Procalcitonin after cardiac arrest - an indicator of severity of illness, ischemia-reperfusion injury and outcome.

AIM: To investigate serial serum concentrations of procalcitonin (PCT) and C-reactive protein (CRP) in patients treated with mild hypothermia after cardiac arrest, and to study their association to severe infections, post cardiac arrest syndrome (PCAS) and long-term outcome.

METHODS: Serum samples from cardiac arrest patients treated with mild hypothermia were collected serially at admission, 2, 6, 12, 24, 36, 48 and 72 h after cardiac arrest. PCT and CRP concentrations were determined and tested for association with three definitions of infection, two surrogate markers of PCAS (circulation-SOFA and time to return of spontaneous circulation (ROSC)) and cerebral performance category (CPC) at six months.

RESULTS: Eighty-four patients were included. PCT displayed an earlier release pattern than CRP with a significant increase within 2h, increasing further at 6h and onwards in patients with poor outcome. CRP increased later and continued to rise during the study period. PCT was strongly associated with circulation-SOFA and time to ROSC, and predicted a poor neurologic outcome with high accuracy (area under the receiver operating characteristic curve of 0.88, 0.86 and 0.87 at 12, 24 and 48 h respectively). No association of PCT or CRP to infection was observed.

CONCLUSION: Our results suggest that PCT is released early after resuscitation following cardiac arrest, is associated with markers of PCAS but not with infection, and is an accurate predictor of poor outcome. Validation of these findings in larger studies is warranted.