Children with single-ventricle physiology do not benefit from higher hemoglobin levels post cavopulmonary connection: results of a prospective, randomized, controlled trial of a restrictive versus liberal red-cell transfusion strategy

Hematocrit Levels, Blood Testing, and Blood Transfusion in Infants After Heart Surgery

OBJECTIVE

To determine whether judicious blood testing impacts timing or amount of packed RBC transfusions in infants after heart surgery.

DESIGN

A retrospective study comparing before and after initiation of a quality improvement process.

SETTING

A university-affiliated cardiac ICU at a tertiary care children's hospital.

PATIENTS

Infants less than 1 year old with Risk Adjustment for Congenital Heart Surgery category 4, 5, 6, or d-transposition of great arteries (Risk Adjustment for Congenital Heart Surgery 3) consecutively treated during 2010 through 2013.

INTERVENTION

A quality improvement process implemented in 2011 to decrease routine laboratory testing after surgery.

MEASUREMENTS AND MAIN RESULTS

Fifty-two infants preintervention and 214 postintervention had similar age, weight, proportion of cyanotic lesions, and surgical complexity. Infants with single versus biventricular physiology were compared separately. The number of laboratory tests per patient adjusted for cardiac ICU length of stay (laboratory tests/patient/day) was significantly lower in postintervention populations for single and biventricular groups (9 vs 15 and 10 vs 15, respectively; p < 0.001). The proportion of single ventricle patients transfused post- and preintervention was not statistically different (72% vs 90%; p = 0.130). Transfusion in the biventricular groups was the same over time (65% vs 65%). Time to first transfusion was significantly longer in the postintervention single ventricle group (4 vs 1 d; p < 0.001), and was not statistically different in the biventricular patients (4 vs 7 d; p = 0.058). The median hematocrit level at first transfusion was significantly lower (37% vs 40%; p = 0.004) postintervention in the cyanotic population, but did not differ in the biventricular group (31% vs 31%; p = 0.840).

CONCLUSION

In infants after heart surgery, blood testing targeted to individual needs significantly decreased the number of blood tests, but did not significantly decrease postoperative blood transfusion.

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.

Exploring the Role of Polycythemia in Patients With Cyanosis After Palliative Congenital Heart Surgery

OBJECTIVES

To understand the relationship between polycythemia and clinical outcome in patients with hypoplastic left heart syndrome following the Norwood operation.

DESIGN

A retrospective, single-center cohort study.

SETTING

Pediatric cardiovascular ICU, university-affiliated children's hospital.

PATIENTS

Infants with hypoplastic left heart syndrome admitted to our medical center from September 2009 to December 2012 undergoing stage 1/Norwood operation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Baseline demographic and clinical information including first recorded postoperative hematocrit and subsequent mean, median, and nadir hematocrits during the first 72 hours postoperatively were recorded. The primary outcomes were in-hospital mortality and length of hospitalization. Thirty-two patients were included in the analysis. Patients did not differ by operative factors (cardiopulmonary bypass time and cross-clamp time) or traditional markers of severity of illness (vasoactive inotrope score, lactate, saturation, and PaO2/FIO2 ratio). Early polycythemia (hematocrit value > 49%) was associated with longer cardiovascular ICU stay (51.0 [± 38.6] vs 21.4 [± 16.2] d; p < 0.01) and total hospital length of stay (65.0 [± 46.5] vs 36.1 [± 20.0] d; p = 0.03). In a multivariable analysis, polycythemia remained independently associated with the length of hospitalization after controlling for the amount of RBC transfusion (weight, 4.36 [95% CI, 1.35-7.37]; p < 0.01). No difference in in-hospital mortality rates was detected between the two groups (17.6% vs 20%).

CONCLUSIONS

Early polycythemia following the Norwood operation is associated with longer length of hospitalization even after controlling for blood cell transfusion practices. We hypothesize that polycythemia may be caused by hemoconcentration and used as an early marker of capillary leak syndrome.

