In this review, we summarize the best available evidence to guide the conduct of adult cardiopulmonary bypass (CPB) to achieve "optimal" perfusion. At the present time, there is considerable controversy relating to appropriate management of physiologic variables during CPB. Low-risk patients tolerate mean arterial blood pressures of 50-60 mm Hg without apparent complications, although limited data suggest that higher-risk patients may benefit from mean arterial blood pressures >70 mm Hg. The optimal hematocrit on CPB has not been defined, with large data-based investigations demonstrating that both severe hemodilution and transfusion of packed red blood cells increase the risk of adverse postoperative outcomes. Oxygen delivery is determined by the pump flow rate and the arterial oxygen content and organ injury may be prevented during more severe hemodilutional anemia by increasing pump flow rates. Furthermore, the optimal temperature during CPB likely varies with physiologic goals, and recent data suggest that aggressive rewarming practices may contribute to neurologic injury. The design of components of the CPB circuit may also influence tissue perfusion and outcomes. Although there are theoretical advantages to centrifugal blood pumps over roller pumps, it has been difficult to demonstrate that the use of centrifugal pumps improves clinical outcomes. Heparin coating of the CPB circuit may attenuate inflammatory and coagulation pathways, but has not been clearly demonstrated to reduce major morbidity and mortality. Similarly, no distinct clinical benefits have been observed when open venous reservoirs have been compared to closed systems. In conclusion, there are currently limited data upon which to confidently make strong recommendations regarding how to conduct optimal CPB. There is a critical need for randomized trials assessing clinically significant outcomes, particularly in high-risk patients.

/pdf/optimal-perfusion-during-cardiopulmonary-bypass-an-evidence-4wnfriyp4s.pdf

Optimal Perfusion During Cardiopulmonary Bypass: An Evidence-Based Approach

An evidence-based review of the practice of cardiopulmonary bypass in adults: A focus on neurologic injury, glycemic control, hemodilution, and the inflammatory response

Mathias H. Aazami Torkel Aberg Clemens Aigner Cary W. Akins Nawwar Al-Attar Johannes M. Albes Ivan Aleksic Joseph Alex Vladimir Alexi-Meskishvili Christos Alexiou Ottavio R. Alfieri Zohair Y. Al-Halees Cem H. Alhan Imtiaz S. Ali Marco Alifano Nelson Alphonso Sharif Al-Ruzzeh Muhammad Muneer Amanullah Joseph J. Amato Vincenzo Ambrogi Marcello Carlo Ambrogi Gabriel Amir Luca Ampollini Robert H. Anderson Udo Christian Anegg Gianni D. Angelini Marco Anile Martine Antoine Carlo Antona Manuel J. Antunes Anelechi Anyanwu Jose I. Aramendi Jose Luis Aranda Olgun Kadir Aribas Kitipan V. Arom Hisao Asamura Athanasios C. Athanasiou Kalliopi Athanassiadi Tim Attmann Stephane Aubert Adel Khader Ayed Omer Aziz Jacques F. Azorin Jean Bachet Akin Eraslan Balci Xavier Baldo Yaron Bar-El Hendrick B. Barner David J. Barron Murat Basaran Cristina Basso Roberto Rafael Battellini Eugene Baudet Erwin P. Bauer Robert Bauernschmitt Urs Bauersfeld Yusuf Bayrak Matthias Bechtel David F. Beggs Ion P. Bellenis Jaroslav Benedik Federico Jose Benetti John R. Benfield Stefano Benussi Pascal A. Berdat Marius Berman Jose M. Bernal Marc-Andre Bernath Richard G. Berrisford Antoine A. Beuchat Friedhelm Beyersdorf Olivier Michel Bical Benjamin Bidstrup Paolo Biglioli Dietrich E. Birnbaum Gianluigi Bisleri Hartmuth B. Bittner Edward Black Antonio Bobbio Massimo Bonacchi Johannes Bonatti Pramod Bonde Philipp Bonhoeffer Andreas A. Boning Damien Bonnet Robert Stuart Bonser Michael A. Borger Ahmad Boseila Torsten Bossert Wolfgang Bothe Dietmar Bothig Tomaso Bottio Denis Bouchard Edward Thomas Brackenbury Michael Brandt William J. Brawn Pierre-Yves Brichon Christian Pierre Brizard Ivan Bruschweiler Alan J. Bryan Eric E. Buchser Gerald D. Buckberg Eric Gordon Butchart Jose M. Caffarena Antonio M. Calafiore Ayten K. Cangir Massimo Caputo Paolo Carbognani John Alfred Carr Thierry Carrel Angelo Carretta Raymond Cartier Aaron R. Casha Thierry Caus Alfredo Giuseppe Cerillo Stepan Cerny Alfredo Cesario Juan C. Chachques David J. Chambers Dominique Chapelle Pierre-Guy Chassot Nilanjan Chaudhuri Sylvain Chauvaud Olivier Chavanon Massimo Chello Yih-Sharng Chen Rene Chiolero Ray Chu-Jeng Chiu Cliff K. Choong Emmanuel Choukroun Thomas Decker Christensen Jan T. Christenson Paola Ciriaco Ali Civelek Massimiliano Codispoti Dennis V. Cokkinos Juan V. Comas John V. Conte Massimo Conti Graham J. Cooper Antonio F. Corno Joseph S. Coselli Maurizio Cotrufo Jacques Cotting Elvio Covino Jeremiah N. Cox Jochen T. Cremer John C. Criscione Martin Czerny Sabine H. Dabritz Willem Daenen Mark H.D. Danton Otto E. Dapunt John Dark Hiroshi Date Tirone E. David Michele De Bonis Tiziano De Giacomo Marc R. de Leval Sergio A. de Oliveira Ruggero De Paulis Marc de Perrot Raffaele De Simone Marek Andrzej Deja Alain Francois Delabays Dominique Delay Roland G. Demaria Murat M. Demirtas Thomas Deneke Joseph J. DeRose Paola D’Errigo Mohan P. Devbhandari Roberto Di Bartolomeo Duccio Di Carlo Roberto Di Donato Marco Di Eusanio Verdi J. Di Sesa Giovanni Dialetto Interactive CardioVascular and Thoracic Surgery 6 (2007) 143–146

