Risks and predictors of blood transfusion in pediatric patients undergoing open heart operations

Red blood cell transfusion management for people undergoing cardiac surgery for congenital heart disease

BACKGROUND

Congenital heart disease is the most common neonatal congenital condition. Surgery is often necessary. Patients with congenital heart disease are potentially exposed to red cell transfusion preoperatively, intraoperatively and postoperatively when admitted for cardiac surgery. There are a number of risks associated with red cell transfusion that may increase morbidity and mortality.

OBJECTIVES

To evaluate the association of red blood cell transfusion management with mortality and morbidity in people with congenital heart disease who are undergoing cardiac surgery.

SEARCH METHODS

We searched multiple bibliographic databases and trials registries, including the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), Embase (Ovid), CINAHL (EBSCOhost), Transfusion Evidence Library, ClinicalTrials.gov and the World Health Organization (WHO) ICTRP. The most recent search was on 2 January 2024, with no limitation by language of publication.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing red blood cell transfusion interventions in patients undergoing cardiac surgery for congenital heart disease. Participants of any age (neonates, paediatrics and adults) and with any type of congenital heart disease (cyanotic or acyanotic) were eligible for inclusion. No comorbidities were excluded.

DATA COLLECTION AND ANALYSIS

Two of five (AA, CK, KW, SB, SF) review authors independently extracted data and assessed the risk of bias in the trials. We contacted study authors for additional information. Two review authors (CK, KW) used GRADE methodology to assess evidence certainty for critical outcomes and comparisons.

MAIN RESULTS

We identified 19 relevant trials. The trials had 1606 participants, all of whom were neonates or children. No trials were conducted in the preoperative period or with adults. The trials compared different types of red blood cell transfusions. No trial compared red blood cell transfusion versus no red blood cell transfusion. None of the trials was at low risk of bias overall. Eight trials had a high risk of bias in at least one domain, most commonly, blinding of participants and personnel. For our critical outcomes, we judged the certainty of the evidence based on GRADE criteria to be low or very low. Five trials (497 participants) compared a restrictive versus a liberal transfusion-trigger. It is very uncertain whether a restrictive transfusion-trigger has an effect on all-cause mortality in the short-term (0 to 30 days post-surgery) (risk ratio (RR) 1.12, 95% confidence interval (CI) 0.42 to 3.00; 3 RCTs, 347 participants; very low certainty evidence) or long term (31 days to two years post-surgery) (RR 0.33, 95% CI 0.01 to 7.87; 1 RCT, 60 participants; very low certainty evidence). The evidence is also very uncertain on the incidence of severe adverse cardiac events (RR 1.00, 95% CI 0.73 to 1.37; 2 RCTs, 232 participants) and infection (RR 0.81, 95% CI 0.47 to 1.39; 2 RCTs, 232 participants) (both very low certainty evidence). A restrictive transfusion-trigger may have little to no effect on the duration of mechanical ventilation (mean difference (MD) -1.65, 95% CI -3.51 to 0.2; 2 RCTs, 168 participants; low-certainty evidence) or of ICU stay (MD 0.15, 95% CI -0.72 to 1.01; 3 RCTs, 228 participants, low-certainty evidence). Five trials (231 participants) compared washed red blood cells in CPB prime versus unwashed red blood cells in CPB prime. Washing red blood cells in CPB prime may have little to no effect on all-cause mortality in the short term (0 to 30 days post-surgery) (RR 0.25, 95% CI 0.03 to 2.18; 2 RCTs, 144 participants) or long term (31 days to 2 years post-surgery) (RR 0.50, 95% CI 0.05 to 5.38; 1 RCT, 128 participants) (both low-certainty evidence). The evidence is very uncertain about the effect of washed CPB prime on severe cardiac adverse events (RR 0.88, 95% CI 0.47 to 1.64), infection (RR 1.00, 95% CI 0.50 to 1.99) and duration of ICU stay (MD -0.3, 95% CI -4.32 to 3.72) (1 RCT, 128 participants; very low certainty evidence). Two trials (76 participants) compared crystalloid (bloodless) CPB prime versus red-blood-cell-containing CPB prime. It is very uncertain whether bloodless prime has an effect on the duration of mechanical ventilation (median 8.0 hours, interquartile range (IQR) 6.8 to 9.0 hours versus median 7.0 hours, IQR 6.0 to 8.0 hours; 1 RCT, 40 participants) or duration of ICU stay (median 23.0 hours, IQR 21.8 to 41.5 hours versus median 23.5 hours, IQR 21.0 to 29.0 hours; 1 RCT, 40 participants) (both very low certainty evidence). Two trials (160 participants) compared ultrafiltration of CPB prime versus no ultrafiltration. It is very uncertain whether ultrafiltration of CPB prime has an effect on all-cause mortality in the short term (0 to 30 days post-surgery) (RR not estimable; 1 RCT, 50 participants; very low certainty evidence). Ultrafiltration may reduce the duration of mechanical ventilation (MD -16.00, 95% CI -25.00 to -7.00) and the duration of ICU stay (MD -0.6, 95% CI -0.84 to -0.36) (1 RCT, 50 participants; low-certainty evidence). One trial (59 participants) compared retrograde autologous CPB prime versus standard CPB prime. It is very uncertain whether retrograde autologous CPB prime has an effect on the duration of mechanical ventilation (MD 0.02, 95% CI -0.03 to 0.07) or duration of ICU stay (MD 0, 95% CI -0.01 to 0.01) (1 RCT, 59 participants; very low certainty evidence). One trial (178 participants) compared 'fresh' (not near expiry date) versus 'old' (near expiry date) red blood cell transfusion but did not report on our outcomes.

AUTHORS' CONCLUSIONS

No randomised controlled trial compared red blood cell transfusion against no red blood cell transfusion in people with congential heart disease undergoing cardiac surgery. There are only small, heterogeneous trials in children that compare different forms of red blood cell transfusion, and there are no trials at all in adults. There is therefore insufficient evidence to accurately assess the association of red blood cell transfusion with the morbidity and mortality of patients with congenital heart disease undergoing cardiac surgery. It is possible that trial outcomes are affected by the presence or absence of cyanosis, so this should be considered in future trial design. Further adequately powered, high-quality trials in both children and adults are required.

Safety of bloodless open-heart surgery on cardiopulmonary bypass in selected children: A single center experience with minimal invasive extracorporeal circulation

INTRODUCTION

Bloodless cardiac surgery refers to open-heart surgery without blood or blood products. The cardiopulmonary bypass (CPB) circuits are primed with crystalloid solely, and there is no intraoperative blood transfusion.

METHODS

Our program considers bloodless congenital cardiac surgery with a minimal invasive extracorporeal circulation (MiECC) system for patients above 10 kg of weight. We performed a single-center retrospective cohort study of all consecutive patients undergoing bloodless cardiac surgery for congenital heart defects between January 2016 and December 2018.

RESULTS

A total of 164 patients were reviewed (86 male and 78 female) at a median age of 9.6 years (interquartile range (IQR), 4.5-15), a weight of 32 kg (IQR, 16-55), preoperative hemoglobin 13.7 g/dl (IQR, 12.6-14.9), and preoperative hematocrit of 40.4% (IQR, 37.2-44.3). Median CPB time was 81.5 min (IQR, 58-125), and median hematocrit coming off CPB was 26% (IQR, 23-29.7). The congenital heart surgery risk (STAT) category was distributed in STAT 1 for 70, STAT 2 for 80, STAT 3 for 9, and STAT 4 for 5 patients. Most patients (95%) were extubated in the operating room with a low complication rate during the hospital stay (14.6%). Only 6 (4%) patients needed a blood transfusion during the postoperative period, with a higher incidence of complications during the hospital course (p < 0.001).

CONCLUSIONS

Bloodless congenital heart surgery with MiECC system is safe in low-surgical-risk patients. Our patients had a low rate of complications and short hospital stays.

Impact of Phlebotomy Volume Knowledge on Provider Laboratory Ordering and Transfusion Practices in the Pediatric Cardiac ICU

OBJECTIVES

Phlebotomy can account for significant blood loss in post-surgical pediatric cardiac patients. We investigated the effectiveness of a phlebotomy volume display in the electronic medical record (EMR) to decrease laboratory sampling and blood transfusions. Cost analysis was performed.

DESIGN

This is a prospective interrupted time series quality improvement study. Cross-sectional surveys were administered to medical personnel pre- and post-intervention.

SETTING

The study was conducted in a 19-bed cardiac ICU (CICU) at a Children's hospital.

