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IntroductionSystemic anticoagulation (AC) is standard practice in extracorporeal membrane oxygenation (ECMO). Adults on ECMO have been successfully managed AC-free. However, slower flow rates in pediatric circuits have mostly prevented this strategy. Thus, ECMO is often avoided in children with intractable hemorrhage.Case ReportA 12-year-old female with microscopic polyangiitis was admitted with diffuse alveolar hemorrhage and acute on chronic renal failure requiring venovenous (VV)-ECMO and continuous kidney replacement therapy (CKRT). Systemic AC was withheld entirely, and the CKRT circuit was regionally anticoagulated with citrate. High ECMO flow rates and positioning of the CKRT return line pre-oxygenator enabled an effective AC-free VV-ECMO run of 15 days.DiscussionThis highlights an innovative approach to a rare but successful pediatric VV-ECMO run without systemic AC in conjunction with regional AC for CKRT.ConclusionAlterations to ECMO circuitry including high flow rates and regional anticoagulation may liberalize candidacy for children with hemorrhage.

A 44-year-old male with pulmonary sarcoidosis related interstitial lung disease and pulmonary hypertension was admitted for pre-transplant evaluation. During hospitalization, he developed cardiac arrest due to worsening respiratory failure and was immediately placed on veno-arterial (VA) extracorporeal membrane oxygenation (ECMO). Despite initial improvement, he developed differential oxygenation, which was managed by converting the support to veno-venoarterial (VVA) ECMO. However, pulmonary artery pressure increased, placing a greater load on the right ventricle, and oxygenation remained inadequate, leading to further optimization of the ECMO settings. The support was switched to veno-pulmoarterial (VPA) ECMO, which improved oxygenation and, through the combined effects of oxygenation and circulatory support, stabilized his condition. After 24 days of ECMO support, the patient underwent successful lung transplantation. His postoperative course was uncomplicated, and he was discharged on postoperative day 32. Over the subsequent 2 years of follow-up, he has remained active, independent of oxygen, and free of functional limitations.

Introduction: Complex aortic surgery involving Jehovah's Witness patients presents a significant challenge due to their refusal of blood products.Case report: This case report details the management of a 50-year-old female Jehovah's Witness with anaemia and a low body surface area, undergoing an urgent ascending aorta and hemi-arch replacement for a type A dissection. A broad range of blood conservation strategies were utilised in order to preserve haematocrit and clotting factors.Conclusions: This report highlights the importance of careful planning, team collaboration, and the meticulous application of blood conservation techniques in achieving a favourable postoperative outcome.

BackgroundA gap in knowledge exists related to optimal bivalirudin dosing in children. The purpose of our analysis is to use quantitative methods and baseline data to quickly predict the optimal therapeutic bivalirudin dose for children.MethodsWe developed an internal database of pediatric patients on ECMO or VAD, including baseline patient information, bivalirudin doses, and partial thromboplastin time (PTT) measurements throughout the treatment period. We fit an analysis of covariance (ANCOVA) model to the baseline data to determine the best predictors of therapeutic bivalirudin dose. We used five-fold cross-validation to ensure the model was not overfitting to any specific data subset.ResultsThe most notable variables that were statistically significant (p < .05) were: the primary use of bivalirudin for heart failure prophylaxis, no complications before bivalirudin administration, other reasons for bivalirudin use, other race (including Asian, pacific islander, and native American), Hispanic or Latinx ethnicity, primary diagnosis of heart failure, and primary diagnosis of myocarditis. To compare our model-predicted dose and the actual starting dose administered to the patients, we looked at how far off each of those was from the therapeutic dose. The mean of absolute differences was 0.28 mg/kg/hr for the administered starting dose and 0.23 mg/kg/hr for the model-predicted dose; therefore, the model results in an improvement of 18% in the difference from the therapeutic dose.ConclusionOur model provides an initial framework for determining a starting bivalirudin dose that takes into account patient demographic information and baseline admission data.

BackgroundAnticoagulation in pediatric extracorporeal membrane oxygenation (ECMO) presents unique challenges due to developmental hemostasis, coagulation factor production, and response to anticoagulants. This process requires close monitoring to prevent bleeding and thrombotic events. Limited data exist on how traditional coagulation tests correlate with these complications in this population in the first 24 h after ECMO cannulation.MethodsThis institutional review board-approved retrospective review was conducted on 126 children requiring ECMO between January 2017 and March 2022. Pre- and post-cannulation partial thromboplastin time (PTT), prothrombin time (PT), international normalized ratio (INR), hemoglobin, platelet count, and fibrinogen were collected. Also measured were initial activated clotting time (ACT), time to reach target ACT post-heparin bolus (≤250 s), initial unfractionated heparin (UFH) infusion rate, and post-cannulation antithrombin III activity (ATIII).ResultsCompared to those who did not experience complications, patients who experienced bleeds showed a longer time until target ACT was reached (p = 0.003), prolonged post-cannulation PT and INR (p = 0.002 for both), lower pre- and post-cannulation fibrinogen levels (p = 0.008 and p = <0.001, respectively), and lower post-cannulation platelet counts (p = 0.035). However, those who experienced thrombotic complications showed only higher pre-cannulation fibrinogen levels (p = 0.017).ConclusionsOur data shows that fibrinogen is an important parameter which defines the risk of early bleeding or thrombotic complications during the first 24 hours of ECMO cannulation. Attention to these baseline and immediate post-cannulation laboratory values may be important to determine initial bolus dosing and adjustment of anticoagulation in these patients. Continued multi-center collaboration to determine the utility of incorporation of other coagulation studies, like anti-factor Xa and viscoelastic assays, is needed.

