CARDIOVASCULAR ANESTHESIA SECTION EDITOR KENNETH J. TUMAN SOCIETY FOR CARDIOVASCULAR ANESTHESIOLOGISTS Predictive Factors for Usefulness of Fiberoptic Pulmonary Artery Catheter for Continuous Oxygen Saturation in Mixed Venous Blood Monitoring in Cardiac Surgery Catherine Vedrinne, MD, Olivier Bastien, MD, Roland De Varax, MD, Pascale Blanc, MD, Pierre-Georges Durand, MD, Bernard Du G&s, MD, H&ne Bouvier, MD, Christine Saroul, MD, and Jean-Jacques Lehot, MD, PhD Department of Cardiothoracic Anesthesia and Intensive Care, Hopital Cardiovasculaire & Pneumologique Louis Pradel, Lyon, France The main goal of this prospective study was to identify among cardiac surgery patients, usually monitored through a standard pulmonary artery catheter (PAC), those in whom a fiberoptic catheter oximeter to meas- ure oxygen saturation in mixed venous blood (Svo,PAC) would be most useful. Data from 286 pa- tients who underwent coronary artery bypass graft (50%) or valvular surgery were recorded, including ASA physical status, New York Heart Association (NYHA) classification, and Parsonnet score (P’S). He- modynamic events and Svo, changes were collected intra- and postoperatively until weaning from mechan- ical ventilation. The anesthesiologist in charge graded the usefulness of SvoJ’AC, and another anesthesiolo- gist carried out a blindly controlled overall evaluation. Usefulness was defined as the presence of a change in therapeutic maneuver triggered solely by continuous Svo, data that would not have occurred based on other routine parameters. Svo, was also considered useful if earlier recognition of significant adverse events oc- curred. Svo,PAC was useful in 57% of the patients. In- dependent predictive factors (multivariate analysis) for the perioperative usefulness of Svo, in the whole pop- ulation consisted of ASA class ~4 (P < 10K5; relative risk [RR] 1.78, 1.51-2.07), mitral surgery (P < 10e4; RR 1.72,1.4-2.02), and NYHA score 23 (P < 0.01; RR 1.66, 1.35-2.05). Independent predictive factors for the peri- operative usefulness of Svo, in the coronary artery by- pass graft population were NYHA score 23 (P < 10e5; RR 1.90,1.42-2.55) and ASA class ~4 (P < 0.01; RR 1.99, 1.51-2.63). The presence of three stenosed coronary ar- teries showed borderline significance (P < 0.06). Inde- pendent predictive factors for perioperative usefulness of Svo, in the valvular population were mitral pathol- ogy (P < 10V5) and ASA class ~4 (P < 0.01). The re- ceiver operator characteristic curve assessed the predic- tivity of the PS. Svo,PAC was more useful in the group of patients with the greatest severity of illness (I’S in useful group 17.0 -C 10.3; in nonuseful group 8.7 + 6.6; P < 10V4). Intensive care unit duration and hospital stay in the useful group was prolonged compared with the nonuseful group. Similarly, morbidity was frequent in the useful group, although it was not always signifi- cantly different from the nonuseful group according to the type of complications. Mortality was comparable in the groups despite their different degree of illness and was reduced when taking into account the predictive and observed mortality provided by the PS. This study defined independent preoperative factors associated with Svo,PAC monitoring and proposed a cutoff point above which Svo, may be useful. (Anesth Analg 1997;85:2-10) V alues for in viva oxygen saturation in mixed venous blood (Svo,) obtained by in vitro ab- sorptance spectrophotometry correlate with Svo, measured in a mixed venous blood sample by cooximetry (1,2). Since most factors determining SVO~, This study was presented in part at the 1996 Society of Cardio- vascular Anesthesiologists annual meeting, Salt Lake City, UT, May 4-8, 1996. Accepted for publication April 2, 1997. Address correspondence and reprint requests to Dr. Catherine Vedrinne, Hopital Louis Pradel, 28 Avenue du Doyen Lepine, 69500 Lyon, France. 2 Anesth Analg 1997;85:2-10 such as oxygen consumption (Vo,), cardiac output (CO), hemoglobin concentration, and arterial oxygen saturation (Sao,), are subject to rapid changes intra- and postoperatively, reliable continuous monitoring could obviate most limitations of the intermittent sam- pling. A pulmonary artery catheter (PAC) for contin- uous Svo, measurement (SvoJAC) might thus allow detection of inadequate or impaired oxygen transport prior to this information becoming available either from routinely timed measurements or before hemo- dynamic deterioration occurs. It might also permit evaluation of corrective maneuvers. However, new 01997 by the International Anesthesia Research Society 0003-2999/97/$5.00