Preoperative platelet dysfunction predicts blood product transfusion in children undergoing cardiac surgery

Plasma and Platelet Transfusions Strategies in Neonates and Children Undergoing Cardiac Surgery With Cardiopulmonary Bypass or Neonates and Children Supported by Extracorporeal Membrane Oxygenation: From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present the recommendations and consensus statements with supporting literature for plasma and platelet transfusions in critically ill neonates and children undergoing cardiac surgery with cardiopulmonary bypass or supported by extracorporeal membrane oxygenation from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding.

DESIGN

Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children.

SETTING

Not applicable.

PATIENTS

Critically ill neonates and children following cardiopulmonary bypass or supported by extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of nine experts developed evidence-based and, when evidence was insufficient, expert-based statements for plasma and platelet transfusions in critically ill neonates and children following cardiopulmonary bypass or supported by extracorporeal membrane oxygenation. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed one good practice statement, two recommendations, and three expert consensus statements.

CONCLUSIONS

Whereas viscoelastic testing and transfusion algorithms may be considered, in general, evidence informing indications for plasma and platelet transfusions in neonatal and pediatric patients undergoing cardiac surgery with cardiopulmonary bypass or those requiring extracorporeal membrane oxygenation support is lacking.

Use of Coagulation Point-of-Care Tests in the Management of Anticoagulation and Bleeding in Pediatric Cardiac Surgery: A Systematic Review

Bleeding and coagulation management are essential aspects in the management of neonates and children undergoing cardiac surgery. The use of point-of-care tests (POCTs) in a pediatric setting is not as widely used as in the adult setting. This systematic review aims to summarize the evidence showed by the literature regarding the use of POCTs in children undergoing cardiac surgery. We included all studies examining the pediatric population (<18 years old) undergoing cardiac surgery in which the coagulation profile was assessed with POCTs. Three electronic databases (PubMed, Embase, and the Cochrane Controlled Clinical Trials register) were searched. Tests involved were heparin effect tests, viscoelastic tests, and platelet function tests. Due to the wide heterogeneity of the patients and tests studied, a formal meta-analysis was impossible, and the results are therefore presented through a systematic review. Eighty articles were found, of which 47 are presented in this review. At present, literature data are too weak to define POCTs as a "gold standard" for the treatment of perioperative bleeding in pediatric cardiac surgery. Nevertheless, introduction of POCTs into postoperative algorithms has shown to improve bleeding management, patient outcome, and cost efficiency.

Platelet Function Changes during Neonatal Cardiopulmonary Bypass Surgery: Mechanistic Basis and Lack of Correlation with Excessive Bleeding

Thrombocytopenia and platelet dysfunction induced by extracorporeal blood circulation are thought to contribute to postsurgical bleeding complications in neonates undergoing cardiac surgery with cardiopulmonary bypass (CPB). In this study, we examined how changes in platelet function relate to changes in platelet count and to excessive bleeding in neonatal CPB surgery. Platelet counts and platelet P-selectin exposure in response to agonist stimulation were measured at four times before, during, and after CPB surgery in neonates with normal versus excessive levels of postsurgical bleeding. Relative to baseline, platelet counts were reduced in patients while on CPB, as was platelet activation by the thromboxane A2 analog U46619, thrombin receptor activating peptide (TRAP), and collagen-related peptide (CRP). Platelet activation by adenosine diphosphate (ADP) was instead reduced after platelet transfusion. We provide evidence that thrombocytopenia is a likely contributor to CPB-associated defects in platelet responsiveness to U46619 and TRAP, CPB-induced collagen receptor downregulation likely contributes to defective platelet responsiveness to CRP, and platelet transfusion may contribute to defective platelet responses to ADP. Platelet transfusion restored to baseline levels platelet counts and responsiveness to all agonists except ADP but did not prevent excessive bleeding in all patients. We conclude that platelet count and function defects are characteristic of neonatal CPB surgery and that platelet transfusion corrects these defects. However, since CPB-associated coagulopathy is multifactorial, platelet transfusion alone is insufficient to treat bleeding events in all patients. Therefore, platelet transfusion must be combined with treatment of other factors that contribute to the coagulopathy to prevent excessive bleeding.

Strategies for blood conservation in pediatric cardiac surgery

Cardiac surgery accounts for the majority of blood transfusions in a hospital. Blood transfusion has been associated with complications and major adverse events after cardiac surgery. Compared to adults it is more difficult to avoid blood transfusion in children after cardiac surgery. This article takes into account the challenges and emphasizes on the various strategies that could be implemented, to conserve blood during pediatric cardiac surgery.