An Ultrafiltration Technique for Directly Reinfusing Residual Cardiopulmonary Bypass Blood

Given the shortages of banked blood, the risks of transfusion reactions, disease transmissions, and transfusion errors, we perfusionists must find ways to avoid blood transfusions. At the end of any given bypass run, there is residual blood left in the bypass circuit, the perfusionist must get this blood back to the patient. Most commonly either a cell saver or a hemoconcentrator (HC) has been used, in some fashion, to reinfuse residual circuit blood. The ideal method should: 1) be simple; 2) raise the hematocrit (HCT); 3) allow for changes in the patient’s volume status; and 4) not compromise the integrity of the cardiopulmonary bypass (CPB) circuit allowing for rapid re-institution of CPB. We describe a technique in which residual CPB circuit blood is pumped through an HC directly to the patient via a 3/16-inch diameter line into a 16-gauge intravenous needle positioned in a peripheral or central vein. This allows the perfusionist to give back concentrated blood that is protein-rich while maintaining the above criteria

Oxidative Stress and Cerebral Vascular Tone: The Role of Reactive Oxygen and Nitrogen Species

The brain’s unique characteristics make it exceptionally susceptible to oxidative stress, which arises from an imbalance between reactive oxygen species (ROS) production, reactive nitrogen species (RNS) production, and antioxidant defense mechanisms. This review explores the factors contributing to the brain’s vascular tone’s vulnerability in the presence of oxidative damage, which can be of clinical interest in critically ill patients or those presenting acute brain injuries. The brain’s high metabolic rate and inefficient electron transport chain in mitochondria lead to significant ROS generation. Moreover, non-replicating neuronal cells and low repair capacity increase susceptibility to oxidative insult. ROS can influence cerebral vascular tone and permeability, potentially impacting cerebral autoregulation. Different ROS species, including superoxide and hydrogen peroxide, exhibit vasodilatory or vasoconstrictive effects on cerebral blood vessels. RNS, particularly NO and peroxynitrite, also exert vasoactive effects. This review further investigates the neuroprotective effects of antioxidants, including superoxide dismutase (SOD), vitamin C, vitamin E, and the glutathione redox system. Various studies suggest that these antioxidants could be used as adjunct therapies to protect the cerebral vascular tone under conditions of high oxidative stress. Nevertheless, more extensive research is required to comprehensively grasp the relationship between oxidative stress and cerebrovascular tone, and explore the potential benefits of antioxidants as adjunctive therapies in critical illnesses and acute brain injuries

Prolonged postoperative respiratory support after proximal thoracic aortic surgery: Is deep hypothermic circulatory arrest a risk factor?

PURPOSE: In addition to the pulmonary risks associated with cardiopulmonary bypass, thoracic aortic surgery using deep hypothermic circulatory arrest (DHCA) may subject the lungs to further injury. However, this topic has received little investigation to date. MATERIALS AND METHODS: A prospective cohort review was performed on all patients undergoing proximal thoracic aortic surgery with (n = 478) and without (n = 135) DHCA between July 2005 and February 2013 at a single institution. The primary outcome was prolonged postoperative respiratory support (PPRS), defined as any of the following: >1 day of mechanical ventilation at either fraction of inspired oxygen >0.4 and/or positive end-expiratory pressure >5 mm Hg, >2 days of supplemental O(2) requirement of at least 2.5 L/min, or discharge with new O(2) requirement. Independent risk factors for PPRS were identified using multivariable logistic regression. RESULTS: Postoperative respiratory support was required in 100 patients (20.9%) with and 30 patients (22.2%) without DHCA (P = .74). Independent predictors of PPRS after proximal aortic surgery included the following: age, diabetes, history of stroke, preoperative creatinine, American Society of Anesthesiologists class 4, redo-sternotomy, total arch replacement, and transfusion requirement. Use of DHCA was not an independent risk factor for PPRS in the entire cohort. Subanalysis of only DHCA patients revealed that longer DHCA times were independently associated with PPRS. CONCLUSIONS: Prolonged postoperative respiratory support is common after proximal aortic surgery. The use of DHCA was not associated with this complication in the overall cohort, although longer DHCA times were predictive when only the subset of patients undergoing DHCA was analyzed. Knowledge of the risk factors for PPRS after proximal aortic surgery should improve preoperative risk stratification and postoperative management of these patients

Society of Cardiovascular Anesthesiologists Clinical Practice Improvement Advisory for Management of Perioperative Bleeding and Hemostasis in Cardiac Surgery Patients

Bleeding after cardiac surgery is a common and serious complication leading to transfusion of multiple blood products and resulting in increased morbidity and mortality. Despite the publication of numerous guidelines and consensus statements for patient blood management in cardiac surgery, research has revealed that adherence to these guidelines is poor, and as a result, a significant variability in patient transfusion practices among practitioners still remains. In addition, although utilization of point-of-care (POC) coagulation monitors and the use of novel therapeutic strategies for perioperative hemostasis, such as the use of coagulation factor concentrates, have increased significantly over the last decade, they are still not widely available in every institution. Therefore, despite continuous efforts, blood transfusion in cardiac surgery has only modestly declined over the last decade, remaining at ≥50% in high-risk patients. Given these limitations, and in response to new regulatory and legislature requirements, the Society of Cardiovascular Anesthesiologists (SCA) has formed the Blood Conservation in Cardiac Surgery Working Group to organize, summarize, and disseminate the available best-practice knowledge in patient blood management in cardiac surgery. The current publication includes the summary statements and algorithms designed by the working group, after collection and review of the existing guidelines, consensus statements, and recommendations for patient blood management practices in cardiac surgery patients. The overall goal is creating a dynamic resource of easily accessible educational material that will help to increase and improve compliance with the existing evidence-based best practices of patient blood management by cardiac surgery care teams