PATIENTS

One hundred nine post-surgical pediatric cardiac patients weighing 10 kg or less with an ICU stay of 30 days or less were included.

INTERVENTIONS

We implemented a phlebotomy volume display in the intake and output section of the EMR along with a calculated maximal phlebotomy volume display based on 3% of patient total blood volume as a reference.

MEASUREMENTS AND MAIN RESULTS

Providers poorly estimated phlebotomy volume regardless of role, practice setting, or years in practice. Only 12% of providers reported the availability of laboratory sampling volume. After implementation of the phlebotomy display, there was a reduction in mean laboratories drawn per patient per day from 9.5 to 2.5 ( p = 0.005) and single electrolytes draw per patient over the CICU stay from 6.1 to 1.6 ( p = 0.016). After implementation of the reference display, mean phlebotomy volume per patient over the CICU stay decreased from 30.9 to 14.4 mL ( p = 0.038). Blood transfusion volume did not decrease. CICU length of stay, intubation time, number of reintubations, and infections rates did not increase. Nearly all CICU personnel supported the use of the display. The financial cost of laboratory studies per patient has a downward trend and decreased for hemoglobin studies and electrolytes per patient after the intervention.

CONCLUSIONS

Providers may not readily have access to phlebotomy volume requirements for laboratories, and most estimate phlebotomy volumes inaccurately. A well-designed phlebotomy display in the EMR can reduce laboratory sampling and associated costs in the pediatric CICU without an increase in adverse patient outcomes.

Association of preoperative monocyte/lymphocyte ratio with postoperative oxygenation impairment in patients with acute aortic syndrome

BACKGROUND

Postoperative oxygenation impairment represents a common complication in patients with the acute aortic syndrome (AAS). The study aimed to explore the relationship between inflammatory indicators and AAS patients with oxygenation impairment after operation.

METHODS

In this study, 330 AAS patients who underwent surgery were enrolled and divided into 2 groups based on postoperative oxygenation impairment (non-oxygenation impairment group and oxygenation impairment group). Regression analysis was performed to assess the relationship between inflammatory indicators and postoperative oxygenation impairment. A smooth curve and interaction analysis were further conducted. Stratified analysis was used according to preoperative monocyte/lymphocyte ratio (MLR) (Tertiles).

RESULTS

Multivariate analysis showed that preoperative MLR was independently related to oxygenation impairment after surgery in AAS patients (OR, 95% CI, P: 2.77, 1.10-7.00, 0.031). The smooth curve indicated the risk of postoperative oxygenation impairment was higher with the elevated preoperative MLR. Interaction analysis revealed that patients with AAS with high preoperative MLR who had coronary artery disease (CAD) had a higher risk of oxygenation impairment after operation. Moreover, stratified analysis was performed according to baseline MLR (Tertiles), and a higher baseline MLR level in AAS patients was correlated with a lower arterial oxygen tension (P_aO2) / inspiratory oxygen fraction (F_iO2) ratio perioperatively.

CONCLUSIONS

In AAS patients, preoperative MLR level was independently related to postoperative oxygenation impairment.

Blood Transfusion is Associated With Adverse Outcomes in Pediatric Solid Tumor Oncology Patients Following Tumor Resection

BACKGROUND

Packed red blood cell (PRBC) transfusion is a lifesaving intervention that also has proinflammatory and immunosuppressive effects. Adults with a malignancy who receive PRBC transfusion have increased rates of infection, tumor recurrence, and decreased survival. The effect of PRBC transfusion among children with solid tumors is unknown.

METHODS

We performed a retrospective review of all children who underwent operative resection of a solid tumor malignancy. Data collected included demographic information, location of operation, nadir hemoglobin, and any PRBC transfusion within 30 days of tumor resection.

RESULTS

Three hundred sixty children underwent tumor resection at our institution between 2002 and 2013; 194 (54%) received a perioperative blood transfusion. After adjusting for stage at diagnosis, tumor location, preoperative chemotherapy and nadir hemoglobin, blood transfusion was associated with a higher rate of postoperative infectious complications, shorter disease-free interval, and a higher rate of tumor recurrence. Each additional transfused unit increased the risk of postoperative infection (odds ratio 3.83; 95% confidence interval 1.21, 14.22, P =0.031).

CONCLUSIONS

Among children with solid tumor malignancies, PRBC transfusion within 30 days of operation is associated with higher rates of postoperative infection. If transfusion becomes necessary, single unit increments should be transfused.

LEVEL OF EVIDENCE

Level III.

Intraoperative blood product transfusion in pediatric cardiac surgery patients: A retrospective review of adverse outcomes

BACKGROUND

Resuscitation with blood products is often required for pediatric cardiac surgery patients following cardiopulmonary bypass. However, data suggest that blood product transfusion is an independent predictor of adverse outcomes. Most studies have specifically found detrimental effects of overall transfusion of red blood cells in particular, but few have analyzed outcomes by the other specific blood product components.

AIMS

The objective of this study is to analyze adverse outcomes associated with intraoperative transfusion of specific blood product components.

METHODS

A retrospective review was performed on 643 pediatric patients who underwent cardiac surgery requiring cardiopulmonary bypass to evaluate the risk of selected adverse outcomes associated with intraoperative blood product transfusion. Adverse outcomes included thrombotic complications, stroke, acute kidney injury, prolonged mechanical ventilation, and death. Univariate logistic and linear regression analyses were performed to explore the association between various blood products and the occurrence of postoperative complications. Multiple logistic and linear regression analyses were performed adjusting for age, cyanotic status, The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Score (STAT score), and cardiopulmonary bypass time.

RESULTS

Unadjusted analysis using univariate logistic and linear regressions showed statistically significant associations of almost all blood components (per 10 mL/kg dose increments) with multiple postoperative complications, including mortality, thrombotic complications, stroke, and days of mechanical ventilation. After adjusting for patient age, cyanotic status, STAT score, and cardiopulmonary bypass time, multivariable logistic and linear regression analyses revealed no association between transfusion of blood products with acute kidney injury and stroke. Administration of red blood cells was the only category significantly correlated with increased days of mechanical ventilation (0.5 days increase in mechanical ventilation per 10 mL/kg transfusion of red blood cells). The only blood product to show complete lack of a statistically significant association with any of the studied outcomes was cryoprecipitate.

CONCLUSIONS

Transfusion of blood products following cardiopulmonary bypass is associated with postoperative adverse outcomes. Future studies aimed at strategies to reduce intraoperative bleeding and decrease the amount of blood products administered are warranted.

A Surgeon's Perspective on Blood Conservation Practice in Pediatric Cardiac Surgery

Blood conservation practice in pediatric cardiac surgery has not been consistently adopted as quality improvement in many centers despite known risks associated with allogeneic blood products, shortage of donors, and costs. There are many blood conservation strategies available which collectively minimize exposure to allogeneic transfusion by maximizing the use of autologous red cells. These strategies are safe, reproducible, and have been implemented in clinical practice collectively with great efficacy for all patient ages and complexity levels. Institutional commitment to a set guideline will improve their blood conservation practice and quality outcome. The purpose of this article is to provide early career and practicing congenital cardiac surgeons with practical information concerning blood conservation strategies which can be considered for implementation in any pediatric cardiac surgery program, and which may be of particular value in resource-limited programs.

Preoperative Iron Deficiency Is Associated With Increased Blood Transfusion in Infants Undergoing Cardiac Surgery

Background

Iron deficiency (ID) is common in patients undergoing cardiac surgery, which is associated with adverse outcomes. However, the relevance of ID in congenital heart disease is still unclear. This study aimed to investigate the characteristics of preoperative ID and its association with clinical outcomes in infants undergoing cardiac surgery with cardiopulmonary bypass.

Methods

In this retrospective study, 314 patients undergoing cardiac surgery were assigned into three groups according to their preoperative ID status. Absolute ID was defined by serum ferritin <12 μg/L, and functional ID was defined by serum ferritin level at 12–30 μg/L and transferrin saturation <20%. Baseline characteristics were compared between groups and multiple logistic regression was used to identify predictors for ID. The association between ID and clinical outcomes, including allogenic blood transfusion requirements, was also evaluated.

Results

Among the 314 patients included, 32.5% were absolute ID and 28.7% were functional ID. Patients with absolute ID were more often of higher weight, cyanotic heart disease, and anemia. The presence of absolute ID was associated with an increase in postoperative blood transfusion (OR 1.837, 95% CI 1.016–3.321, p = 0.044). There was no significant difference in postoperative morbidity, mortality, and the length of hospital stay.

