CALCA and pneumonia: Procalcitonin is reported to be superior to other infection markers in diagnosing acute bacterial infections.18,19 In a retrospective study by Zhang et al,20 infection markers were evaluated in terms of perioperative pneumonia, urinary infections, and superficial surgical site infections in 500 patients who underwent hip and knee arthroplasty and it has been reported that PCT has a high sensitivity (96%) and specificity (100%) in the diagnosis of bacterial infection.