Abstract
Acute appendicitis is one of the most common causes of abdominal pain, with an incidence of approximately 8.5% in males and 6.7% in females; the mortality rate is approximately 0.5%. Although acute appendicitis can occur at any age, it most commonly occurs in the second or third decades. Conventional wisdom holds that acute appendicitis is the result of obstruction of the appendicular lumen with subsequent impairment of the wall leading to perforation and phlegmon formation. More recent thinking posits that mild uncomplicated appendicitis and severe complicated appendicitis are caused by different pathologic processes and are in fact two completely separate diseases requiring very different treatments.
The diagnosis is made on clinical grounds in many countries and appendectomy has remained the standard of care in the treatment of acute appendicitis for the last century. This is despite that approximately 15% of appendectomies yield a pathologically normal appendix and that appendectomy is not without morbidity and, rarely, mortality. The routine use of imaging, including ultrasound and computerized tomography as an adjunct to the clinical diagnosis of acute appendicitis, has decreased the number of “normal result” appendectomies to approximately 10%. Recent interest in the nonsurgical management of mild uncomplicated acute appendicitis is also impacting this statistic.
Abdominal pain is a common feature of acute appendicitis. Although the clinical presentation of the pain of acute appendicitis can be variable, its classic clinical presentation begins as mild periumbilical pain that becomes more severe and then migrates to the right lower quadrant at a point that is one third the distance from the anterior superior iliac spine and the umbilicus known as McBurney’s point. The pain becomes more localized and constant with associated anorexia, nausea, vomiting, and fever. Constipation and diarrhea, as well as urinary tract symptoms, may also occur. Symptoms are usually present for less than 48 hours before the patient seeks medical attention.
Keywords
appendicitis, abdominal pain, right lower quadrant pain, peritonitis, MeBurney’s point, rebound tenderness, Rovsing sign, Dunphy sign, Markle Sign, obturator sign, psoas sign, Alvorado score
ICD-10 CODE K35 Acute appendicitis
K35.2 Acute appendicitis with generalized peritonitis
K35.3 Acute appendicitis with localized peritonitis
Keywords
appendicitis, abdominal pain, right lower quadrant pain, peritonitis, MeBurney’s point, rebound tenderness, Rovsing sign, Dunphy sign, Markle Sign, obturator sign, psoas sign, Alvorado score
ICD-10 CODE K35 Acute appendicitis
K35.2 Acute appendicitis with generalized peritonitis
K35.3 Acute appendicitis with localized peritonitis
The Clinical Syndrome
Acute appendicitis is one of the most common causes of abdominal pain, with an incidence of approximately 8.5% in males and 6.7% in females; the mortality rate is approximately 0.5%. Although acute appendicitis can occur at any age, it most commonly occurs in the second or third decades. Conventional wisdom holds that acute appendicitis is the result of obstruction of the appendicular lumen with subsequent impairment of the wall leading to perforation and phlegmon formation. More recent thinking posits that mild uncomplicated appendicitis and severe complicated appendicitis are caused by different pathologic processes and are in fact two completely separate diseases requiring very different treatments.
The diagnosis is made on clinical grounds in many countries, and appendectomy has remained the standard of care in the treatment of acute appendicitis for the last century. This is despite that approximately 15% of appendectomies yield a pathologically normal appendix and that appendectomy is not without morbidity and, rarely, mortality. The routine use of imaging, including ultrasound and computerized tomography as an adjunct to the clinical diagnosis of acute appendicitis, has decreased the number of “normal result” appendectomies to approximately 10%. Recent interest in the nonsurgical management of mild uncomplicated acute appendicitis is also impacting this statistic.
Abdominal pain is a common feature of acute appendicitis ( Fig. 79.1 ). Although the clinical presentation of the pain of acute appendicitis can be variable, its classic clinical presentation begins as mild periumbilical pain that becomes more severe and then migrates to the right lower quadrant at a point that is one third the distance from the anterior superior iliac spine and the umbilicus known as McBurney’s point ( Fig. 79.2 ). The pain becomes more localized and constant with associated anorexia, nausea, vomiting, and fever. Constipation and diarrhea, as well as urinary tract symptoms, may also occur. Symptoms are usually present for less than 48 hours before the patient seeks medical attention.