Conclusions

Absolute ID was associated with preoperative anemia and cyanotic heart disease, and was an independent risk factor for postoperative blood transfusion. Further research should better explore the definition of ID and its impact on outcomes in pediatric cardiac surgery.

No Difference in the Incidence of Complications in Pediatric Patients with Moderate Anemia 30 Days after Pediatric Hip Surgery with and without Blood Transfusion

This study investigated the association between postoperative blood transfusion and the incidence of postoperative complications 30 days after pediatric hip surgery as well as factors significantly associated with 30-day postoperative complications. Patients were divided into two groups: those with postoperative complications and those with no complications. Postoperative hematocrit (Hct) was categorized as <25%, 25–30%, and >30%. Comparison was made between all postoperative complications at the 30-day follow-up that were influenced by anemia in patients who received transfusion and those who did not. A multivariate logistic regression model was used to identify factors independently associated with postoperative complications. The overall 30-day postoperative complication rate for all patients was 17% (24/138). No significant difference between the transfusion and the non-transfusion patients was found. Preoperative hematocrit (Hct) was significantly lower in the complications group (p = 0.030), and both length of stay and 30-day readmission were significantly higher in patients with complications (p = 0.011 and p < 0.001, respectively). Multivariate analysis revealed female gender (OR: 3.50, 95% CI: 1.18–10.36; p = 0.026) and length of hospital stay (OR: 1.23, 95% CI: 1.08–1.41; p = 0.004) to be factors independently associated with 30-day postoperative complications. However, no statistically significant difference in the incidence of complications at 30 days following pediatric hip dysplasia surgery was found between patients who received blood transfusion to maintain a Hct level ≥25% and those not receiving transfusion.

Plasma and Platelet Transfusions Strategies in Neonates and Children Undergoing Cardiac Surgery With Cardiopulmonary Bypass or Neonates and Children Supported by Extracorporeal Membrane Oxygenation: From the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding

OBJECTIVES

To present the recommendations and consensus statements with supporting literature for plasma and platelet transfusions in critically ill neonates and children undergoing cardiac surgery with cardiopulmonary bypass or supported by extracorporeal membrane oxygenation from the Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding.

DESIGN

Systematic review and consensus conference of international, multidisciplinary experts in platelet and plasma transfusion management of critically ill children.

SETTING

Not applicable.

PATIENTS

Critically ill neonates and children following cardiopulmonary bypass or supported by extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A panel of nine experts developed evidence-based and, when evidence was insufficient, expert-based statements for plasma and platelet transfusions in critically ill neonates and children following cardiopulmonary bypass or supported by extracorporeal membrane oxygenation. These statements were reviewed and ratified by the 29 Transfusion and Anemia EXpertise Initiative-Control/Avoidance of Bleeding experts. A systematic review was conducted using MEDLINE, EMBASE, and Cochrane Library databases, from inception to December 2020. Consensus was obtained using the Research and Development/University of California, Los Angeles Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method. We developed one good practice statement, two recommendations, and three expert consensus statements.

CONCLUSIONS

Whereas viscoelastic testing and transfusion algorithms may be considered, in general, evidence informing indications for plasma and platelet transfusions in neonatal and pediatric patients undergoing cardiac surgery with cardiopulmonary bypass or those requiring extracorporeal membrane oxygenation support is lacking.

Transfusion Practices in Pediatric Cardiac Surgery Requiring Cardiopulmonary Bypass: A Secondary Analysis of a Clinical Database

OBJECTIVES

To describe blood component usage in transfused children with congenital heart disease undergoing cardiopulmonary bypass surgery across perioperative settings and diagnostic categories.

DESIGN

Datasets from U.S. hospitals participating in the National Heart, Lung, and Blood Institute Recipient Epidemiology and Donor Evaluation Study-III were analyzed.

SETTING

Inpatient admissions from three U.S. hospitals from 2013 to 2016.

PATIENTS

Transfused children with congenital heart disease undergoing single ventricular, biventricular surgery, extracorporeal membrane oxygenation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Eight hundred eighty-two transfused patients were included. Most of the 185 children with single ventricular surgery received multiple blood products: 81% RBCs, 79% platelets, 86% plasma, and 56% cryoprecipitate. In the 678 patients undergoing biventricular surgery, 85% were transfused plasma, 75% platelets, 74% RBCs, and 48% cryoprecipitate. All 19 patients on extracorporeal membrane oxygenation were transfused RBCs, plasma, and cryoprecipitate, and 18 were transfused platelets. Intraoperatively, patients commonly received all three components, while postoperative transfusions were predominantly single blood components. Pretransfusion hemoglobin values were normal/low-normal for age for all phases of care for single ventricular surgery (median hemoglobin 13.2-13.5 g/dL). Pretransfusion hemoglobin values for biventricular surgeries were higher intraoperatively compared with other timing (12.2 g/dL vs 11.2 preoperative and postoperative; p < 0.0001). Plasma transfusions for all patients were associated with a near normal international normalized ratio: single ventricular surgeries median international normalized ratio was 1.3 postoperative versus 1.8 intraoperative and biventricular surgeries median international normalized ratio was 1.1 intraoperative versus 1.7 postoperative. Intraoperative platelet transfusions with biventricular surgeries had higher median platelet count compared with postoperative pretransfusion platelet count (244 × 109/L intraoperative vs 69 × 109/L postoperative).

CONCLUSIONS

Children with congenital heart disease undergoing cardiopulmonary bypass surgery are transfused many blood components both intraoperatively and postoperatively. Multiple blood components are transfused intraoperatively at seemingly normal/low-normal pretransfusion values. Pediatric evidence guiding blood component transfusion in this population at high risk of bleeding and with limited physiologic reserve is needed to advance safe and effective blood conservation practices.

Cell Saver Blood Reinfusion Up to 24 Hours Post Collection in Pediatric Cardiac Surgical Patients Does Not Increase Incidence of Hospital-Acquired Infections or Mortality

Cell saver blood reinfusion, a blood conservation technique recently available for pediatric use, is typically limited to 6 hours post processing to guard against bacterial contamination. We hypothesize that reinfusion of cell saver blood up to 24 hours post collection in children after cardiac surgery will not increase the incidence of hospital-acquired infections (HAI). The primary aim is to compare incidence of HAI between children receiving cell saver blood ≤6 hours vs. >6 to ≤24 hours from its collection. The secondary aim is to compare mortality and clinical outcomes. Retrospective chart review of children ≤18 years undergoing cardiac surgery with cardiopulmonary bypass (CPB) from 2013 to 2018 when cell saver collection and bedside temperature controlled storage became standard of care. Patients on extracorporeal membrane oxygenation (ECMO) within 48 hours postoperatively and those who did not receive cell saver were excluded. The primary outcome was HAI incidence postoperative days 0-6. Demographic data included diagnosis, surgical severity score, and clinical outcomes. 466 patients, 45% female. No significant between-group differences identified. There was no significant difference in HAI (control 8.5% vs. treatment 8.0%, p = .80) and death (control 7.9% vs. treatment 4.9%, p = .20). Noninferiority testing indicated the treatment group was not statistically inferior to the control group (p = .0028). Kaplan-Meier curve depicted similar status between-group rates of no infection or death; 92% treatment vs. 91% control. Total volume allogeneic red blood cell transfusion (allogeneic blood transfusion [ABT]) up to 24 hours postoperatively was significantly less in the treatment group, p < .0001. Incidence of HAI or mortality was not increased in patients receiving cell saver blood reinfusion >6 to ≤24 hours post collection. Treatment subjects received significantly less volume of ABT. Considering the risks of ABT, these findings support cell saver blood reinfusion up to 24 hours post collection.

Preoperative heart failure is not associated with impaired coagulation in paediatric cardiac surgery

OBJECTIVE

The objectives of the present study were to determine whether there was any association between the grade of heart failure, as expressed by preoperative levels of brain natriuretic peptide and Ross score, and the preoperative coagulation status in patients with non-restrictive ventricular shunts and determine whether there were any postoperative disturbances of the coagulation system in these patients, as measured by thromboelastometry and standard laboratory analyses of coagulation.

DESIGN

Perioperative coagulation was analysed with laboratory-based coagulation tests and thromboelastometry before, 8 hours after, and 18 hours after cardiac surgery. In addition, brain natriuretic peptide was analysed before and 18 hours after surgery.

PATIENTS

40 children less than 12 months old with non-restrictive congenital ventricular or atrio-ventricular shunts scheduled for elective repair of their heart defects.