Interactive CardioVascular and Thoracic Surgery - 2006 Reviewers

Objective: Cardiac surgery on cardiopulmonary bypass (CPB) is associated with postoperative renal dysfunction and up to 4% of patients with normal preoperative renal function develop acute renal failure (ARF) requiring dialysis. According to recent investigations, CPB management is not evidence-based and, thus, current clinical CPB practice may favor renal dysfunction. The purpose of our study was to investigate if postcardiac surgery renal dysfunction is influenced by CPB management.Methods: We selected three groups of patients with normal preoperative renal function who had been subjected to cardiac surgical procedures on CPB: 44 patients with postoperative ARF requiring hemofiltration/dialysis (ARF group), 51 patients with postoperative renal dysfunction not requiring hemofiltration/dialysis (serum creatinine increase > 0.5 mg/dl within 48 h postsurgery: CREAgroup), and 48 patients with normal postoperative renal function (Control group). The patients’ on-line CPB records were analyzed for CPB duration...

Impact of cardiopulmonary bypass management on postcardiac surgery renal function.

Background: Cardiac surgery-associated acute kidney injury (CSA-AKI) contributes to increased morbidity and mortality. However, its pathophysiology remains incompletely understood. We hypothesized that intra-operative mean arterial pressure (MAP) relative to pre-operative MAP would be an important predisposing factor for CSA-AKI. Methods: We performed a prospective observational study of 157 consecutive high-risk patients undergoing cardiac surgery with cardiopulmonary bypass (CPB). The primary exposure was delta MAP, defined as the preoperative MAP minus average MAP during CPB. Secondary exposure was CPB flow. The primary outcome was early CSA-AKI, defined by a minimum RIFLE class - RISK. Univariate and multivariate logistic regression were performed to explore for association between delta MAP and CSA-AKI. Results: Mean (± SD) age was 65.9 ± 14.7 years, 70.1% were male, 47.8% had isolated coronary bypass graft (CABG) surgery, 24.2% had isolated valve surgery and 16.6% had combined procedures. Mean (± SD) pre-operative, intra-operative and delta MAP were 86.6 ± 13.2, 57.4 ± 5.0 and 29.4 ± 13.5 mmHg, respectively. Sixty-five patients (41%) developed CSA-AKI within in the first 24 hours post surgery. By multivariate logistic regression, a delta MAP≥26 mmHg (odds ratio [OR], 2.8; 95%CI, 1.3-6.1, p = 0.009) and CPB flow rate ≥54 mL/kg/min (OR, 0.2, 0.1-0.5, p < 0.001) were independently associated with CSA-AKI. Additional variables associated with CSA-AKI included use of a side-biting aortic clamp (OR, 3.0; 1.3-7.1, p = 0.012), and body mass index ≥25 (OR, 4.2; 1.6-11.2, p = 0.004). Conclusion: A large delta MAP and lower CPB flow during cardiac surgery are independently associated with early post-operative CSA-AKI in high-risk patients. Delta MAP represents a potentially modifiable intra-operative factor for development of CSA-AKI that necessitates further inquiry.

/pdf/difference-between-pre-operative-and-cardiopulmonary-bypass-1361ischfj.pdf

Difference between pre-operative and cardiopulmonary bypass mean arterial pressure is independently associated with early cardiac surgery-associated acute kidney injury

Cardiopulmonary bypass: Evidence or experience based?

Aortic cross-clamping during cardiac operations may injure the vessel wall and cause tissue lesions. This experimental study analyses the influence of the intravascular and external pressure and the duration of aortic cross-clamping on endothelial tissue damage. Fresh porcine aortas (n=20) were tested with intravascular pressures from 30 to 80 mmHg. The external clamp pressure, necessary to occlude the aorta, was applied by using the second cog of a commercial aortic clamp and cross-clamping was performed for 1 and 30 min. The observed pressure curves were compared to the histological findings. For occlusion of the aorta, an external pressure of at least 10-fold higher than the intravascular pressure (max. 812 mmHg) had to be applied. After 30 min of clamping, a complete endothelial destruction was observed, irrespective of intra-aortic pressure. The aortic media remained intact. After 1 min clamping, fractions of intact endothelial cells were left, ranging from 40 to 70% at different intra-aortic pressures. These results indicate that endothelial tissue lesions due to aortic cross-clamping are not avoidable, even in moderate clamp application. The duration of aortic cross-clamping but not intravascular pressure is the pivotal factor. The integrity of the aortic media can be preserved if low-force cross-clamping is achieved.

/pdf/influence-of-clamp-duration-and-pressure-on-endothelial-1hl6leiz0g.pdf

Jörg Babin-Ebell

Papers

Cardiopulmonary bypass: Evidence or experience based?

Influence of clamp duration and pressure on endothelial damage in aortic cross-clamping

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