Respiratory-related arterial pressure variability as an indicator of graded blood loss: Involvement of the autonomic nervous system

Hsien Yong Lai, Cheryl C H Yang, Fan Yen Huang, Yi Lee, Yu Ling Kuo, Terry B J Kuo

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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 β-adrenoceptors.

Original languageEnglish
Pages (from-to)491-497
Number of pages7
JournalClinical Science
Issue number4
Publication statusPublished - Oct 1 2003
Externally publishedYes



  • Blood volume
  • Frequency domain
  • Power spectral analysis
  • Sympathetic activity
  • Systolic pressure variation

ASJC Scopus subject areas

  • Medicine(all)

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