Positive Predictive Value of Serum Amylase in Predicting Acute Appendicitis taking Histopathology as Gold Standard
Muhammad Aslam Javed, Sajeel Ahmad, Vishal Farid Raza, Khalid Javeed Khan
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ABSTRACT
Background: Worldwide acute appendicitis is one of the most commonly encountered
abdominal emergencies. Despite recent advances in imaging and laboratory
parameters, the diagnosis still remains clinical. This study was carried out to
determine positive predictive value of serum amylase in diagnosing acute
appendicitis taking into account histopathology as gold standard.
Methods: Total 103 patients of both genders aged between 15-40 years presenting
with pain and tenderness in right iliac fossa and vomiting having raised serum
amylase > 85U/L were included. These patients underwent appendectomy
followed by histopathology of excised tissue. Diagnosis of appendicitis was
confirmed on histopathology postoperatively and results of increased serum
amylase levels were interpreted accordingly as true positive/ false positive. Informed
consent was taken from all enrolled patients.
Results: Mean age of the enrolled patients was 27.8±7.5 years. There were 59
(57.3%) male and 44 (42.7%) female patients, with a male to female ratio of
1.3:1. The BMI of enrolled patients ranged from 22.0 Kg/m2 to 34.4 Kg/m2 with a
mean of 26.9±3.4 Kg/m2. Diagnosis of appendicitis was confirmed in 93 (90.3%)
patients on histopathology. Thus there were 93 true positive and 10 false
positive cases. It yielded a positive predictive value of 90.3% for serum
amylase in predicting acute appendicitis taking histopathology as gold
standard. Similar positive predictive value was noted across various subgroups
based on age, gender and BMI.
Conclusion: In the present study, the positive predictive value of raised serum
amylase was found to be 90.3% in predicting acute appendicitis which along with
simplicity and routine availability of the test and low cost advocate the
preferred use of this novel biomarker in the diagnostic workup of such patients
in future surgical practice.
Keywords: Appendicitis, Serum
Amylase, Positive Predictive Value