RESULTS

All coagulation parameters measured were within normal ranges preoperatively. There was a significant correlation between brain natriuretic peptide and plasma fibrinogen concentration preoperatively. There was no statistically significant correlation between brain natriuretic peptide and INTEM-MCF, FIBTEM-MCF, plasma fibrinogen, activated partial thromboplastin time, prothrombin time, or platelet count at any other time point, either preoperatively or postoperatively. Postoperatively, fibrinogen plasma concentration and FIBTEM-MCF decreased significantly at 8 hours, followed by a large increase at 18 hours to higher levels than preoperatively.

CONCLUSIONS

There was no evidence of children with non-restrictive shunts having coagulation abnormalities before cardiac surgery. Brain natriuretic peptide levels or Ross score did not correlate with coagulation parameters in any clinically significant way.

Preoperative Anemia and Outcomes After Corrective Surgery in Neonates With Dextro-Transposition of the Great Arteries

OBJECTIVES

The authors aimed to assess whether untreated preoperative anemia was associated with increased risk for adverse outcomes after the arterial switch operation in neonates with dextro-transposition of the great arteries (d-TGA).

DESIGN

Retrospective cohort study.

SETTING

Single cardiac surgery center.

PARTICIPANTS

Eighty-two newborns with d-TGA.

INTERVENTIONS

The authors categorized the cohort into the following two groups: the infants with preoperative anemia group (defined as a hematocrit <0.40 L/L) and the control group.

MEASUREMENTS AND MAIN RESULTS

Preoperative anemia was diagnosed in 21 (25.6%) infants. Anemic infants received intraoperative red blood cell transfusions significantly more often than controls (81.0% v 34.4%, p < 0.001). No differences were observed in the incidence of adverse events, duration of hospitalization (median 27 days v 26 days, p = 0.881), and mortality (0% v 4.9%, p = 0.566). Postnatal hematocrit was the only variable independently associated with preoperative anemia in multivariate logistic regression analysis (unit odds ratio, 0.832; 95% confidence interval, 0.743-0.931; p = 0.001).

CONCLUSIONS

Untreated preoperative anemia was not associated with adverse outcomes in neonates undergoing reparative surgery for d-TGA.

Transfusion Strategies for Pediatric Cardiac Surgery: A Meta-Analysis and Trial Sequential Analysis

This study aimed to compare the effects of restrictive and liberal red blood cell (RBC) transfusion strategies on pediatric patients undergoing cardiac surgery, including cyanotic and non-cyanotic children. A literature search of the MEDLINE, EMBASE, PubMed, and the Cochrane Library database was conducted. Meta-analyses were carried out comparing restrictive and liberal transfusion strategies. Subgroup analyses were performed based on the basis of cyanotic status. Five randomized controlled trials with a total of 497 children were included. There was no significant difference in the risk of in-hospital mortality between the two transfusion strategies (risk ratio 1.21; 95% confidence interval 0.49 to 2.99; P = 0.68). The trial sequential analysis suggested that the current meta-analysis had an absence of evidence for in-hospital mortality, and the data were insufficient. Moreover, no significant differences existed between groups in terms of risk of infection, blood loss, duration of mechanical ventilation, pediatric intensive care unit (PICU) stay duration, or hospital stay duration. Cyanotic children treated with a liberal transfusion strategy had a shorter ventilator duration, but the transfusion strategy did not affect in-hospital mortality, infection, hospital stay, or PICU stay duration. On the basis of the available data, our analysis indicates that a liberal transfusion strategy did not lead to a better outcomes, but the data are extremely sparse, which highlights the need for clearer transfusion guidelines specific to this specific population.Trial registration number CRD42018102283.

Bleeding in Critically Ill Children-Review of Literature, Knowledge Gaps, and Suggestions for Future Investigation

Clinically significant bleeding complicates up to 20% of admissions to the intensive care unit in adults and is associated with severe physiologic derangements, requirement for significant interventions and worse outcome. There is a paucity of published data on bleeding in critically ill children. In this manuscript, we will provide an overview of the epidemiology and characteristics of bleeding in critically ill children, address the association between bleeding and clinical outcomes, describe the current definitions of bleeding and their respective limitations, and finally provide an overview of current knowledge gaps and suggested areas for future research.

Randomized Pilot Trial of Acute Normovolemic Hemodilution in Pediatric Cardiac Surgery Patients

BACKGROUND

Due to the substantial improvement in survival among pediatric patients undergoing congenital heart surgery, reducing early and long-term morbidity is becoming the major focus of care. Blood transfusion is associated with worse postoperative outcomes after cardiac surgery. Acute normovolemic hemodilution (ANH) is a blood conservation strategy that aims to reduce allogenic blood transfusion during cardiac surgery. However, there are scant data regarding its efficacy for pediatric cardiac surgery patients.

METHODS

We designed a single-center, controlled, randomized, pilot trial in patients between 6 and 36 months old undergoing pediatric heart surgery. Patients were equally assigned to undergo ANH prior to initiation of cardiopulmonary bypass or to be managed per usual care. The primary end point was the amount of blood product transfused perioperatively. Secondary end points were markers of morbidity: postoperative bleeding, hematocrit, inotropic agents use, intensive care unit, and hospital stay. The analysis was by intention-to-treat. Estimates of differences between groups are presented with 95% CIs.

RESULTS

Twelve pediatric heart surgery patients were randomized to each group, ANH and usual care. Baseline characteristics were similar between groups. Acute normovolemic hemodilution implementation did not result in a reduction in the administration of blood product transfused (difference between ANH and usual care among patients transfused = -1.4 mL [-29.4 to 26.6], P = .92). Secondary end points were not different between groups.

CONCLUSIONS

In this small trial of pediatric cardiac surgery patients, ANH as a strategy to reduce blood component therapy was safe; however, the study failed to show a reduction in perioperative transfusion or other postoperative outcomes.

Are Blood Products Routinely Required in Pediatric Heart Surgery?

A restrictive blood transfusion strategy has emerged in adult cardiac surgery. However, the feasibility in children is poorly investigated. 352 consecutive patients undergoing open-heart surgery were retrospectively reviewed, excluding patients requiring extracorporeal membrane oxygenation. Patient demographics, perioperative blood product usage, and clinical outcome parameters were investigated. Variables predicting the need for blood products were delineated. Of the 352 study patients, 148 patients (42%) underwent bloodless surgery and 204 (58%) were transfused. Of the 204 transfused patients, 170 (83.4%) patients received one blood transfusion and 34 (16.6%) received two or more blood transfusions. Patient's weight and preoperative hematocrit (Hct) were statistically significant in predicting the need for blood priming the CPB circuit (AUC 0.99, p < 0.001, sensitivity 96.6%, specificity 95.2%). A body weight of 8.5 kg carried a sensitivity of 100% and specificity of 94.5% (p < 0.001) for a blood prime. Among patients with a weight less than 8.5 kg (n = 171), only 27 patients (15.8%, p < 0.001) required additional transfusion of PRBCs. Factors impacting the need for a blood transfusion during CPB included redo surgery [odds ratio (OR) 4.61, p = 0.001] and the highest lactate level on CPB (OR 1.65, p = 0.006). Redo surgery had the highest impact (OR 7.27, p = 0.012) for requiring a postoperative PRBC transfusion. A restrictive transfusion strategy can be safely implemented in pediatric cardiac surgery. The majority of children with a BW > 8.5 kg required no blood products and those with a BW ≤ 8.5 kg required only 1 unit of blood, to prime the cardiopulmonary bypass circuit.

Risk Factors Associated With Allogenic Blood Transfusion in Primary Infant Cranial Vault Remodeling

INTRODUCTION

Cranial vault remodeling is commonly associated with high blood loss and high transfusion rates. Blood management protocols have recently been developed to minimize blood loss and reduce transfusion requirements. We sought to determine risk factors associated with blood product transfusion for infants undergoing primary cranial vault remodeling after the implementation of a blood management protocol.

METHODS

A retrospective review of patients who underwent cranial vault remodeling at a single center was performed. Patients under 18 months of age who underwent cranial vault remodeling after the establishment of a blood management protocol were included.

RESULTS

Thirty-five patients were identified. Eleven patients (31%) received allogenic blood transfusions. Patients who received allogenic blood transfusions had a lower absolute weight (8.8 kg versus 9.6kg P = 0.04), longer procedure times (337 minutes versus 275 minutes P < 0.01), and were more likely to have undergone fronto orbital advancement (91% versus 46% P = 0.02). There were no significant differences in age, weight percentile, and patient diagnosis between patients who received allogenic blood transfusions and those that did not (P > 0.05).

CONCLUSION

Low weight, longer operative times, and fronto orbital advancement are associated with allogenic blood transfusion despite the use of a blood management protocol. Attempts to modify these factors may further improve outcomes.

