Intraoperative red blood cell transfusion, delayed graft function, and infection after kidney transplant: an observational cohort study

Development and Validation of a Risk Model to Predict Intraoperative Blood Transfusion

Importance

Crossmatched packed red blood cells (pRBC) that are not transfused result in significant waste of this scarce resource. Efficient utilization should be part of a patient blood management strategy.

Objective

To develop and validate a prediction model to identify surgical patients at high risk of intraoperative pRBC transfusion.

Design, Setting, and Participants

This prognostic study used hospital registry data from 2 quaternary hospital networks from January 2016 to June 2021 (development: Montefiore Medical Center [MMC], Bronx, New York), June 2021 to February 2023 (internal validation: MMC), and January 2008 to June 2022 (external validation: Beth Israel Deaconess Medical Center [BIDMC], Boston, Massachusetts). Participants were patients aged 18 years or older undergoing surgery.

Main Outcome and Measures

The outcome was intraoperative transfusion of 1 or more pRBC units. Based on a priori-defined candidate predictors, stepwise backward regression was applied to develop a computational model of independent predictors for intraoperative pRBC transfusion.

Results

The development and validation cohorts consisted of 816 618 patients (273 654 at MMC: mean [SD], age 57.5 [17.2] years; 161 481 [59.0%] female; 542 964 at BIDMC: mean [SD] age, 56.0 [17.1] years; 310 272 [57.1%] female). Overall, 18 662 patients (2.3%) received at least 1 unit of pRBC. The final model contained 24 preoperative predictors: nonambulatory surgery; American Society of Anesthesiologists physical status; international normalized ratio; redo surgery; emergency surgery or surgery outside of regular working hours; estimated surgical duration of at least 120 minutes; surgical complexity; liver disease; hypoalbuminemia; thrombocytopenia; mild, moderate, or severe anemia; and surgery type. The area under the receiver operating characteristic curve (AUC) was 0.93 (95% CI, 0.92-0.93), suggesting high predictive accuracy and generalizability. Positive predictive value (PPV) and negative predictive value (NPV) were 8.9% (95% CI, 8.7%-9.2%) and 99.7% (95% CI, 99.7%-99.7%), respectively, with increased predictive values for operations with a higher a priori risk of pRBC transfusion. The model's performance was confirmed in internal and external validation. The prediction tool outperformed the established Transfusion Risk Understanding Scoring Tool (AUC, 0.64 [0.63-0.64]; PPV, 2.6% [95% CI, 2.5%-2.6%]; NPV, 99.2% [95% CI, 99.1%-99.3%]) (P < .001) and was noninferior to 3 machine learning-derived scores.

Conclusions and Relevance

In this prognostic study of surgical patients, the Transfusion Forecast Utility for Surgical Events (TRANSFUSE) model for predicting intraoperative pRBC transfusion was developed and validated. The instrument can be used independently of machine learning infrastructure availability to inform preoperative pRBC orders and to minimize waste of nontransfused red blood cell units.

Trends, risk factors, and complications of blood transfusion in primary total knee arthroplasty in China: a nationwide retrospective study

INTRODUCTION

Identifying risk factors and prognosis associated with red blood cell (RBC) transfusions will be meaningful in establishing effective blood management strategies. We aimed to examine the trends, risk factors, and complications of RBC transfusions in primary total knee arthroplasty (TKA) in China.

MATERIALS AND METHODS

The Hospital Quality Monitoring System was analyzed for patients undergoing primary TKA between 2013 and 2019. Trends in RBC transfusion rates, mean volume and cost were analyzed. Risk factors for transfusion were identified using multivariable logistic regression. After propensity score matching, the effects of transfusion on complications were examined using logistic regression, with the calculation of odds ratio (OR) and 95% confidence interval (CI).