Signs and Symptoms
Patients with acute appendicitis appear ill and anxious. A low-grade fever is often present. Patients will often flex their hips and draw up their knees in an effort to splint the abdomen and decrease the pain. Early in the course of the disease, there is diffuse periumbilical tenderness and non-specific findings including decreased bowel sounds on physical examination. As the pain localizes to the right lower quadrant at McBurney’s point, peritoneal signs including abdominal guarding, pain on percussion, and rebound tenderness become prominent. In addition to these physical findings, a number of physical examination tests can increase the diagnostic specificity of the physical examination ( Table 79.1 ). All exploit the consistent finding of increased pain at the point of peritoneal or structural irritation when the test is performed in patients suffering from acute appendicitis. Although nonspecific, increased right-sided pain on rectal and vaginal examination may support the diagnosis of acute appendicitis, but more importantly helps rule out other pathologic processes that may mimic the disease.
| Test | Maneuver | Basis of Physical Findings |
|---|---|---|
| McBurney’s Point | Palpation at a point that is one third the distance from the anterior superior iliac spine and the umbilicus yields maximal pain | Suggests peritoneal irritation at point where appendix attaches to cecum |
| Rovsing Sign | Palpation of left lower quadrant yields pain at McBurney’s point | Suggests peritoneal irritation at McBurney’s point |
| Dunphy Sign | Having patient cough elicits sharp pain at McBurney’s point | Suggests peritoneal irritation at McBurney’s point |
| Markle Sign | When the standing patient drops from standing on toes to the heels with a jarring landing, the pain increases at McBurney’s point | Suggests peritoneal irritation at McBurney’s point |
| Obturator Sign | Internal and external rotation of the flexed right hip yields pain at McBurney’s point | Suggests peritoneal irritation at McBurney’s point and may point to a retrocecal appendix |
| Psoas Sign | Extension of the right hip or with flexion of the right hip against resistance yields pain at McBurney’s point | Suggests appendix may lie against the psoas muscle |
Testing
Currently, there is no specific laboratory test for acute appendicitis, but the finding of leukocytosis with a left shift and elevated C-reactive protein levels increase the likelihood of acute appendicitis by a factor of 5 when history and physical findings support that clinical diagnosis. Urinalysis may reveal mild pyuria that is thought to be caused by inflammation of the ureter secondary to the proximity of the inflamed appendix to the right ureter. Recent studies suggest that levels of urinary 5-hydroxyindoleacetic acid (5-HIAA) may be elevated in the early stages of acute appendicitis secondary to the inflammation of serotonin-containing cells within the appendix. A downward trajectory of urinary 5-HIAA levels after initial elevations are thought to correlatewith disease progression. It should be noted that pregnancy testing is mandatory in all female patients of child-bearing age presenting with abdominal pain.
Because of the desire to avoid unnecessary appendectomy, a scoring tool to improve the accuracy of diagnosis of acute appendicitis has been developed. The Alvarado score provides a consistent and reproducible tool to help diagnosis acute appendicitis. The score is based on the scoring of symptoms, and physical and laboratory findings ( Table 79.2 ). A score of 9 to 10 suggests that a diagnosis of appendicitis is highly probable, a score of 7 to 8, that the diagnosis is probable, and with a score of 5 to 6 compatible with the diagnosis of acute appendicitis. Experience with use of the Alvarado score suggests that appendectomy should be considered in those patients with clinical findings suggesting acute appendicitis who have an Alvarado score of 7 or greater. Other scoring systems designed to improve the accuracy of acute appendicitis have been proposed. The Andersson Inflammatory Response Score expands the parameters of the Alvarado scoring system by adding gradations of physical findings and laboratory parameters, including the C-reactive protein, and deducting points for temperatures above 38 degrees centigrade ( Table 79.3 ).
