ISPUB.COM The Internet Journal of Surgery Volume 24 Number 1 1 of 7 Role Of Total Leukocyte Count, Neutrophil Percentage, C- Reactive Protein And Ultrasonography In The Diagnosis Of Acute Appendicitis. S Ali, O Shah, M Shah, L Ahmed, S Mallik, N Wani Citation S Ali, O Shah, M Shah, L Ahmed, S Mallik, N Wani. Role Of Total Leukocyte Count, Neutrophil Percentage, C-Reactive Protein And Ultrasonography In The Diagnosis Of Acute Appendicitis.. The Internet Journal of Surgery. 2009 Volume 24 Number 1. Abstract Total leucocyte count (TLC), neutrophil percentage (NP), C-reactive protein (CRP) and ultrasonographic (USG) examination of the abdomen were studied prospectively in 197 patients who underwent appendectomy for suspected appendicitis. On histopathological study of the resected appendices, only 176 patients had acutely inflamed, perforated or gangrenous appendices. The sensitivity, specificity and predictive value of single tests and test combinations were calculated using standard reference intervals. CRP demonstrated the best sensitivity (89%) followed by ultrasonography (78%), though the best specificity (90.47%) was observed in the latter test. The sensitivity decreased when raised TLC, NP, CRP and suggestive USG were used together to predict appendicitis but the specificity increased markedly (95%) indicating the fact that acute appendicitis is unlikely when all these tests are simultaneously negative. Early USG, preferably combined with CRP, and leucocyte counts is a very useful diagnostic aid in acute appendicitis and clinicians should suspect that appendicitis is less likely if all four investigations are simultaneously negative. INTRODUCTION Acute appendicitis is one of the most frequent causes of acute abdomen in nearly all age groups (1) and hence appendectomy is one of the most common surgeries being performed world wide. The diagnosis remains one of the most difficult clinical problems in abdominal emergencies with reported diagnostic accuracy varying from 25-90 % (2). A retrospective review of 1,243 appendicitis patients has shown that normal appendices were removed in 25.7 % (3) while another review revealed 13.5 % normal appendices at laparotomy (4). It is believed that the optimal accuracy rate is around 80 %, since a less than 20 % negative appendectomy rate would involve a high perforation rate (<20%) with resultant complications (2). The negative exploration itself carries a complication rate not much lower than that after removal of a pathological appendix (5). This warrants supplementary investigations that can improve diagnostic accuracy and further reduce the number of negative appendicectomies without thereby increasing the perforation rate. In acute appendicitis, TLC and NP are the most frequently used laboratory tests (6). Most of the studies conclude that 60-90 % of all patients with acute appendicitis have total and differential leucocyte counts suggestive of the diagnosis (5). CRP is an acute phase reactant, synthesized by liver which exhibits an exponential rise in serum concentration within eight hours in bacterial infection (7, 8). It also appears in the sera of individuals in response to a variety of inflammatory conditions and tissue necrosis. USG, if performed by proper hands, has a specificity of 85-95% (9, 10, 11) but due to its variable sensitivity, it is not used as a routine test (12). However some authors believe that immediate use of USG examination of the abdomen helps in improving the diagnostic acumen (13). AIM OF THE STUDY: To evaluate prospectively the clinical applicability of TLC, NP, CRP, and USG in acute appendicitis. The study was designed to assess the significance of the tests (separately and jointly) in patients operated for acute appendicitis. MATERIALS AND METHODS During a period of 12 months, 197 consecutive patients between the ages of 12 and 60 years operated upon for