There is no dose-response relationship between allogeneic blood transfusion and healthcare-associated infection: a retrospective cohort study

Structural optimization and prospect of constructing hemoglobin oxygen carriers based on hemoglobin

The current global shortage of organ resources, the imbalance in donor-recipient demand and the increasing number of high-risk donors make organ preservation a necessity to consider appropriate storage options. The current method of use often has risks such as blood group mismatch, short shelf life, and susceptibility. HBOCs have positive effects such as anti-apoptotic, anti-inflammatory, antioxidant and anti-proliferative, which have significant advantages in organ storage. Therefore, it is the common pursuit of researchers to design and synthesize HBOCs with safety, ideal oxygen-carrying capacity, easy storage, etc. that are widely applicable and optimal for different organs. There has been a recent advancement in understanding HBOCs mechanisms, which is discussed in this review.

Red Blood Cell Transfusion and Postoperative Infection in Patients Having Coronary Artery Bypass Grafting Surgery: An Analysis of the Society of Thoracic Surgeons Adult Cardiac Surgery Database

BACKGROUND

Coronary artery bypass grafting (CABG) is the most common cardiac surgical procedure in the world and up to one-third of patients are transfused red blood cells (RBCs). RBC transfusion may increase the risk for health care-associated infection (HAI) after CABG, but previous studies have shown conflicting results and many did not establish exposure temporality. Our objective was to explore whether intraoperative RBC transfusion is associated with increased odds of postoperative HAI. We hypothesized that intraoperative RBC transfusion would be associated with increased odds of postoperative HAI.

METHODS

We performed an observational cohort study of isolated CABG patients in the Society of Thoracic Surgeons adult cardiac surgery database from July 1, 2017, to June 30, 2019. The exposure was intraoperative RBC transfusion modeled as 0, 1, 2, 3, or 4+ units. The authors focused on intraoperative RBC transfusion as a risk factor, because it has a definite temporal relationship before postoperative HAI. The study's primary outcome was a composite HAI variable that included sepsis, pneumonia, and surgical site infection (both deep and superficial). Mixed-effects modeling, which controlled for hospital as a clustering variable, was used to explore the relationship between intraoperative RBC transfusion and postoperative HAI.

RESULTS

Among 362,954 CABG patients from 1076 hospitals included in our analysis, 59,578 patients (16.4%) received intraoperative RBCs and 116,186 (32.0%) received either intraoperative or postoperative RBCs. Risk-adjusted odds ratios for HAI in patients who received 1, 2, 3, and 4+ intraoperative RBCs were 1.11 (95% confidence interval [CI], 1.03-1.20; P = .005), 1.13 (95% CI, 1.05-1.21; P = .001), 1.15 (95% CI, 1.04-1.27; P = .008), and 1.14 (95% CI, 1.02-1.27; P = .02) compared to patients who received no RBCs.

CONCLUSIONS

Intraoperative RBC transfusion is associated with a small increase in odds of HAI in CABG patients. Future studies should explore whether reductions in RBC transfusion can also reduce HAIs.

Hemoglobin-Based Oxygen Carriers: Potential Applications in Solid Organ Preservation

Ameliorating graft injury induced by ischemia and hypoxia, expanding the donor pool, and improving graft quality and recipient prognosis are still goals pursued by the transplant community. The preservation of organs during this process from donor to recipient is critical to the prognosis of both the graft and the recipient. At present, static cold storage, which is most widely used in clinical practice, not only reduces cell metabolism and oxygen demand through low temperature but also prevents cell edema and resists apoptosis through the application of traditional preservation solutions, but these do not improve hypoxia and increase oxygenation of the donor organ. In recent years, improving the ischemia and hypoxia of grafts during preservation and repairing the quality of marginal donor organs have been of great concern. Hemoglobin-based oxygen carriers (HBOCs) are “made of” natural hemoglobins that were originally developed as blood substitutes but have been extended to a variety of hypoxic clinical situations due to their ability to release oxygen. Compared with traditional preservation protocols, the addition of HBOCs to traditional preservation protocols provides more oxygen to organs to meet their energy metabolic needs, prolong preservation time, reduce ischemia–reperfusion injury to grafts, improve graft quality, and even increase the number of transplantable donors. The focus of the present study was to review the potential applications of HBOCs in solid organ preservation and provide new approaches to understanding the mechanism of the promising strategies for organ preservation.