Post-operative blood loss is higher among African American neonates undergoing open-heart surgery with cardiopulmonary bypass for CHD

BACKGROUND

Neonates are at high risk of bleeding after open-heart surgery. We sought to determine pre-operative and intra-operative risk factors for increased bleeding after neonatal open-heart surgery with cardiopulmonary bypass.

METHODS

We conducted a retrospective cohort study of neonates (0-30 days old) who underwent open-heart surgery with cardiopulmonary bypass from January, 2009, to March, 2013. Cardiac diagnosis; demographic and surgical data; and blood products, haemostatic agents, and anti-thrombotic agents administered before, during, and within 24 hours after surgery were abstracted from the electronic health record and anaesthesia records. The outcome of interest was chest tube output (in ml/kg body weight) within 24 hours. Relationships between chest tube output and putative associated factors were evaluated by unadjusted and adjusted linear regression.

RESULTS

The cohort consisted of 107 neonates, of whom 79% had a Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) Mortality Category of 4 or 5. Median chest tube output was 37 ml/kg (range 9-655 ml/kg). Age, African-American race, and longer durations of surgery and cardiopulmonary bypass each had statistically significant associations with increased chest tube output in unadjusted analyses. In multivariable analysis, African-American race retained an independent, statistically significant association with increased chest tube output; the geometric mean of chest tube output among African-American neonates was 71% higher than that of Caucasians (95% confidence interval, 29-125%; p = 0.001).

CONCLUSION

Among neonates with CHD undergoing open-heart surgery with cardiopulmonary bypass, African-American race is independently associated with greater chest tube output over the first 24 hours post-operatively.

Aprotinin versus tranexamic acid in children undergoing cardiac surgery: an observational study

OBJECTIVES

The upcoming release of aprotinin in paediatric cardiac surgery prompted a re-evaluation of its use in comparison to tranexamic acid (TXA) focusing on their effect on exposure to blood transfusions as well as severe postoperative morbidity or mortality.

METHODS

This retrospective study was conducted in a tertiary children hospital from 2002 to 2015. Patients receiving aprotinin (Aprotinin group: 2002-2007) were compared with those receiving TXA group (2008-2015) using propensity score analysis. Primary outcome measures were 'exposure to blood products' and 'severe postoperative morbidity or mortality'. High-risk subgroups that included neonates, complex (Risk Adjusted Classification for Congenital Heart Surgery-1 ≥ 3) and redo surgery were also analysed.

RESULTS

The study included 2157 patients, 1136 in the Aprotinin group and 1021 in the TXA group. Exposure to blood products was significantly higher in the Aprotinin group (78% vs 60%; P < 0.001) as well as in the complex and redo surgery subgroups. Incidence of mortality and/or severe morbidity was higher in the Aprotinin group (33% vs 28%; P = 0.007), as well as in the neonate group. However, cardiopulmonary bypass priming volume and intraoperative fluid balance were significantly decreased, and the use of modified ultrafiltration significantly increased in the TXA group.

CONCLUSIONS

In our population, children receiving aprotinin were more frequently transfused and were at a higher risk of developing severe postoperative morbidity or mortality than those receiving TXA. Subgroups at high risk of bleeding or inflammation did not seem to benefit from aprotinin. These differences might be explained by a safer profile of TXA, but also attributed to major changes in our patient blood management strategies over years.

Patient Blood Management in Pediatric Cardiac Surgery: A Review

Efforts to reduce blood product transfusions and adopt blood conservation strategies for infants and children undergoing cardiac surgical procedures are ongoing. Children typically receive red blood cell and coagulant blood products perioperatively for many reasons, including developmental alterations of their hemostatic system, and hemodilution and hypothermia with cardiopulmonary bypass that incites inflammation and coagulopathy and requires systemic anticoagulation. The complexity of their surgical procedures, complex cardiopulmonary interactions, and risk for inadequate oxygen delivery and postoperative bleeding further contribute to blood product utilization in this vulnerable population. Despite these challenges, safe conservative blood management practices spanning the pre-, intra-, and postoperative periods are being developed and are associated with reduced blood product transfusions. This review summarizes the available evidence regarding anemia management and blood transfusion practices in the perioperative care of these critically ill children. The evidence suggests that adoption of a comprehensive blood management approach decreases blood transfusions, but the impact on clinical outcomes is less well studied and represents an area that deserves further investigation.

Red blood cell transfusion threshold after pediatric cardiac surgery: A systematic review and meta-analysis

BACKGROUND

Restrictive red blood cell transfusion strategy is implemented to minimize risk following allogeneic blood transfusion in adult cardiac surgery. However, it is still unclear if it can be applied to pediatric cardiac patients. The purpose of this systematic review and meta-analysis was to determine the effect of postoperative restrictive transfusion thresholds on clinical outcomes based on up-to-date results of randomized controlled trials (RCTs) and observational studies in pediatric cardiac surgery.

METHOD

We searched for RCTs and observational studies in the following databases: the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and ClinicalTrials.gov from their inception to October 26, 2017. We also searched reference lists of published guidelines, reviews, and relevant articles, as well as conference proceedings. No language restrictions were applied and no observational study met the inclusion criteria.

RESULTS

Four RCTs on cardiac surgery involving 454 patients were included. There were no differences in the pooled fixed effects of intensive care unit (ICU) stay between the liberal and restrictive transfusion thresholds (standardized mean difference SMD, 0.007; 95% confidence interval CI, -0.18-0.19; P = .94). There were also no differences in the length of hospital stay (SMD, -0.062; 95% CI, -0.28-0.15; P = .57), ventilation duration (SMD, -0.015; 95% CI, -0.25-0.22; P = .90), mean arterial lactate level (SMD, 0.071; 95% CI, -0.22-0.36; P = .63), and mortality (risk ratio, 0.49; 95% CI, 0.13-1.94; P = .31). There was no inter-trial heterogeneity for any pooled analysis. Publication bias was tested using Egger, Begg, or the trim-and-fill test, and the results indicated no significant publication bias.

CONCLUSION

Evidence from RCTs in pediatric cardiac surgery, though limited, showed non-inferiority of restrictive thresholds over liberal thresholds in length of ICU stay and other outcomes following red blood cell transfusion. Further high-quality RCTs are necessary to confirm the findings.

Bloodless priming of the cardiopulmonary bypass circuit: determinants of successful transfusion-free operation in neonates and infants with a maximum body weight of 7 kg

We currently perform open-heart procedures using bloodless priming of cardiopulmonary bypass circuits regardless of a patient's body weight. This study presents results of this blood-saving approach in neonates and infants with a body weight of up to 7 kg. It tests with multivariate analysis factors that affect perioperative transfusion. A total of 498 open-heart procedures were carried out in the period 2014-2016 and were analysed. Priming volume ranged from 73 ml for patients weighing up to 2.5 kg to 110 ml for those weighing over 5 kg. Transfusion threshold during cardiopulmonary bypass was 8 g/dl of haemoglobin concentration. Transfusion factors were first analysed individually. Variables with a p-value lower than 0.2 underwent logistic regression. Extracorporeal circulation was conducted without transfusion of blood in 335 procedures - that is, 67% of cases. Transfusion-free operation was achieved in 136 patients (27%) and was more frequently observed after arterial switch operation and ventricular septal defect repair (12/18=66.7%). It was never observed after Norwood procedure (0/33=0%). Lower mortality score (p=0.001), anaesthesia provided by a certain physician (p=0.006), first chest entry (p=0.013), and higher haemoglobin concentration before going on bypass (p=0.013) supported transfusion-free operation. Early postoperative mortality was 4.4% (22/498). It was lower than expected (6.4%: 32/498). In conclusion, by adjusting the circuit, cardiopulmonary bypass could be conducted without donor blood in majority of patients, regardless of body weight. Transfusion-free open-heart surgery in neonates and infants requires team cooperation. It was more often achieved in procedures with lower mortality score.

Predictors and outcomes of perioperative blood transfusions in classic bladder exstrophy repair: A single institution study

BACKGROUND

Primary bladder closure of classic bladder exstrophy (CBE) is a major operation that occasionally requires intraoperative or postoperative (within 72 h) blood transfusions.

OBJECTIVE

This study reported perioperative transfusion rates, risk factors for transfusion, and outcomes from a high-volume exstrophy center in primary bladder closure of CBE patients.

STUDY DESIGN

A prospectively maintained, institutional exstrophy-epispadias complex database of 1305 patients was reviewed for primary CBE closures performed at the authors' institution (Johns Hopkins Hospital) between 1993 and 2017. Patient and surgical factors were analyzed to determine transfusion rates, risk factors for transfusions, and outcomes. Patients were subdivided into two groups based upon the time of closure: neonatal and delayed closure.

