Kara E Hennelly, MD,
Fellow, Department of Pediatric Emergency
Medicine, Children's Hospital Boston
Nothing to disclose.
Coauthor(s)
Richard G Bachur, MD,
Associate Professor of Pediatrics, Harvard
Medical School; Associate Chief and Fellowship Director,
Attending Physician, Division of Emergency Medicine,
Children's Hospital of Boston
Nothing to disclose.
Specialty Editor(s)
John D Halamka, MD, MS,
Associate Professor of Medicine, Harvard
Medical School, Beth Israel Deaconess Medical Center; Chief
Information Officer, CareGroup Healthcare System and Harvard
Medical School; Attending Physician, Division of Emergency
Medicine, Beth Israel Deaconess Medical
Center
Nothing to disclose.
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
Nothing to disclose.
Mary L Windle, PharmD,
Adjunct Associate Professor, University of
Nebraska Medical Center College of Pharmacy; Pharmacy Editor,
eMedicine
Nothing to disclose.
Wayne Wolfram, MD, MPH,
Associate Professor, Department of Emergency
Medicine, Mercy St Vincent Medical Center
Nothing to disclose.
Chief Editor
Richard G Bachur, MD,
Associate Professor of Pediatrics, Harvard
Medical School; Associate Chief and Fellowship Director,
Attending Physician, Division of Emergency Medicine,
Children's Hospital of Boston
Nothing to disclose.
Background
Appendicitis, the most common pediatric surgical emergency, is caused by inflammation of the vermiform appendix. Four of 1,000 children younger than age 14 years will be diagnosed with appendicitis. Common symptoms of appendicitis include abdominal pain, fever, and vomiting. The diagnosis of appendicitis can be difficult in children because the classic symptoms are often not present.
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.
The appendix arises from the inferior tip of the cecum as a long, thin diverticulum. For most children, the cecum is located in the right lower quadrant. The base of the appendix is fixed to the cecum. However, the tip can be located in the pelvis, retrocecum, or extraperitoneum.
The exact function of the appendix is unknown. It is a highly lymphatic structure, suggesting an immunologic role.
Appendicitis results from a luminal obstruction. This obstruction can be caused by fecaliths, lymphoid hyperplasia, foreign bodies, or parasites. Children and adults have also developed appendicitis following severe blunt abdominal trauma.
Once the appendiceal lumen is blocked, the appendiceal mucosa becomes edematous. A cycle begins where intraluminal pressure increases, inflammation ensues, and exudate drains from the appendix. Fecal bacterial overgrowth occurs within the obstructed lumen, thereby enhancing the inflammatory response and further increasing the intraluminal pressure. The increase in intraluminal pressure leads to a dull generalized discomfort. The patient experiences increased focal pain as the transmural inflammation extends to the peritoneum.
With delayed diagnosis of appendicitis, the obstruction progresses, the wall of the appendix stretches due to the further rise in intraluminal pressure, and perforation occurs. When the inflammatory fluid and bacterial contents are released into the abdominal cavity, peritonitis develops. Concomitantly, the patient complains of more intense and generalized abdominal pain.
In adults and adolescents, the omentum can wall off the inflamed or perforated appendix, causing a focal abscess. In the younger child, the omentum is less well developed and less likely to wall off a perforation, making peritonitis more likely.
Appendicitis has an incidence of 70,000 pediatric cases per year in the United States. Appendicitis has an incidence of 1-2 cases per 10,000 children per year between birth and age 4 years. The incidence increases to 25 cases per 10,000 children per year between age 10 and 17 years.
Mortality/Morbidity
The rate of appendiceal perforation is 80-100% for children younger than 3 years compared to less than 10-20% of children aged 10-17 years. The mortality rate for children with appendicitis ranges from 0.1-1%. Delay in diagnosis increases perforation rate.
Race
The role of race, ethnicity, health insurance, education, access to health care, and economic status on the development and treatment of appendicitis are widely debated. Cogent arguments have been made on both sides for and against the significance of each socioeconomic or racial condition.
Sex
The male-to-female ratio of appendicitis is approximately 1.4:1.
