Variation in red cell transfusion practice in the intensive care unit: a multicentre cohort study

Appropriateness of Allogeneic Red Blood Cell Transfusions in Non-Bleeding Patients in a Large Teaching Hospital: A Retrospective Study

In hemodynamically stable patients, both anemia and red blood cell (RBC) transfusion may be detrimental to patients; hence, a decision regarding RBC transfusion should be based on thorough risk-benefit assessment. According to hematology and transfusion medicine organizations, RBC transfusion is indicated when recommended hemoglobin (Hb) triggers are met, and symptoms of anemia are present. The aim of our study was to examine the appropriateness of RBC transfusions in non-bleeding patients at our institution. We performed a retrospective analysis of all RBC transfusions performed between January 2022 and July 2022. The appropriateness of RBC transfusion was based on the most recent Association for the Advancement of Blood and Biotherapies (AABB) guidelines and some additional criteria. The overall incidence of RBC transfusions at our institution was 10.2 per 1000 patient-days. There were 216 (26.1%) RBC units appropriately transfused and 612 (73.9%) RBC units that were transfused with no clear indications. The incidence of appropriate and inappropriate RBC transfusions were 2.6 and 7.5 per 1000 patient-days, respectively. The most frequent clinical situations when RBC transfusion was classified as appropriate were: Hb < 70 g/L plus cognitive problems/headache/dizziness (10.1%), Hb < 60 g/L (5.4%), and Hb < 70 g/L plus dyspnea despite oxygen therapy (4.3%). The most frequent causes of inappropriate RBC transfusions were: no Hb determination pre-RBC transfusion (n = 317) and, among these, RBC transfused as a second unit in a single-transfusion episode (n = 260); absence of anemia sings/symptoms pre-transfusion (n = 179); and Hb concentration ≥80 g/L (n = 80). Although the incidence of RBC transfusions in non-bleeding inpatients in our study was generally low, the majority of RBC transfusions were performed outside recommended indications. Red blood cell transfusions were evaluated as inappropriate mainly due to multiple-unit transfusion episodes, absence of anemia signs and/or symptoms pre- transfusion, and liberal transfusion triggers. There is still the need to educate physicians on appropriate indications for RBC transfusion in non-bleeding patients.

Predicting organ functioning with and without blood transfusion in critically ill patients with anemia

BACKGROUND

To develop a model for the prediction of the (most likely) effect of red blood cell (RBC) transfusion on subsequent organ functioning in nonbleeding critically ill patients with hemoglobin concentrations between 6 and 9 g/dL.

STUDY DESIGN AND METHODS

We conducted a retrospective cohort study using electronic health care data of nonbleeding patients admitted between November 2004 and May 2016 at the intensive care unit (ICU) of the Leiden University Medical Center, The Netherlands. We analyzed the associations between transfusion (yes/no) and next-day SOFA scores (Sequential Organ Failure Assessment-as a measure for organ functioning) for all observed combinations of hemoglobin values (between 6 and 9 g/dL) and concurrent clinical variables.

RESULTS

Data of 6425 ICU admission of 5756 critically ill patients with 28,702 hemoglobin values between 6 and 9 g/dL (transfusion decision moments) of which 22.1% were followed by a transfusion were analyzed. The adjusted average difference between the next-day SOFA score of transfused versus not-transfused patients was 0.08 (95% confidence interval [CI] -0.03 to 0.18). At singular transfusion decision moments, the score predicted a beneficial effect of transfusion on next-day SOFA score for some subgroups and medical conditions and a harmful effect in other occasions.

CONCLUSIONS

Among these critically ill patients with hemoglobin concentrations between 6 and 9 g/dL the population average effect of transfusion on the next SOFA score was negligible. Further, our results support caution in clinical decision-making regarding transfusion of critical ill, nonbleeding ICU patients.

