Acute appendicitis. Update of clinical scores

Abstract

OBJECTIVES: Evaluate Alvarado Score’s (AS) accuracy related with C-reactive protein (CRP). Evaluate the accuracy rate of ultrasonography (US).

MATERIALS AND METHODS: We analyzed data on 290 patients admitted to Emergency Department (ED) of Sant’Andrea Hospital (Rome – Italy) presenting abdominal pain in lower quadrants between Jan2009-Apr2015. AS, laboratory tests, images and report from CT-scan and US were collected. Histological examination is considered as Gold Standard. We calculated Specificity(Sp), Sensitivity(Se), Accuracy(Ac), positive predictive value(PPV), and negative predictive value(NPV).

We use Exact Fisher Test (EFT) for samples less than 50 units, and Chi square test (χ 2 ). CRP were assessed as possible laboratory marker to be added to AS.

RESULTS: Two hundred and forty patients (82%) were enrolled following the inclusion criteria. The variations obtained from the AS with C-reactive protein show no difference. CT-scan vs US results show a higher Sp for US despite CT (p= 0.0509 χ 2=3.803. Se and NPV are higher in CT compared to the US (Se: p=0.000315 χ 2= 12.88 NVP: p=0.015.

We evaluated Ac of US and CT within the individual groups (low(L), Intermediate(I), High(H): L; 37 patients show no statistically significant difference (EFT=1; p>0.05). I: show superiority of CT-scan in Se and NPV (FE:0.0162 p<0.05; FE:0.0432 p<0.05). Regarding H only Se show an acceptable p-value (p<0.0021).

CONCLUSION: Alvarado score (AS) can be used as the first diagnostic approach in the diagnosis of acute appendicitis (AA). Ultrasound must be considered the first level instrumental examination; necessary and sufficient in low risk patients (0-3 pt) to exclude, with a high reliability rate, the diagnosis of acute appendicitis.