RESULTS

A total of 11,894 transfused patients and 162,349 non-transfused patients were included. Transfusion rates substantially declined from 20.0% in 2013 to 3.0% in 2019 (P for trend < 0.001), accompanied by a continuous decrease in mean volume (3.9 unit [U] to 2.9 U, P for trend < 0.001) and cost (1,021.8 Chinese Yuan [CNY] to 811.1 CNY, P for trend < 0.001) of transfusion. Risk factors for transfusion included older age (OR 1.37; 95%CI 1.24-1.51), female sex (OR 1.30; 95%CI 1.23-1.35), non-osteoarthritis indication (OR 1.57; 95%CI 1.47-1.69), preoperative anemia (OR 3.76; 95%CI 3.11-4.55), higher Charlson Comorbidity Index score (OR 1.16; 95%CI 0.99-1.36), and hospitals in central (OR 1.47; 95%CI 1.41-1.53) and west (OR 1.41; 95%CI 1.34-1.49) regions. On propensity-adjusted analyses, transfusion was associated with higher risk of 30-day readmission (OR 1.25; 95%CI 1.07-1.47) and deep vein thrombosis (OR 1.49; 95%CI 1.22-1.83), and increased costs (66,845.39 vs. 61,263.56 CNY, P < 0.001).

CONCLUSIONS

Rates, volumes, and costs of RBC transfusion in TKA have fallen substantially in China. However, several risk factors for transfusion should be recognized and appropriately managed, as RBC transfusion increased complication rates and socioeconomic burden.

Transfusion-induced HLA sensitization in wait-list patients and kidney transplant recipients

Human leukocyte antigen (HLA) sensitization remains an impediment to successful solid organ transplantation, whether it be chances of receiving a transplant offer or subsequent transplant longevity. Current treatments targeting HLA antibodies lack long-term effectiveness; therefore, preventing HLA sensitization should remain a priority in all potential wait-list candidates and transplant recipients. Recent advances in the management of anemia in patients with chronic kidney disease may reduce the need for red cell transfusions. However, data from several anemia intervention studies of novel therapeutic agents have shown that a need for transfusion will remain. It has also been increasingly recognized that blood transfusions following kidney transplantation, especially in the peri-operative period, are common. Routine data on transfusion incidence, indications, and outcomes are not captured by most kidney and transplant registries across the globe. This restricts the evidence to inform both clinicians and patients on the clinical effects of transfusion, which have been considered both an allogeneic stimulus and to be immunomodulatory.This review aims to provide an update on what is currently known about transfusion-induced HLA sensitization in wait-list candidates and transplant recipients, summarizes where evidence is lacking, and demonstrates the distinct need for patient blood management guidelines in the field of kidney transplantation.

Association between blood transfusion after kidney transplantation and risk for the development of de novo HLA donor-specific antibodies and poor clinical outcomes: A single-center retrospective study

BACKGROUND

Blood transfusion after kidney transplantation may increase the risk of sensitization and development of de novo human leukocyte antigen (HLA) donor-specific antibodies (DSAs). This study aimed to evaluate whether blood transfusion during the first year after kidney transplantation influences the development of de novo DSAs and clinical outcomes of kidney transplantation recipients.

METHODS

This retrospective cohort study included nonsensitized first-time kidney transplantation recipients at Tianjin First Central Hospital from 2010 to 2022. The incidence of de novo DSA development and clinical outcomes between the groups were compared. Luminex single antigen beads were used to monitor DSAs.

RESULTS

Of the 538 non-HLA-sensitized kidney transplantation recipients included in the study, 164 patients who received at least one unit of leukoreduced red blood cell transfusion within the first year (the transfused group), whereas the remaining 374 patients received no blood transfusion (the non-transfused group). Our analysis showed that there was a significant difference in the development of de novo DSAs and de novo anti-class I HLA-Ab between the two groups. Indeed, the transfused recipients had a higher serum creatinine and lower estimated glomerular filtration rate (eGFR) at 1-, 6-, and 12-month (all p > 0.05) after transplantation. Futhermore, a higher incidence of CMV infection, antibody-mediated rejection (AMR), hyper acute rejection (HAR), and delayed graft function (DGF) was identified in the transfused group (all p < 0.05). The graft survival was lower in the transfused group compared with patients in the non-transfused group (P = 0.002). Blood transfusion post-transplantation was a risk factor for de novo DSAs development but not an independent predictive factor for AMR and graft loss (odds ratio = 2.064 [1.243-3.429], p = 0.005).

CONCLUSIONS

Our study showed that blood transfusion after transplantation is associated with the occurrence of de novo DSAs increasing an immunological risk for poor clinical outcomes for kidney transplantation recipients.

