Which clinical manifestation is associated with acute appendicitis

Introduction

Acute appendicitis (AA) is a very common disease and represents the most common cause of abdominal emergency. It is usually seen in the second and third decades of life, but can occur at any age.1 A male preponderance exists (ratio 1.4:1); the overall lifetime risk of developing AA is 8.6% for males and 6.7% for females.2

Although the etiology of AA is still poorly understood, the most common hypothesis refers to appendix obstruction followed by impairment of wall appendix barrier and subsequent wall perforation and/or abscess formation.1 However, some studies suggest that uncomplicated and complicated appendicitis are different entities that require a different treatment.3,4 This might explain why up to 20% of AA resolves spontaneously, as was observed 125 years ago by Fitz.5

Worldwide, the standard of care for AA is appendectomy, which is to date generally considered a routine and safe operation. Appendicitis can be notoriously difficult to diagnose, as its clinical presentation can be subtle, and the rate of unnecessary appendectomies is approximately 15%6,7; the routine use of ultrasonography (US) reduces this to 10%, and preoperative computer tomography (CT) further decreases it to 5–10%, but not to zero.8,9 Furthermore, most European surgeons do not routinely perform imaging studies as they trust the clinical diagnosis.10

Despite the fact that surgery represents the gold standard treatment of AA, several attempts have been made to investigate the role of antibiotic treatment. The conservative management of AA was considered a long time ago. In 1959, Coldrey reported on a five-year experience with 471 unselected patients who were non-operatively treated for AA, with low morbidity and mortality rates.11 In 1977, 425 unselected patients were treated by traditional Chinese medicine and antibiotic treatment and recurrent appendicitis was described in 7/100 patients.12

Since then the question has remained open.

Acute Appendicitis

Acute appendicitis is a ubiquitous problem, accounting for approximately 5% of all emergency department visits for patients under 65 years of age21 and 30% of acute surgical abdominal emergencies in patients under 50 years of age worldwide.22 Appendicitis accounted for 318,000 hospital admissions in the USA in 2006,23 and has an overall incidence of approximately 82 to 110/100,000 population in North America.24 The lifetime risk of appendicitis is 8.6% for males and 6.7% for females in Western countries,25 and may be twice this risk in Asia.26

Typically, acute appendicitis begins with prodromal symptoms of anorexia, nausea, and vague periumbilical pain. Within 6 to 8 hours, the pain migrates to the right lower quadrant and peritoneal signs develop. In uncomplicated appendicitis, a low-grade fever to 38°C and mild leukocytosis are usually present. A higher temperature and WBC count are associated with perforation and abscess formation. Common features of the history, physical examination, and WBC count in patients with appendicitis have been combined into a predictive tool known as theAlvarado score (Table 11.4).27 For men, a score of 4 or less accurately excludes appendicitis; the score is less useful in women and children.28 Atypical presentations of acute appendicitis, however, are common, and a diagnosis of acute appendicitis should not be rejected simply on the basis of the patient’s history and physical examination alone. An Appendicitis Inflammatory Response score has also been proposed.29 In children, mesenteric adenitis (or lymphadenitis) is frequently mistaken for acute appendicitis but is often preceded by a sore throat and is self-limited. Mesenteric adenitis may also be caused byYersinia enterocolitica (seeChapter 110).

Whereas plain abdominal films are not diagnostic and have little role in the diagnosis of acute appendicitis, CT has dramatically improved the accuracy of diagnosis in patients with acute appendicitis. An appendix diameter greater than 10 mm is generally considered diagnostic of appendicitis, although the normal range for the diameter of the appendix may extend to nearly 13 mm.30 Other CT signs of acute appendicitis include periappendiceal fat inflammation, presence of fluid in the RLQ, and failure of contrast dye to fill the appendix.31 The addition of CT has reduced the negative appendectomy rate to about 5%.32 Because CT entails radiation exposure,18 some authorities advocate avoiding CT in children and adolescents,33 in whom a higher degree of diagnostic uncertainty is tolerated in favor of lower radiation exposure (seeChapter 120). In this setting, US of the appendix has a sensitivity of 0.86 and specificity of 0.81 for detecting acute appendicitis.34 In a pregnant patient in whom radiation exposure is also a significant concern, MRI has become the imaging method of choice, with a sensitivity and specificity approaching those of CT.35

