Usha Rani Dalal1, Ashwani Kumar Dalal2, Saurabh Jindal3, Jasbindar Kaur4, Purnima Aggarwal5, Rajpal Punia6
Acute appendicitis is the most common surgical emergency. So far no single criteria can accurately confirm the preoperative diagnosis of acute appendicitis in the suspected cases. Every effort should be made to establish an exact diagnosis. This has resulted in considerable research to find out the role of various clinical scores, laboratory, radiological parameters and diagnostic laparoscopy in diagnosing appendicitis. However, despite availability of various biochemical and radiological diagnostic investigations like total leucocyte count (TLC), C-reactive protein (CRP), Procalcitonin (PCT), D-dimer and ultrasonography (USG) and computed tomography (CT) scan, a negative appendectomy rate of 5% - 30% has been reported in literature. A wide variation exists in sensitivity, specificity, positive predictive value and negative predictive value of these parameters in various studies conducted earlier. The present study is aimed to evaluate, correlate and compare the diagnostic efficacy of clinical score, various biochemical investigations and USG in cases operated with pre-operative diagnosis of acute appendicitis with confirmation of final diagnosis by histopathology.
MATERIALS AND METHODS
This study was carried out during a period from February 2014 to July 2015 and included 100 consecutive patients of acute appendicitis. Alvarado score, total leucocyte count, C–reactive protein, Procalcitonin, D-dimer and ultrasonography were performed in all cases preoperatively and histopathological examination done postoperatively.
Age of patients ranged from 10 to 74 years with mean age of 29.24 years; 71 were males and rest were females with the maleto-female ratio being 2.44: 1. Alvarado score was ≥ 7 in 75 cases of proven appendicitis and in 4 cases of normal appendix with sensitivity, specificity, PPV, NPV and diagnostic accuracy of 78.94%, 20.00%, 94.93%, 4.76% and 76%. TLC was ≥ 10,000/mm3 in 55 cases of the patients with acute appendicitis and in 3 cases of normal appendix. The sensitivity, specificity, PPV, NPV and diagnostic values of TLC were 57.89%, 40.00%, 94.83%, 4.76% and 57.00% respectively. CRP was ≥ 5 mg/dL in 90 cases and 86 cases had acute appendicitis on histopathology. The sensitivity, specificity, PPV and NPV of CRP were 90.53%, 20.00%, 95.56% and 10.00% respectively with a diagnostic value of 87%. D-dimer ≥ 0.5 µg/dL was seen in 69 cases and 65 cases were having acute appendicitis on histopathology. The difference was not found to be significant (p= 1). Sensitivity, specificity, PPV, NPV and diagnostic accuracy were 68.42%, 80%, 98.48%, 11.76%, 66% respectively. Procalcitonin level in 33 cases was ≥ 1 ng/dL, out of which 32 cases had acute appendicitis on histopathology. Sensitivity, specificity, PPV, NPV and diagnostic accuracy of PCT were 33.68%, 80%, 96.97%, 05.97% and 36% respectively. USG findings suggested acute appendicitis in 90 cases, out of which 86 patients had acute appendicitis. The sensitivity, specificity, PPV, NPV and diagnostic accuracy were 90.53%, 20.00%, 95.55%, 10.00%, 87% respectively. Histopathological findings of acute appendicitis were confirmed in 95 cases, while in five cases appendix was normal on histopathology.
Negative appendectomy rate in our study was 5%. Alvarado score, various laboratory investigations or USG are not sufficient on their own for taking the decision for surgery. USG and CRP were the most sensitive investigations with equal diagnostic value. Among the inflammatory markers, the diagnostic value of CRP was higher than PCT and D-dimer. CRP and USG along with Alvarado score can increase the diagnostic accuracy in acute appendicitis.