Effect of non-hypotensive haemorrhage on plasma catecholamine levels and cardiovascular variability in man.
BACKGROUND
It is well known from animal research that non-hypotensive haemorrhage produces sympathoexcitatory responses assessable by both the rise in plasma catecholamine levels and the shift of autonomic influences on the heart to more sympathetic and less parasympathetic control. Data in humans are restricted.


METHODS
Heart rate variability (HRV), systolic blood pressure (FINAPRES) variability (BPV), and catecholamine plasma levels were measured before and after haemorrhage in 30 healthy blood donors and compared with those from 10 control subjects without blood loss. Spectral power of HRV and BPV in very low (0.02-0.06 Hz), low (0.07-0.14 Hz), and high (0.15-0.40 Hz) frequency bands were calculated by Fourier analysis. Catecholamine plasma levels were assayed by dual column reverse-phased high-performance liquid chromatography (HPLC).


RESULTS
Haemorrhage of 5.6 +/- 1.2 ml kg-1 body weight increased plasma norepinephrine levels (215 +/- 92 pg ml-1 versus 254 +/- 95 pg ml-1; P = 0.002), increased BPV in the low frequency band (Mayer waves; 1.8 +/- 1.0 ln [mmHg(2)] versus 2.0 +/- 0.9 ln [mmHg(2)]; P = 0.021), and decreased the vagally transmitted high frequency HRV (6.9 +/- 1.1 ln [MI(2)] versus 6.5+/-1.2 ln [MI(2)]; P<0.0001), but did not induce significant changes in heart rate (66 +/- 11 bpm versus 67 +/- 11 bpm; P = 0.79) and arterial blood pressure (mean values: 84 +/- 13 mmHg versus 87 +/- 13 mmHg; P = 0.12).


CONCLUSIONS
As suggested by plasma norepinephrine levels, systolic BPV and HRV, non-hypotensive haemorrhage produces sympathoexcitatory responses as well as vagal withdrawal of heart rate control in humans.
Haberthür
Christoph
C
Medical Intensive Care Unit,University Hospital, and Blutspendedienst SRK beider Basel, Basel, Switzerland. christoph.haberthuer@ksl.ch
Schächinger
Hartmut
H
Seeberger
Manfred
M
Gysi
Christine Stebler
CS
D000222:Adaptation, Physiological; D000328:Adult; D000367:Age Factors; D001782:Blood Donors; D001794:Blood Pressure; D002395:Catecholamines / Q000097:blood; D004562:Electrocardiography / Q000379:methods*; D004837:Epinephrine / Q000097:blood*; D006339:Heart Rate; D006470:Hemorrhage / Q000097:blood* / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D007022:Hypotension / Q000209:etiology; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood*
D002395:Catecholamines; D009638:Norepinephrine; D004837:Epinephrine