Traumatic respiratory failure and veno-venous extracorporeal membrane oxygenation support.

BACKGROUND: Respiratory failure (RF) is a common cause of death and morbid complication in trauma patients. Extracorporeal membrane oxygenation (ECMO) is increasingly used in adults with RF refractory to invasive mechanical ventilation. However, use of ECMO remains limited for this patient population as they often have contraindications for anticoagulation. STUDY DESIGN: Medical records were retroactively searched for all adult patients who were admitted to the trauma service and received veno-venous ECMO (VV ECMO) support between June 2015 and August 2018. Survival to discharge and ECMO-related complications were collected and analyzed. RESULTS: Fifteen patients from a large Level I trauma center met the criteria. The median PaO2/FiO2 ratio was 53.0 (IQR, 27.0-76.0), median injury severity score was 34.0 (IQR, 27.0-43.0), and the median duration of ECMO support was 11 days (IQR, 7.5-20.0). For this cohort, the survival-to-discharge rate was 87% (13/15). The incidence of neurologic complications was 13%, and deep vein thrombosis was reported in two cases (13%). CONCLUSIONS: Survival rates of trauma patients in this study are equivalent to, or may exceed, those of non-trauma patients who receive ECMO support for other types of RF. With the employment of a multidisciplinary team assessment and proper patient selection, early cannulation, traumatic RF may be safely supported with VV ECMO in experienced centers.

Utilization of therapeutic plasma exchange for hyperbilirubinemia in a premature newborn on extracorporeal membrane oxygenation.

BACKGROUND: We report a case of a premature newborn girl with a hospital course complicated by suspected respiratory syncytial virus pneumonitis for which she was placed on veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Despite phototherapy, her total bilirubin steadily increased to a peak of 50.4 mg/dL with concern for bilirubin-induced neurologic dysfunction, kernicterus. STUDY DESIGN AND METHODS: Therapeutic plasma exchange (TPE) was achieved via connection with the VA-ECMO circuit. Our institution's standard apheresis procedural parameters were adjusted to account for the small body weight and thus the low blood volume of the neonate while on ECMO. These included calculating the total blood volume to include the patient as well as the ECMO circuit, priming of the apheresis instrument with packed red blood cells to limit the extracorporeal volume, using a lower inlet flow rate, the connection setup of the inlet and return line, and monitoring of ionized calcium and anticoagulation throughout the procedure. RESULTS: A total of three TPE procedures were performed over three consecutive days. This resulted in improvement and stabilization of the patient's bilirubin. CONCLUSION: This case emphasizes that TPE is feasible on a neonate with a suboptimal body weight and thus a low blood volume due to the increased blood volume provided while on ECMO. In the absence of ECMO, whole blood manual exchange transfusion is recommended as TPE would be unsafe due to significant extracorporeal volume that would occur during TPE in a pediatric patient with low body weight.

Successful management of severe red blood cell alloimmunization in pregnancy with a combination of therapeutic plasma exchange, intravenous immune globulin, and intrauterine transfusion.

BACKGROUND: Antibodies to Rhesus and Kell antigens have been associated with severe hemolytic disease of the fetus and newborn (HDFN) necessitating intrauterine transfusion (IUT) of red blood cells (RBCs). We report a case series of five women with severe HDFN secondary to maternal RBC alloimmunization who were successfully managed with therapeutic plasma exchange (TPE), intravenous immune globulin (IVIG), and IUT. STUDY DESIGN AND METHODS: This is a retrospective case series of five women with severe HDFN who underwent a total of three TPE procedures during Weeks 10 to 13 of pregnancy, followed by weekly IVIG infusions. They were followed with serial middle cerebral artery peak systolic velocity studies beginning at 16 weeks' gestation to detect fetal anemia. For IUT, fetuses were administered RBC units that fully matched the maternal phenotype to D, C, E, K, Fy, Jk, and S antigen groups. The delivery outcomes and newborn information were followed. RESULTS: Anti-D and anti-K alloantibodies were implicated in HDFN. A two- to fourfold dilution reduction in anti-D and anti-K titers was observed after TPE. IUT was initiated between 21 to 27 weeks' gestation. The total number of IUTs for each patient ranged from four to seven. All five women delivered healthy infants at 33 to 38 weeks' gestation. CONCLUSION: A combined regimen of TPE and IVIG early in pregnancy and IUT later in pregnancy results in successful management of severe maternal RBC alloimmunization and HDFN. IUT with fully phenotypically matched RBC units may help prevent further RBC alloimmunization in complex cases of HDFN.

