Respiratory-related arterial pressure variability as an indicator of graded blood loss: involvement of the autonomic nervous system.
During positive pressure mechanical ventilation, percentile systolic pressure variation (%SPV) or respiratory-related arterial pressure variability (RAPV) have both been used in assessment of graded haemorrhage. We aimed to investigate whether changes in %SPV and RAPV are correlated during graded haemorrhage (by 5, 10 or 20% of the estimated blood volume) in anaesthetized positive pressure ventilated rats and to investigate the involvement of autonomic regulation. Saline vehicle or atropine produced no discernible effect on baseline %SPV or RAPV but, thereafter, %SPV and RAPV increased progressively with graded haemorrhage. Propranolol significantly decreased baseline %SPV and RAPV and changes induced in %SPV and RAPV by graded haemorrhage. Phentolamine significantly enhanced baseline %SPV and RAPV, and further enhancement of %SPV and RAPV by graded haemorrhage did not occur until 20% of the estimated blood volume was removed. RAPV was significantly correlated with %SPV in all experimental groups. We conclude that RAPV is comparable with%SPV as an indicator of graded haemorrhage and that, in anaesthetized and positive pressure ventilated rats, both are dependent on autonomic function, especially beta-adrenoceptors.
Lai
Hsien Yong
HY
Institute of Clinical Medicine, National Yang-Ming University, Taipei 112, Taiwan.
Yang
Cheryl C H
CC
Huang
Fan-Yen
FY
Lee
Yi
Y
Kuo
Yu Ling
YL
Kuo
Terry B J
TB
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000758:Anesthesia; D000818:Animals; D001158:Arteries; D001285:Atropine / Q000494:pharmacology; D001341:Autonomic Nervous System / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D006470:Hemorrhage / Q000175:diagnosis*; D008297:Male; D010276:Parasympatholytics / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D011175:Positive-Pressure Respiration; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012815:Signal Processing, Computer-Assisted; D013599:Systole
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D010276:Parasympatholytics; D001285:Atropine; D011433:Propranolol; D010646:Phentolamine