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Myocardial blood flow and oxygen consumption during positive end-expiratory pressure ventilation at different levels of cardiac inotropy and frequency
- Source :
- Critical care medicine. 17(1)
- Publication Year :
- 1989
-
Abstract
- Effects of PEEP on cardiac function, myocardial blood flow (MBF) and myocardial oxygen consumption (mVO2) were studied in eight mongrel dogs anesthetized with pentobarbital. Myocardial oxygen demand was increased by isoproterenol infusion or atrial pacing, or decreased by beta-receptor blockade. PEEP was set to 15 cm H2O in all groups. The greatest reduction in cardiac output due to PEEP was seen during isoproterenol infusion (44%), and the smallest during beta-receptor blockade (18%). This is attributed to increased sensitivity to the reduced left ventricular (LV) preload induced by PEEP, when cardiac inotropy is augmented by isoproterenol, compared to normal and reduced cardiac inotropy. PEEP decreased MBF similarly and significantly in all groups. However, myocardial oxygen extraction did not increase, and reduction in MBF caused by PEEP was closely related to concomitant reduction in mVO2. A significant correlation was also observed between reductions in LV work and reduction in mVO2 when PEEP was applied in all groups. We conclude that the reduced MBF observed with use of PEEP was probably due to reduced myocardial oxygen demand.
- Subjects :
- Cardiac function curve
Artificial ventilation
Cardiac output
medicine.medical_treatment
Critical Care and Intensive Care Medicine
Positive-Pressure Respiration
Coronary circulation
Dogs
Oxygen Consumption
Heart Rate
Coronary Circulation
medicine
Animals
Positive end-expiratory pressure
business.industry
Myocardium
Isoproterenol
Heart
Blood flow
respiratory system
Myocardial Contraction
Propranolol
respiratory tract diseases
Preload
medicine.anatomical_structure
Anesthesia
cardiovascular system
Breathing
business
therapeutics
circulatory and respiratory physiology
Subjects
Details
- ISSN :
- 00903493
- Volume :
- 17
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Critical care medicine
- Accession number :
- edsair.doi.dedup.....42a127ee087270067da4694d079da3a3