Acute kidney injury secondary to urinary tract infection in kidney transplant recipients

Acute kidney injury (AKI) in kidney transplant recipients (KTRs) is a common, yet poorly investigated, complication of urinary tract infections (UTI) and urosepsis. A retrospective comparative analysis was performed, recruiting 101 KTRs with urosepsis, 100 KTRs with UTI, and 100 KTRs without history of UTI or sepsis. The incidences of AKI in the urosepsis and UTI groups were 75.2% and 41%, respectively. The urosepsis group has also presented with a significantly higher prevalence of AKI stage 2 and 3 than the UTI group. The rates of recovery from AKI stages 1, 2 and 3, were 75,6%, 55% and 26.1%, respectively. Factors independently associated with renal recovery from AKI were: AKI severity grade (AKI stage 2 with OR = 0.25 and AKI stage 3 with OR = 0.1), transfusion of red blood cells (RBC) (OR = 0.22), and the use of steroid bolus in the acute phase of treatment (OR = 4). The septic status (urosepsis vs UTI) did not influence the rates of renal recovery from AKI after adjustment for the remaining variables. The dominant cause of RBC transfusions in the whole population was upper GI-bleeding. In multivariable analyses, the occurrence of AKI was also independently associated with a greater decline of eGFR at 1-year post-discharge and with a greater risk of graft loss. In KTRs with both urosepsis and UTI, the occurrence of AKI portends poor transplantation outcomes. The local transfusion policy, modulation of immunosuppression and stress ulcer prophylaxis (which is not routinely administered in KTRs) in the acute setting may be modifiable factors that significantly impact long-term transplantation outcomes.

Retrospective Analysis of the Risk Factors of Perioperative Bacterial Infection and Correlation with Clinical Prognosis in Kidney Transplant Recipients

Background

Infection remains a leading cause of morbidity and mortality in kidney transplant patients. This study aimed to investigate the risk factors of bacterial infection during the perioperative period of transplantation and the effects of infection on long-term clinical outcomes.

Methods

In total, 295 kidney transplantation recipients were included in this retrospective study and assigned to two groups: non-infected and infected. The tacrolimus concentration, pharmacogenomics, laboratory parameters, and clinical outcomes of both groups were evaluated.

Results

A relatively low incidence of urinary tract infection was observed in our cohort, and lung was identified as the most frequent site of infection. Gram-negative bacteria, such as Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae, were the most common infecting strains in kidney transplant recipients. Patients with diabetes showed greater susceptibility to infection. Compared with the non-infected group, tacrolimus concentration was significantly lower on day 7 and 14 in the infected group. White blood cell count, neutrophil count, and C-reactive protein (CRP) in the infected group were markedly higher post-transplantation, while albumin levels were lower relative to the non-infected group. ABCB1 (rs2032582) genotype showed clear associations with infection. Furthermore, the incidence of delayed graft function (DGF) and early acute rejection (AR) before infection was significantly greater in the infected group. Finally, early post-transplant infection was associated with a marked increase in the incidence of AR, post-transplant diabetes mellitus (PTDM), and secondary infection.

Conclusion

Pre-diabetes, longer duration of catheterization, lower albumin, higher CRP, tacrolimus concentration on the day 7 and 14, early AR before infection, and DGF were closely related to postoperative infection in kidney transplantation recipients. Moreover, bacterial infection during the perioperative period was closely associated with AR, PTDM and secondary infection.

Blood transfusion and the risk for infections in kidney transplant patients

BACKGROUND

Receipt of a red blood cell transfusion (RBCT) post-kidney transplantation may alter immunity which could predispose to subsequent infection.

METHODS

We carried out a single-center, retrospective cohort study of 1,258 adult kidney transplant recipients from 2002 to 2018 (mean age 52, 64% male). The receipt of RBCT post-transplant (468 participants transfused, total 2,373 RBCT) was analyzed as a time-varying, cumulative exposure. Adjusted cox proportional hazards models were used to calculate hazard ratios (HR) for outcomes of bacterial or viral (BK or CMV) infection.