Patterns and determinants of blood transfusion in intensive care in Sweden between 2010 and 2018: A nationwide, retrospective cohort study

Background

Intensive care unit (ICU) patients are transfused with blood products for a number of reasons, from massive ongoing hemorrhage, to mild anemia following blood sampling, combined with bone marrow depression due to critical illness. There's a paucity of data on transfusions in ICUs and most studies are based on audits or surveys. The aim of this study was to provide a complete picture of ICU‐related transfusions in Sweden.

Methods

We conducted a register based retrospective cohort study with data on all adult patient admissions from 82 of 84 Swedish ICUs between 2010 and 2018, as recorded in the Swedish Intensive Care Register. Transfusions were obtained from the SCANDAT‐3 database. Descriptive statistics were computed, characterizing transfused and nontransfused patients. The distribution of blood use comparing different ICUs was investigated by computing the observed proportion of ICU stays with a transfusion, as well as the expected proportion.

Results

In 330,938 ICU episodes analyzed, at least one transfusion was administered for 106,062 (32%). For both red‐cell units and plasma, the fraction of patients who were transfused decreased during the study period from 31.3% in 2010 to 24.6% in 2018 for red‐cells, and from 16.6% in 2010 to 9.4% in 2018 for plasma. After adjusting for a range of factors, substantial variation in transfusion frequency remained, especially for plasma units.

Conclusion

Despite continuous decreases in utilization, transfusions remain common among Swedish ICU patients. There is considerable unexplained variation in transfusion rates. More research is needed to establish stronger critiera for when to transfuse ICU patients.

7 Is the New 8: Improving Adherence to Restrictive PRBC Transfusions in the Pediatric ICU

Up to 30%-40% of children admitted to the pediatric intensive care unit (PICU) have anemia, and approximately 15% receive packed red blood cell (pRBC) transfusions. Current literature supports a pRBC transfusion threshold of hemoglobin less than or equal to seven for most PICU patients. Our objective was to determine pRBC transfusion rates, assess compliance with transfusion guidelines, understand patient-level variables that affect transfusion practices, and use cross-industry innovation to implement a practice strategy. This was a pre-post study of pediatric patients admitted to our PICU. We collected baseline data on pRBC transfusion practices. Next, we organized an innovation platform, which generated multi-industry ideas and produced an awareness campaign to effect pRBC ordering behavior. Innovative educational interventions were implemented, and postintervention transfusion practices were monitored. Statistical analysis was performed using linear mixed models. A p value < .05 was considered statistically significant. At baseline, 41% of pRBC transfusions met restrictive transfusion guidelines with a pretransfusion hemoglobin less than or equal to 7 g/dl. In the postintervention period, 53% of transfusions met restrictive transfusion guidelines (odds ratio 1.66, 95% confidence interval 1.21-2.28). Implementation of a behavioral campaign using multi-industry innovation led to improved adherence to pRBC transfusion guidelines in a tertiary care PICU.

Red blood cell transfusion associated with increased morbidity and mortality in patients undergoing elective open abdominal aortic aneurysm repair

BACKGROUND

Red blood cell (RBC) transfusions are associated with increased mortality and morbidity. The aim of this analysis was to examine the association between RBC transfusions and long-term survival for patients undergoing elective open infrarenal abdominal aortic aneurysm (AAA) repair with up to 15 years of follow-up.

METHODS

Prospective cohort study using data from The Danish Vascular Registry from 2000-2015. Primary endpoint was all-cause mortality. Secondary endpoints were in-hospital complications. Transfused patients were divided into subgroups based on received RBC transfusions (1, 2-3, 4-5 or > 5). Using Cox regression multi-adjusted analysis, non-transfused patients were compared to transfused patients (1, 2-3, 4-5, >5 transfusions) for both primary and secondary endpoints.

RESULTS

There were 3 876 patients included with a mean survival of 9.1 years. There were 801 patients who did not receive transfusions. Overall 30-day mortality was 3.1% (121 patients) and 3.6% (112) for all transfused patients. For the five subgroups 30-day mortality was: No transfusions 1.1% (9 patients), 1 RBC 1.2% (4 patients), 2-3 RBC 2.2% (26 patients), 4-5 RBC 1.9% (14 patients) and > 5 RBC 7.9% (68 patients). After receiving RBCs, the hazard ratio for death was 1.54 (95% CI 1.27-1.85) compared to non-transfused patients. There was a significant increase in mortality when receiving 2-3 RBC: HR 1.32 (95% CI 1.07-1.62), 4-5 RBC: 1.64 (1.32-2.03) and >5 RBC: 1.96 (1.27-1.85) in a multi-adjusted model.

