Red Blood Cell Transfusion Requirements Before and After Implementation of a Perioperative Patient Blood Management Program in Adult Patients Undergoing Cardiac Surgery. A Before and After Observational Study.

OBJECTIVES: Anemia and transfusion are common in cardiac surgery patients, and are associated with significant morbidity and mortality. Multiple perioperative interventions have been described to reduce blood transfusion, but are rarely combined altogether. The aim of this study was to compare the incidence of red blood cell (RBC) transfusion in adult patients undergoing cardiac surgery before and after the implementation of a perioperative patient blood management (PBM) program. DESIGN: Before-and-after observational study. SETTING: Single-center French university teaching hospital. PARTICIPANTS: Adult patients scheduled for cardiac surgery. INTERVENTIONS: Perioperative patient blood management program including pre-, intra-, and postoperative interventions aimed at identifying and correcting anemia, minimizing blood loss during surgery, and optimizing coagulation. MEASUREMENTS AND MAIN RESULTS: Four hundred thirty-four patients were included in the study from January 2021 to July 2022. The incidence of perioperative RBC transfusion (intraoperatively and during the first 2 postoperative days) was significantly reduced from 43% (90/213) in the pre-PBM period to 27% (60/221) in the post-PBM period (p < 0.001). The application of a PBM program was associated with a reduction in perioperative RBC transfusion by multivariate analysis (odds ratio 0.55, 95% CI 0.36-0.85, p = 0.007), and was associated with a reduction in the median number of RBC units transfused within transfused patients (p = 0.025). These effects persisted at day 30 after surgery (p = 0.029). CONCLUSION: A perioperative PBM program in adult patients undergoing cardiac surgery was associated with a significant reduction in perioperative RBC transfusion, which persisted at day 30.

Quantitative and sensitive detection of rare mutations using droplet-based microfluidics.

Somatic mutations within tumoral DNA can be used as highly specific biomarkers to distinguish cancer cells from their normal counterparts. These DNA biomarkers are potentially useful for the diagnosis, prognosis, treatment and follow-up of patients. In order to have the required sensitivity and specificity to detect rare tumoral DNA in stool, blood, lymph and other patient samples, a simple, sensitive and quantitative procedure to measure the ratio of mutant to wild-type genes is required. However, techniques such as dual probe TaqMan(®) assays and pyrosequencing, while quantitative, cannot detect less than ∼1% mutant genes in a background of non-mutated DNA from normal cells. Here we describe a procedure allowing the highly sensitive detection of mutated DNA in a quantitative manner within complex mixtures of DNA. The method is based on using a droplet-based microfluidic system to perform digital PCR in millions of picolitre droplets. Genomic DNA (gDNA) is compartmentalized in droplets at a concentration of less than one genome equivalent per droplet together with two TaqMan(®) probes, one specific for the mutant and the other for the wild-type DNA, which generate green and red fluorescent signals, respectively. After thermocycling, the ratio of mutant to wild-type genes is determined by counting the ratio of green to red droplets. We demonstrate the accurate and sensitive quantification of mutated KRAS oncogene in gDNA. The technique enabled the determination of mutant allelic specific imbalance (MASI) in several cancer cell-lines and the precise quantification of a mutated KRAS gene in the presence of a 200,000-fold excess of unmutated KRAS genes. The sensitivity is only limited by the number of droplets analyzed. Furthermore, by one-to-one fusion of drops containing gDNA with any one of seven different types of droplets, each containing a TaqMan(®) probe specific for a different KRAS mutation, or wild-type KRAS, and an optical code, it was possible to screen the six common mutations in KRAS codon 12 in parallel in a single experiment.