SERUM PROCALCITONIN VERSUS C-REACTIVE PROTEIN FOR EARLY DIAGNOSIS OF SEPSIS IN THE EMERGENCY DEPARTMENT

Abstract

Background: Sepsis is a life-threatening condition that needs prompt diagnosis, and timely intervention, particularly in the emergency department where clinical features are often non-specific. The use of biomarkers like serum procalcitonin and C-reactive protein (CRP) is common for early recognition of infection and systemic inflammation.

Objective: To compare the diagnostic performance of serum procalcitonin and C-reactive protein for early diagnosis of sepsis among patients presenting to the emergency department.

Methods: The comparative diagnostic study was carried out at Kabir Medical College, Peshawar, from January 2025 to June 2025. There were 82 patients with suspected infection. Demographic data, clinical features, and suspected source of infection, serum procalcitonin, C-reactive protein, total leukocyte count, serum lactate, blood culture results, ICU admission, requirement of vasopressors, and mortality were documented. Patients were included in sepsis and non-sepsis groups. The performance of the two markers, serum procalcitonin and CRP was evaluated using sensitivity, specificity, positive predictive value, negative predictive value and overall accuracy.

Results: Out of 82 patients, 50 (61.0%) were diagnosed with sepsis and 32 (39.0%) were classified as non-sepsis cases. Mean serum procalcitonin was significantly higher in the sepsis group compared with the non-sepsis group (5.82 ± 3.41 ng/mL vs 0.91 ± 0.58 ng/mL; p < 0.001). Mean C-reactive protein was also significantly increased in sepsis patients (96.4 ± 41.8 mg/L vs 48.7 ± 26.5 mg/L; p < 0.001). Procalcitonin showed sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 88.0%, 75.0%, 84.6%, 80.0%, and 82.9%, respectively. Corresponding values for C-reactive protein were 82.0%, 59.4%, 75.9%, 67.9%, and 73.2%.

Conclusion: Serum procalcitonin demonstrated better diagnostic accuracy than C-reactive protein for early diagnosis of sepsis in emergency department patients. Although both biomarkers were significantly elevated in sepsis, procalcitonin showed higher specificity and overall accuracy, making it a more reliable supportive marker for early sepsis identification.