Utility of white cell count and ultrasound in the diagnosis of acute appendicitis.

BACKGROUND: Despite considerable advances in imaging, the diagnosis of acute appendicitis remains a clinical one. Nonetheless, knowledge of the characteristics of commonly used investigations for appendicitis may aid surgical decision-making. METHODS: The pathology, full blood counts and ultrasounds of 1013 patients who underwent appendicectomy were reviewed and subjected to statistical analysis in order to determine diagnostic characteristics of various white cell count and ultrasound results. RESULTS: Total white cell count was found to be higher among patients with complicated appendicitis than those with simple appendicitis or normal appendices. Ultrasound was found to be less accurate than white cell count and neutrophil count in the diagnosis of acute appendicitis by estimation of area under the receiver operator characteristic curve. CONCLUSION: Knowledge of the meaning of various white cell count values may be invaluable in clinical decision-making with regard to the diagnosis of acute appendicitis. Ultrasound is of limited utility in the diagnosis of appendicitis and should only be used in selected clinical situations.