IntroductionHeparin is usually added to infant cardiopulmonary bypass circuit primes. Ultrafiltration is often used to minimise prime volume before commencing bypass. The extent of heparin removal from bypass primes by ultrafiltration is unknown, however at our institution it was assumed that heparin is freely filtered. The primary aim of this study was to investigate heparin removal during pre-bypass ultrafiltration of a bypass prime for infants. The secondary aim was to investigate the effect of pre-bypass ultrafiltration on heparinization of the patient shortly after commencing bypass.MethodsPatients under 1 year of age having cardiopulmonary bypass were enrolled. Prime solutions contained red blood cells, albumin, PlasmaLyte and 3 IU/ml heparin prior to pre-bypass ultrafiltration. Patient blood samples were collected before and after commencing bypass along with samples of the filtrate and the priming solution. Anti-Xa and antithrombin levels were measured by chromogenic assay.ResultsNineteen patients were enrolled. Patient weight ranged from 2.4 kg to 7.7 kg. Anti-Xa in the filtrate was 0.94 IU/ml (IQR 0.84 to 1.06 IU/ml). Anti-Xa in the primes was 6.80 IU/ml (IQR 6.68 to 7.84 IU/ml). Anti-Xa once on bypass was 3.31 IU/ml (IQR 2.08 to 4.46 IU/ml). Antithrombin level on bypass was 38 % (IQR 26 to 57 %). On bypass anti-Xa level was associated with patient weight and antithrombin level but not with activated clotting time.ConclusionsHeparin is not freely filtered from the prime, leading to more heparin being present in the prime than desired. Anti-Xa levels on commencing bypass appear to be predictably influenced by hemodilution such that the gap between total heparin present and anti-Xa activity is wider in smaller patients. The activated clotting time does not differentiate lower levels of anti-Xa activity in the setting of extreme haemodilution.

IntroductionIn patients with prior valve replacement requiring venoarterial extracorporeal membrane oxygenation (VA ECMO), there is a risk of prosthetic valve thrombosis (PVT) due to intracardiac stasis. We describe our experience with PVT in patients on VA ECMO.MethodsThis was a retrospective cohort study of patients with prior valve replacement undergoing VA ECMO. Patients who developed PVT on VA ECMO were compared to those who did not.ResultsForty-six patients who had prior valve replacement (total of 63 valves) were placed on VA ECMO. Six patients (13%) suffered PVT on VA ECMO. There was no difference in the rate of PVT in mitral versus aortic valve prostheses (22% [5/23] vs 3% [1/32]; p = .07) or between tissue and mechanical valves (16% [8/50] vs 0% [0/13]; p = .19). There were no differences in ECMO parameters, including site of cannulation (central vs peripheral), initial ECMO flow, time to initiation of anticoagulation, or use of a concomitant IABP between patients who did and did not develop PVT. Patients who developed PVT demonstrated significantly lower pulse pressures compared to those who did not (12.7 mmHg vs 32.7 mmHg; p = .03). Surgical thrombectomy was performed in three of the six patients with PVT and one survived to discharge.ConclusionPVT occurred in 13% of patients on VA ECMO after prior valve replacement. The only predictor of PVT on VA ECMO was a lower pulse pressure. Strategies to maintain intracardiac flow and pulsatility may reduce this risk. Treatment options are limited and pose significant risk, and therefore prevention is key.

IntroductionBlood transfusions during paediatric cardiac surgery with (cardiopulmonary bypass) CPB carry increased risks, including infection and immunological complications. This study evaluates blood product use in the Clinic for Paediatric Cardiology and Cardiac Surgery at the Children's University Hospital following the implementation of a revised blood management protocol from 2020 to 2023.MethodsA retrospective review of 135 paediatric patients who underwent congenital cardiac surgery with CPB was conducted. Patients were categorized into three age groups: Group 1 (<1 year), Group 2 (1 - 4 years), and Group 3 (>4 years). Data on erythrocyte, fresh frozen plasma (FFP), cryoprecipitate, and platelet use were analysed using the Kruskal-Wallis and Spearman's rho tests, with significance set at p < .05, and confidence interval (CI) of 95% quoted when applicable.ResultsErythrocyte use significantly declined over 4 years, with the largest reductions observed from 2020 to 2023 [p < .0001]. Older and heavier patients required fewer transfusions, with a significant inverse correlation between weight and erythrocyte use [Spearman's rho = -0.29, p = .001]. Platelet use also decreased significantly from 2020 to 2023 [p = .04], while FFP and cryoprecipitate use declined notably over the same period [p < 0.01].ConclusionOver 4 years, significant reductions in blood product use were observed, particularly for erythrocytes and platelets. Patients' age and weight were inversely related to erythrocyte transfusion needs. These trends may reflect improvements in surgical techniques and blood management protocols, with potential benefits for patient outcomes.

The use of extracorporeal membrane oxygenation (ECMO) to support the pregnant patient and fetus requires a complex decision-making process. Peripartum ECMO requires coordinated and informed decision-making between an interdisciplinary team of experts, incorporating the unique considerations and, at times, competing physiologic priorities of the pregnant patient. It is often confounded by a scarcity of local relevant experience engendered by its rare occurrence. No event has made the need for an organized approach to the utilization of ECMO in pregnant patients more pressing than the COVID pandemic. The conditions affecting pregnant patients that warrant ECMO consideration are high stakes and, at times, ethically challenging, although outcomes are favourable compared to the general population. This review provides background information and context, followed by a practical approach to the care and specific medical management of patients who are facing life-threatening conditions warranting ECMO while pregnant.