ANH and AP on Blood Management

Al Stammers, MSA, CCP
Director of Clinical Quality and Outcomes Research
February 16, 2017

Recently I attended the 2017 Annual Meeting of The American Academy of Cardiovascular Perfusion. The AACP, as always, offered strong educational content and a great opportunity to meet up with friends and colleagues. While there, I had the pleasure of presenting co-authored research on “The Effectiveness of Acute Normovolemic Hemodilution and Autologous Prime on Intraoperative Blood Management during Cardiac Surgery.” The AACP honored our team, which includes our perfusion associates and their tireless dedication to clinical excellence and data collection, by selecting this work as the meeting’s Best Paper. I encourage you to read the abstract for additional detail, but here’s a summary of our findings, which highlight the value of thoughtful perfusion strategies that can reduce the need for costly transfusions and increase the likelihood of better clinical outcomes.

Cardiac surgery with cardiopulmonary bypass is known to result in significant hemodilution, which places patients at both an increased risk for bleeding and for receiving blood transfusions. Clinicians can employ a multitude of techniques to reduce both of these unwanted situations. The combination of these interventions has been described as the study of blood management, which transcends all phases of an operative procedure. Although there are numerous opportunities to reduce these risks, two of the more value-based techniques include acute normovolemic hemodilution (ANH) and autologous priming (AP), both requiring that the cardiac team work in unison to employ them successfully.

Our perfusion associates work closely with surgeons and anesthesiologists to practice ANH and AP. The results of these blood management techniques are recorded as part of the continuous quality improvement process using SpecialtyCare’s Case Documentation System for data capture. This information serves as the foundation for SCOPE™, the SpecialtyCare Operative Procedural Registry, which we use to define clinical standards that improve care and optimize outcomes for patients. SCOPE also serves as a vast repository of clinical information from which research hypotheses can be generated.

SpecialtyCare researchers have examined the utilization of ANH and AP as either isolated techniques or in combination as blood sparing measures. The outcomes of this research have shown the following:

  1. The use of ANH resulted in the greatest drop in intraoperative hematocrit
  2. Combining AP with ANH reduced the change in hematocrit compared to ANH alone
  3. The smallest drop in hematocrit occurred in patients receiving AP alone
  4. Red blood cell transfusion rates were lowest in the ANH group and highest when neither technique was used

The use of ANH resulted in the greatest change in intraoperative hematocrit, but also the lowest transfusion rate for red blood cells. The authors commend the SpecialtyCare perfusion associates for their commitment to patient care and their continued dedication to improving outcomes. Although the highest level of research remains randomized clinical trials, results from SCOPE studies that involve multiple centers across a wide range of practice patterns, such as reported here, add to the overall knowledge of blood management and serve as the basis for future research.