How do we manage cardiopulmonary bypass coagulopathy?

BACKGROUND: Patients who undergo cardiopulmonary bypass (CPB) are at risk for coagulopathy. Suboptimal turnaround time (TAT) of laboratory coagulation testing results in empiric administration of blood products to treat massive bleeding. We describe our initiative in establishing the coagulation-based hemotherapy (CBH) service, a clinical pathology consultation service that uses rapid TAT coagulation testing and provides comprehensive assessment of bleeding in patients undergoing CPB. A transfusion algorithm that treats the underlying cause of coagulopathy was developed. STUDY DESIGN AND METHODS: The coagulation testing menu includes all aspects of coagulopathy with close proximity of the laboratory to the operating room to allow for rapid test results. The hemotherapy pathologist monitors laboratory results at several stages in surgery and uses a comprehensive algorithm to monitor a patient's hemostasis. The optimal number and type of blood products are selected when the patient is taken off CPB. RESULTS: The CBH service was consulted for 44 ventricular assist device implants, 30 heart transplants, and 31 other cardiovascular surgeries from May 2012 through November 2013. The TAT for laboratory tests was 15 minutes for complete blood count, antithrombin, and coagulation panel and 30 minutes for VerifyNow and thromboelastography, in comparison to 45 to 60 minutes in normal settings. The transfusion algorithms were used with optimal administration of blood components with preliminary data suggestive of reduced blood product usage and better patient outcomes. CONCLUSION: We described the successful introduction of a novel pathology consultation service that uses a rapid TAT coagulation testing menu with transfusion algorithms for improved management of CPB patients.

Aortic root repair in a patient with acquired hemophilia A: case report.

BACKGROUND: Patients with acquired hemophilia A (AHA) who require open heart surgery have a life-threatening risk of hemorrhage. Limited data exist to guide perioperative management of these patients. CASE PRESENTATION: A 53-year-old female with rheumatoid arthritis, concomitant aortic valve endocarditis, and severe aortic regurgitation presented to our hospital. Bleeding and abnormal coagulation tests were noted during the initial workup, and she was diagnosed with AHA. The perioperative management plan included the use of pharmaceuticals, porcine recombinant factor VIII, and blood products. Extensive preoperative coagulation data were obtained, and factor VIII levels were continuously monitored to mitigate bleeding complications. The aortic valve replacement and root repair were uneventful. CONCLUSION: Cardiac surgery in patients with AHA is possible as long as complex perioperative hemostatic and hematology management is used.

New Onset Iron Deficiency Anemia in Chronic Therapeutic Plasma Exchange Patients.

Iron deficiency has been recognized as a complication of whole blood and red blood cell apheresis donation; however, the effect of chronic therapeutic plasma exchange (TPE) on patient iron status is largely unknown. We performed a retrospective review of all patients undergoing chronic TPE (at least 1 TPE every 2 weeks for 1 month with a minimum of 8 TPE treatments) with 5% albumin at our institution from 2011 to 2016. After review of serum iron level and iron saturation status, six out of ten (60%) of the patients who meet the study criteria were found to develop iron deficiency anemia (IDA). This data supports the notion that chronic TPE, especially when combined with additional risk factors, can increase the risk of IDA.

A Case of Suspected Streptococcus Pneumoniae Hemolytic Uremic Syndrome (pHUS) with Utilization of Minor Crossmatching for Platelet Blood Products Lead to a Diagnosis of Atypical Hemolytic Uremic Syndrome (aHUS).

BACKGROUND: The action of bacterial neuraminidase of Streptococcus pneumoniae (SPN) results in exposure of the normally "hidden" Thomsen-Freidenreich antigen (T-antigen) found on erythrocytes and other tissues. This may lead to SPN-induced hemolytic uremic syndrome (pHUS) with subsequent hemolysis and end organ damage. pHUS can be identified by minor crossmatch incompatibility. We present a case of suspected pHUS that resulted in a compatible minor crossmatch which led to concern and eventually diagnosis of atypical HUS (aHUS). DESIGN: A 6-month-old boy presented with respiratory failure. He was found to have blood cultures positive for SPN. Shiga toxin was negative and he had normal levels of ADAMTS 13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13). The clinical team was concerned for pHUS and requested washed platelet product prior to a surgical procedure. Alternatively, a minor crossmatching was performed to determine the presence of T activation. An aHUS genetic panel was performed to sequence and analyze 12 genes encoding complement factors. RESULTS: Minor crossmatch was performed using the patient's erythrocytes and plasma of ABO-identical platelets to be transfused. No agglutination was seen at immediate spin, 37°C, or anti-human globulin phase with valid controls. Genetics testing for complement mutations was consistent with aHUS. CONCLUSIONS: We present a case that is clinically consistent with pHUS. Confirmation of this entity is done with lectins or anti-sera that are not readily available. An alternative means of identifying pHUS is by demonstrating minor crossmatch incompatibility. By doing so, we excluded the possibility of pHUS and helped to elucidate a definitive diagnosis of aHUS. Our goal is to share our experience of a practical approach in a time-sensitive situation that other clinical pathologists could utilize in suspected cases of T activation with a clinical picture of thrombotic microangiopathy.