Association of Hematocrit and Red Blood Cell Transfusion with Outcomes in Infants Undergoing Norwood Operation

The objective of this study was to investigate the association between red blood cell (RBC) transfusion and hematocrit values with outcomes in infants undergoing Norwood operation. This study included infants ≤2 months of age who underwent Norwood operation with either a modified Blalock-Taussig shunt or a right ventricle-pulmonary artery shunt. Demographics, preoperative, operative, daily laboratory data, and postoperative variables were collected. The primary outcome measures evaluated included mortality, ICU length of stay, length of mechanical ventilation, and days to chest closure. The secondary outcome measures evaluated included lactate levels, estimated glomerular filtration rate, and inotrope score in the first 14 days after heart operation. Cox proportional hazard models were fitted to study the probability of study outcomes as a function of hematocrit values and RBC transfusions after operation. Eighty-nine patients qualified for inclusion. With a median hematocrit of 46 (IQR 44, 49), and a median RBC transfusion of 92 ml/kg (IQR 31, 384) in the first 14 days after operation, 81 (91 %) patients received RBC transfusions. A multivariable analysis adjusted for risk factors, including the age, weight, prematurity, cardiopulmonary bypass and cross-clamp time, and postoperative need for nitric oxide and dialysis, demonstrated no association between hematocrit and RBC transfusion with majority of study outcomes. This single-center study found that higher hematocrit values and increasing RBC transfusions are not associated with improved outcomes in infants undergoing Norwood operation.

Blood Transfusions After Pediatric Cardiac Operations: A North American Multicenter Prospective Study

BACKGROUND

Red blood cell transfusion is an important supportive measure after pediatric cardiac operations. However, no clear hemoglobin threshold has been established. This study characterized anemia development and red blood cell transfusions in the pediatric intensive care unit (PICU) after cardiac operations.

METHODS

A prospective, multicenter, 6-month cohort study on the management of anemia in critically ill pediatric patients was conducted in 30 North American PICUs. This observational study enrolled 977 consecutive children (aged <18 years) who stayed in the PICU for 48 hours or more. We analyzed a subgroup of postcardiac surgical patients from this study.

RESULTS

Included were 175 cardiac patients, 56% of whom had cyanotic heart disease. The mean Pediatric Risk of Mortality (PRISM III) score was 6.4 ± 5.4. Fifty-four percent of children were anemic in the PICU (20% on admission, 34% during PICU stay). Most patients (79%) received at least one red blood cell transfusion in the PICU. Patients who received a transfusion had a significantly longer PICU stay (9.3 ± 6.3 vs 6.1 ± 5.4 days, p = 0.01). Pretransfusion hemoglobin was different in acyanotic and cyanotic patients (mean ± standard deviation: 11.1 ± 2.2 g/dL and 11.8 ± 2.1 g/dL, respectively). According to the attending physician, a low hemoglobin level was the primary indication for transfusion in only 17% of cases.

CONCLUSIONS

Pediatric cardiac surgical patients are at high risk of receiving red blood cell transfusions. This study, which showed great variability in transfusion practices across North American PICUs, highlights the need for clearer transfusion guidelines in this specific population.

Red blood cell transfusion decision making in critically ill children

PURPOSE OF REVIEW

To discuss the tradeoff between permissive anemia and administering red blood cell transfusion to children in pediatric ICUs.

RECENT FINDINGS

Postsurgical mortality in adults increases abruptly if their nadir hemoglobin level falls below 5 g/dl. Patients with sepsis, even those in septic shock, and patients with upper gastrointestinal bleeding do not require red blood cell (RBC) transfusion if their hemoglobin level is above 7 g/dl.

SUMMARY

Anemia is common in critically ill children and is well tolerated most of the time. RBC transfusion is required in cases of hemorrhagic shock and in children with a hemoglobin level below 5 g/dl. Children with sepsis, including septic shock, those with a severe upper gastrointestinal bleeding and all stable critically ill children, including noncyanotic cardiac children older than 28 days, do not require an RBC transfusion if their hemoglobin level is above 7 g/dl. Transfusion threshold in children with univentricular physiology and in critically ill children with a hemoglobin level between 5 and 7 g/dl remains to be determined.

Restrictive versus liberal transfusion strategy for red blood cell transfusion: systematic review of randomised trials with meta-analysis and trial sequential analysis

OBJECTIVE

To compare the benefit and harm of restrictive versus liberal transfusion strategies to guide red blood cell transfusions.

DESIGN

Systematic review with meta-analyses and trial sequential analyses of randomised clinical trials.

DATA SOURCES

Cochrane central register of controlled trials, SilverPlatter Medline (1950 to date), SilverPlatter Embase (1980 to date), and Science Citation Index Expanded (1900 to present). Reference lists of identified trials and other systematic reviews were assessed, and authors and experts in transfusion were contacted to identify additional trials.

TRIAL SELECTION

Published and unpublished randomised clinical trials that evaluated a restrictive compared with a liberal transfusion strategy in adults or children, irrespective of language, blinding procedure, publication status, or sample size.

