Could serum procalcitonin play a role in an emergency setting for patients with pyogenic spondylodiscitis?

Spinal infections, represent quite rare but often severe conditions. However, due to symptoms' non-specificity and the lack of specific laboratory tests, diagnosis is often delayed with serious consequences for the patient's outcomes. The present investigation aimed at evaluating the role of procalcitonin (PCT) and other clinical features on the risk stratification and the clinical outcomes in spondylodiscitis patients treated in our Emergency Department.

The present investigation represents a single-center retrospective study. Clinical records of consecutive patients admitted to our Emergency Department from 1 January 2015 to 31 March 2021 were evaluated and patients with spondylodiscitis diagnosis in this period were recruited. Our primary outcome was the degree of autonomy of patients following the acute event. Our secondary outcome was the resolution of the infection.

In the study period, a total of 345 patients were evaluated. Among these, 165 met the inclusion criteria, and constituted the study cohort. Concerning the primary outcome, we observed that the most significant predictive factors for being non-autonomous were elevated serum creatinine (> 1.05 mg/dl), Blood Urea Nitrogen (BUN) > 23 mg/dl, Lactate dehydrogenase > 228 U/L, PCT > 0.11 ng/mL. Patients with higher PCT (PCT > 0.11 ng/mL) and higher BUN (BUN > 23 mg/dl) had higher odds of infection persistence (the Odd Ratio, OR, were respectively 3.78 for PCT and 3.14 for BUN).

PCT assay may play a role in diagnosing spondylodiscitis in an emergency setting. A PCT value > 0.11 ng/mL should be considered as a red flag, a predictor of worse clinical outcomes and persistence of infection.