The Pandemic Allocation of Ventilators Model Penalizes Infants with Bronchopulmonary Dysplasia.

During the COVID-19 pandemic, institutions developed ventilator allocation models. In one proposed model, neonates compete with adults for ventilators using a scoring system. Points are given for conditions that increase one- and five-year (y) mortality. For example, comparable points were added for adult conditions with mortality of 71.3% and for neonates with moderate or severe bronchopulmonary dysplasia (mod/sBPD). We hypothesized that this model overestimates mortality in neonates with BPD and would penalize these infants unfairly. There was little information available on 1 y and 5 y mortality risk for mod/sBPD. To evaluate this allocation protocol, a retrospective chart review was performed on infants born ≥22 weeks and weighing <1500 g admitted to Rainbow Babies and Children's Hospital in 2015 to identify babies with BPD. The main outcomes were 1 and 5 y mortality. In 2015, 28 infants were diagnosed with mod/s BPD based on NIH 2001 definition; 4 infants had modBPD and 24 had sBPD. All infants (100%) with modBPD survived to 5 y; 2 infants with sBPD died by 1 y (8%) and 22 survived (92%) to 1 y; 3 died (12.5%) by 5 y; and at least 13 survived (54%) to 5 y. Infants with mod/s BPD had lower-than-predicted 1 and 5 y mortality, suggesting the points assigned in the model are too high for these conditions. We believe this model would unfairly penalize these babies.

In Vitro Evaluation of the Fresenius Kabi CATSmart Autotransfusion System.

Use of autotransfusion systems to collect, wash, and concentrate shed blood during surgical procedures is a widely used method for reducing postoperative anemia and the need for blood transfusions. The aim of this study was to evaluate the CATSmart Continuous Autotransfusion System wash program performance with small (200 or 700 mL) and large volumes (1,000 mL) of shed blood and to determine non-inferiority of the CATSmart to the C.A.T.S plus system. Human whole blood was collected in citrate phosphate dextrose, diluted, and divided into two aliquots to be processed as a pair using the C.A.T.S plus and CATSmart systems with their corresponding wash programs: low-volume, high quality/smart, or emergency wash. Final packed red cell product was analyzed for red blood cell (RBC), white blood cell, and platelet counts; hemoglobin; hemolysis; RBC recovery rates; and elimination of albumin, total protein, and potassium. The mean hematocrit (HCT) after processing with CATSmart and C.A.T.S plus systems were 59.63% and 57.71%, respectively. The calculated overall RBC recovery rates on the CATSmart and C.A.T.S plus systems were 85.41% and 84.99%, respectively. Elimination of albumin (97.5%, 98.0%), total proteins (97.1%, 97.5%), and potassium (92.1%, 91.9%) were also calculated for the CATSmart and C.A.T.S plus systems. The CATSmart and C.A.T.S plus systems both provided a high-quality product in terms of HCT, protein elimination, and hemolysis rates across the range of tested shed blood volumes and all wash programs. The study was able to confirm the CATSmart is non-inferior to the C.A.T.S plus system.

Reduced use of allogeneic platelets through high-yield perioperative autologous plateletpheresis and reinfusion.

BACKGROUND: Intraoperative autologous platelet (PLT) collection as part of a multimodal blood conservation program carries a Class IIa recommendation from the Societies of Thoracic Surgeons and Cardiovascular Anesthesiologists, but achieving a suitable PLT yield limits its application. A novel, autologous, intraoperative, high-yield plateletpheresis collection program was established and retrospectively analyzed to identify potential improvements over previously reported plateletpheresis protocols. STUDY DESIGN AND M-ETHODS: Targeting complex cardiothoracic surgery patients without recent anti-PLT agents, thrombocytopenia, or severe anemia, the program aimed to achieve a PLT yield of at least one standard apheresis unit (3.0 × 10(11) ) within 60 to 90 minutes and using an automated plateletpheresis device (Trima, Terumo BCT). Anesthetized and invasively monitored patients underwent plateletpheresis via a large-bore, indwelling central line placed for the surgery. Collection-related data for quality control purposes and subsequent PLT transfusion requirements were analyzed and reported. RESULTS: Forty-two patients donated autologous PLTs between 2011 and 2012. PLT yield was 4.5 (3.9-5.0) × 10(11) , which significantly exceeds previously reported yields, and procedure duration was 53.2 (48.4-57.9) minutes. As anticipated, postcollection PLT count decreased from 268 (242-293) × 10(9) to 182 (163-201) × 10(9) /L; hypocalcemia was minimized by infusion of 1 g of CaCl2 . Autologous PLT yield was inversely correlated with allogeneic PLT use, and avoidance of allogeneic PLT transfusion was increased when the autologous yield was the equivalent of 2 or more apheresis units. CONCLUSION: High-yield, intraoperative autologous PLT collection is achievable using an automated plateletpheresis device. Initial experience shows a reduction in reliance on allogeneic PLTs for complex cardiothoracic surgery.

