Background: Excess activation of the sympathetic nervous system may be a risk factor for mortality in patients with the systemic inflammatory response syndrome (SIRS) or sepsis.
Aim: To examine whether excessive tachycardia, relative to the degree of fever is an independent risk factor for death in patients with SIRS.
Design: Prospective observational study.
Setting: Departments of medicine in three university hospitals in Israel, Germany and Italy.
Methods: We collected data for 3382 patients with SIRS, whether community- or hospital-acquired, 91% with sepsis, as part of an ongoing trial.
Results: Overall 30-day mortality was 12% (408/3382). The pulse/temperature ratio was significantly higher in patients who died than in survivors: mean +/- SD 2.55 +/- 0.57 vs. 2.40 +/- 0.48 bpm/ degrees C (p < 0.0001). Excessive tachycardia was significantly associated with a mortality in a logistic model accounting for other strong predictors of mortality (OR 1.54, 95%CI 1.10-2.17). Patients with septic shock were the only group for whom this association did not hold.
Discussion: Our data are compatible with the hypothesis that some patients with sepsis experience an excess activation of the sympathetic nervous system, leading to a fatal outcome.