DATA EXTRACTION

Two authors independently screened titles and abstracts of trials identified, and relevant trials were evaluated in full text for eligibility. Two reviewers then independently extracted data on methods, interventions, outcomes, and risk of bias from included trials. random effects models were used to estimate risk ratios and mean differences with 95% confidence intervals.

RESULTS

31 trials totalling 9813 randomised patients were included. The proportion of patients receiving red blood cells (relative risk 0.54, 95% confidence interval 0.47 to 0.63, 8923 patients, 24 trials) and the number of red blood cell units transfused (mean difference -1.43, 95% confidence interval -2.01 to -0.86) were lower with the restrictive compared with liberal transfusion strategies. Restrictive compared with liberal transfusion strategies were not associated with risk of death (0.86, 0.74 to 1.01, 5707 patients, nine lower risk of bias trials), overall morbidity (0.98, 0.85 to 1.12, 4517 patients, six lower risk of bias trials), or fatal or non-fatal myocardial infarction (1.28, 0.66 to 2.49, 4730 patients, seven lower risk of bias trials). Results were not affected by the inclusion of trials with unclear or high risk of bias. Using trial sequential analyses on mortality and myocardial infarction, the required information size was not reached, but a 15% relative risk reduction or increase in overall morbidity with restrictive transfusion strategies could be excluded.

CONCLUSIONS

Compared with liberal strategies, restrictive transfusion strategies were associated with a reduction in the number of red blood cell units transfused and number of patients being transfused, but mortality, overall morbidity, and myocardial infarction seemed to be unaltered. Restrictive transfusion strategies are safe in most clinical settings. Liberal transfusion strategies have not been shown to convey any benefit to patients.

TRIAL REGISTRATION

PROSPERO CRD42013004272.

Transfusion triggers for guiding RBC transfusion for cardiovascular surgery: a systematic review and meta-analysis*

OBJECTIVE

Restrictive red cell transfusion is recommended to minimize risk associated with exposure to allogeneic blood. However, perioperative anemia is an independent risk factor for adverse outcomes after cardiovascular surgery. The purpose of this systematic review and meta-analysis is to determine whether perioperative restrictive transfusion thresholds are associated with inferior clinical outcomes in randomized trials of cardiovascular surgery patients.

DATA SOURCES

The Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE from inception to October 2013; reference lists of published guidelines, reviews, and associated articles, as well as conference proceedings. No language restrictions were applied.

STUDY SELECTION

We included controlled trials in which adult patients undergoing cardiac or vascular surgery were randomized to different transfusion thresholds, described as a hemoglobin or hematocrit level below which RBCs were transfused.

DATA EXTRACTION

Two authors independently extracted data from included trials. We pooled risk ratios of dichotomous outcomes and mean differences of continuous outcomes across trials using random-effects models.

DATA SYNTHESIS

Seven studies (enrolling 1,262 participants) met inclusion criteria with restrictive and liberal transfusion thresholds most commonly differing by a hemoglobin of 1 g/dL or hematocrit of 6-7%, resulting in decreased transfusions by 0.71 units of RBCs (95% CI, 0.31-1.09, p = 0.0002) without an associated change in adverse events: mortality (risk ratio, 1.12; 95% CI, 0.65-1.95; p = 0.60), myocardial infarction (risk ratio, 0.94; 95% CI, 0.30-2.99; p = 0.92), stroke (risk ratio, 1.15; 95% CI, 0.57-2.32; p = 0.70), acute renal failure (risk ratio, 0.98; 95% CI, 0.64-1.49; p = 0.91), infections (risk ratio, 1.23; 95% CI, 0.85-1.78; p = 0.27), or length of stay. There was no between-trial heterogeneity for any pooled analysis. Including four pediatric trials (456 participants) and 10 trials utilizing only intraoperative acute normovolemic hemodilution (872 participants) did not substantially change the results except that unlike the transfusion threshold trials, the hemodilution trials did not reduce the proportion of patients transfused (interaction p = 0.01).

CONCLUSIONS

Further randomized controlled trials are necessary to determine the optimal transfusion strategy for patients undergoing cardiovascular surgery.

Blood transfusion practices in cardiac anaesthesia

The primary reasons for blood transfusion in cardiac surgery are to correct anaemia and to improve tissue oxygen delivery. However, there is a considerable debate regarding the actual transfusion trigger at which the benefits of transfusion overweight the risk. The association between extreme haemodilution, transfusion and adverse outcome after cardio pulmonary bypass (CPB) is not clear and the current available literature is not sufficient to provide a strong recommendation regarding the safe haematocrit range during CPB. There is no quality evidence to support use of fresh red blood cell except during massive transfusion or exchange transfusion in neonate. Overall concern regarding the safety of allogeneic blood transfusion resulted in the search for autologous blood transfusion and perioperative blood salvage. The aim of this review is to provide cardiac surgery specific clinically useful guidelines pertaining to transfusion triggers, optimal haemodilution during CPB, autologous blood transfusion and role of perioperative blood salvage based on available evidence.

