Changes in the pulmonary capillary pressure after cardiac surgery.
The changes in the pulmonary circulation in 37 cardiac surgery patients undergoing coronary artery bypass (CABG), n=16; aortic valve replacement (AVR), n=13; and mitral valve replacement (MVR), n=8 were studied. The visual technique for the determination of pulmonary capillary pressure (Pc) was used in the preoperative and postoperative periods. The ratio of Pc to the pulmonary artery wedge pressure (Pw) was calculated to determine whether Pc and Pw varied independently. In addition, total pulmonary vascular resistance (PVR) was divided into precapillary (ra) and postcapillary (rv) components. Results from the CABG patients showed that the relationship between Pc and Pw remained constant despite an increased cardiac output. This differs from the data obtained from AVR and MVR patients in whom the Pc/Pw ratio was significantly higher after surgery. Therefore, Pw would underestimate Pc in this group of patients. In addition, MVR patients showed a significant postoperative increase in PVR and rv as compared with their preoperative values. This was also significantly higher than the rv in either AVR or CABG patients. The etiology of this change is unknown.
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Department of Anesthesiology, The University of South Alabama Medical Center, Mobile, AL, USA.
Allison
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RC
Dumond
M E
ME
Taylor
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AE
D001021:Aortic Valve / Q000601:surgery; D021721:Balloon Occlusion / Q000379:methods; D001794:Blood Pressure; D002196:Capillaries / Q000503:physiopathology*; D002302:Cardiac Output / Q000502:physiology; D006348:Cardiac Surgical Procedures; D002407:Catheterization, Swan-Ganz / Q000379:methods; D001026:Coronary Artery Bypass / Q000706:statistics & numerical data; D017558:Elective Surgical Procedures; D006801:Humans; D008943:Mitral Valve / Q000601:surgery; D008991:Monitoring, Physiologic / Q000379:methods; D015588:Observer Variation; D011184:Postoperative Period; D011300:Preoperative Care; D011651:Pulmonary Artery / Q000503:physiopathology; D011652:Pulmonary Circulation / Q000502:physiology; D011669:Pulmonary Wedge Pressure; D014655:Vascular Resistance / Q000502:physiology