Clinical Management and Treatment

The treatment for acute appendicitis is appendectomy. Early acute appendicitis is generally managed with surgery and prophylactic antibiotics to minimize the risk of surgical site infection (SSI). If no perforation or focal peritonitis is encountered, there is generally no need for continuation of antibiotics after surgery, because the main infectious source has been removed—source control. For perforated appendicitis, appendectomy should be performed and systemic antibiotics continued for 5 to 7 days or until fever and leukocytosis have resolved. Escherichia coli and Bacteroides fragilis are the main organisms isolated in acute simple and perforated appendicitis. However, both anaerobic bacteria and other gram-negative organisms may be present, and polymicrobial infections are most common. The Surgical Infection Society (SIS) has recommended different single- and multiple-agent regimens based on the best available evidence, generally derived from randomized controlled trials. Single-agent regimens include cefoxitin, cefotetan, and ticarcillin-clavulanic acid; and multiple-agent therapies include a third-generation cephalosporin, monobactam, or aminoglycoside combined with antianaerobic coverage with agents such as metronidazole or clindamycin.

Delayed presentation, usually defined as presentation after 5 days or longer since onset of symptoms, is associated with abscess formation plus or minus phlegmon or diffuse peritonitis. Outcomes in these patients are worse than in those with early presentation. For these patients a CT scan is generally recommended. If a phlegmon is identified, the patient is admitted and treated with systemic antibiotics, bowel rest, and physiologic support. If the CT scan reveals an abscess, it should be drained via a percutaneous approach whenever feasible, and medical treatment as described previously should be initiated. Nonsurgical treatment has been reported to fail in approximately 7% to 10% of patients. Failure of medical treatment is defined as worsening abdominal pain, continuous fever, leukocytosis, and/or progression to focal or diffuse peritonitis. In these cases the patient should be taken promptly to the operating room for surgical management to include drainage and resection of the involved tissues, which often requires a cecectomy or hemicolectomy, and drain placement.

Management of nonperforated appendicitis with antibiotics alone (nonsurgical management) has been reported after initial experience in cases where surgical treatment was not available, such as in remote areas or isolated conditions (e.g., submarines). A recently published randomized controlled trial involving 252 male patients concluded that this nonsurgical strategy could be used in the setting of acute appendicitis. However, this approach is associated with adverse outcomes such as a high readmission rate (14% to 35%) and failure of medical treatment requiring surgery in the presence of more advanced disease. Because of these potential complications and the relatively benign course after appendectomy, early operative intervention with or without antibiotics (following previously outlined guidelines) is the treatment of choice whenever this strategy is available, and medical or antibiotic treatment alone should be reserved for well-selected patients in whom an operation may pose a greater risk or for those in whom surgical management is not immediately available.

For patients in whom appendectomy was not performed during the acute presentation, an interval appendectomy can follow 6 weeks to 3 months after the patient has recovered from the initial event. Although the need for this subsequent operation remains somewhat controversial, different studies have reported a high recurrence rate (10% to 30%), supporting strongly considering subsequent appendectomy. If an observant strategy is followed, subsequent studies must be completed to rule out neoplastic disease in selected individuals.

Lastly, there has been some debate regarding the best surgical approach for appendectomy: laparoscopic versus open. Results from multiple randomized controlled trials have been reported, and a recent review of the literature favored the laparoscopic approach because of better postoperative outcomes including lower rate of SSI, shorter length of stay, and faster return to work. Although the direct costs, operative time, and incidence of intraabdominal abscesses may be higher, the laparoscopic approach is currently the standard of care given the reported benefits after surgery.

