Case 6--1993. Cardiopulmonary bypass in two patients with previously undetected cold agglutinins

Cardiopulmonary bypass surgery-cold alert!

The term "cold agglutinin (CA)" refers to a group of disorders caused by anti-erythrocyte autoantibodies that preferentially bind RBCs at cold temperatures (4°C-18°C). CAs contribute to 10 to 15% of autoimmune hemolytic anemia. We report a case of CAs diagnosed intraoperatively during emergency mitral valve replacement.

Red Blood Cell Disorders: Perioperative Considerations for Patients Undergoing Cardiac Surgery

Disorders affecting red blood cells (RBCs) are uncommon yet have many important physiologic considerations for patients undergoing cardiac surgery. RBC disorders can be categorized by those that are congenital or acquired, and further by disorders affecting the RBC membrane, hemoglobin, intracellular enzymes, or excessive RBC production. A foundational understanding of the physiologic derangement for these disorders is critical when considering perioperative implications and optimization, strategies for cardiopulmonary bypass, and the rapid recognition and treatment if complications occur. This review systematically outlines the RBC disorders of frequency and relevance with an emphasis on how the disorder affects normal physiologic processes, a review of the literature related to the disorder, and the implications and recommendations for patients undergoing cardiac surgery.

Anaesthetic management for cardiac surgery in patients with cold haemagglutinin disease

Cold haemagglutination is a primary or acquired autoimmune disease involving antibodies that lead to agglutination of red blood cells at low temperature followed by complement fixation and haemolysis on rewarming. This disease can lead to adverse consequences in patients undergoing cardiothoracic surgery, especially when hypothermic cardiopulmonary bypass is applied. The authors discuss the management of two patients who underwent mitral valve replacement surgery while cold agglutinins were detected in the perioperative period. In the first patient, the diagnosis was made preoperatively followed by administration of glucocorticoids to achieve acceptable level of antibody titers. The second patient experienced haemoglobinuria during her intensive care unit stay. The case report describes the pathophysiology of cold agglutination, relevant laboratory investigations such as antibody titers and thermal amplitude, identification of at-risk patients, and management strategies to avoid serious complications.

Use of an Intravascular Warming Catheter during Off-Pump Coronary Artery Bypass Surgery in a Patient with Severe Cold Hemagglutinin Disease

Cold hemagglutinin disease with broad thermal amplitude and high titers presents challenges in treating cardiac-surgery patients. Careful planning is needed to prevent the activation of cold agglutinins and the agglutination of red blood cells as the patient's temperature drops during surgery. We describe our approach to mitigating cold agglutinin formation in a 77-year-old man with severe cold hemagglutinin disease who underwent off-pump coronary artery bypass surgery without the use of preoperative plasmapheresis. This experience shows that the use of an intravascular warming catheter can maintain normothermia and prevent the activation and subsequent formation of cold agglutinins. To our knowledge, this is the first reported use of this technique in a patient with cold hemagglutinin disease. The chief feature in this approach is the use of optimal thermal maintenance-rather than the more usual decrease in cold-agglutinin content by means of therapeutic plasma exchange.

Cold Antibodies in Cardiovascular Surgery: Is Preoperative Screening Necessary?

OBJECTIVES

Cold antibodies (CAs) are rarely significant for transfusion, but they can cause complications under the hypothermic conditions of cardiovascular surgery. The purpose of this study was to determine the incidence of such complications.

METHODS

Patients with CAs who underwent cardiovascular surgery were identified, and their records were reviewed for intraoperative complications attributable to CAs.

RESULTS

Over 14.5 years, of the 47,373 patients who underwent cardiovascular surgery, 99 had CAs before or within 30 days after surgery. Ninety-seven patients had hypothermic surgery, and intraoperative agglutination was noted in four; two of these cases were never reported to the transfusion service.

CONCLUSIONS

The incidence of intraoperative complications among our patients with CAs was only 4%; therefore, the use of special testing protocols for the preoperative identification of CAs is neither necessary nor justified. Patient risk is best managed by preoperative clinical evaluation for potentially pathogenic CAs and intraoperative vigilance for agglutination.

Anesthetic and Cardiopulmonary Bypass Considerations for Cardiac Surgery in Unique Pediatric Patient Populations: Sickle Cell Disease and Cold Agglutinin Disease

Physiological disturbances induced by cardiopulmonary bypass (CPB) and hypothermia during cardiac surgery are particularly pronounced in certain unique patient populations, such as patients with sickle cell disease (SCD) and cold agglutinin disease. Red blood cells containing hemoglobin S (HbS) are at increased risk of sickling under conditions encountered during cardiac surgery, leading to SCD-related complications such as vaso-occlusive events. While a target level of HbS has not been determined for patients with SCD undergoing CPB, a safe practice includes increasing the Hb level to 10 g/dL and reducing the proportion of HbS to approximately 30%. This can be accomplished through simple or exchange transfusion prior to surgery or via the modification of the CPB circuit prime. There is no clear consensus on the formulation or the delivery temperature of the cardioplegia solution necessary to prevent sickling and microvascular occlusion. The presence of cold agglutinins is another entity requiring extra vigilance for the conduct of CPB, where hypothermia can lead to activation of cold agglutinins inducing massive hemagglutination, hemolysis, microvascular thrombosis, and possibly intracoronary thrombosis. Determination of thermal amplitude is important to provide a safe reference range of temperature during surgery. High-volume plasmapheresis may be warranted to reduce cold agglutinin titers. Both warm blood cardioplegia and cold crystalloid cardioplegia above the thermal amplitude have been utilized with success.

Practical management of anticoagulation, bleeding and blood product support for cardiac surgery part two: Transfusion issues

We summarise recent advances in transfusion medicine applicable to cardiac surgery and cardiac transplantation. It is important that clinicians know the risks of blood transfusion in Australia. They should also be aware of the different types of transfusion reaction so that there is early recognition and investigation. Blood conservation strategies including acceptance of normovolaemic anaemia in clinically stable patients are important in reducing the requirement for red cell transfusion. Cytomegalovirus (CMV) seronegative blood products are recommended for heart transplant recipients with no evidence of prior CMV infection. Leucodepletion of units of unknown CMV status reduces the risk of CMV infection and are an acceptable alternative when seronegative units are unavailable. Leucodepletion of cellular blood products has been shown to reduce infection rates postoperatively in a large trial involving cardiac surgical patients. Further studies are needed to confirm this promising finding. Irradiation of blood products eliminates the risk of transfusion-associated graft versus host disease. Routine preoperative screening for cold agglutinins is no longer recommended.

Cardiac surgery and cold-reactive proteins

Cold agglutinins are commonly found in sera of healthy persons. They rarely become clinically apparent due to their activity at low temperatures. In these patients, cardiovascular operations requiring hypothermia can result in complications such as hemolysis, renal failure, and myocardial damage and can cause unexpected morbidity and mortality. The literature on cold-reactive proteins is reviewed, and methods of diagnosis and management related to cardiac surgery are suggested. Ideally all patients should be routinely tested preoperatively for the antibodies, and appropriate changes in cardiopulmonary bypass and myocardial management plans should be made in positive patients. Preoperative plasmapheresis may be a useful adjunct, especially in patients requiring operation under profound hypothermia and circulatory arrest. Currently, warm heart surgery appears to be the most expedient method. Unexpected detection of agglutination during operation or hemolysis after operation requires a specific treatment plan.