The use of C‐reactive protein to predict uncomplicated appendicitis and increase uptake of laparoscopy in low resource hospitals—A retrospective cohort study

Abstract

AbstractBackgroundAcute appendicitis remains the most common surgical emergency worldwide. There has been a low uptake of laparoscopic appendicectomy in the South African public sector. Preoperative identification of cases of uncomplicated appendicitis that are amenable to a laparoscopic approach may facilitate the implementation of laparoscopic appendicectomy programs in training hospitals. With limited access to preoperative imaging, alternative strategies for this preoperative prediction are needed.MethodsA retrospective audit of patients over the age of 12 years with a histologically confirmed diagnosis of acute appendicitis over a 5‐year period was performed. Patients were categorized as uncomplicated or complicated appendicitis and C‐reactive protein (CRP) and white cell count (WCC) reviewed. Receiver operating characteristics curves were constructed for these blood tests and acute appendicitis severity. Youden's J statistic was used to determine optimal cut off values for diagnosing complicated appendicitis.Results358 patients had confirmed appendicitis and complete blood results. Of these, 189 (52.79%) had complicated appendicitis with a 40.22% perforation rate. Median CRP in uncomplicated and complicated groups were 68 mg/L (IQR 19–142) and 216 mg/L (IQR 103–313) with an area under the curve (AUC) of 0.75 (95% CI: 0.70–0.80). The median WCC in the two groups were 12.6 × 109 cells/L (IQR 9.9–15.6) and 14.4 × 109 cells/L (IQR 11.5–18.28) with an AUC of 0.61 (95% CI: 0.56–0.67). The optimal cut off value for CRP was found to be 110 mg/L with a sensitivity of 74.74% and specificity of 69.23%.ConclusionA cutoff value of 110 mg/dl CRP can distinguish patients with early appendicitis from those with complicated disease and when used in conjunction with clinical assessment may help identify patients in whom laparoscopic appendicectomy is appropriate.