Utility of procalcitonin as a predictor of bloodstream infections and supportive modality requirements in critically ill cancer patients.

BACKGROUND

We evaluated the diagnostic utility of procalcitonin (PCT) in predicting bacterial bloodstream infections (BSI) in critically ill cancer patients with and without neutropenia. We also investigated the role of PCT as a prognostic marker of supportive modalities (vasopressors, invasive mechanical ventilation, and renal replacement therapy (RRT)) in the intensive care unit (ICU).

METHODS

We retrospectively analyzed 2200 PCT and blood cultures from adult cancer patients with suspected sepsis. Primary outcome was BSI, defined by positive blood culture, collected within 72 h of PCT collection.

RESULTS

Median PCT values were higher in encounters with BSI (3.2 vs 0.5 ng/ml, p < 0.001). The area under the ROC curve (AUC) was 0.726 (95%CI 0.698, 0.754). PCT > 2.0 ng/ml was significantly associated with greater likelihood of BSI and this effect was significantly stronger for neutropenic (OR 9.09, 95%CI: 4.39, 18.79) compared with non-neutropenic patients (OR 4.00 (95% CI: 3.13, 5.10), interaction p = 0.036). PCT > 2.0 was associated with vasopressor requirement on ICU admission (OR 1.82 (95% CI 1.31, 2.53), p < 0.001) and RRT (OR 2.20 (95% CI 1.24, 3.91), p = 0.007).

CONCLUSIONS

Procalcitonin is a fair discriminator of BSI in critically ill cancer patients with and without neutropenia and a PCT > 2.0 ng/ml was significantly more likely to require vasopressors and RRT in the ICU.