Predictors of Clinical Outcomes in Acute Appendicitis: A Retrospective Study.

INTRODUCTION

Acute appendicitis is one of the most common causes of intra-abdominal emergency surgery worldwide. This study was conducted to contribute to global databases by presenting data from our institution, which consist of multi-racial population. We aimed to evaluate the presentation, diagnosis, and management of acute appendicitis and post-operative outcome in our institution and evaluate the risks factors associated with severe complications and prolonged length of stay (LOS).

MATERIALS AND METHODS

We performed a retrospective analysis using multivariate regression analysis of all patients who underwent appendectomy (2009-2014) in our institution. The primary outcomes included demographics, presentation, and perioperative management, and the secondary outcomes included risk factors associated with prolonged LOS.

RESULTS

Of the 1185 patients, the mean age was 36.4 years, and 940 (79.3%) were male. Majority (98.1%) of patients were ASA (American Society of Anaesthesiologists) 1 or 2. Most of them (83.9%) were from the four racial subgroups (Chinese, Malay, Bangladeshi, and Indian). There was no racial variation in the diagnosis and presentation of disease. The mean duration of symptoms was 1.8 days. The history was commonly a localised or migratory abdominal pain associated with anorexia, nausea, vomiting, and fever. The commonest physical findings were right-sided abdominal tenderness associated with rebound and guarding. About 42.9% of the patients underwent pre-operative CT scan to establish the diagnosis of appendicitis prior to surgery, whilst 57.1% underwent surgery on clinical diagnosis and blood investigation (NWR and CRP). An open appendectomy was performed in 13.2% of the patients. The conversion rate of laparoscopic appendectomy was 4.9% (n = 50). The mean length of hospital stay was 3.6 days. On multivariate Cox regression, patients of Burmese and Thai descent were independently associated with a prolonged LOS. The postoperative morbidity was 5.5%. The 30-day readmission rate was 2.4%. There was no mortality in our study.

DISCUSSION

Our study showed that pre-operative diagnosis of acute appendicitis can be made accurately by classical clinical presentation or by imaging. Independent risk factors associated with increased LOS included increased age, male gender, prolonged duration of symptoms pre-admission, fever, generalised tenderness, and prolonged operative time. The effect of race on LOS has been observed in the literature for other surgical procedures. The prolonged LOS found in Burmese and Thai patients contribute to the possibility of intrinsic racial differences in the post-surgery recovery. However, the numbers are small and therefore prone to type I error. Compared to the open approach, the use of laparoscopic appendectomy was associated with shorter LOS. This has similar outcomes to those reported in the literature.

CONCLUSION

The identification of risks factors could help surgical team to predict the clinical outcomes and develop risk reduction strategy in post-operative care of these patients.