Blood product conservation is associated with improved outcomes and reduced costs after cardiac surgery.

BACKGROUND: Efforts to reduce blood product use have the potential to avoid transfusion-related complications and reduce health care costs. The purpose of this investigation was to determine whether a multi-institutional effort to reduce blood product use affects postoperative events after cardiac surgical operations and to determine the influence of perioperative transfusion on risk-adjusted outcomes. METHODS: A total of 14,259 patients (2006-2010) undergoing nonemergency, primary, isolated coronary artery bypass grafting operations at 17 different statewide cardiac centers were stratified according to transfusion guideline era: pre-guideline (n = 7059, age = 63.7 ± 10.6 years) versus post-guideline (n = 7200, age = 63.7 ± 10.5 years). Primary outcomes of interest were observed differences in postoperative events and mortality risk-adjusted associations as estimated by multiple regression analysis. RESULTS: Overall intraoperative (24% vs 18%, P < .001) and postoperative (39% vs 33%, P < .001) blood product transfusion were significantly reduced in the post-guideline era. Patients in the post-guideline era demonstrated reduced morbidity with decreased pneumonia (P = .01), prolonged ventilation (P = .05), renal failure (P = .03), new-onset hemodialysis (P = .004), and composite incidence of major complications (P = .001). Operative mortality (1.0% vs 1.8%, P < .001) and postoperative ventilation time (22 vs 26 hours, P < .001) were similarly reduced in the post-guideline era. Of note, after mortality risk adjustment, operations performed in the post-guideline era were associated with a 47% reduction in the odds of death (adjusted odds ratio, 0.57; P < .001), whereas the risk of major complications and mortality were significantly increased after intraoperative (adjusted odds ratio, 1.86 and 1.25; both P < .001) and postoperative (adjusted odds ratio, 4.61 and 4.50, both P < .001) transfusion. Intraoperative and postoperative transfusions were associated with increased adjusted incremental total hospitalization costs ($4408 and $10,479, respectively). CONCLUSIONS: Implementation of a blood use initiative significantly improves postoperative morbidity, mortality, and resource utilization. Limiting intraoperative and postoperative blood product transfusion decreases adverse postoperative events and reduces health care costs. Blood conservation efforts are bolstered by collaboration and guideline development.

Retinal angiography: noninvasive, real-time bubble assessment from the ocular fundus.

Formation of bubbles in tissue and vasculature from a sudden reduction in ambient pressure is likely an underlying cause of the clinical symptoms of decompression sickness (DCS). Thus, tools detecting bubbles in the vasculature may be important for evaluating DCS. Sheep were air-compressed to 6.0 ATA (30 minutes bottom time) then rapidly decompressed to the surface. A fundus camera was quickly positioned for continuous observation of the retinal vasculature. Bubbles were observed in the retinal vasculature of 25.8% (n = 31) of the sheep. Bubble onset time ranged from 5-22 minutes post-chamber and lodge time ranged from 0-70+ minutes. Bubbles were visualized mostly in the arteries of the retinal circulation. Severe vasoconstriction was captured using red-free angiography in two sheep. In two other sheep, fluorescein angiography demonstrated occluded blood flow caused by arterial gas emboli. This study demonstrates that retinal angiography is a practical tool for real-time, noninvasive detection of bubbles in the retinal circulation, a visible window to the cerebral circulation. Thus retinal angiography may prove invaluable in the early detection of arterial gas emboli in the cerebral circulation, the resolution of which is imperative to favorable neurological outcomes. This study also presents for the first time images of bubbles in the retinal circulation associated with DCS captured by a fundus camera.

Developing a blood conservation program in cardiac surgery.

The beneficial effects of blood transfusions have been described and widely accepted. Multiple factors, including shortages, costs, infectious risks, immunologic risks, and the risk/benefit ratio to the patient, have made the medical community reassess the guidelines for transfusion. Cardiac surgery presents a unique subset of patients, because intervention at multiple stages in the care of these patients is possible to decrease the need for transfusion. An algorithm for a cardiac surgery program was developed and a reassessment performed. Once it was seen that no detrimental effect on patient care occurred, the program was expanded, was enhanced, and subsequently has been offered to the rest of the health care system. This program has resulted in a decrease in cost while maintaining patient outcomes. The success of the program is believed to be a result of the multidisciplinary approach taken, with a commitment from all members of the blood reduction team being the key component of this success.

Assessment of hemostatic activation during cardiopulmonary bypass for coronary artery bypass grafting with bivalirudin: results of a pilot study.

OBJECTIVE: Bivalirudin has been successfully used as a replacement for heparin during on-pump coronary artery bypass grafting. This study was conducted to assess the effects of the currently suggested protocol for bivalirudin on hemostatic activation during cardiopulmonary bypass with and without cardiotomy suction. METHODS: Ten patients scheduled for coronary artery bypass grafting were enrolled. Bivalirudin was given with a bolus of 50 mg in the priming solution and 1.0 mg/kg for the patient, followed by an infusion of 2.5 mg . kg(-1) . h(-1) until 15 minutes before the conclusion of cardiopulmonary bypass. Cardiopulmonary bypass was performed with a closed system in 5 patients with and in 5 patients without the use of cardiotomy suction. Blood samples were obtained before and after cardiopulmonary bypass. D-dimers, fibrinopeptide A, prothrombin 1 and 2 fragments, thrombin-antithrombin, and factor XIIa were determined. RESULTS: Values for factor XIIa remained almost unchanged in both groups, indicating a minor effect of contact activation. In patients without cardiotomy suction, post-cardiopulmonary bypass values for D-dimers, fibrinopeptide A, prothrombin 1 and 2 fragments, and thrombin-antithrombin were not significantly increased compared with pre-cardiopulmonary bypass values. In patients with cardiotomy suction, values obtained for these parameters had significantly increased compared with pre-cardiopulmonary bypass values and the values obtained in the group without cardiotomy suction after cardiopulmonary bypass. CONCLUSIONS: With this protocol, hemostatic activation during cardiopulmonary bypass was almost completely attenuated when cardiotomy suction was avoided. Cardiotomy suction results in considerable activation of the coagulation system and should therefore be restricted and replaced by cell saving whenever possible.

An assessment of different filter systems for extracorporeal elimination of bivalirudin: an in vitro study.

IMPLICATIONS: Bivalirudin is a new, direct thrombin inhibitor. We investigated the extracorporeal elimination rate of different hemofilters and one plasmapheresis filter for bivalirudin. Our data show that bivalirudin can be effectively eliminated via hemofiltration and plasmapheresis, although there were significant differences in the elimination rates among the filter systems investigated.