Age
Appendicitis occurs in all age groups. The diagnosis of appendicitis in a younger child is more difficult and often the condition is more advanced. Appendicitis affects patients in the second decade of life most frequently (aged 10-19 y), at a rate of 23.3 cases per 10,000 per year. The rate of appendicitis in children younger than age 4 years is 1-2 per 10,000 per year. Children younger than 4 years almost universally present after perforation. Appendicitis is extremely rare in the neonate, and the diagnosis in this age group is typically made after perforation.
Understanding the typical clinical manifestations of appendicitis is essential in order to make an early and accurate diagnosis prior to perforation. The classic history of anorexia and periumbilical pain, followed by right lower quadrant (RLQ) pain, fever, and vomiting, is observed in fewer than 60% of patients.[1] The clinician is more likely to make the diagnosis by maintaining a high degree of suspicion and a broad differential diagnosis, and looking for the atypical case rather than the classic appendicitis.
Vomiting, RLQ pain, focal tenderness, and guarding are significantly associated with appendicitis.
The initial symptom is poorly defined periumbilical pain, often associated with anorexia. A unique feature of appendicitis is gradual onset of pain followed by vomiting. Vomiting first is more typical of gastroenteritis. Abrupt onset of pain should prompt the clinician to consider acute ischemic conditions, such as volvulus, testicular torsion, ovarian torsion, or intussusception.
After a few hours, the pain migrates to the RLQ due to inflammation of the parietal peritoneum. This pain is more intense, continuous, and more localized than the initial pain. This shift of pain rarely occurs in other abdominal conditions.
Most children with appendicitis either are afebrile or have a low-grade fever. High fever is not a common presenting feature unless perforation has occurred.
Becker et al found that 44% of patients diagnosed with appendicitis presented with 6 or more atypical features.[2] Examples of atypical features include absence of anorexia, nausea, migration of pain, RLQ pain, and pyrexia. Abrupt onset of pain, diarrhea, and pain longer than 48 hours are further examples of atypical features of appendicitis.
Children vary in their ability to cooperate with the physical examination. It is important to tailor the physical examination with respect to the child's age and developmental stage. It is also important to exclude extra-abdominal causes of abdominal pain, such as urinary tract infection (UTI) or pneumonia. Note the following:
In early appendicitis, children may have focal tenderness in the RLQ without significant guarding or peritoneal signs.
Observation of the child's interaction and gait prior to the examination can be extremely helpful. If able to stand, asking a child to hop is helpful in assessing for peritoneal irritation. If the child is unwilling to stand, shaking the bed or pelvis can also evaluate for peritoneal signs.
A child with advanced appendicitis typically prefers to lie still due to peritoneal irritation.
The child may have localized guarding or rebound tenderness.
Typically, maximal tenderness can be found at McBurney's point, which is halfway between the umbilicus and the anterior superior iliac spine in the RLQ.
On examination, bowel sounds may be decreased.
Rovsing sign is pain in the RLQ in response to palpation of the left lower quadrant (LLQ), suggestive of peritoneal irritation.
The psoas sign is elicited by placing the child on the left side and hyperextending the right hip.
The obturator sign is determined by internal rotation of the flexed right thigh. Pain on movement may be caused by an inflammatory mass overlying the psoas muscle.
A mass may be palpable in the RLQ if the appendix is perforated.
An external genitourinary (GU) examination is helpful to rule out testicular or scrotal tenderness in males and hematocolpos in pubertal females.
A rectal examination should be performed last and may reveal impacted stool, right-sided tenderness, or a mass. Be sure to perform a rectal examination (inspection, palpation, and digital examination) in children who have any abdominal tenderness, a history of constipation, a history of rectal bleeding, trauma, or suspected physical abuse. A retrocecal appendix may cause exquisite tenderness on rectal examination.
A pelvic examination should be considered in sexually active females to evaluate for tenderness (adnexal and/or cervical motion tenderness), masses, bleeding, or discharge.
Appendicitis results from a luminal obstruction. This obstruction can be caused by fecaliths, lymphoid hyperplasia, foreign bodies, or parasites. Children and adults have also developed appendicitis following severe blunt abdominal trauma.
Laboratory findings may increase the suspicion for appendicitis but are not diagnostic.
A minimum laboratory evaluation for patients with possible appendicitis includes a CBC with differential and urinalysis. Electrolytes may be useful if concern of dehydration or diabetic ketoacidosis. Liver function tests and amylase and lipase levels may additionally be helpful if other diagnoses are considered.