RESULTS

A total of 116 patients had a primary bladder closure during 1993-2017. Seventy-three patients were closed in the neonatal period, and 43 were delayed closures. In total, 64 (55%) patients received perioperative transfusions. No transfusion reactions were observed. Twenty-five transfusions were in the neonatal closure group, yielding a transfusion rate of 34%. In comparison, 39 patients were transfused in the delayed closure group, giving a transfusion rate of 91%. Pelvic osteotomy, delayed bladder closure, higher estimated blood loss (EBL), larger pubic diastasis, and longer operative time were all associated with blood transfusion. In multivariable logistic regression, pelvic osteotomy (OR 5.4; 95% CI 1.3-22.8; P < 0.001), higher EBL-to-weight ratio (OR 1.3; 95% CI 1.1-1.6; P = 0.029), and more recent years of primary closure (OR 1.1; 95% CI 1.0-1.2; P = 0.018) remained independent predictors of receiving a transfusion (Summary Table). No adverse transfusion reactions or complications were observed.

DISCUSSION

This was the first study from a single high-volume exstrophy center to explore factors that contribute to perioperative blood transfusions. Pelvic osteotomy as a risk factor was unsurprising, as the osteotomy may bleed both during and immediately after closure. However, it is important to use osteotomy for successful closure, despite the increased transfusion risk. The risks accompanying contemporary transfusions are minimal and osteotomies are imperative for successful bladder closure.

CONCLUSIONS

More than half of CBE patients undergoing primary closure at a single institution received perioperative blood transfusions. While there was an association between transfusions and osteotomy, delayed primary closure, larger diastasis, increased operative time, and increased length of stay, only the use of pelvic osteotomy, higher EBL-to-weight ratio, and recent year of closure independently increased the odds of receiving a transfusion on multivariate analysis.

Recommendations on RBC Transfusion in General Critically Ill Children Based on Hemoglobin and/or Physiologic Thresholds From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the consensus recommendations and supporting literature for RBC transfusions in general critically ill children from the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of international, multidisciplinary experts in RBC transfusion management of critically ill children.

METHODS

The panel of 38 experts developed evidence-based and, when evidence was lacking, expert-based recommendations and research priorities regarding RBC transfusions in critically ill children. The subgroup on RBC transfusion in general critically ill children included six experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 30, 2017, using a combination of keywords to define concepts of RBC transfusion and critically ill children. Recommendation consensus was obtained using the Research and Development/UCLA Appropriateness Method. The results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Three adjudicators reviewed 4,399 abstracts; 71 papers were read, and 17 were retained. Three papers were added manually. The general Transfusion and Anemia Expertise Initiative subgroup developed, and all Transfusion and Anemia Expertise Initiative members voted on two good practice statements, six recommendations, and 11 research questions; in all instances, agreement was reached (> 80%). The good practice statements suggest a framework for RBC transfusion in PICU patients. The good practice statements and recommendations focus on hemoglobin as a threshold and/or target. The research questions focus on hemoglobin and physiologic thresholds for RBC transfusion, alternatives, and risk/benefit ratio of transfusion.

CONCLUSIONS

Transfusion and Anemia Expertise Initiative developed pediatric-specific good practice statements and recommendations regarding RBC transfusion management in the general PICU population, as well as recommendations to guide future research priorities. Clinical recommendations emphasized relevant hemoglobin thresholds, and research recommendations emphasized a need for further understanding of physiologic thresholds, alternatives to RBC transfusion, and hemoglobin thresholds in populations with limited pediatric literature.

Recommendations on RBC Transfusion in Infants and Children With Acquired and Congenital Heart Disease From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the recommendations and supporting literature for RBC transfusions in critically ill children with acquired and congenital heart disease developed by the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of 38 international, multidisciplinary experts in RBC transfusion management of critically ill children.

METHODS

Experts developed evidence-based and, when evidence was lacking, expert-based clinical recommendations and research priorities for RBC transfusions in critically ill children. The cardiac disease subgroup included three experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 2017. Agreement was obtained using the Research and Development/UCLA appropriateness method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Twenty-one recommendations were developed and reached agreement. For children with myocardial dysfunction and/or pulmonary hypertension, there is no evidence that transfusion greater than hemoglobin of 10 g/dL is beneficial. For children with uncorrected heart disease, we recommended maintaining hemoglobin greater than 7-9.0 g/dL depending upon their cardiopulmonary reserve. For stable children undergoing biventricular repairs, we recommend not transfusing if the hemoglobin is greater than 7.0 g/dL. For infants undergoing staged palliative procedures with stable hemodynamics, we recommend avoiding transfusions solely based upon hemoglobin, if hemoglobin is greater than 9.0 g/dL. We recommend intraoperative and postoperative blood conservation measures. There are insufficient data supporting shorter storage duration RBCs. The risks and benefits of RBC transfusions in children with cardiac disease requires further study.

CONCLUSIONS

We present RBC transfusion management recommendations for the critically ill child with cardiac disease. Clinical recommendations emphasize relevant hemoglobin thresholds, and research recommendations emphasize need for further understanding of physiologic and hemoglobin thresholds and alternatives to RBC transfusion in subpopulations lacking pediatric literature.

Recommendations on RBC Transfusions in Critically Ill Children With Acute Respiratory Failure From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the recommendations and supporting literature for RBC transfusions in critically ill children with bleeding developed by the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of international, multidisciplinary experts in RBC transfusion management of critically ill children.

METHODS

The panel of 38 experts developed evidence-based and, when evidence was lacking, expert-based clinical recommendations as well as research priorities for RBC transfusions in critically ill children. The respiratory subgroup included six experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 2017. Agreement was obtained using the Research and Development/UCLA Appropriateness Method. Results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Transfusion and Anemia Expertise Initiative experts developed seven recommendations focused on children with acute respiratory failure. All recommendations reached agreement (> 80%). Transfusion of RBCs in children with respiratory failure with an hemoglobin level less than 5 g/dL was strongly recommended. It was strongly recommended that RBCs not be systematically administered to children with respiratory failure who are hemodynamically stable and who have a hemoglobin level greater than or equal to 7 g/dL. Experts could not make a recommendation for children with hemodynamic instability, with severe hypoxemia and/or with an hemoglobin level between 5 and 7 g/dL. Specific RBC transfusion strategies using physiologic-based metrics and biomarkers could not be elaborated.

CONCLUSIONS

The Transfusion and Anemia Expertise Initiative Consensus Conference developed specific recommendations regarding RBC transfusion management in critically ill children with respiratory failure, as well as recommendations to guide future research. Clinical recommendations emphasize relevant hemoglobin thresholds. Research recommendations emphasize the need to identify appropriate physiologic thresholds, suggest a better understanding of alternatives to RBC transfusion, and identify the need for better evidence on hemoglobin thresholds that might be used in specific subpopulations of critically ill children.

The use of acute normovolemic hemodilution in paediatric cardiac surgery

BACKGROUND

Acute normovolemic hemodilution (ANH) is considered safe and effective in decreasing perioperative transfusion in paediatric populations undergoing high blood-loss surgeries. We determined the association between ANH and the intraoperative use of allogeneic blood products in paediatric cardiac surgery patients.

METHODS

This is a single-centre retrospective cohort study including paediatric patients between 0 and 36 months of age undergoing surgical repair or palliation of their cardiac defect with the use of cardiopulmonary bypass between November 2013 and November 2014. Our primary endpoint was the volume per kilogram of body weight of any blood product administered. Secondary endpoints were postoperative bleeding, coagulation profile, creatinine, vasoactive support, duration of mechanical ventilation, and hospital stay.

RESULTS

In all, 50 patients met eligibility criteria and were included. Of those, seven were exposed to ANH and while 43 patients were treated according to usual care. Baseline characteristics were similar in both groups. After adjustment for baseline characteristics including age, American Society of Anaesthesiologists (ASA) classification, and Risk Adjusted Congenital Heart Surgery score, ANH was associated with reduced administration of allogenic blood products, with the mean difference between groups of 57.5 ml/kg (95% CI: 34.8, 80.2). The ANH group had lower blood losses at 6 and 24 h postoperatively. There were no differences in the duration of ICU or hospital stay.

CONCLUSION

We found a reduction in the administration of blood products and lower postoperative blood losses associated with the use of ANH in paediatric cardiac surgery patients. The data suggest that ANH might be beneficial in reducing perioperative morbidity in this patient population.

