[Autonomic dysfunction and beta-adrenergic blockers in multiple organ dysfunction syndrome]

The multiple organ dysfunction syndrome (MODS), a failure of two or more organ systems, is the endstage of initial trigger events in diseases such as acute coronary syndrome or sepsis. The mortality is high (40 - 60 %). The present study aimed to detect whether beta-adrenergic blockers (BAB) which may affect sympathetic-parasympathetic balance have a positive influence on outcome.

Data on 157 patients with MODS (83 male, 74 female, mean age 61.3 +/- 13.4 years) were retrospectively analysed concerning BAB medication and autonomic dysfunction. A 24-hour-Holter-ECG which had been applied within the initial 48 hours of illness was analysed for heart rate variability (HRV). All patients were followed to determine 28-day mortality.

69 of the 157 MODS patients had received BAB. This treatment was associated with a higher survival probability (hazard ratio [HR] 0.4, 95 % confidence interval [CI] 0.23 - 0.68; p = 0.001). Survival benefit was especially seen in the subgroup of MODS patients who had an ischemically triggered MODS (HR 0.2 [0.1 - 0.5], p = 0.001). HRV was less reduced in the BAB group compared to patients without this medication.

MODS patients treated with beta-adrenercic blockers may have a survival benefit which is especially seen in the subgroup of MODS patients with ischemically triggered MODS. Moreover, BAB medication is associated with a less pronounced autonomic dysfunction in MODS (especially the vagal modulation of heart rate) which might result in a lower inflammatory response. Hence, future prospective studies have to show the relevance of beta-adrenergic blockers in MODS.