The WBC count is neither sensitive nor specific for appendicitis. The WBC count is elevated in approximately 70-90% of patients with acute appendicitis, but it also is elevated in many other abdominal conditions. The predictive value of the WBC count is limited. Because at least 10% of patients with appendicitis have a WBC count within the reference range, appendicitis cannot be excluded based on a normal WBC count. It is important to interpret the WBC count with respect to the clinical presentation. A WBC count of more than 15,000 cells/mm3 is suggestive of perforation. Cardall et al found no difference in the WBC count between children with simple appendicitis and those with a perforated appendicitis.[3]
Urinalysis is useful for detecting urinary tract disease, such as infection or renal stones. Pyuria can be present in children with appendicitis. Irritation of the bladder or ureter by an inflamed appendix may result in a few WBCs in the urine, but the presence of more than 20 WBCs/hpf suggests a urinary tract infection or vaginitis. Possible causes of hematuria include renal stones; urinary tract infection; Henoch-Schönlein purpura (HSP); or hemolytic uremic syndrome (HUS), in this case related to hemolysis and not red blood cells by microscopy). Normal findings on urinalysis are of limited diagnostic value for appendicitis. Grossly abnormal urinalysis findings may suggest another cause of abdominal pain.
C-reactive protein (CRP) is a nonspecific inflammatory marker. A normal CRP does not exclude appendicitis, especially early in the illness.
The triple test consists of CRP, total white blood cell count (WBC), and neutrophil percentage. Positive triple test result is indicated by CRP values of more than 8 mcg/mL, and total WBC count of more than 11,000/µL, and neutrophil percentage of more than 75%.
Liver function tests, serum amylase level, and serum lipase level may be helpful when the etiology of the abdominal pain is unclear. Electrolytes and renal function tests are more helpful in the management than in the diagnosis of appendicitis. Indications for assessing electrolytes include a significant history of vomiting or clinical suspicion of dehydration.
Urine human chorionic gonadotropin-beta subunit (hCG) should be obtained to rule out pregnancy (intrauterine and ectopic) in adolescent females.
Blood cultures should be obtained in an ill-appearing child.
Plain radiographs rarely add to the diagnosis because they are typically normal in appendicitis. Abdominal radiographs should be obtained in any patient with an examination concerning for intestinal obstruction or with peritoneal signs. The presence of a calcified appendiceal fecalith occurs in fewer than 10% of cases. Note the image below.
View Image
Perforated appendicitis.
Ultrasonography
Ultrasonography is the preferred imaging modality in the evaluation of acute appendicitis in pediatrics when available. Ultrasonography advantages include noninvasiveness, no contrast or radiation exposure, and minimal pain. One disadvantage is that the examination is operator-dependent, and patients with larger body mass indexes (BMIs) are difficult to examine. Ultrasonography has had an overall sensitivity of 85% and specificity of 94% in pediatric patients in experienced hands.[4]
Specific findings can support the diagnosis. The finding of a noncompressible dilated appendix is a strong indicator of nonperforated appendicitis. After perforation, ultrasonography can identify a periappendiceal phlegmon or abscess formation. Additional findings that can support the diagnosis of appendicitis include the presence of appendicoliths, fluid in the appendiceal lumen, focal tenderness over the inflamed appendix, and a transverse diameter of 6 mm or more.
Ultrasonography is especially helpful in adolescent females, as it is useful in diagnosing alternate pathology, such as a tubo-ovarian abscess, ovarian torsion, and ovarian cyst.
An ultrasonographic image that does not identify the appendix should not be interpreted as normal, but it should prompt further investigation if clinical suspicion remains.
CT scanning
In adults, a CT scan is used widely to diagnose appendicitis.
In children, numerous studies have investigated the use of CT in the evaluation of pediatric appendicitis. CT scanning appears to have its greatest value among patients with large BMIs for which ultrasonography is difficult or when ultrasonography is inconclusive. No exact CT protocol is best; some centers use intravenous contrast alone and others use intravenous contrast plus enteral contrast.
CT scans are useful for patients in whom the ultrasonographic findings are equivocal.
A CT scan may be beneficial in complicated cases with abscess formation and bowel-wall thickening. For such cases, oral contrast is most helpful for defining the abscess.
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.