Superior blood-saving effect and postoperative recovery of comprehensive blood-saving strategy in infants undergoing open heart surgery under cardiopulmonary bypass

BACKGROUND

Optimization of blood-saving strategies during open heart surgery in infants is still required. This study aimed to study a comprehensive blood-saving strategy during cardiopulmonary bypass (CPB) on postoperative recovery in low-weight infants undergoing open heart surgery.

METHODS

This was a prospective study of 86 consecutive infants (weighing <5 kg) with acyanotic congenital heart disease treated at the Tianjin Chest Hospital between March and December 2016, and randomized to the control (traditional routine CPB) and comprehensive blood-saving strategy groups. The primary endpoints were blood saving and clinical prognosis. The secondary endpoints were safety and laboratory indicators, prior to CPB (T1), after 30 minutes of CPB (T2), after modified ultrafiltration (T3), and postoperative 12 (T4), 24 (T5), 48 (T6), and 72 h (T7).

RESULTS

The total priming volume and banked red blood cells in the comprehensive strategy group were significantly lower than in the control group (P = .009 and P = .04, respectively). In the comprehensive strategy group, immediately after CPB, the amount of salvaged red blood cells exceeded the priming red blood cells by 40 ± 11 mL. Postoperatively, the comprehensive strategy group showed a significant decrease in the inotrope score (P = .03), ventilation time (P = .03), intensive care unit stay (P = .04), and hospital stay (P = .03) in comparison with the control group.

CONCLUSION

The comprehensive blood-saving strategies for CPB were associated with less blood use and favorable postoperative recovery in low-weight infants with congenital heart disease undergoing open heart surgery.

Oxygenation impairment after total arch replacement with a stented elephant trunk for type-A dissection

OBJECTIVE

To study the risk factors of oxygenation impairment in patients with type-A acute aortic dissection who underwent total arch replacement with a stented elephant trunk.

METHODS

In this study, 169 consecutive patients were enrolled who were diagnosed with type-A acute aortic dissection and underwent a total arch replacement procedure at the Qilu Hospital of Shandong University between January 2015 and February 2017. Postoperative oxygenation impairment was defined as arterial oxygen partial pressure/inspired oxygen fraction ≤ 200 with positive end expiratory pressure ≥ 5 cm H₂O that occurred within 72 hours of surgery. Perioperative clinical characteristics of all patients were collected and univariable analyses were performed. Risk factors associated with oxygenation impairment identified by univariable analyses were included in the multivariable regression analysis.

RESULTS

The incidence of postoperative oxygenation impairment was 48.5%. Postoperative oxygenation impairment was associated with prolonged mechanical ventilation time, intensive care unit stay, and hospital stay. Multivariable regression analysis demonstrated that body mass index (odds ratio [OR], 1.204; 95% confidence interval [CI], 1.065-1.361; P = .003), preoperative oxygenation impairment (OR, 9.768; 95% CI, 4.159-22.941; P < .001), preoperative homocysteine (OR, 1.080; 95% CI, 1.006-1.158; P = .032), circulatory arrest time (OR, 1.123; 95% CI, 1.044-1.207; P = .002), and plasma transfusion (OR, 1.002; 95% CI, 1.001-1.003; P = .002) were significantly associated with postoperative oxygenation impairment.

CONCLUSIONS

Postoperative oxygenation impairment is a common complication of surgery for type-A acute aortic dissection. Body mass index, preoperative oxygenation impairment, preoperative homocysteine, circulatory arrest time, and plasma transfusion were independent risk factors for oxygenation impairment after a total arch replacement procedure.

The Effect of Diagnostic Blood Loss on Anemia and Transfusion Among Postoperative Patients With Congenital Heart Disease in a Pediatric Intensive Care Unit

PURPOSE

To evaluate whether diagnostic blood loss can lead to anemia and consequent blood transfusion among postoperative patients with congenital heart disease (CHD) in the pediatric intensive care unit (PICU).

DESIGN AND METHODS

This prospective observational study was conducted in a university-affiliated tertiary hospital between January and August 2016. CHD patients aged <12years, undergoing cardiac surgery, with a PICU stay >48h were included (n=205). Multivariate logistic regression analyses were used to determine the effect of diagnostic blood loss on anemia and transfusion.

RESULTS

The mean daily phlebotomy volume was 5.40±1.94mL/d during the PICU stay (adjusted for body weight, 0.63±0.36mL/kg/d). Daily volume/kg was associated with cyanotic CHD, Pediatric Risk of Mortality III score, and Pediatric Logistic Organ Dysfunction (PELOD)-2 score. In total, 101 (49.3%) patients presented with new or more severe anemia after admission to PICU, which was not associated with phlebotomy volume. Forty-one (20.0%) children received one or more RBC transfusions during their PICU stay. Multivariate analysis indicated that PELOD-2 score>5, new or more severe anemia, and daily volume/kg of phlebotomy >0.63mL/kg/d were significantly associated with transfusion after 48h of admission to PICU.

CONCLUSIONS

Our findings indicate that diagnostic blood loss is not related to postoperative anemia in children with CHD; however, this factor does correlate with blood transfusion, since it somewhat reflects the severity of illness.

PRACTICE IMPLICATIONS

Strategies should be applied to reduce diagnostic blood loss, as appropriate.

Validation of a definition of excessive postoperative bleeding in infants undergoing cardiac surgery with cardiopulmonary bypass

OBJECTIVE

To derive and validate an objective definition of postoperative bleeding in neonates and infants undergoing cardiac surgery with cardiopulmonary bypass.

METHODS

Using a retrospective cohort of 124 infants and neonates, we included published bleeding definitions and cumulative chest tube output over different postoperative periods (eg, 2, 12, or 24 hours after intensive care unit admission) in a classification and regression tree model to determine chest tube output volumes that were associated with red blood cell transfusions and surgical re-exploration for bleeding in the first 24 hours after intensive care unit admission. After the definition of excessive bleeding was determined, it was validated via a prospective cohort of 77 infants and neonates.

RESULTS

Excessive bleeding was defined as ≥7 mL/kg/h for ≥2 consecutive hours in the first 12 postoperative hours and/or ≥84 mL/kg total for the first 24 postoperative hours and/or surgical re-exploration for bleeding or cardiac tamponade physiology in the first 24 postoperative hours. Excessive bleeding was associated with longer length of hospital stay, increased 30-day readmission rate, and increased transfusions in the postoperative period.

CONCLUSIONS

The proposed standard definition of excessive bleeding is based on readily obtained objective data and relates to important early clinical outcomes. Application and validation by other institutions will help determine the extent to which our specialty should consider this definition for both clinical investigation and quality improvement initiatives.

Reducing Blood Testing in Pediatric Patients after Heart Surgery: Proving Sustainability

Introduction

Frequent blood testing increases risk of iatrogenic anemia, infection, and blood transfusion. This study describes 3 years of sustained blood testing reduction from a quality improvement (QI) initiative which began in 2011.

Methods

The cohort consisted of postop children whose surgery had a Risk Adjustment for Congenital Heart Surgery (RACHS) classification consecutively admitted to a tertiary Cardiac Intensive Care Unit. Data were collected for a 2010 preintervention, 2011 intervention, and 2012-13 postintervention periods, tabulating common laboratory studies per patient (labs/pt) and adjusted for length of stay (labs/pt/d). The QI initiative eliminated standing laboratory orders and changed to testing based on individualized patient condition. Adverse outcomes data were collected including reintubation, central line-associated bloodstream infections and hospital mortality. Safety was measured by the number of abnormal laboratory studies, electrolyte replacements, code blue events, and arrhythmias.

Results

A total of 1169 patients were enrolled (303 preintervention, 315 intervention, and 551 postintervention periods). The number of labs/pt after the QI intervention was sustained (38 vs. 23 vs. 23) and labs/pt/d (15 vs. 11 vs. 10). The postintervention group had greater surgical complexity (P = 0.002), were significantly younger (P = 0.002) and smaller (P = 0.008). Children with RACHS 3-4 classification in the postintervention phase had significant increased risk of reintubation and arrhythmias.

Conclusions

After the implementation of a QI initiative, blood testing was reduced and sustained in young, complex children after heart surgery. This may or may not have contributed to greater reintubation and arrhythmias among patients with RACHS 3-4 category procedures.

Risk factors for hypoxemia following surgical repair of acute type A aortic dissection

Objectives

To identify the risk factors for hypoxaemia following surgical repair of acute type A aortic dissection.

