Delayed Fever and Neurological Outcome after Cardiac Arrest: A Retrospective Clinical Study

Background

The aim of this study was to evaluate the association between fever after the first days of ICU stay and neurological outcome after cardiac arrest (CA).

Methods

We retrospectively analyzed CA patients admitted to intensive care unit (ICU). Inclusion criteria: age ≥18 years, Glasgow Coma Scale score ≤8 at ICU admission and assessment of body core temperature (BCT) using bladder or intravascular probes. Exclusion criteria: ICU length of stay (LOS) <3 days and pregnancy. The primary endpoint was neurological outcome assessed with Cerebral Performance Category (CPC) scale 6 months after CA.

Results

One hundred thirty-two patients were analyzed. Fever was present in 105 (79.6 %) patients. Variables associated with unfavorable outcome were (1) older age (p < 0.0025); (2) non-shockable cardiac rhythms (p < 0.0001); (3) higher Simplified Acute Physiology Score (SAPS) II (p < 0.0001); (4) pupillary abnormalities at ICU admission (p < 0.018); and (5) elevated degree of maximal BCT (Tmax) during ICU stay (p < 0.046). After multivariate analysis, Tmax maintained a significant relationship with neurological outcome. An increase of 1 °C in Tmax during ICU stay decreased the odds ratio for a favorable outcome by a factor of 31 % (p < 0.001). Moreover, we discovered a significant interaction between the day of Tmax (t-Tmax) and Tmax (p = 0.004); the later Tmax occurs, the more deleterious effects are observed on outcome.

Conclusions

Fever is frequent after CA, and Tmax in ICU is associated with worsened neurological outcome. This association becomes stronger as the timing of Tmax extends further from the CA.