One of the difficult challenges in evaluating children with abdominal pain is making a timely diagnosis prior to appendiceal perforation. In the ED, classifying patients with abdominal pain into the following 3 categories may be helpful:
Diagnosis not consistent with appendicitis: This group includes patients whose history and physical examination are not consistent with appendicitis, classic or atypical. These patients have a nonconcerning abdominal examination and history. Importantly, a complete physical examination should be completed before discharge from the ED.
Classic history for appendicitis: Patients with a classic history for appendicitis should undergo surgical consultation. Further imaging and laboratory data may be requested to confirm the diagnosis. Any patient with peritoneal signs should also have a surgical evaluation. Antibiotic therapy is an important aspect of the treatment of ruptured appendicitis. Antibiotic therapy should be directed against gram-negative and anaerobic organisms such as Escherichia coli and Bacteroides species. The administration of antibiotics, nasogastric tubes (when necessary), intravenous lines, urethral catheters (when necessary), antiemetic medicine, antipyretic medicine, and analgesia should ideally be part of the ED protocol for managing the preoperative child. Patients should receive appropriate preoperative antibiotics, such as piperacillin/tazobactam.
Unclear diagnosis: In these children, the history may be consistent with appendicitis, while the examination is not, or the examination may be suggestive of appendicitis in the face of an unremarkable history. Laboratory studies, serial abdominal examinations, and radiologic studies are helpful to determine the need for surgical consultation. Serial examinations of the patient in the ED along with results of the studies may help to clarify the diagnosis. If uncertainty persists after a period of observation, surgical consultation should be obtained.
Evaluation rules and algorithms have been proposed to help the clinician make the correct diagnosis and treatment plan. These decision rules can help predict which children are at low risk for appendicitis.
One such numerically based system was proposed by Kharbanda et al.[5] The proposed system is based on a 6-part scoring system: nausea (2 points), history of focal RLQ pain (2 points), migration of pain (1 point), difficulty walking (1 point), rebound tenderness/pain with percussion (2 points), and absolute neutrophil count of >6.75 X 103/µL (6 points). A score less than or equal to 5 had a sensitivity of 96.3% (95% confidence interval [CI], 87.5-99.0), a negative predictive value of 95.6% (95% CI, 90.8-99.0), and a negative likelihood ratio of 0.102 (95% CI, 0.026-0.405) in the validation set.
The Samuel score, or Pediatric Appendicitis Score, based on 8 variables, including migration of pain to RLQ, anorexia, nausea/vomiting, tenderness in RLQ, cough, hopping, percussion tenderness in RLQ, elevated temperature, leukocytosis, and left shift. The Samuel scoring system recommends that a score less than or equal to 5 should be observed, and a score greater than or equal to 6 should undergo surgical consultation.
The Alvarado, or MANTRELS score was originally derived from adult data. The MANTRELS score is based on 7 variables, including migration of pain to RLQ, anorexia, nausea/vomiting, tenderness in RLQ, rebound pain, elevated temperature (>37.3), leukocytosis (>103/µL), and left shift. Schneider et al found that an Alvarado score greater than or equal to 7 yielded a sensitivity of 73% and a specificity of 80%.[6] This scoring system is limited to risk stratification of suspected appendicitis in children.
Pediatric patients with appendicitis can undergo laparoscopic appendectomy (versus open appendectomy) without incurring a greater risk for complications.
Fifteen to 20% of appendectomies are performed in cases for which test results are later determined to be falsely positive, as appendicitis is difficult to diagnose in infants and toddlers.
Nontoxic patients with a localized walled-off abscess may be candidates for initial medical management with antibiotics, followed by an elective appendectomy.
The keys to any evaluation and treatment plan that involve equivocal history, physical examination findings, and inconclusive supporting test results include relieving the patient's pain and discomfort early and often, communicating with the patient and family about the plans, repeating the examination often, adjusting the differential diagnosis, and keeping the patient for observation if a firm diagnosis is not made or for follow-up. Algorithms, scoring systems, imaging studies, and consultation reports are part of the clinician's armamentarium. Documentation of medical decision making is important, as is a knowledge of the current literature.
