Modified Ultrafiltration Reduces Morbidity After Adult Cardiac Operations A Prospective, Randomized Clinical Trial Giovanni Battista Luciani, MD; Tiziano Menon, CP; Barbara Vecchi, MD; Stefano Auriemma, MD; Alessandro Mazzucco, MD Background—Extracorporeal circulation contributes to morbidity after open-heart surgery by causing a systemic inflammatory reaction. Modified ultrafiltration is a technique able to remove the fluid overload and inflammatory mediators associated with use of cardiopulmonary bypass. It has been shown to reduce morbidity after cardiac operations in children, but the impact on adult cardiac procedures is unknown. Methods and Results—Five hundred seventy-three consecutive adult patients were prospectively randomized to either ultrafiltration after cardiopulmonary bypass (treatment) or to no ultrafiltration (control). Parsonnet score was used to assess the severity of the patients’ clinical conditions. Analysis was done with Student’s t test or Mann-Whitney U test for continuous variables and Fisher’s exact test or Pearson’s  2 for discrete variables. Hospital mortality was 2.5% (7 of 284) in the treatment group versus 3.8% (11 of 289) in the control group (P=0.357). Hospital morbidity was lower in treated patients (66 of 284 [23.2%] versus 117 of 289 [40.5%], P=0.0001). Cardiac morbidity was similar (26 of 284 [9.1%] versus 35 of 289 [12.1%], P=0.251), whereas significantly lower rates of respiratory (20 of 284 [7.0%] versus 36 of 289 [12.5%], P=0.029), neurological (5 of 284 [1.8%] versus 14 of 289 [4.8%], P=0.039), and gastrointestinal (0 of 284 versus 4 of 289 [1.4%], P=0.044) complications were found in treated patients. Transfusion requirements were also lower in treated patients (1.662.6 versus 2.253.8 U/patient, P=0.039). Duration of intensive care (39.949.2 versus 46.372.8 hours, P=0.218) and hospital stay (7.63.5 versus 7.94.4 days, P=0.372) were comparable. Conclusions—Modified ultrafiltration after cardiopulmonary bypass is associated with a lower prevalence of early morbidity and lower blood transfusion requirements. The impact on length of hospital stay needs further analysis. Routine application of modified ultrafiltration after adult cardiac operations is warranted. (Circulation. 2001;104[suppl I]:I-253-I-259.) Key Words: cardiopulmonary bypass  ultrafiltration  surgery  morbidity T he use of cardiopulmonary bypass for cardiac surgical procedures may be responsible for postoperative morbid- ity by causing a systemic inflammatory response syndrome (SIRS). 1,2 Many consequences of extracorporeal circulation have been implicated in the genesis of the systemic inflam- matory state, including the exposure of blood components to synthetic surfaces, the fluid overload necessary for priming the circuit, body temperature changes, nonpulsatile flow, ischemia, and reperfusion of end organs. 1,2 It is currently believed that cellular and humoral factors, including cyto- kines, may be activated during bypass, which will mediate organ damage. 3 The clinical manifestations of the SIRS include cardiac, respiratory, renal, hepatic, and neurological dysfunction, bleeding diathesis, and even multiple-system organ failure. 2,4–6 Among the therapeutic maneuvers proposed to mitigate the consequences of postperfusion syndrome, modified ultrafil- tration has recently increasingly come into favor. The tech- nique entails removal of water and low-molecular-weight substances under a hydrostatic pressure gradient after sepa- ration from cardiopulmonary bypass. This method has been demonstrated to induce hemoconcentration and reduce bleed- ing and total body water accumulation in children. 7 Because of the properties of counteracting tissue edema and eliminat- ing inflammatory mediators, further observations have attrib- uted to modified ultrafiltration the ability to improve post- perfusion end-organ function and to attenuate morbidity after pediatric cardiac operations. 8 –14 Information on the clinical effects, if any, of modified ultrafiltration after open-heart surgery in the adult population is limited to 2 trials on highly selected patient cohorts undergoing coronary artery bypass graft surgery. 15,16 The present study was undertaken in an effort to define the impact of modified ultrafiltration on early morbidity after adult cardiac operations. From the Division of Cardiac Surgery, University of Verona, Verona, Italy. Correspondence to Giovanni Battista Luciani, MD, Division of Cardiac Surgery, University of Verona, OCM Piazzale Stefani 1, Verona, 37126, Italy. E-mail luciani@netbusiness.it © 2001 American Heart Association, Inc. Circulation is available at http://www.circulationaha.org I-253 Downloaded from http://ahajournals.org by on January 24, 2022