CALCA and susceptibility to pneumonia measurement: The white blood cell (WBC) count and serum C-reactive protein (CPR) are both common infectious disease detection indicators, but some studies have demonstrated their unsatisfactory detection effect [10], so further clinical analysis is still in need; procalcitonin (PCT) is a common precursor of calcitonin in laboratory tests, and its level increases distinctively in MDRAB pneumonia, as explained in relevant medical studies [11].