Preoperative antibiotics are given to children with suspected appendicitis and stopped after surgery if no perforation exists. Patients presenting with perforated appendicitis may be volume depleted and require aggressive fluid resuscitation. The combination of ampicillin, clindamycin, and gentamicin is administered to treat infection from aerobic and anaerobic organisms. Alternative regimens include ampicillin and sulbactam, cefoxitin, cefotetan, piperacillin and tazobactam, ticarcillin and clavulanate, and imipenem and cilastatin.
Clinical Context:
Aminoglycoside with activity against gram-negative bacteria including Pseudomonas species. Also produces a synergistic effect when used in conjunction with a beta-lactam against Enterococci. Interferes with bacterial protein synthesis by binding to the 30S and 50S ribosomal subunits. Not the DOC. Consider if penicillins or other less toxic drugs are contraindicated, when clinically indicated, and in mixed infections caused by susceptible staphylococci and gram-negative organisms. Dosing regimens are numerous. Adjust dose based on CrCl and changes in volume of distribution. May be given IV/IM.
Clinical Context:
Lincosamide for treatment of serious skin and soft tissue staphylococcal infections. Also effective against aerobic and anaerobic streptococci (except enterococci). Inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes causing RNA-dependent protein synthesis to arrest.
Clinical Context:
Antipseudomonal penicillin plus beta-lactamase inhibitor. Inhibits biosynthesis of cell wall mucopeptide and is effective during stage of active multiplication.
Clinical Context:
Second-generation cephalosporin indicated for gram-positive cocci and gram-negative rod infections. Infections caused by cephalosporin-resistant or penicillin-resistant gram-negative bacteria may respond to cefoxitin. Inhibits bacterial cell wall synthesis during active multiplication by binding one or more penicillin-binding proteins.
Clinical Context:
Second-generation cephalosporin used as single-drug therapy to provide broad gram-negative coverage and anaerobic coverage. Also provides some coverage of gram-positive bacteria. Half-life is 3.5 h. Inhibits bacterial cell wall synthesis by binding to one or more of the penicillin-binding proteins; inhibits final transpeptidation step of peptidoglycan synthesis, resulting in cell wall death.
Dosage and route of administration depends on condition of patient, severity of infection, and susceptibility of causative organism.
Clinical Context:
Inhibits biosynthesis of cell wall mucopeptide and is effective during stage of active growth. Antipseudomonal penicillin plus beta-lactamase inhibitor that provides coverage against most gram-positives, most gram-negatives, and most anaerobes.
Clinical Context:
For treatment of multiple organism infections in which other agents do not have wide-spectrum coverage or are contraindicated due to potential for toxicity.
Pain management is a contentious topic for some emergency physicians and surgeons. Several classes of analgesic medications have proven 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 administering analgesic, antiemetic, and antipyretic agents.
Clinical Context:
Inhibits prostaglandin synthesis by decreasing the activity of the enzyme, cyclooxygenase, which results in decreased formation of prostaglandin precursors.
With proper dosing, does not cause a significant decrease in hematocrit, increase in creatinine, or overall complications. It does have the ability to decrease hospital stay and narcotic requirements in postoperative children.
Clinical Context:
A synthetic opioid that is 75-200 times more potent and much shorter half-life than morphine sulfate. 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 addition of benzodiazepines or other sedatives may result in decreased cardiac output and blood pressure.
Highly lipophilic and protein-bound. Prolonged exposure leads to accumulation in fat and delays weaning process.
Consider continuous infusion because of the short half-life of fentanyl. Parenteral form is DOC for conscious sedation analgesia. Ideal for analgesic action of short duration during anesthesia and immediate postoperative period.
Excellent choice for pain management and sedation with short duration (30-60 min) and easy to titrate. Easily and quickly reversed by naloxone.
After initial parenteral dose, subsequent parenteral doses should not be titrated more frequently than q3h or q6h thereafter.
Clinical Context:
Reliable and predictable effects, safety profile, and ease of reversibility with naloxone. Various IV doses are used; commonly titrated until desired effect obtained.
Remember to write legibly and clearly: morphine sulfate. JCAHO has placed the abbreviation on the banned abbreviation list. Therefore, do not abbreviate morphine as MSO4.
Laparoscopic appendectomy is performed for the treatment of appendicitis. Potential advantages of laparoscopic appendectomy versus open appendectomy include reduced postoperative pain and lower wound infection rate. Laparoscopy can be diagnostic for alternative diagnoses.
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