Autonomic dysfunction predicts mortality in patients with multiple organ dysfunction syndrome of different age groups.
OBJECTIVE
Multiple organ dysfunction syndrome (MODS) is the sequential failure of several organ systems after a trigger event, like sepsis or cardiogenic shock. Mortality rate is high, up to 70%. Autonomic dysfunction may substantially contribute to the development of MODS. Our study aimed to characterize a) the spectrum of autonomic dysfunction of critically ill MODS patients; b) whether autonomic dysfunction is different in patients receiving sedation, mechanical ventilation, or catecholamines; c) the age dependency of autonomic dysfunction in MODS; and d) whether autonomic dysfunction predicts mortality in MODS.


METHODS
Prospective cohort study.


METHODS
Twelve-bed medical intensive care unit in a university center.


METHODS
Ninety consecutively admitted score-defined MODS patients.


METHODS
Assessment of heart rate variability, baroreflex sensitivity, and chemoreflex sensitivity as markers of autonomic dysfunction. The patients were followed for 28-day mortality.


RESULTS
Baroreflex sensitivity, chemoreflex sensitivity, and almost all indexes of heart rate variability were attenuated in comparison to normal range data. There was no association between the assessed heart rate variability variables, baroreflex sensitivity or chemoreflex sensitivity, and the presence of sedation or catecholamine therapy. Except for frequency-domain variables, pNN50 (percentage of differences of successive RR intervals differing >50 msecs) and rMSSD (root mean square of successive difference of N-N intervals), none of the measured variables were related to the presence of mechanical ventilation. Age dependency was detected for baroreflex sensitivity but not for heart rate variability indexes or chemoreflex sensitivity (across ages 24-96 yrs). lnVLF predicted 28-day mortality best in the entire cohort of patients and in a subgroup of patients with cardiogenic-triggered MODS.


CONCLUSIONS
Autonomic function of MODS patients is blunted, and this attenuation has prognostic implications. The extensive influence of MODS on autonomic function overwhelms and masks the well-known age dependency of autonomic function seen in healthy persons.
Schmidt
Hendrik
H
Martin Luther University, Halle-Wittenberg, Germany. hendrik.schmidt@medizin.uni-halle.de
Müller-Werdan
Ursula
U
Hoffmann
Thomas
T
Francis
Darrel P
DP
Piepoli
Massimo F
MF
Rauchhaus
Mathias
M
Prondzinsky
Roland
R
Loppnow
Harald
H
Buerke
Michael
M
Hoyer
Dirk
D
Werdan
Karl
K
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001341:Autonomic Nervous System / Q000503:physiopathology*; D017704:Baroreflex; D002395:Catecholamines / Q000627:therapeutic use; D015331:Cohort Studies; D016292:Procedural Sedation; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000401:mortality*; D011379:Prognosis; D011446:Prospective Studies; D012121:Respiration, Artificial
D002395:Catecholamines