate of perforation in children with appendicitis. Am J Emerg Med. Oct 2011;29(8):890-3. [View Abstract]
  2. Rothrock SG, Pagane J. Acute appendicitis in children: emergency department diagnosis and management. Ann Emerg Med. Jul 2000;36(1):39-51. [View Abstract]
  3. Becker T, Kharbanda A, Bachur R. Atypical clinical features of pediatric appendicitis. Acad Emerg Med. Feb 2007;14(2):124-9. [View Abstract]
  4. Wiersma F, Toorenvliet BR, Bloem JL, Allema JH, Holscher HC. US examination of the appendix in children with suspected appendicitis: the additional value of secondary signs. Eur Radiol. Feb 2009;19(2):455-61. [View Abstract]
  5. Gracey D, McClure MJ. The impact of ultrasound in suspected acute appendicitis. Clin Radiol. Jun 2007;62(6):573-8. [View Abstract]
  6. Sulowski C, Doria AS, Langer JC, Man C, Stephens D, Schuh S. clinical outcomes in obese and normal-weight children undergoing ultrasound for suspected appendicitis. Acad Emerg Med. Feb 2011;18(2):167-73. [View Abstract]
  7. Lowe LH, Penney MW, Stein SM, Heller RM, Neblett WW, Shyr Y, et al. Unenhanced limited CT of the abdomen in the diagnosis of appendicitis in children: comparison with sonography. AJR Am J Roentgenol. Jan 2001;176(1):31-5. [View Abstract]
  8. Peck J, Peck A, Peck C, Peck J. The clinical role of noncontrast helical computed tomography in the diagnosis of acute appendicitis. Am J Surg. Aug 2000;180(2):133-6. [View Abstract]
  9. Mullins ME, Kircher MF, Ryan DP, Doody D, Mullins TC, Rhea JT, et al. Evaluation of suspected appendicitis in children using limited helical CT and colonic contrast material. AJR Am J Roentgenol. Jan 2001;176(1):37-41. [View Abstract]
  10. Callahan MJ, Rodriguez DP, Taylor GA. CT of appendicitis in children. Radiology. Aug 2002;224(2):325-32. [View Abstract]
  11. [Best Evidence] Kharbanda AB, Taylor GA, Fishman SJ, Bachur RG. A clinical decision rule to identify children at low risk for appendicitis. Pediatrics. Sep 2005;116(3):709-16. [View Abstract]
  12. Samuel M. Pediatric appendicitis score. J Pediatr Surg. Jun 2002;37(6):877-81. [View Abstract]
  13. [Best Evidence] Schneider C, Kharbanda A, Bachur R. Evaluating appendicitis scoring systems using a prospective pediatric cohort. Ann Emerg Med. Jun 2007;49(6):778-84, 784.e1. [View Abstract]
  14. Whyte C, Tran E, Lopez ME, Harris BH. Outpatient interval appendectomy after perforated appendicitis. J Pediatr Surg. Nov 2008;43(11):1970-2. [View Abstract]
  15. Andersson RE, Petzold MG. Nonsurgical treatment of appendiceal abscess or phlegmon: a systematic review and meta-analysis. Ann Surg. Nov 2007;246(5):741-8. [View Abstract]

Ultrasonographic examination of the right lower quadrant reveals a greater than 6-mm noncompressible tubular structure shown in cross section. Discomfort was noted as the probe was depressed over this structure. A small amount of free fluid is also noted surrounding the appendix.

CT scan depicting a distended tubular structure descending into the pelvis and containing a round calcification (ie, an appendicolith).

Ultrasonographic examination of the right lower quadrant reveals a greater than 6-mm noncompressible tubular structure shown in cross section. Discomfort was noted as the probe was depressed over this structure. A small amount of free fluid is also noted surrounding the appendix.

Ultrasonographic examination of the right lower quadrant reveals a greater than 6-mm noncompressible tubular structure shown in cross section. Discomfort was noted as the probe was depressed over this structure. A small amount of free fluid is also noted surrounding the appendix.

CT scan depicting a distended tubular structure descending into the pelvis and containing a round calcification (ie, an appendicolith).

CT scan revealing an enhancing tubular structure descending into the pelvis. Periappendiceal inflammation and streaking, so-called dirty fat, is noted surrounding the appendix.

Ultrasonographic examination of the right lower quadrant reveals a greater than 6-mm noncompressible tubular structure shown in cross section. Discomfort was noted as the probe was depressed over this structure. A small amount of free fluid is also noted surrounding the appendix.

Ultrasonographic examination of the right lower quadrant reveals a greater than 6-mm noncompressible tubular structure shown in cross section. Discomfort was noted as the probe was depressed over this structure. A small amount of free fluid is also noted surrounding the appendix.

CT scan depicting a distended tubular structure descending into the pelvis and containing a round calcification (ie, an appendicolith).

CT scan revealing an enhancing tubular structure descending into the pelvis. Periappendiceal inflammation and streaking, so-called dirty fat, is noted surrounding the appendix.