CONCLUSION

There is a dose-dependent association between RBC transfusions received during elective AAA repair and an increase in short- and long-term mortality. Approximately 25% of included patients had preoperative anemia. These findings should raise awareness regarding potentially unnecessary and harmful RBC transfusions.

Transfusion Practices Among General Surgeons at a Tertiary Care Center: a Survey Based Study

INTRODUCTION

Blood transfusion practices affect both patient's outcomes and utilization of institutional resources. Evidence shows that liberal blood transfusion has a detrimental effect on patient's outcome. A restrictive approach of blood transfusion is recommended by current clinical guidelines.

AIM

The aim of this study was to evaluate the attitudes, knowledge, and practices of general surgery (GS) staff and residents regarding peri-operative blood transfusion and anemia management.

MATERIAL AND METHODS

A self-administered, web-based questionnaire was developed, and its link was sent to the emails of all general surgeons at King Abdul-Aziz University Hospital (KAUH), Jeddah city, Saudi Arabia. The questionnaire included four parts: 1) background of surgeons; 2) preoperative assessment and management of anemia; 3) post-operative blood transfusion and alternatives; and 4) enablers and barriers.

RESULTS

56 surgeons responded to the questionnaire. We found variations in blood transfusion practices, notably the hemoglobin threshold. For stable non-cardiac cases, 7 g/dL was considered the threshold by 50% of respondents. For stable patients with past cardiac disease, a higher threshold was chosen by most (9 g/dL by 43% and 10 gm/dL by 21%). Most respondents believed that transfusion had no effect on the risk of survival (73%) and on the risk of cancer recurrence (55%) after oncologic surgical resection. Recognized facilitators were the availability of scientific evidence (84%), medicolegal concerns (57%), preference (52%), and institutional protocols (50%).

CONCLUSION

Although current clinical guidelines recommend a restrictive transfusion practice, most respondents tended to over-order blood for elective procedures and were not aware of the potential complications of liberal blood transfusion. To implement the restrictive transfusion policies, health institutions should improve the awareness of surgeons and incorporate a strong supporting evidence in formulating local institutional guidelines.

Changes in the hemoglobin level after one unit of packed red blood cell transfusion in Intensive Care Unit patients

Background:

Blood transfusion is essential in severely ill patients whose hemoglobin (Hb) levels are low, but there are some factors that inhibit optimal increase in Hb. The aim of this study was to evaluate the amount of increase in Hb levels after packed red blood cell (PRBC) transfusions in the Intensive Care Unit (ICU) patients and its related factors.

Materials and Methods:

This cross-sectional study included 124 patients admitted to the ICU, and needed PRBC transfusion. Demographic information, Hb on the 1^st day of admission, blood volume transfusions during the 7 days, and the 7^th day of admission Hb level were extracted from patients’ records.

Results:

The average initial Hb level of patients was reported as 6.17 ± 1.43 g/dl, and after administrating PRBC (4.23 ± 1.87 units during 7 days), the Hb level was 8.09 ± 1.66 g/dl after 7 days (mean difference was 1.91 ± 1.93, t = 11.06, P < 0.001). No significant differences were found between change in Hb level in the terms of age, gender, underlying illness, body mass index, hospitalization history, fever, and duration of hospitalization (P > 0.05). However, the mean increased Hb level in hospitalized patients with internal disorders was the lowest (0.25 g/dl, P = 0.002).

Conclusion:

The results of our study showed that the increased Hb level based on one unit of received PRBC was low, especially in patients with internal. Therefore, based on high frequency of anemia in ICU patients and relative complications, physicians should pay attention to factors affecting Hb levels after PRBC transfusion such as medical history.