Association of haematocrit and red blood cell transfusion with outcomes in infants with shunt-dependent pulmonary blood flow and univentricular physiology

BACKGROUND

The aim of this study was to investigate the association between red blood cell (RBC) transfusion and haematocrit values with outcomes in infants with univentricular physiology undergoing surgery for a modified Blalock-Taussig shunt.

MATERIAL AND METHODS

This study included infants ≤ 2 months of age who underwent modified Blalock-Taussig shunt surgery at the Arkansas Children's Hospital (2006-2012). Infants undergoing a Norwood operation or Damus-Kaye-Stansel operation with modified Blalock-Taussig shunt were excluded. Demographics, pre-operative, operative, daily laboratory data, and post-operative variables were collected. We studied the association between haematocrit and blood transfusion with a composite clinical outcome. Multivariable logistic regression models were fitted to study the probability of study outcomes as a function of haematocrit values and RBC transfusions after operation.

RESULTS

Seventy-three patients qualified for inclusion. All study patients received blood transfusion within the first 48 hours after heart surgery. The median haematocrit was 44.3 (interquartile range [IQR] 42.5-46.2), and the median volume of RBC transfused was 28 mL/kg (IQR, 10-125) in the first 14 days after surgery. The overall in-hospital mortality rate was 13.6% (10 patients). A multivariable analysis adjusted for risk factors, including weight, prematurity, cardiopulmonary bypass and postoperative need for nitric oxide and dialysis, revealed no association between haematocrit values and RBC transfusion with the composite clinical outcome.

DISCUSSION

We did not find an association between higher haematocrit values and increasing RBC transfusions with improved outcomes in infants with shunt-dependent pulmonary blood flow and univentricular physiology. The power of our study was small, which prevents any strong statement on this lack of association. Future multi-centre, randomised controlled trials are needed to investigate this topic in further detail.

Anemia and red blood cell transfusion in critically ill cardiac patients

Anemia and red blood cell (RBC) transfusion occur frequently in hospitalized patients with cardiac disease. In this narrative review, we report the epidemiology of anemia and RBC transfusion in hospitalized adults and children (excluding premature neonates) with cardiac disease, and on the outcome of anemic and transfused cardiac patients. Both anemia and RBC transfusion are common in cardiac patients, and both are associated with mortality. RBC transfusion is the only way to rapidly treat severe anemia, but is not completely safe. In addition to hemoglobin (Hb) concentration, the determinant(s) that should drive a practitioner to prescribe a RBC transfusion to cardiac patients are currently unclear. In stable acyanotic cardiac patients, Hb level above 70 g/L in children and above 70 to 80 g/L in adults appears safe. In cyanotic children, Hb level above 90 g/L appears safe. The appropriate threshold Hb level for unstable cardiac patients and for children younger than 28 days is unknown. The optimal transfusion strategy in cardiac patients is not well characterized. The threshold at which the risk of anemia outweighs the risk of transfusion is not known. More studies are needed to determine when RBC transfusion is indicated in hospitalized patients with cardiac disease.

Survey on stated transfusion practices in PICUs*

OBJECTIVES

To analyze the RBC transfusion practice patterns among pediatric intensivists in light of the new evidence advocating for a restrictive transfusion strategy.

DESIGN

Self-administered questionnaire.

SETTING

PICUs.

SUBJECTS

Intensivists and fellows in pediatric critical care medicine.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Scenario-based survey carried out among North American and European intensivists, working in tertiary-care PICUs. Respondents were asked to report their decisions with regard to RBC transfusion in stable critically ill children with bronchiolitis, septic shock, trauma, or tetralogy of Fallot repair scenarios. Answers were compared with those of a similar scenario-based survey administered to pediatric intensivists in 1997. Ninety-seven respondents were retained for the study, the majority from the United States, Canada, and France. In 2010, respondents reported that the mean (± SD) transfusion threshold was a hemoglobin level of 7.7 ± 1.0 g/dL for bronchiolitis, 8.1 ± 1.2 g/dL for trauma, 9.1 ± 1.2 g/dL for a tetralogy of Fallot repair, and 9.2 ± 1.0 g/dL for septic shock. For all clinical scenarios, there was a trend toward a more restrictive transfusion approach (a threshold ≤ 7 g/dL) in 2010 compared with 1997: a restrictive strategy was adopted by 55.7% of respondents in 2010 versus 37.0% in 1997 (p = 0.01) with the scenario of bronchiolitis, 8.3% versus 3.4% (p = 0.16) with septic shock, 38.1% versus 9.0% (p < 0.001) with trauma, and 16.0% versus 7.9% (p = 0.10) with tetralogy of Fallot repair.

