Low antithrombin levels in neonates and infants undergoing congenital heart surgery result in more red blood cell and plasma transfusion on cardiopulmonary bypass.

BACKGROUND: Neonates have lower levels of antithrombin (AT) due to immature liver synthetic function. AT deficiency may lead to inadequate anticoagulation with heparin during cardiac surgery resulting in consumption of coagulation factors and increased blood transfusion. The goal of this study is to examine the effect of AT level on the transfusion requirements of neonates and infants undergoing open heart surgery. STUDY DESIGN AND METHODS: This is a prospective, observational study at a tertiary pediatric referral center. Neonates and infants up to 6 months of age undergoing congenital heart surgery with cardiopulmonary bypass (CPB) were enrolled. Demographic, intraoperative, transfusion, and complications data were collected. Preoperative AT level was measured after induction of anesthesia. Prior to separation from CPB, a second blood sample was drawn and AT, thrombin antithrombin complex (TAT), D-dimer, and anti-Xa levels were measured. Linear and logistic regression were performed for data analysis. RESULTS: Preoperative low AT level was significantly associated with increased transfusion of red blood cells (RBCs) and fresh frozen plasma (FFP) during CPB, but not after separation from CPB. The incidence of thrombosis and re-operation were not associated with preoperative AT levels. There was no association between TAT, D-dimer, and anti-Xa levels at the end of CPB and preoperative AT levels. CONCLUSION: Low preoperative AT level is associated with increased transfusion of RBC and FFP on CPB in neonates and infants undergoing congenital heart surgery. Low preoperative AT level did not result in coagulation activation after CPB and after surgery.

Hemostatic Management of Extracorporeal Circuits Including Cardiopulmonary Bypass and Extracorporeal Membrane Oxygenation.

Cardiopulmonary bypass and extracorporeal membrane oxygenation (ECMO) cause hemostatic derangements that can predispose patients to both bleeding and thrombotic complications. Often, patients present for urgent surgery while taking medications including antiplatelet agents, vitamin K antagonists, and direct oral anticoagulants, which must be recognized, monitored, and managed. During extracorporeal circulation, appropriate anticoagulation, most commonly with heparin, is required to maintain blood flow and avoid thrombotic complications. However, anticoagulation and other effects of extracorporeal circuits can also have an undesired consequence of bleeding. Extracorporeal circulation leads to coagulopathy that may require therapy with blood products such as platelets, cryoprecipitate, and plasma in case a patient bleeds. Platelet dysfunction related to exposure to a foreign circuit is a primary concern, as is the development of acquired von Willebrand syndrome, which frequently remains undetected on routine testing. Hemorrhagic complications in ECMO, such as intracranial hemorrhage, pulmonary hemorrhage, and hemithorax, can occur. Hemostatic agents including antifibrinolytics, desmopressin, fibrinogen concentrates, and other factor concentrates may be needed to achieve hemostasis in these often-challenging patients. Managing bleeding on extracorporeal support requires careful monitoring and a thoughtful approach.

Preoperative Thromboelastographic Profile of Patients with Congenital Heart Disease: Association of Hypercoagulability and Decreased Heparin Response.

OBJECTIVE: To describe the demographic and thromboelastographic characteristics of patients with congenital heart disease presenting with decreased heparin response before cardiac surgery. DESIGN: Retrospective, observational study. SETTING: Single institution, tertiary, academic, university hospital. PARTICIPANTS: The study comprised 496 pediatric and adult patients undergoing cardiac surgery for congenital heart disease. INTERVENTIONS: Retrospective review of medical records. MEASUREMENTS AND MAIN RESULTS: Data on preoperative thromboelastography (TEG), demographics, and response to heparin were collected retrospectively. Logistic regression analysis was used to study the association between TEG and response to heparin. Decreased heparin response (defined as activated clotting time <480 s initial bolus of 300 U/kg heparin) was observed in 23.6% of patients presenting for surgery. Age distribution and preoperative coagulation profiles were similar for both nonresponders and responders to heparin. Preoperatively, nonresponders demonstrated all thromboelastrographic characteristics consistent with a hypercoagulable profile (shorter reaction time, K value, wider angle, and maximum amplitude). Univariate logistic regression identified all TEG variables significantly associated with decreased heparin response. After adjustment for age, procedure type, and the presence of cyanosis, a multivariate logistic regression model identified the TEG variable K (≤1.3 min) as being significantly associated with decreased heparin response (odds ratio 3.7; confidence interval 2.3-5.8; p < 0.0001). CONCLUSIONS: Decreased response to heparin before cardiac surgery in patients with congenital heart disease is associated with preoperative hypercoagulability identified using a viscoelastic test. Additional studies are needed to better understand the etiology of decreased heparin response and potential clinical strategies to improve anticoagulation management.

Modified shock index and mortality rate of emergency patients.

BACKGROUND: This study aimed to determine whether modified shock index (MSI) is associated with mortality that is superior to heart rate, blood pressure, or the shock index (SI) in emergency patients. METHODS: A retrospective database review was performed on 22 161 patients who presented to Peking Union Medical College Hospital Emergency Department and received intravenous fluids from January 1 to December 31, 2009. We gathered data of the patients on age, gender, vital signs, levels of consciousness, presenting complaints, and SI and MSI were calculated for all patients. RESULTS: Multivariate regression analysis was performed to determine the correlation between risk factors and outcome. There is a significant correlation between emergency patient mortality rate and patient's vital signs obtained at the triage desk (HR>120 beats/min, systolic BP<90 mmHg, diastolic BP<60 mmHg). MSI is a stronger predictor of emergency patient mortality compared to heart rate and blood pressure alone, whereas SI does not have a significant correlation with emergency patient mortality rate. CONCLUSION: MSI is a clinically significant predictor of mortality in emergency patients. It may be better than using heart rate and blood pressure alone. SI is not significantly correlated with the mortality rate of the emergency patient.

Comparing continuation rates and side effects of hormonal contraceptives in East Asian and Caucasian women after abortion.

BACKGROUND: The purpose of this study was to determine whether East Asian women had more side effects and a higher discontinuation rate than Caucasian women when choosing to use hormonal contraceptives. STUDY DESIGN: This was an observational cohort study of usual care using questionnaires for 2 months after being given hormonal contraceptives following an abortion in Vancouver, Canada. RESULTS: In the first month, 73 (64.4%) of the 110 East Asian and 86 (80.4%) of the 107 Caucasian women took any of the sample provided (p=.020). In the second month, 52 (47.3%) of the East Asian and 62 (57%) of the Caucasian women used the prescription to buy and take their hormonal contraception (p=.12). Total side effects were similar, but there was more nausea in the East Asian women (23.3% vs. 8.1%) (p=.03) and more acne in the Caucasian women (8.2% vs. 20.9%) (p=.05). CONCLUSIONS: There may be both physiological and cultural differences leading East Asian women to use less hormonal contraception.