Document Detail

The ventilation-perfusion relation and gas exchange in mitral valve disease and coronary artery disease. Implications for anesthesia, extracorporeal circulation, and cardiac surgery.
MedLine Citation:
PMID:  9105225     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Patients with mitral valve disease (MVD) are at greater risk for respiratory complications after cardiac surgery compared with patients with coronary artery disease (CAD). The authors hypothesized that ventilation-perfusion (VA/Q) inequality is more pronounced in patients with MVD before and after induction of anesthesia and during and after surgery when extracorporeal circulation (ECC) is used. METHODS: In patients with MVD (n = 12) or with CAD (n = 12), VA/Q distribution was determined using the multiple inert gas elimination technique. Intrapulmonary shunt (Qs/Qr) defined as regions with VA/Q < 0.005 [% of total perfusion (Qr)], perfusion of "low" VA/Q areas (0.005 < or = VA/Q < 0.1, [% of Qr]), ventilation of "high" VA/Q regions (10 < or = VA/Q < or = 100 [% of total ventilation VE]), and dead space (VA/Q > 100 [% of VE]) were calculated from the retention/excretion data of the inert gases. Recordings were obtained while patients spontaneously breathed air in the awake state, during mechanical ventilation after induction of anesthesia, after separation of patients from ECC, and 4 h after operation. RESULTS: Qs/Qr was low in the awake state (MVD group, 3% +/- 3%; CAD group, 3% +/- 4%) and increased after induction of anesthesia to 10% +/- 8% (MVD group, P < 0.05) and 11% +/- 7% (CAD group, P < 0.01). Qs/Qr increased further after separation from ECC (MVD group, 24% +/- 9%, P < 0.01; CAD group, 23% +/- 7%, P < 0.01). Similarly, alveolar-arterial oxygen tension difference (PA-aO2) increased from 168 +/- 54 mmHg (anesthetized state) to 427 +/- 138 mmHg after ECC (MVD group, P < 0.01) and from 153 +/- 65 mmHg to 377 +/- 101 mmHg (CAD group, P < 0.01). In both groups, PA-aO2 was correlated with Qs/Qr. Four hours after operation, Qs/Qr had decreased significantly to 8% +/- 6% (CAD group) and 10% +/- 6% (MVD group). PA-aO2 and Qs/Qr showed no significant differences between the CAD and MVD groups. CONCLUSIONS: Qs/Qr is the main pathophysiologic mechanism of gas exchange impairment during cardiac surgery for MVD or CAD. Impairment of pulmonary gas exchange secondary to general anesthesia, cardiac surgery, and ECC are comparable for patients undergoing myocardial revascularization or mitral valve surgery.
T Hachenberg; A Tenling; H E Hansson; H Tydén; G Hedenstierna
Related Documents :
20719725 - Outcomes of de vega versus biodegradable ring annuloplasty in the surgical treatment of...
10475425 - The long-term results of commissure plication annuloplasty for congenital mitral insuff...
20549455 - Midterm outcome of leaflet folding plasty for mitral regurgitation due to posterior lea...
20043935 - Poisoning of goats by the pods of luetzelburgia auriculata.
1642935 - Iv diclofenac in post-thoracotomy pain.
17265505 - Methotrexate as an alternative therapy for chronic calcium pyrophosphate deposition dis...
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Anesthesiology     Volume:  86     ISSN:  0003-3022     ISO Abbreviation:  Anesthesiology     Publication Date:  1997 Apr 
Date Detail:
Created Date:  1997-05-01     Completed Date:  1997-05-01     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  1300217     Medline TA:  Anesthesiology     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  809-17     Citation Subset:  AIM; IM    
Department of Cardiothoracic Anesthesiology, University Hospital, Uppsala, Sweden.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Coronary Disease / physiopathology*,  surgery
Extracorporeal Circulation*
Middle Aged
Mitral Valve / surgery
Mitral Valve Insufficiency / physiopathology*,  surgery
Mitral Valve Stenosis / physiopathology*,  surgery
Myocardial Revascularization
Pulmonary Gas Exchange*
Ventilation-Perfusion Ratio*

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

Previous Document:  The rate of blood withdrawal affects the accuracy of jugular venous bulb. Oxygen saturation measurem...
Next Document:  Effects of a dobutamine-induced increase in splanchnic blood flow on hepatic metabolic activity in p...