CONCLUSIONS

Stated transfusion practice patterns of pediatric intensivists appear to be evolving toward a more restrictive approach two and a half years after the publication of the Transfusion Requirement in PICU trial. Incomplete implementation of new knowledge with regard to the safety of a restrictive transfusion approach in stable PICU patients is perplexing and requires further studies.

Health care-associated infection after red blood cell transfusion: a systematic review and meta-analysis

IMPORTANCE

The association between red blood cell (RBC) transfusion strategies and health care-associated infection is not fully understood.

OBJECTIVE

To evaluate whether RBC transfusion thresholds are associated with the risk of infection and whether risk is independent of leukocyte reduction.

DATA SOURCES

MEDLINE, EMBASE, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, Cochrane Database of Sytematic Reviews, ClinicalTrials.gov, International Clinical Trials Registry, and the International Standard Randomized Controlled Trial Number register were searched through January 22, 2014.

STUDY SELECTION

Randomized clinical trials with restrictive vs liberal RBC transfusion strategies.

DATA EXTRACTION AND SYNTHESIS

Twenty-one randomized trials with 8735 patients met eligibility criteria, of which 18 trials (n = 7593 patients) contained sufficient information for meta-analyses. DerSimonian and Laird random-effects models were used to report pooled risk ratios. Absolute risks of infection were calculated using the profile likelihood random-effects method.

MAIN OUTCOMES AND MEASURES

Incidence of health care-associated infection such as pneumonia, mediastinitis, wound infection, and sepsis.

RESULTS

The pooled risk of all serious infections was 11.8% (95% CI, 7.0%-16.7%) in the restrictive group and 16.9% (95% CI, 8.9%-25.4%) in the liberal group. The risk ratio (RR) for the association between transfusion strategies and serious infection was 0.82 (95% CI, 0.72-0.95) with little heterogeneity (I2 = 0%; τ2 <.0001). The number needed to treat (NNT) with restrictive strategies to prevent serious infection was 38 (95% CI, 24-122). The risk of infection remained reduced with a restrictive strategy, even with leukocyte reduction (RR, 0.80 [95% CI, 0.67-0.95]). For trials with a restrictive hemoglobin threshold of <7.0 g/dL, the RR was 0.82 (95% CI, 0.70-0.97) with NNT of 20 (95% CI, 12-133). With stratification by patient type, the RR was 0.70 (95% CI, 0.54-0.91) in patients undergoing orthopedic surgery and 0.51 (95% CI, 0.28-0.95) in patients presenting with sepsis. There were no significant differences in the incidence of infection by RBC threshold for patients with cardiac disease, the critically ill, those with acute upper gastrointestinal bleeding, or for infants with low birth weight.

CONCLUSIONS AND RELEVANCE

Among hospitalized patients, a restrictive RBC transfusion strategy was associated with a reduced risk of health care-associated infection compared with a liberal transfusion strategy. Implementing restrictive strategies may have the potential to lower the incidence of health care-associated infection.

Red cell transfusion management for patients undergoing cardiac surgery for congenital heart disease

BACKGROUND

Congenital heart disease is the most commonly diagnosed neonatal congenital condition. Without surgery, only 30% to 40% of patients affected will survive to 10 years old. Mortality has fallen since the 1990s with 2006 to 2007 figures showing surgical survival at one year of 95%. Patients with congenital heart disease are potentially exposed to red cell transfusion at many points in the surgical pathway. There are a number of risks associated with red cell transfusion that may be translated into increased patient morbidity and mortality.

OBJECTIVES

To evaluate the effects of red cell transfusion on mortality and morbidity on patients with congenital heart disease at the time of cardiac surgery.