Acute Appendicitis

Appendicitis is the most common cause for acute surgery in childhood. Between 30% and 40% of children do not present with the typical clinical presentation of appendicitis and, in particular, preschool patients often present with atypical features, more rapid progression and higher incidence of complications. Very young children often have a diagnostic delay and hence they have a higher risk of perforation at presentation. Consequently, imaging is often necessary to confirm, suggest or refute the clinical diagnosis and the use of imaging has dramatically reduced the false-positive appendectomy rates. Ultrasound should be the primary imaging investigation and performing a comprehensive ultrasound examination will make CT redundant in most cases. The ultrasound should be performed with a high-frequency linear transducer using a graded compression technique. The primary criteria of acute appendicitis are typically a tubular, blind-ending, non-compressible structure with maximal outer diameter over 6 mm. Other findings include wall hyperaemia or hypoperfusion (depending on the degree of inflammation/necrosis), surrounding hyperechoic mesenteric fat and the presence of an appendicolith (Fig. 71.17).

CT is rarely necessary but can be an important diagnostic tool in difficult cases where ultrasound is unable to clarify and the clinical situation enforces acute surgery. CT is also often performed when complicated periappendicular abscess formation is suspected. Note that the appendix may be retrocaecal and an inflamed retrocaecal appendix may cause subcapsular liver abscesses (Fig. 71.18).

Sonographic mimics of acute appendicitis may be acute salpingitis in teenage girls or terminal ileitis (see below) (Fig. 71.19).

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.

CLINICAL FEATURES

Acute appendicitis is a disease of the young, most typically presenting in children and adolescents (5 to 15 years), although no age group is exempt.9, 10 A crude estimate of the incidence of acute appendicitis in the United States is 11 cases per 10,000 population.11 The pathogenesis of appendicitis is believed (although not by all) to reflect an initial insult to the mucosa resulting from luminal obstruction by a fecalith, a fragment of undigested food, or lymphoid hyperplasia, followed by bacterial infection that progressively spreads from the mucosa into the wall. However, the evidence for this is circumstantial at best, and some observers believe that acute appendicitis is instead a manifestation of a range of injuries encompassing hypersensitivity reactions, infections, and ischemic lesions. The potential causes of acute appendicitis have been summarized by Carr.11

Imaging methods to detect acute appendicitis have improved,12, 13 and laparoscopic appendectomy has emerged as a safe technique.14 About 70% of patients suspected of having appendicitis on clinical and imaging grounds prove to have acute appendicitis on resection.15, 16 Some observers believe that all appendices, even when grossly normal, should be removed during surgery for suspected acute appendicitis, as close to 20% of normal-appearing appendices may have acute inflammation on microscopic examination.15, 16 A possible exception is in those patients who might require urologic surgery in the future, as their appendices may prove useful as urinary conduits.17 Patients with appendicitis in the setting of HIV infection have similar clinical presentations, although sometimes with a less striking elevation in the peripheral white blood cell count. In one surgical series of appendicitis and HIV infection, delays before operation increased the likelihood of perforation.18

Appendicitis

Acute appendicitis is one of the most common causes of the acute abdomen, occurring at all ages. Inflammation of the appendiceal wall leads to ischemia, necrosis, and eventually perforation, which may result in a localized abscess or generalized peritonitis. The inciting event is obstruction of the appendix, which is commonly due to fecaliths or calculi. However, the cause of the appendiceal obstruction varies by age, with lymphoid hyperplasia being common in children and tumors occasionally found in adults. In areas where schistosomiasis is endemic, schistosome ova have been found in the appendiceal wall in patients undergoing appendectomy, suggesting a potential causative role for certain parasitic infestations in the pathogenesis of acute appendicitis. Regardless of the etiology, the clinical features of acute appendicitis are similar: the classic symptoms include pain that migrates from the periumbilical area to the right iliac fossa, fever, anorexia and vomiting, though the diagnosis may be more challenging in children and the elderly who present with less specific features. Laboratory findings are nonspecific, though a leukocytosis is usually present. In areas with access to radiographic studies, ultrasonography or computed tomography may establish the diagnosis, though imaging should not delay surgical exploration in cases where the diagnosis of acute appendicitis is very likely based on the clinical assessment. For patients presenting soon after the onset of symptoms, the treatment of choice is immediate appendectomy, with the addition of broad-spectrum antibiotics in those with frank perforation; patients with a longer duration of symptoms may be managed non-operatively with antibiotics. The differential diagnosis of acute appendicitis includes acute gastroenteritis, in which diarrhea is usually a prominent symptom and abdominal pain is more diffuse. In contrast, gastroenteritis due to Yersinia infection may present with little diarrhea and right lower quadrant abdominal pain, causing it to be misdiagnosed as appendicitis.