Red Blood Cell Product Transfusion Thresholds and Clinical Outcomes

OBJECTIVE

To determine whether patients transfused red blood cell (RBC) products according to guideline-specified pretransfusion hemoglobin (Hb) concentrations or for other reasons were more likely to survive their intensive care unit (ICU) stay.

DESIGN

An observational study of 375 478 episodes of ICU care, over 5 years, was performed with ICU survival as the primary outcome. Outcomes were analyzed as a function of pretransfusion Hb concentration for groups with distinct transfusion indications while adjusting for potential confounders.

SETTING AND PATIENTS

This study included all adult patients discharged from 1 of 203 adult ICUs from 32 US health-care systems. The patients were from community hospitals, tertiary, and academic medical centers.

INTERVENTION

Transfusion of allogenic packed RBCs or whole blood was prescribed at the discretion of the treating clinicians.

MEASUREMENTS AND MAIN RESULTS

We found that 15% of adult ICU patients are transfused RBC products, and most transfusions for hemodynamically stable patients are administered above the guideline-specified pretransfusion Hb threshold of 7 g/dL. Hemodynamically stable patients transfused below this threshold were significantly more likely to survive their ICU stay than those not transfused (odds ratio [OR] 0.59, 95% confidence interval [CI], 0.43-0.81; P = .001), and patients transfused at thresholds above 9 g/dL were less likely to survive their ICU stay than those not transfused. Patients of the acute blood loss group who were transfused appeared to benefit or were not harmed by transfusion.

CONCLUSION

Conservative RBC product transfusion practices for groups that are targeted by guidelines are justified by outcomes observed in clinical practice. This study provides evidence for the liberal administration of RBC products to critically ill adults with acute blood loss based on association with lower risk of mortality.

Factors Associated with Bleeding and Thrombosis in Children Receiving Extracorporeal Membrane Oxygenation

RATIONALE

Extracorporeal membrane oxygenation (ECMO) is used for respiratory and cardiac failure in children but is complicated by bleeding and thrombosis.

OBJECTIVES

(1) To measure the incidence of bleeding (blood loss requiring transfusion or intracranial hemorrhage) and thrombosis during ECMO support; (2) to identify factors associated with these complications; and (3) to determine the impact of these complications on patient outcome.

METHODS

This was a prospective, observational cohort study in pediatric, cardiac, and neonatal intensive care units in eight hospitals, carried out from December 2012 to September 2014.

MEASUREMENTS AND MAIN RESULTS

ECMO was used on 514 consecutive patients under age 19 years. Demographics, anticoagulation practices, severity of illness, circuitry components, bleeding, thrombotic events, and outcome were recorded. Survival was 54.9%. Bleeding occurred in 70.2%, including intracranial hemorrhage in 16%, and was independently associated with higher daily risk of mortality. Circuit component changes were required in 31.1%, and patient-related clots occurred in 12.8%. Laboratory sampling contributed to transfusion requirement in 56.6%, and was the sole reason for at least one transfusion in 42.2% of patients. Pump type was not associated with bleeding, thrombosis, hemolysis, or mortality. Hemolysis was predictive of subsequent thrombotic events. Neither hemolysis nor thrombotic events increased the risk of mortality.

CONCLUSIONS

The incidences of bleeding and thrombosis are high during ECMO support. Laboratory sampling is a major contributor to transfusion during ECMO. Strategies to reduce the daily risk of bleeding and thrombosis, and different thresholds for transfusion, may be appropriate subjects of future trials to improve outcomes of children requiring this supportive therapy.

Optimal hematocrit in an artificial microvascular network

BACKGROUND

Higher hematocrit increases the oxygen-carrying capacity of blood but also increases blood viscosity, thus decreasing blood flow through the microvasculature and reducing the oxygen delivery to tissues. Therefore, an optimal value of hematocrit that maximizes tissue oxygenation must exist.

