Diagnosing Appendicitis: Evidence-Based Review of the Diagnostic Approach in 2014

Abstract

IntroductionAcute appendicitis is the most common abdominal emergency requiring emergency surgery. However, the diagnosis is often challenging and the decision to operate, observe or further work-up a patient is often unclear. The utility of clinical scoring systems (namely the Alvarado score), laboratory markers, and the development of novel markers in the diagnosis of appendicitis remains controversial. This article presents an update on the diagnostic approach to appendicitis through an evidence-based review.MethodsWe performed a broad Medline search of radiological imaging, the Alvarado score, common laboratory markers, and novel markers in patients with suspected appendicitis.ResultsComputed tomography (CT) is the most accurate mode of imaging for suspected cases of appendicitis, but the associated increase in radiation exposure is problematic. The Alvarado score is a clinical scoring system that is used to predict the likelihood of appendicitis based on signs, symptoms and laboratory data. It can help risk stratify patients with suspected appendicitis and potentially decrease the use of CT imaging in patients with certain Alvarado scores. White blood cell (WBC), C-reactive protein (CRP), granulocyte count and proportion of polymorphonuclear (PMN) cells are frequently elevated in patients with appendicitis, but are insufficient on their own as a diagnostic modality. When multiple markers are used in combination their diagnostic utility is greatly increased. Several novel markers have been proposed to aid in the diagnosis of appendicitis; however, while promising, most are only in the preliminary stages of being studied.ConclusionWhile CT is the most accurate mode of imaging in suspected appendicitis, the accompanying radiation is a concern. Ultrasound may help in the diagnosis while decreasing the need for CT in certain circumstances. The Alvarado Score has good diagnostic utility at specific cutoff points. Laboratory markers have very limited diagnostic utility on their own but show promise when used in combination. Further studies are warranted for laboratory markers in combination and to validate potential novel markers.

Risk factors associated with complications of acute appendicitis

“…Studies with US showed that its sensitivity ranged from 68 to 96%, and specificity, from 46.7 to 95.9%, with PPV between 82.2 and 94% and accuracy from 65.7 to 87% [14][15][16][17] . CT has sensitivity and specificity of 90 to 100% and 91 to 99%, respectively.…”

The use of ultrasonographic and Alvarado scores in evaluating abdominal pain suggestive of acute appendicitis

“…9 The Alvarado score has been adopted by several centres as a clinical tool to stratify the level of suspicion regarding appendicitis and to help in the decision-making process. 10 Ultimately, surgeons must determine whether a patient requires surgery based on clinical, laboratory and imaging findings. In the present study, the Alvarado score had a sensitivity of 93.8% and specificity of 82.3%, confirming it is an excellent tool to identify patients with appendicitis when the score is 7 or more.…”

“…It also involves radiation exposure, and allergic reactions to the contrast medium are a possibility. [9][10][11] An Alvarado score ≥ 7 is useful to identify those patients who have a higher probability of acute appendicitis and therefore would require a surgical consultation or further diagnostic imaging.…”

Predictors of Perforated Appendix among Children

“…Making a diagnosis is hard because of overlapping of symptoms with other conditions and atypical clinical presentation [2]. A higher rate of appendix perforation has been noted in children compared to adults [3].…”