RESULTS

Over a median follow-up of 3.8 years, bacterial infection occurred in 34% of participants at a median of 409 days post-transplant and viral infection occurred in 25% at a median of 154 days post-transplant. Transfusion was associated with a step-wise higher risk of bacterial infection (HR 1.35, 95%CI 0.95-1.91; HR 1.29, 95%CI 0.92-1.82; HR 2.63, 95%CI 1.94-3.56; HR 3.38, 95%CI 2.30-4.95, for 1, 2, 3-5 and >5 RBCT respectively), but not viral infection. These findings were consistent in multiple additional analyses, including accounting for reverse causality.

CONCLUSION

Blood transfusion after kidney transplant is associated with a higher risk for bacterial infection, emphasizing the need to use transfusions judiciously in this population already at risk for infections.

The Impact of Intraoperative Donor Blood on Packed Red Blood Cell Transfusion During Deceased Donor Liver Transplantation: A Retrospective Cohort Study

BACKGROUND

Blood from deceased organ donors, also known as donor blood (DB), has the potential to reduce the need for packed red blood cells (PRBCs) during liver transplantation (LT). We hypothesized that DB removed during organ procurement is a viable resource that could reduce the need for PRBCs during LT.

METHODS

We retrospectively examined data on LT recipients aged over 18 y who underwent a deceased donor LT. The primary aim was to compare the incidence of PRBC transfusion in LT patients who received intraoperative DB (the DB group) to those who did not (the nondonor blood [NDB] group).

RESULTS

After a propensity score matching process, 175 patients received DB and 175 did not. The median (first-third quartile) volume of DB transfused was 690.0 mL (500.0-900.0), equivalent to a median of 3.1 units (2.3-4.1). More patients in the NDB group received an intraoperative PRBC transfusion than in the DB group: 74.3% (95% confidence intervals, 67.8-80.8) compared with 60% (95% confidence intervals, 52.7-67.3); P = 0.004. The median number of PRBCs transfused intraoperatively was higher in the NDB group compared with the DB group: 3 units (0-6) compared with 2 units (0-4); P = 0.004. There were no significant differences observed in the secondary outcomes.

CONCLUSIONS

Use of DB removed during organ procurement and reinfused to the recipient is a viable resource for reducing the requirements for PRBCs during LT. Use of DB minimizes the exposure of the recipient to multiple donor sources.

Impact of Preoperative Platelet Count on Bleeding Risk and Allogeneic Transfusion in Multilevel Spine Surgery

STUDY DESIGN

This was an observational cohort study of patients receiving multilevel thoracic and lumbar spine surgery.

OBJECTIVE

The aim of this study was to identify which patients are at high risk for allogeneic transfusion which may allow for better preoperative planning and employment of specific blood management strategies.

SUMMARY OF BACKGROUND DATA

Multilevel posterior spine surgery is associated with a significant risk for major blood loss, and allogeneic blood transfusion is common in spine surgery.

METHODS

A univariate logistic regression model was used to identify variables that were significantly associated with intraoperative allogeneic transfusion. A multivariate forward stepwise logistic regression model was then used to measure the adjusted association of these variables with intraoperative transfusion.

RESULTS

Multilevel thoracic and lumbar spine surgery was performed in 921 patients. When stratifying patients by preoperative platelet count, patients with pre-operative thrombocytopenia and severe thrombocytopenia had a significantly higher rate of transfusion than those who were not thrombocytopenic. Furthermore, those with severe thrombocytopenia had a higher rate of red blood cells, fresh frozen plasma, and platelet transfusion than those with higher platelet counts. Multivariate logistic regression found that preoperative platelet count was the most significant contributor to transfusion, with a platelet count ≤100 having an adjusted odds ratio (OR) of transfusion of 4.88 (95% confidence interval [CI] 1.58-15.02, P = 0.006). Similarly, a platelet count between 101and 150 also doubled the risk of transfusion with an adjusted OR of 2.02 (95% CI 1.01-4.04, P = 0.047). The American Society of Anesthesiologists classification score increased the OR of transfusion by 2.5 times (OR = 2.52, 95% CI 1.54-4.13), whereas preoperative prothrombin time and age minimally increased the risk.

