Document Detail

Factors affecting the respiratory ratio during cardiopulmonary by-pass.
MedLine Citation:
PMID:  9988357     Owner:  NLM     Status:  MEDLINE    
Despite the wide use of hypothermic cardiopulmonary bypass (CPB) during open heart surgery there is little information about the patient metabolism. In particular no complete studies addressed the assessment of the respiratory ratio (RR) during CPB at different core temperatures. Therefore a clinical study was performed in order to evaluate the oxygen consumption (VO2) and carbon dioxide production (VCO2) in adult patients with valvular or coronary heart disease undergoing CPB. Twenty-five patients (16 male, 9 female) aged between 26 and 76 (54.2+/-12.4 mean +/- SD) were the subjects of this study. Measurements (102) were taken at various perfusion flow rates (from 1.6 to 2.9 L/min(-1) x m(-2)) and temperatures (from 24 to 37 degrees C). Arterial and mixed venous gas analyses were performed and O2 and CO2 concentrations were calculated, including the carbamate contribute. We calculated VO2, VCO2 and then RR from artero-venous differences in O2 and CO2 contents. Both VO2 and VCO2 showed a positive linear correlation with temperature (r = 0.82 and r = 0.59 respectively) and with blood flow rate (r = 0.61 and r = 0.29 respectively). The mean RR was 0.78+/-0.28 and more than 84% of RR values fell in the range 0.5-1.2. No significant correlation between RR and temperature and blood flow rate was observed. VCO2 and RR showed a positive linear correlation with the gas to blood flow rate ratio (r = 0.37 and r = 0.49 respectively).
F Boschetti; G Pennati; F M Montevecchi
Related Documents :
41627 - The influence of blood flow and arterial blood pressure during cardiopulmonary bypass o...
3190337 - A new pericardial sucker: omni sucker for better aspiration of intrapericardial blood.
16817287 - Influence of hematocrit and pump prime on cerebral oxygen saturation in on-pump coronar...
7887717 - Effect of cannula length on aortic arch flow: protection of the atheromatous aortic arch.
8353887 - Effects of active compression-decompression resuscitation on myocardial and cerebral bl...
11575347 - Tissue/blood and tissue/water partition coefficients for propofol in sheep.
Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  The International journal of artificial organs     Volume:  21     ISSN:  0391-3988     ISO Abbreviation:  Int J Artif Organs     Publication Date:  1998 Dec 
Date Detail:
Created Date:  1999-05-11     Completed Date:  1999-05-11     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  7802649     Medline TA:  Int J Artif Organs     Country:  ITALY    
Other Details:
Languages:  eng     Pagination:  802-8     Citation Subset:  IM    
Dipartimento di Bioingegneria, Politecnico di Milano, CeBITeC, Politecnico di Milano and IRCCS S. Raffaele, Italy.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Blood Flow Velocity / physiology
Blood Gas Analysis
Body Temperature / physiology
Carbon Dioxide / blood,  metabolism
Cardiopulmonary Bypass*
Hypothermia, Induced
Middle Aged
Oxygen / blood
Oxygen Consumption / physiology*
Respiratory Mechanics / physiology*
Reg. No./Substance:
124-38-9/Carbon Dioxide; 7782-44-7/Oxygen

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Intradialytic hypotension in relation to pre-existent autonomic dysfunction in hemodialysis patients...
Next Document:  Haemodynamic changes in patients undergoing high-risk PTCA under protection of transfemoral heart- l...