Standards and Best Practice for Acute Normovolemic Hemodilution: Evidence-based Consensus Recommendations.

OBJECTIVE: To develop a standardized approach to the implementation and performance of acute normovolemic hemodilution (ANH) in order to reduce the incidence of bleeding and allogeneic blood transfusion in high-risk surgical bleeding-related cardiac surgery with cardiopulmonary bypass (CPB). DESIGN: A 2-round modified RAND-Delphi consensus process. PARTICIPANTS: Seven physicians from multiple geographic locations and clinical disciplines including anesthesiology and cardiac surgery and 1 cardiac surgery perfusionist participated in the survey. One registered nurse, specializing in Patient Blood Management, participated in the discussion but did not participate in the survey. METHODS: A modified RAND-Delphi method was utilized that integrated evidence review with a face-to-face expert multidisciplinary panel meeting, followed by repeated scoring using a 9-point Likert scale. Consensus was determined as a result from the second round survey, as follows: median rating of 1-3: ANH acceptable; median rating of 7-9: ANH not acceptable; median rating of 4-6: use clinical judgment. RESULTS: Evidentiary review identified 18 key peer-reviewed manuscripts for discussion. Through the consensus-building process, 39 statements including 26 contraindications to ANH and 10 CPB patient variables were assessed. In total, 22 statements were accepted or modified for the second scoring round. CONCLUSIONS: Consensus was reached on 6 conditions in which ANH would or would not be acceptable, showing that development of a standardized approach for the use of ANH in high-risk surgical bleeding and allogeneic blood transfusion is clearly possible. The recommendations developed by this expert panel may help guide the management and inclusion of ANH as an evidence and consensus-based blood conservation modality.

Physiologic aspects of anemia.

The most important adaptive responses from a physiological stance involved the cardiovascular system, consisting in particular of elevation of the cardiac output and its redistribution to favor the coronary and cerebral circulations, at the expense of the splanchnic vascular beds. The evidence regarding these physiological responses, especially in experimental studies that permit the control of many variables, is particularly powerful and convincing. On the other hand, there is a remarkable lack, in quality and quantity, of clinical studies addressing how normal physiological adaptive responses may be affected by a variety of diseases and conditions that often accompany and may complicate anemia, and interactions with other such compounding variables as age and different patient populations. For these reasons, it is not possible to offer guidelines on how to increase, maintain, or even to determine optimal DO2 in high-risk patients and how best transfusion strategies might be used under these conditions. From the brief review of physiological principles and the strong consensus in the literature, it is evident that cardiac function must be a central consideration in decisions regarding transfusion in anemia, because of the critical role it plays in assuring adequate oxygen supply of all vital tissues. Particular attention should be paid to the possible presence of CAD or incipient or cardiac failure, as these conditions may require careful transfusions to improve DO2 at levels that may not necessitate such interventions when cardiac disease is absent. Although the cerebral circulation also serves an obligate aerobic organ unable to tolerate significant hypoxia, there is little convincing evidence to support the notion that cerebral ischemia is aggravated by anemia and that this can be prevented by improved DO2 through rapid correction of anemia. Consequently, the arguments favoring transfusions in the presence of ischemic heart disease do not appear to apply to occlusive cerebrovascular disease. Because firm evidence is lacking on the interactions of concurrent diseases and anemia in various patient populations, understanding of the physiological consequences of anemia, and of the diseases concerned, is useful but not fully sufficient to provide firm and rational guidance to transfusion practice in specific complex clinical instances. A good deal of clinical and experimental investigation is required to support fully rational and comprehensive guidelines. In the meantime, prudent and conservative management, based on awareness of risks and sound understanding of the normal and pathological physiology, must remain the guiding principle.

Ready-to-use injection preparations versus conventional reconstituted admixtures: economic evaluation in a real-life setting.

OBJECTIVE: To measure, in a real-life setting, the benefits of using ready-to-use (RTU) injection preparations compared with conventional reconstituted admixtures (Admix) in terms of cost savings. DESIGN AND PERSPECTIVE: An economic model was developed, based on a randomised study. The perspective of the economic evaluation was that of the hospital administration. A microcosting approach was used to determine costs. SETTING: Department of Cardiac Surgery at the Charleroi University Hospital in Belgium. STUDY PARTICIPANTS: Fifty-eight patients undergoing cardiac surgery under cardiopulmonary bypass were randomised to Admix dobutamine or to the RTU dobutamine group and were followed up during 24 hours after initiation of dobutamine therapy. MAIN OUTCOME MEASURES AND RESULTS: Nursing time was reduced by 32% in the RTU group compared with the Admix group. Material cost was also reduced and the overall cost savings in the RTU group amounted to a 60% reduction in the cost of the conventional Admix process (p<0.001). When drug cost was included in the equation, cost savings varied from 1.60 euros (EUR) to EUR21.40 per patient depending on dosage. There was no difference between the two groups in terms of safety and efficacy. A user satisfaction survey showed that medical staff especially welcomed improved ease of preparation and potential for prevention of errors and risks of handling. CONCLUSION: This study confirmed the potential for RTU forms to reduce nursing time associated with preparation and administration of intravenous admixtures and to enable overall cost savings.