CONCLUSION

Preoperative thrombocytopenia significantly contributes to intraoperative transfusion in multilevel thoracic lumbar spine surgery. Identifying factors that may increase the risk for transfusion could be of great benefit in better preoperative counseling of patients and in reducing overall cost and postoperative complications by implementing strategies and techniques to reduce blood loss and blood transfusions.

LEVEL OF EVIDENCE

2.

Transfusion Status in Liver and Kidney Transplantation Recipients-Results from Nationwide Claims Database

BACKGROUND

This study analyzed the status and trends of transfusion and its associated factors among liver and kidney transplantation recipients.

METHODS

A total of 10,858 and 16,191 naïve liver or kidney transplantation recipients from 2008 to 2017 were identified through the National Health Insurance Service database. The prescription code for transfusion and the presence, number, and amount of each type of transfusion were noted. The odds ratios and 95% confidence intervals were determined to identify significant differences in transfusion and blood components by liver and kidney transplantation recipient characteristics.

RESULTS

In this study, 96.4% of liver recipients and 59.7% of kidney recipients received transfusions related to the transplantation operation, mostly platelet and fresh frozen plasma. Higher perioperative transfusion in women and declining transfusion rates from 2008 to 2017 were observed in both liver and kidney recipients. In liver recipients, the transfusion rate in those who received organs from deceased donors was much higher than that in those who received organs from living donors; however, the mortality rate according to transfusion was higher only in recipients of deceased donor organs. In kidney recipients, a higher mortality rate was observed in those receiving transfusion than that in patients without transfusion.

CONCLUSIONS

In Korea, the transfusion rates in liver and kidney recipients were relatively higher than those in other countries. Sociodemographic factors, especially sex and year of transplantation, were associated with transfusion in solid organ recipients, possibly as surrogates for other causal clinical factors.

Perioperative Allogeneic Red Blood Cell Transfusion and Wound Infections: An Observational Study

BACKGROUND

It remains unclear whether the benefits of performing perioperative allogeneic red blood cell (RBC) transfusion outweigh the risks of postoperative wound infection. The aim of this study was to assess the impact of perioperative RBC transfusion as well as dose-response relationship on wound infections in surgical patients in a large cohort.

METHODS

As a retrospective observational study, the national Hospital Quality Monitoring System database was used to retrieve information about in-hospital surgical patients without limitations on surgical types in the People's Republic of China between 2013 and 2018. Patients were divided into the perioperative RBC transfusion and non-RBC transfusion groups, and wound infection rates (the primary end point) were compared. Secondary end points included in-hospital mortality, nosocomial infections, and length of hospital stay. Furthermore, patients who underwent RBC transfusion were subdivided into 6 groups based on the volume of transfused RBCs to investigate the dose-response relationship between RBC transfusions and wound infections. The association between RBC transfusion and patient outcomes were analyzed using multivariable logistic regression models adjusted for potential confounders.

RESULTS

A total of 1,896,584 patients from 29 provinces were included, among whom 76,078 (4.0%) underwent RBC transfusions; the overall wound infection rate was 0.7%. After adjusting for confounding factors, perioperative RBC transfusion was associated with higher odds of wound infection (odds ratio [OR] = 2.24, 95% confidence interval [CI], 2.09-2.40; P < .001). As the volume of transfused RBCs increased, so did the odds of wound infection with a clear dose-response relationship (OR of >0 and ≤1 U, >1 and ≤2 U, >2 and ≤4 U, >4 and ≤8 U, >8 U transfusion compared with no RBC transfusion were 1.20, 95% CI, 0.76-1.91; 1.27, 95% CI, 1.10-1.47; 1.70, 95% CI, 1.49-1.93; 2.12, 95% CI, 1.83-2.45 and 3.65, 95% CI, 3.13-4.25, respectively). RBC transfusion was also found to be associated with higher odds of in-hospital mortality, nosocomial infection, and longer hospital stay.

CONCLUSIONS

RBC transfusion was associated with an increased odd of postoperative wound infection in surgical patients, and a significant dose-related relationship was also observed. While there are still essential confounders not adjusted for and the results do not necessarily indicate a causal relationship, we still recommend to lessen perioperative blood loss and optimize blood conservation strategies.