Autonomic control of heart rate after brain injury in children.
OBJECTIVE
To study sequential changes in heart rate, respiratory rate, blood pressure, heart rate power spectra, and plasma catecholamine concentrations in patients with acute brain injury and correlate these variables with the severity of neurologic dysfunction and patient outcome.


METHODS
Prospective, clinical study.


METHODS
Pediatric intensive care unit.


METHODS
Thirty-seven pediatric patients with acute brain injury caused by trauma, anoxia/ischemia, hemorrhage, or infection.


METHODS
None.


RESULTS
We found significant associations between low-frequency (0.01 to 0.15 Hz) heart rate power and severity of neurologic dysfunction (as assessed by the admission Glasgow Coma Scale) (p < .001) and patient outcome (as assessed by the Glasgow Outcome Scale) (p = .05). The admission (p = .05) and maximum (p < .001) values for low-frequency heart rate power and the minimum value for high-frequency (0.15 to 0.50 Hz) heart rate power obtained during hospitalization (p = .001) predicted an increased likelihood of survival. Ten brain-dead patients had significantly decreased low-frequency heart rate power (p = .008) and plasma norepinephrine (p = .015), epinephrine (p = .03), and dopamine (p = .04) concentrations when compared with six non-brain-dead patients with a Glasgow Coma Scale score of 3.


CONCLUSIONS
Our results imply that autonomic nervous system control of heart rate is disrupted in proportion to the degree of neurologic insult in children after acute brain injury. Thus, heart rate power spectral analysis and plasma catecholamine concentrations may prove to be useful adjuncts in determining severity of neurologic injury and prognosis for recovery in children suffering from brain injury. In addition, these techniques may aid in the determination of brain death.
Goldstein
B
B
Department of Pediatrics, University of Rochester School of Medicine and Dentistry, Strong Children's Critical Care Center, NY, USA.
Kempski
M H
MH
DeKing
D
D
Cox
C
C
DeLong
D J
DJ
Kelly
M M
MM
Woolf
P D
PD
D000293:Adolescent; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001926:Brain Death / Q000175:diagnosis; D001930:Brain Injuries / Q000097:blood / Q000503:physiopathology*; D002395:Catecholamines / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D015600:Glasgow Coma Scale; D006339:Heart Rate; D006801:Humans; D007223:Infant; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012815:Signal Processing, Computer-Assisted; D015996:Survival Rate
D002395:Catecholamines