STUDY DESIGN AND METHODS

We used viscometry and an artificial microvascular network device to determine the optimal hematocrit in vitro. Suspensions of fresh red blood cells (RBCs) in plasma, normal saline, or a protein-containing buffer and suspensions of stored red blood cells (at Week 6 of standard hypothermic storage) in plasma with hematocrits ranging from 10 to 80% were evaluated.

RESULTS

For viscometry, optimal hematocrits were 10, 25.2, 31.9, 37.1, and 37.5% for fresh RBCs in plasma at shear rates of 3.2 or less, 11.0, 27.7, 69.5, and 128.5 inverse seconds. For the artificial microvascular network, optimal hematocrits were 51.1, 55.6, 59.2, 60.9, 62.3, and 64.6% for fresh RBCs in plasma and 46.4, 48.1, 54.8, 61.4, 65.7, and 66.5% for stored RBCs in plasma at pressures of 2.5, 5, 10, 20, 40, and 60 cm H₂ O.

CONCLUSION

Although exact optimal hematocrit values may depend on specific microvascular architecture, our results suggest that the optimal hematocrit for oxygen delivery in the microvasculature depends on perfusion pressure. Therefore, anemia in chronic disorders may represent a beneficial physiological response to reduced perfusion pressure resulting from decreased heart function and/or vascular stenosis. Our results may help explain why a therapeutically increasing hematocrit in such conditions with RBC transfusion frequently leads to worse clinical outcomes.

Global Collaboration in Acute Care Clinical Research: Opportunities, Challenges, and Needs

The most impactful research in critical care comes from trials groups led by clinician-investigators who study questions arising through the day-to-day care of critically ill patients. The success of this model reflects both "necessity"-the paucity of new therapies introduced through industry-led research-and "clinical reality"-nuanced modulation of standard practice can have substantial impact on clinically important outcomes. Success in a few countries has fueled efforts to build similar models around the world and to collaborate on an unprecedented scale in large international trials. International collaboration brings opportunity-the more rapid completion of clinical trials, enhanced generalizability of the results of these trials, and a focus on questions that have evoked international curiosity. It has changed practice, improved outcomes, and enabled an international response to pandemic threats. It also brings challenges. Investigators may feel threatened by the loss of autonomy inherent in collaboration, and appropriate models of academic credit are yet to be developed. Differences in culture, practice, ethical frameworks, research experience, and resource availability create additional imbalances. Patient and family engagement in research is variable and typically inadequate. Funders are poorly equipped to evaluate and fund international collaborative efforts. Yet despite or perhaps because of these challenges, the discipline of critical care is leading the world in crafting new models of clinical research collaboration that hold the promise of not only improving the care of the most vulnerable patients in the healthcare system but also transforming the way that we conduct clinical research.

Red blood cell storage time and transfusion: current practice, concerns and future perspectives

Red blood cells (RBCs) units are the most requested transfusion product worldwide. Indications for transfusion include symptomatic anaemia, acute sickle cell crisis, and acute blood loss of more than 30% of the blood volume, with the aim of restoring tissue oxygen delivery. However, stored RBCs from donors are not a qualitative equal product, and, in many ways, this is a matter of concern in the transfusion practice. Besides donor-to-donor variation, the storage time influences the RBC unit at the qualitative level, as RBCs age in the storage bag and are exposed to the so-called storage lesion. Several studies have shown that the storage lesion leads to post-transfusion enhanced clearance, plasma transferrin saturation, nitric oxide scavenging and/or immunomodulation with potential unwanted transfusion-related clinical outcomes, such as acute lung injury or higher mortality rate. While, to date, several studies have claimed the risk or deleterious effects of "old" vs "young" RBC transfusion regimes, it is still a matter of debate, and consideration should be taken of the clinical context. Transfusion-dependent patients may benefit from transfusion with "young" RBC units, as it assures longer inter-transfusion periods, while transfusion with "old" RBC units is not itself harmful. Unbiased Omics approaches are being applied to the characterisation of RBC through storage, to better understand the (patho)physiological role of microparticles (MPs) that are found naturally, and also on stored RBC units. Perhaps RBC storage time is not an accurate surrogate for RBC quality and there is a need to establish which parameters do indeed reflect optimal efficacy and safety. A better Omics characterisation of components of "young" and "old" RBC units, including MPs, donor and recipient, might lead to the development of new therapies, including the use of engineered RBCs or MPs as cell-based drug delivering tools, or cost-effective personalised transfusion strategies.