Can Tranexamic Acid Reduce Blood Loss during Major Cardiac Surgery? A Pilot Study.

We examined the effectiveness of tranexamic acid in preventing intraoperative blood loss during major cardiac surgery. Out of initial 81 patients undergoing major cardiac surgery (both coronary artery bypass and valve repair procedures) at our teaching hospital, sixty-seven patients were selected for this study. We compared estimated blood loss, decrease in percent hemoglobin and hematocrit following surgery between two groups of patients (none of them received any blood product during surgery), one group receiving no tranexamic acid (n=17) and another group receiving tranexamic acid (n=25). In the second study, we combined these patients with patients receiving modest amounts of blood products (1-2 unit) and compared these parameters between two groups of patients (25 patients received no tranexamic acid, 42 patients received tranexamic acid). In patients who received no blood product during surgery, those who received no tranexamic acid showed statistically significant (independent t-test two tailed at p<0.05) reduced estimated blood loss (mean: 713.5 mL, SD: 351.6, n=17) compared to those who received tranexamic acid (mean: 987.2 mL, SD: 459.9, n=25). We observed similar results when the patients receiving no blood products and patients receiving modest amount of blood products were combined based on the use of tranexamic acid or not. No statistically significant difference was observed in percent reduced hemoglobin or hematocrit following surgery in any group of patients. We conclude that intraoperative antifibrinolytic therapy with tranexamic acid does not reduce intraoperative blood loss during major cardiac surgery which contradicts popular belief.

Intra-Pericardial Use of Recombinant Factor VIIa in a Patient With Acute Hemorrhagic Pericardial Effusion Following Transcutaneous Aortic Valve Replacement-A Case Report.

Perioperative bleeding can be a serious life-threatening complication in adult patients undergoing cardiac surgery, given the older age and additional comorbidities present in this patient population. The standard treatment options include transfusion of blood components and surgical re-exploration. We report the first case of an elderly female patient treated with local administration of recombinant factor VIIa (rFVIIa) for intractable hemorrhagic pericardial effusion, which developed following a transcutaneous aortic valve replacement (TAVR) procedure for severe aortic stenosis. No thromboembolic phenomena or adverse effects were observed. Local administration of rFVIIa is an efficacious treatment option for cardiac surgery patients as opposed to systemic administration of rFVIIa, use of massive blood products, or surgical re-exploration.

Post-operative bleeding risk stratification in cardiac pulmonary bypass patients using artificial neural network.

The prediction of bleeding risk in cardiopulmonary bypass (CPB) patients plays a vital role in their postoperative management. Therefore, an artificial neural network (ANN) to analyze intra-operative laboratory data to predict postoperative bleeding was set up. The JustNN software (Neural Planner Software, Cheshire, England) was used. This ANN was trained using 15 intra-operative laboratory parameters paired with one output category - risk of bleeding, defined as units of blood components transfused in 48 hours. The ANN was trained with the first 39 CPB cases. The set of input parameters for this ANN was also determined, and the ANN was validated with the next 13 cases. The set of input parameters include five components: pro-thrombin time, platelet count, thromboelastograph-reaction time, D-Dimer, and thromboelastograph-coagulation index. The validation results show 9 cases (69.2%) with exact match, 3 cases (23.1%) with one-grading difference, and 1 case (7.7%) with two-grading difference between actual blood usage versus predicted blood usage. To the best of our knowledge, ours is the first ANN developed for post-operative bleeding risk stratification of CPB patients. With promising results, we have started using this ANN to risk-stratify our CPB patients, and it has assisted us in predicting post-operative bleeding risk.