Acute Appendicitis

Acute appendicitis is the most common nonobstetric surgical problem in the pregnant patient. The incidence of appendicitis during pregnancy has been estimated to range from 0.06% to 0.1% of deliveries. The incidence of appendicitis is not increased in pregnancy, and the likelihood of its occurrence is equal in all three trimesters.

The diagnosis of appendicitis may be difficult because signs and symptoms may mimic other conditions commonly seen in a normal pregnancy. The most common presenting symptom is vague right lower quadrant abdominal pain. A long-held belief was that as pregnancy progressed, the location of the abdominal pain would migrate upward during gestation as the gravid uterus displaces the appendix. A retrospective review demonstrated that, for all trimesters, the most common location for abdominal pain of acute appendicitis is the right lower quadrant [

The treatment of suspected acute appendicitis in the pregnant patient is emergency appendectomy. Because of the difficulty in diagnosis and the increased morbidity to the patient and fetus in the event of appendiceal perforation or rupture, a higher negative laparotomy rate of 30% to 33% is acceptable.

Both laparotomy and laparoscopy are used during pregnancy. Laparoscopic procedures are used more commonly in acute appendicitis because of the quicker recovery time, shorter hospital stay, and decreased pain. Laparoscopy is often performed at less than 20 weeks of gestation, when there is less chance of penetrating the uterus with the trochar (see the earlier discussion of laparoscopy). Laparotomy is still commonly performed in all trimesters for this indication.

Appendicitis

Acute appendicitis is the most common abdominal surgical emergency, affecting approximately 250,000 people annually in the United States. Although the correct diagnosis can be made in most patients on the basis of history, physical examination, and laboratory tests, diagnosis is uncertain in the 20–33% of patients who present with atypical features. The diagnosis is most difficult to establish in infants and young children, the elderly, and women of reproductive age. In the past, an average negative laparotomy rate of 20% was acceptable. The widespread use of helical CT in patients with suspected appendicitis has been shown to positively affect patient outcome and increase the number of positive laparotomies. Studies evaluating the efficacy of helical CT show sensitivities of 90–100%, specificities of 83–97%, and accuracies of 93–98% for the diagnosis of acute appendicitis.

The CT findings in acute appendicitis reflect the extent and severity of inflammation. In mild disease, the appendix appears as a distended (6–15 mm diameter) fluid-filled structure that shows circumferential, symmetric mural thickening (Fig. 25). Homogenous dense contrast enhancement of the wall is typical but a target sign may be seen when the appendix is axially viewed. Periappendiceal inflammation manifests as slight haziness of the fat of the mesoappendix. A calcified appendicolith is more reliably demonstrated on CT than on plain films.

With disease progression and perforation, the appendix becomes fragmented, destroyed, and replaced by a phlegmon or abscess. There may be associated mural thickening of the adjacent distal ileum and cecum. In these cases, the specific diagnosis of appendicitis can be made if an appendicolith is seen within the abscess or phlegmon.

What is the clinical manifestation for acute appendicitis?

Which clinical manifestation does the nurse expect with acute appendicitis?

What are the common clinical findings in a patient with appendicitis?

What is associated with appendicitis?