Methods

This was a retrospective study of patients treated between October 2013 and December 2014 at the Department of Cardiovascular Surgery, Anzhen Hospital, China. Univariable and multivariable analyses were performed on the clinical data of 160 patients with acute type A dissection and who underwent ascending aortic and arch replacement under deep hypothermic circulatory arrest.

Results

Hypoxaemia occurred in 30% (48/160) of patients (age: 49 ± 7.9 years; 40 males, 83.3%). The duration of ventilation and the lengths of intensive care unit and hospital stays were significantly longer in patients with hypoxemia (77.9 ± 56.0 vs 16.5 ± 11.5 h, P < 0.0001; 6.0 ± 2.3 vs 2.0 ± 1.2 days, P = 0.001; 18.1 ± 6.3 vs 13.5 ± 4.7 days, P = 0.0012; respectively). The difference in operative mortality was not statistically significant between the hypoxaemia and non-hypoxaemia groups (6.25% vs 3.57%, P = 0.351). The independent risk factors of postoperative hypoxaemia were time from symptom onset to surgery ≤72 h [odds ratio, 3.63; 95% confidence interval, 1.31-10.02; P = 0.013], preoperative PaO2/FiO2 ≤300 (odds ratio, 15.30; 95% CI, 5.52-42.43; P < 0.001), preoperative white blood cell count >15 000/μl (odds ratio, 9.79; 95% CI, 2.47-38.87; P = 0.001); and deep hypothermic circulatory arrest time >25 min (odds ratio, 3.26; 95% CI, 1.18-8.99; P = 0.023).

Conclusions

Time from symptom onset to surgery ≤72 h, preoperative PaO2/FiO2 ≤300, white blood cell count >15 000/μl and deep hypothermic circulatory arrest time >25 min were found to be independently associated with hypoxaemia after surgery for acute type A aortic dissection.

Blood conservation pediatric cardiac surgery in all ages and complexity levels

AIM

To demonstrate the feasibility of blood conservation methods and practice across all ages and risk categories in congenital cardiac surgery.

METHODS

We retrospectively analyzed a collected database of 356 patients who underwent cardiac surgery using cardiopulmonary bypass (CPB) from 2010-2015. The patients were grouped into blood conservation (n = 138) and non-conservation (n = 218) groups and sub-grouped based on their ages and procedural complexity scores.

RESULTS

There were no statistical differences in gender, weight, pre-operative and pre-CPB hematocrit levels in both groups. Despite equivalent hematocrit levels during and after CPB for both groups, there was significantly less operative homologous blood utilized in blood conservation group across all ages and complexity levels.

CONCLUSION

Blood conservation surgery can be performed in congenital patients needing cardiac surgery in all age groups and complexity categories. The above findings in addition to attendant risks and side effects of blood transfusion and the rising cost of safer blood products justify blood conservation in congenital cardiac surgery.

Blood derived products in pediatrics: New laboratory tools for optimizing potency assignment and reducing side effects

Neonates and children can develop rare bleeding disorders due to congenital/acquired coagulation Factor deficiencies, or allo-immune/autoimmune complications, or can undergo surgeries at high haemorrhagic risk. They then need specialized transfusion of blood components/products, or purified blood extracted products or recombinant proteins. Blood-derived therapies conventionally used for management of affected infants with genetic/acquired deficiencies, bleeding problems (coagulation Factor reduced or missing) or thrombotic disorders (reduced or missing anticoagulant proteins) pose some additional risks. These remedial therapies can cause tolerance when used very early in life and, sometimes needed, repeatedly. The introduction of recombinant proteins has allowed manufacturers to produce large amounts of the proteins usually present at very low concentration in blood. This has also changed the risk pattern of plasma-extracted products, especially in terms of continual reduction of viral transmission. Many efforts have been made over these past decades to reduce the risks associated with the use of all these products in terms of viral and bacterial safety, as well as immune disorders but they are not the objective of this article. Other associated side effects are the presence of undesired activities in blood products, which can produce thrombotic events or adverse reactions. The progressive introduction of blood derived products has greatly improved the prognosis and quality of life of affected patients. This concerns whole blood, but also blood cell concentrates, mainly platelets and red blood cells, plasma, while the blood extracted products are increasingly replaced by recombinant proteins. All these therapeutic products, i.e. blood extracted drugs, improve health and quality of life for hemophiliac's A or B, or patients with auto/allo-immune thrombocytopenias or with rare bleeding disorders, and those with thrombotic events occurring in childhood, which are mainly due to Protein C or Protein S deficiencies (congenital or acquired). Progress in analytical methods and biotechnology allow better control of the manufacturing processes for all blood derived or plasma extracted products and recombinant proteins, and contribute to improved manufacturing processes to minimize the occurrence of side effects. These adverse events can be due to the aging of the blood cell concentrate with release of their granule content, and generation of EVs, which can produce anaphylactic reactions and risk of thrombosis, but also to the presence of activated coagulation Factors in purified products, such as Factor Xia as recently identified in immunoglobulin concentrates. Characterization and measurement of contaminant products is of special usefulness during product preparation and for optimization of manufacturing processes for purified extracted products, but also for recombinant proteins. The pharmaceutical industry introduces these new methods for validating manufacturing processes, or for quality control assessments. The objective is first to warrant the full quality and safety of the lots produced, and assure the highest efficacy with the lowest risks when used in patients. For cell concentrates and fresh blood, storage conditions are critical and measurement of analytes such as EVs or Annexin V allows evaluation of quality of each individual transfused pouch. In addition to all the rules around viral and bacterial transmission risk, and immune tolerance, our available laboratory methods contribute to reducing the side effects of blood cell concentrates and derived plasma products, as well as those of the therapeutic recombinant proteins.

Transfusion-related immunomodulation: review of the literature and implications for pediatric critical illness

Transfusion-related immunomodulation (TRIM) in the intensive care unit (ICU) is difficult to define and likely represents a complicated set of physiologic responses to transfusion, including both proinflammatory and immunosuppressive effects. Similarly, the immunologic response to critical illness in both adults and children is highly complex and is characterized by both acute inflammation and acquired immune suppression. How transfusion may contribute to or perpetuate these phenotypes in the ICU is poorly understood, despite the fact that transfusion is common in critically ill patients. Both hyperinflammation and severe immune suppression are associated with poor outcomes from critical illness, underscoring the need to understand potential immunologic consequences of blood product transfusion. In this review we outline the dynamic immunologic response to critical illness, provide clinical evidence in support of immunomodulatory effects of blood product transfusion, review preclinical and translational studies to date of TRIM, and provide insight into future research directions.

Red Blood Cell Transfusion in the Postoperative Care of Pediatric Cardiac Surgery: Survey on Stated Practice

The optimal red blood cell transfusion threshold for postoperative pediatric cardiac surgery patients is unknown. This study describes the stated red blood cell transfusion practice of physicians who treat postoperative pediatric cardiac surgery patients in intensive care units. A scenario-based survey was sent to physicians involved in postoperative intensive care of pediatric cardiac surgery patients in all Canadian centers that perform such surgery. Respondents reported their red blood cell transfusion practice in four postoperative scenarios: acyanotic or cyanotic cardiac lesion, in a neonate or an infant. In part A of each scenario, the patient was critically ill, but stabilized; in part B, the patient became unstable. Response rate was 58 % (71 of 123), with 45 respondents indicating direct involvement in postoperative intensive care. There was a wide variability in stated transfusion threshold, ranging from <7.0-14.0 g/dL for stabilized cases. There was no significant difference between neonates and infants in stated transfusion threshold. The mean hemoglobin level below which respondents would transfuse a stabilized patient was 9 g/dL for acyanotic and 11.2 g/dL for cyanotic patients, a statistically significant difference (2.2 ± 0.9 g/dL, p < 0.001). All clinical determinants of instability significantly increased transfusion threshold. Hemodynamic instability increased transfusion threshold by 2.3 ± 1.3 g/dL in acyanotic patients and by 1.3 ± 1.1 g/dL in cyanotic patients. Cyanotic lesion and clinical instability, but not patient age, increased stated red blood cell transfusion threshold. Significant variation in reported red blood cell transfusion practice exists among physicians treating pediatric patients in intensive care following cardiac surgery.

Bleeding and Thrombosis in Pediatric Cardiac Intensive Care

OBJECTIVES

The objective of this article is to review the particular tendencies as well as specific concerns of bleeding and clotting in children with critical cardiac disease.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSION

Children with critical heart disease are at particular risk for bleeding and clotting secondary to intrinsic as well as extrinsic factors. We hope that this review will aid the clinician in managing the unique challenges of bleeding and clotting in this patient population, and serve as a springboard for much needed research in this area.