Triboelectric charging and dissipation characteristics of the Maquet Quadrox-D membrane oxygenator.

Triboelectric charging is commonly detected during cardiopulmonary bypass in circuits using roller pumps and PVC tubing. Dissipation of this charging is needed to prevent a spontaneous discharge from occurring. We evaluated the ability of the Quadrox-D (Maquet) to effectively remove the electrostatic charge accumulation, with and without a heater/cooler connection (H/C). A Quadrox-D oxygenator was evaluated using a Stockert SIII pump head, Cincinnati subzero H/E, and a custom adult extracorporeal membrane oxygenation tubing pack with 1/2" PVC raceway. The circuit was primed and evaluated for triboelectric accumulation with and without H/C use. The results showed a linear relationship between increasing pump flow and static charge buildup when an H/C was not applied. The calculated r2 value was .95. Incorporation of the H/C effectively eliminated charge accumulation. Increasing pump speed increases the amount of static charge created without the use of an H/C. Incorporation of an H/C effectively eliminates charge build-up in the Quadrox-D and is recommended while priming the circuit.

Identification of small molecule antagonists of the human mas-related gene-X1 receptor.

The recently identified mas-related-gene (MRG) family of receptors, located primarily in sensory neurons of the dorsal root ganglion, has been implicated in the perception of pain. Thus, antagonists of this class of receptors have been postulated to be useful analgesics. Toward this end, we developed a cell-based beta-lactamase (BLA) reporter gene assay to identify small molecule antagonists of the human MRG-X1 receptor from a library of compounds. Single-cell clones expressing functional receptors were selected using the BLA reporter gene technology. The EC50 for the MRG agonist peptide, BAM15, appeared to be comparable between the BLA assay and the intracellular Ca2+ transient assays in these cells. Ultra high-throughput screening of approximately 1 million compounds in a 1.8-microl cell-based BLA reporter gene assay was conducted in a 3456-well plate format. Compounds exhibiting potential antagonist profile in the BLA assay were confirmed in the second messenger Ca2+ transient assay. A cell-based receptor trafficking assay was used to further validate the mechanism of action of these compounds. Several classes of compounds, particularly the 2,3-disubstituted azabicyclo-octanes, appear to be relatively potent antagonists at the human MRG-X1 receptors, as confirmed by the receptor trafficking assay and radioligand binding studies. Furthermore, the structure-activity relationship reveals that within this class of compounds, the diphenylmethyl moiety is constant at the 2-substituent, whereas the 3-substituent is directly correlated with the antagonist activity of the compound.

Miniaturization of whole live cell-based GPCR assays using microdispensing and detection systems.

Cell-based beta-lactamase reporter gene assays designed to measure the functional responses of G-protein-coupled receptors (GPCRs) were miniaturized to less than 2 microL total assay volume in a 3456-well microplate. Studies were done to evaluate both receptor agonists and antagonists. The pharmacology of agonists and antagonists for target GPCRs originally developed in a 96-well format was recapitulated in a 3456-well microplate format without compromising data quality or EC(50)/IC(50) precision. These assays were employed in high-throughput screening campaigns, allowing the testing of more than 150,000 compounds in 8 h. The instrumentation used and practical aspects of the assay development are discussed.