SEARCH METHODS

We searched 11 bibliographic databases and three ongoing trials databases including the Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 5, 2013), MEDLINE (Ovid, 1950 to 11 June 2013), EMBASE (Ovid, 1980 to 11 June 2013), ClinicalTrials.gov, World Health Organization (WHO) ICTRP and the ISRCTN Register (to June 2013). We also searched references of all identified trials, relevant review articles and abstracts from between 2006 and 2010 of the most relevant conferences. We did not limit the searches by language of publication.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing red cell transfusion interventions in patients undergoing cardiac surgery for congenital heart disease. We included participants of any age (neonates, paediatrics and adults) and with any type of congenital heart disease (cyanotic or acyanotic). We excluded patients with congenital heart disease undergoing non-cardiac surgery. No co-morbidities were excluded.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. We contacted study authors for additional information.

MAIN RESULTS

We identified 11 trials (862 participants). All trials were in neonatal or paediatric populations. The trials covered only three areas of interest: restrictive versus liberal transfusion triggers (two trials), leukoreduction versus non-leukoreduction (two trials) and standard versus non-standard cardiopulmonary bypass (CPB) prime (seven trials). Owing to the clinical diversity in the participant groups (cyanotic (three trials), acyanotic (four trials) or mixed (four trials)) and the intervention groups, it was not appropriate to pool data in a meta-analysis. No study reported data for all the outcomes of interest to this review. Risk of bias was mixed across the included trials, with only attrition bias being low across all trials. Blinding of study personnel and participants was not always possible, depending on the intervention being used.Five trials (628 participants) reported the primary outcome: 30-day mortality. In three trials (a trial evaluating restrictive and liberal transfusion (125 participants), a trial of cell salvage during CPB (309 participants) and a trial of washed red blood cells during CPB (128 participants)), there was no clear difference in mortality at 30 days between the intervention arms. In two trials comparing standard and non-standard CPB prime, there were no deaths in either randomised group. Long-term mortality was similar between randomised groups in one trial each comparing restrictive and liberal transfusion or standard and non-standard CPB prime.Four trials explored a range of adverse effects following red cell transfusion. Kidney failure was the only adverse event that was significantly different: patients receiving cell salvaged red blood cells during CPB were less likely to have renal failure than patients not exposed to cell salvage (risk ratio (RR) 0.26, 95% confidence interval (CI) 0.09 to 0.79, 1 study, 309 participants). There was insufficient evidence to determine whether there was a difference between transfusion strategies for any other severe adverse events.The duration of mechanical ventilation was measured in seven trials (768 participants). Overall, there was no consistent difference in the duration of mechanical ventilation between the intervention and control arms.The duration of intensive care unit (ICU) stay was measured in six trials (459 participants). There was no clear difference in the duration of ICU stay between the intervention arms in the transfusion trigger and leukoreduction trials. In the standard versus non-standard CPB prime trials, one trial examining the impact of washing transfused bypass prime red blood cells showed no clear difference in duration of ICU stay between the intervention arms, while the trial assessing ultrafiltration of the priming blood showed a shorter duration of ICU stay in the ultrafiltration group.

AUTHORS' CONCLUSIONS

There are only a small number of small and heterogeneous trials so there is insufficient evidence to assess the impact of red cell transfusion on patients with congenital heart disease undergoing cardiac surgery accurately. It is possible that the presence or absence of cyanosis impacts on trial outcomes, which would necessitate different clinical management of two groups. Further adequately powered, specific, high-quality trials are warranted to assess this fully.

Quality and safety in pediatric anesthesia

Health care quality and value are leading issues in medicine today for patients, health care professionals, and policy makers. Outcome, safety, and service-the components of quality-have been used to define value when placed in the context of cost. Health care organizations and professionals are faced with the challenge of improving quality while reducing health care related costs to improve value. Measurement of quality is essential for assessing what is effective and what is not when working toward improving quality and value. However, there are few tools currently for assessing quality of care, and clinicians often lack the resources and skills required to conduct quality improvement work. In this article, we provide a brief review of quality improvement as a discipline and describe these efforts within pediatric anesthesiology.

Safety and effects of two red blood cell transfusion strategies in pediatric cardiac surgery patients: a randomized controlled trial

OBJECTIVE

To investigate the safety and effects of a restrictive red blood cell (RBC) transfusion strategy in pediatric cardiac surgery patients.

DESIGN

Randomized controlled trial.

SETTING

Pediatric ICU in an academic tertiary care center, Leiden University Medical Center, Leiden, The Netherlands.

PATIENTS

One hundred seven patients with non-cyanotic congenital heart defects between 6 weeks and 6 years of age. One hundred three patients underwent corrective surgery on cardiopulmonary bypass.

INTERVENTIONS

Prior to surgery patients were randomly assigned to one of two groups with specific RBC transfusion thresholds: Hb 10.8 g/dl (6.8 mmol/l) and Hb 8.0 g/dl (5.0 mmol/l).

