Which appendicitis scoring system is most suitable for pregnant patients? A comparison of nine different systems

Abstract

Background

Acute appendicitis is the most common non-gynecological emergency during pregnancy. The diagnosis of appendicitis during pregnancy is challenging due to changes in both physiological and laboratory variables. Guidelines suggest patients with suspected acute appendicitis should be stratified based on clinical scoring systems, to optimize the use of diagnostic imaging and prevent unnecessary surgery. Surgeons require additional information beyond that provided by imaging studies before deciding upon exploratory laparoscopy in patients with a high suspicion of appendicitis. Various scoring methods have been evaluated for the diagnosis of acute appendicitis. However, there is no consensus on a method to use during pregnancy, and a detailed comparison of existing scoring methods for this purpose has not yet been conducted. The purpose of this study was to evaluate the efficacy of the most popular scoring systems applied to diagnose acute appendicitis during pregnancy.

Methods

This single-center retrospective study included 79 pregnant patients who were admitted to the emergency department with abdominal pain between May 2014 and May 2019. The patients were diagnosed with acute appendicitis and underwent an appendectomy. As a control group, the study also included 79 non-pregnant patients who underwent appendectomy within the last 1.5 years. To ensure that the groups were similar, women in the case group were stratified according to age, and the proportions of women in the strata were determined. The women in the control group were similarly stratified. Women were randomly selected from the strata to prevent bias.

Both laboratory and examination findings required for each scoring method were obtained and assessed separately for each patient. Negative appendectomy rates were evaluated according to pathology results. Categorical variables were compared using the chi-square test. A p value < 0.05 was considered to indicate significance. Receiver operator characteristic curve analysis was used to identify the best threshold value and to assess the performance of the test scores in terms of diagnosing appendicitis.

Results

Among all scoring systems, the Tzanakis score was most efficacious at predicting appendicitis in non-pregnant women. The positive predictive value (PPV) of the Tzanakis score was 90.6%, whereas the negative predictive value (NPV) was 46.7%. The RIPASA score performed the best among the scoring systems in pregnant women. It was associated with a PPV of 94.40%, NPV of 44%, and sensitivity and specificity of 78.46% and 78.57%, respectively.

Conclusion

Although the RIPASA score can be used to efficaciously diagnose acute appendicitis in pregnant women, a specific scoring system is needed for diagnosis during the gestation period.