Appendicitis in paediatric age group: Correlation between preoperative inflammatory markers and postoperative histological diagnosis

Abstract

Introduction: Clinical diagnosis of appendicitis can be challenging,  particularly in the paediatric age group. There is an increased risk of  perforation in paediatrics; therefore, a need for sensitive and specific  diagnostic tool is mandatory.

Aim: The aim of this study is to evaluate the role of preoperative  inflammatory markers in supporting the clinical diagnosis of appendicitis in
the paediatric age group.

Materials and Methods: Retrospective study of 268 emergency paediatric
appendicectomies performed in a District General Hospital in Wales, over a period of seven years (2002–2009). The data collected from hospital database include preoperative inflammatory markers, C-reactive protein (CRP) and white blood cells count (WBCC) and post-operative histology.  Statistical analysis was performed using Fisher’s exact test.
Results: The median age group in the study was 12 (2–16). 141 (53%) patients were <12 years, while 127 (47%) patients were 12–16 years old. Male : female ratio = 1 : 1 (134 each). Inflammatory markers were not done for 94 patients (35%). CRP was done for 149 cases (55.6%), while WBCC was done for 172 cases (64%). Both markers were done together for 147 cases (54.8%). Histology was positive (inflamed / gangrenous appendix) in 202 cases (75.4%). Eight cases were associated with Enterobious vermicularis infestation and one patient had carcinoid tumour. The sensitivity and specificity of CRP were 82% and 60%, respectively, with positive predictive value (PPV) of 87% (P<0.0001), while those of WBCC were 80% and 59%, respectively, with PPV of 88% (P<0.0001). The sensitivity and specificity of both markers together were 80% and 70%,  respectively, with PPV= 81% (P = 3.11E-8). 94 patients (35%) had an appendicectomy operation based on clinical diagnosis alone without preoperative inflammatory markers having been tested. In 28 cases (30%) out of these, postoperative histology revealed normal appendix (P = 0.18).
Conclusion: CRP and WBCC are simple tests that can provide a significant role supporting the clinical diagnosis of acute appendicitis in the paediatric age group.