MEASUREMENTS

Length of stay in hospital (primary outcome), length of stay in PICU, duration of ventilation (secondary outcome), incidence of adverse events and complications related to randomization (intention to treat analysis).

RESULTS

In the restrictive transfusion group, mean volume of transfused RBC was 186 (±70) ml per patient and in the liberal transfusion group 258 (±87) ml per patient, (95% CI 40.6-104.6), p < 0.001. Length of hospital stay was shorter in patients with a restrictive RBC transfusion strategy: median 8 (IQR 7-11) vs. 9 (IQR 7-14) days, p = 0.047. All other outcome measures and incidence of adverse effects were equal in both RBC transfusion groups. Cost of blood products for the liberal transfusion group was 438.35 (±203.39) vs. 316.27 (±189.96) euros (95% CI 46.61-197.51) per patient in the restrictive transfusion group, p = 0.002.

CONCLUSIONS

For patients with a non-cyanotic congenital heart defect undergoing elective cardiac surgery, a restrictive RBC transfusion policy (threshold of Hb 8.0 g/dl) during the entire perioperative period is safe, leads to a shorter hospital stay and is less expensive.

Red blood cell transfusion in critically ill children (CME)

BACKGROUND

Red blood cell (RBC) transfusions are common in the pediatric intensive care unit (PICU). However, there are no recent data on transfusion practices in the PICU. Our objective was to determine transfusion practice in the PICU, to compare this practice with that observed 10 years earlier, and to estimate the compliance to the recommendation of a large randomized clinical trial, the Transfusion Requirements in Pediatric Intensive Care Unit (TRIPICU) study.

STUDY DESIGN AND METHODS

This was a single-center prospective observational study over a 1-year period. Information was abstracted from medical charts. Determinants of transfusion were searched for daily until the first transfusion in transfused cases or until PICU discharge in nontransfused cases. The justifications for transfusions were assessed using a questionnaire.

RESULTS

Of 913 consecutive admissions, 842 were included. At least one RBC transfusion was given in 144 patients (17.1%). The mean hemoglobin (Hb) level before the first transfusion was 77.3 ± 27.2 g/L. The determinants of a first transfusion event retained in the multivariate analysis were young age (<12 months), congenital cardiopathy, lowest Hb level of not more than 70 g/L, severity of illness, and some organ dysfunctions. The three most frequently quoted justifications for RBC transfusion were a low Hb level, intent to improve oxygen delivery, and hemodynamic instability. The main recommendation of the TRIPICU study was applied in 96.4% of the first transfusion events.

CONCLUSIONS

RBC transfusions are frequent in the PICU. Young age, congenital heart disease, low Hb level, severity of illness, and some organ dysfunctions are significant determinants of RBC transfusions in the PICU. Most first transfusion events were prescribed according to recent recommendations.

Anemia and transfusion in critically ill pediatric patients: a review of etiology, management, and outcomes

This article describes the incidence and etiology of anemia in critically ill children. In addition, the article details the pathophysiology and clinical ramifications of anemia in this population. The use of transfused packed red blood cells as a therapy for anemia in critically ill patients is also discussed, including the indications for and complications associated with this practice as well as potential reasons for these complications. Finally, the article lists some therapeutic practices that may lessen the risks associated with transfusion, and briefly discusses the use of blood substitutes.

Biomarkers and clinical tools in critically ill children: are we heading toward tailored drug therapy?

In pediatric critical care, validated biomarkers are essential for guiding drug therapy. The aim of this article is to present examples of current biomarker developments in its full breadth, including biochemical substances, physiological measurements and clinical scoring tools, with a focus on the field of circulatory, renal and neurophysiologic failure. Within each field we consecutively discuss the rationale for the selected biomarkers, studies in critically ill children, biomarker validation stage and biomarker use or potential use in drug studies and clinical drug dosing. This article demonstrates that there is paucity of properly validated biomarkers. Nevertheless, recent developments in, for instance, the field of sepsis, point us toward a future wherein, for critically ill children, drug therapy may be personalized using proteomic profiling instead of a small number of biomarkers, in order to establish a personal and dynamic disease profile.

