Checking procalcitonin in the ICU saves lives? Maybe

Procalcitonin (PCT) levels can be useful (although limited) in deciding whether and when to start, de-escalate, and stop antibiotic therapy in patients with suspected infection. Physicians' use of procalcitonin in antibiotic decisions has exploded since the FDA approval of a PCT assay whose manufacturer provides specific (albeit oversimplified) cut-off values at which to consider infection more or less likely.

Dozens of randomized trials have been performed testing procalcitonin in hospitalized patients. Most have shown a reduction in antibiotic exposure without improvements in mortality; however, virtually all were too small to detect mortality differences, or were not designed to. Most were also performed outside the ICU or included a mix of critically ill and non-critically ill patients.

A new meta-analysis combined data from 15 randomized trials including more than 6,000 patients in the ICU, using procalcitonin as a discriminator to guide antibiotic therapy (either to start, stop, or both).

Investigators found lower short-term mortality among patients randomized to procalcitonin-guided strategies to guide cessation of antibiotics (21% vs 24%). Length of stay in the ICU and hospital were not reduced. Strategies using procalcitonin to guide initiation of antibiotics (or to withhold antibiotics) were not associated with reduced mortality.

The analysis should bolster physicians' growing reliance on procalcitonin as a decision-making tool in patients with suspected infection. Procalcitonin is unreliable as a standalone test, but normal or falling values can give physicians confidence to stop antibiotics when other clinical data (white blood cell count, vital signs, fever, and culture data) are supportive.

Source: Crit Care Med