Red blood cell transfusion: decision making in pediatric intensive care units

The results of the Transfusion Requirements in Pediatric Intensive Care Unit study suggest that a red blood cell transfusion is not required in stable or stabilized pediatric intensive care unit children as long as their hemoglobin level is >7 g/dL. Subgroup analyses suggest that this recommendation is also adequate for stable critically ill children with a high severity of illness, respiratory dysfunction, acute lung injury, sepsis, neurological dysfunction, severe head trauma, or severe trauma, and during the postoperative period, for noncyanotic patients older than 28 days. A small randomized clinical trial suggests that a hemoglobin level of 9 g/dL is safe in the postoperative care of children with single-ventricle physiology undergoing cavopulmonary connection. Although there is consensus that blood is clearly indicated for the treatment of hemorrhagic shock, the clinical determinants that should prompt pediatric intensivists to prescribe a red blood cell transfusion to unstable PICU children are not well characterized.

Washing red blood cells and platelets transfused in cardiac surgery reduces postoperative inflammation and number of transfusions: results of a prospective, randomized, controlled clinical trial

OBJECTIVES

Children undergoing cardiac surgery with cardiopulmonary bypass are susceptible to additional inflammatory and immunogenic insults from blood transfusions. We hypothesize that washing red blood cells and platelets transfused to these patients will reduce postoperative transfusion-related immune modulation and inflammation.

DESIGN

Prospective, randomized, controlled clinical trial.

SETTING

University hospital pediatric cardiac intensive care unit.

PATIENTS

Children from birth to 17 yrs undergoing cardiac surgery with cardiopulmonary bypass.

INTERVENTIONS

Children were randomized to an unwashed or washed red blood cells and platelet transfusion protocol for their surgery and postoperative care. All blood was leuko-reduced, irradiated, and ABO identical. Plasma was obtained for laboratory analysis preoperatively, immediately, and 6 and 12 hrs after cardiopulmonary bypass. Primary outcome was the 12-hr postcardiopulmonary bypass interleukin-6-to-interleukin-10 ratio. Secondary measures were interleukin levels, C-reactive protein, and clinical outcomes.

MEASUREMENTS AND MAIN RESULTS

One hundred sixty-two subjects were studied, 81 per group. Thirty-four subjects (17 per group) did not receive any blood transfusions. Storage duration of blood products was similar between groups. Among transfused subjects, the 12-hr interleukin ratio was significantly lower in the washed group (3.8 vs. 4.8; p = .04) secondary to lower interleukin-6 levels (after cardiopulmonary bypass: 65 vs.100 pg/mL, p = .06; 6 hrs: 89 vs.152 pg/mL, p = .02; 12 hrs: 84 vs.122 pg/mL, p = .09). Postoperative C-reactive protein was lower in subjects receiving washed blood (38 vs. 43 mg/L; p = .03). There was a numerical, but not statistically significant, decrease in total blood product transfusions (203 vs. 260) and mortality (2 vs. 6 deaths) in the washed group compared to the unwashed group.

CONCLUSIONS

Washed blood transfusions in cardiac surgery reduced inflammatory biomarkers, number of transfusions, donor exposures, and were associated with a nonsignificant trend toward reduced mortality. A larger study powered to test for clinical outcomes is needed to determine whether these laboratory findings are clinically significant.

Red blood cell transfusion for infants with single-ventricle physiology

The purpose of this study was to assess how red blood cell (RBC) transfusions impact hemodynamic parameters in infants with single-ventricle lesions. This was a retrospective chart review. The setting was a pediatric cardiac intensive care unit at a tertiary care children's hospital. Fifty-nine patients <1 year of age with single-ventricle physiology who received a blood transfusion between December 2007 and April 2009 were analyzed. They received a total of 183 transfusions. Exclusion criteria included transfusions given within 72 h of cardiac surgery or transfusions given to patients with active bleeding. There were no interventions. The study population was divided into terciles based on pretransfusion hemoglobin (Hgb) concentration. The pretransfusion Hgb concentration in group A was 7.8 to 12.3 gm/dl, in group B was 12.4 to 13.2 gm/dl, and in group C was 13.3 to 15.7 gm/dl. Heart rate, blood pressure, arterial saturation, and cerebral near-infrared spectroscopy (cNIRS) values before transfusion, as well as at 1, 2, 4, 8, and 12 h after transfusion, were collected. There was significant improvement in diastolic blood pressure, arterial saturation, and cNIRS in group A after 12 h. Transfusions given in group B also resulted in improvement in diastolic blood pressure and arterial saturation, with less robust response of cNIRS. In group C, only arterial saturation values increased significantly. RBC transfusions can improve hemodynamics and markers of oxygen delivery in infants with single-ventricle physiology, but further studies are needed to determine an optimal Hgb level in this population. Interventions to increase Hgb above this level may be of limited benefit.