Blood Conservation Strategies in Cardiac Surgery

Perioperative bleeding in cardiac surgery is related to both surgical trauma of blood vessels and defects in the hemostatic mechanism caused, in part, by cardiopulmonary bypass. Blood transfusion therefore remains a significant risk of cardiac surgery with important health and economic consequences. Blood conservation strategies for cardiac surgery have advanced over the years and the following discussion will focus on the current practices at Toronto General Hospital.

Hemoglobin Level and Hospital Mortality Among ICU Patients With Cardiac Disease Who Received Transfusions

BACKGROUND

There is a paucity of randomized clinical trial data on the use of red blood cell (RBC) transfusion in critically ill patients, specifically in the setting of cardiac disease.

OBJECTIVES

This study examined how hemoglobin (Hgb) level and cardiac disease modify the relationship of RBC transfusion with hospital mortality. The aim was to estimate the Hgb level threshold below which transfusion would be associated with reduced hospital mortality.

METHODS

We performed secondary data analyses of Veterans Affairs intensive care unit (ICU) episodes across 5 years. Logistic regression quantified the effect of transfusion on hospital mortality while adjusting for nadir Hgb level, demographic characteristics, admission information, comorbid conditions, and ICU admission diagnoses.

RESULTS

Among 258,826 ICU episodes, 12.4% involved transfusions. Hospital death occurred in 11.6%. Without comorbid heart disease, transfusion was associated with decreased adjusted hospital mortality when Hgb was approximately <7.7 g/dl, but transfusion increased mortality above this Hgb level. Corresponding Hgb level thresholds were approximately 8.7 g/dl when comorbid heart disease was present and approximately 10 g/dl when the ICU admission diagnosis was acute myocardial infarction (AMI). Sensitivity analysis using additional adjustment for selected blood tests in a subgroup of 182,792 ICU episodes lowered these thresholds by approximately 1 g/dl.

CONCLUSIONS

Transfusion of critically ill patients was associated with reduced hospital mortality when Hgb level was <8 to 9 g/dl in the presence of comorbid heart disease. This Hgb level threshold for transfusion was 9 to 10 g/dl when AMI was the ICU admission diagnosis.

Non-invasive monitoring of oxygen delivery in acutely ill patients: new frontiers

Hypovolemia, anemia and hypoxemia may cause critical deterioration in the oxygen delivery (DO₂). Their early detection followed by a prompt and appropriate intervention is a cornerstone in the care of critically ill patients. And yet, the remedies for these life-threatening conditions, namely fluids, blood and oxygen, have to be carefully titrated as they are all associated with severe side-effects when administered in excess. New technological developments enable us to monitor the components of DO₂ in a continuous non-invasive manner via the sensor of the traditional pulse oximeter. The ability to better assess oxygenation, hemoglobin levels and fluid responsiveness continuously and simultaneously may be of great help in managing the DO₂. The non-invasive nature of this technology may also extend the benefits of advanced monitoring to wider patient populations.

Blood transfusion after percutaneous coronary intervention and risk of subsequent adverse outcomes: a systematic review and meta-analysis

OBJECTIVES

This study sought to define the prevalence and prognostic impact of blood transfusions in contemporary percutaneous coronary intervention (PCI) practice.

BACKGROUND

Although the presence of anemia is associated with adverse outcomes in patients undergoing PCI, the optimal use of blood products in patients undergoing PCI remains controversial.

METHODS

A search of EMBASE and MEDLINE was conducted to identify PCI studies that evaluated blood transfusions and their association with major adverse cardiac events (MACE) and mortality. Two independent reviewers screened the studies for inclusion, and data were extracted from relevant studies. Random effects meta-analysis was used to estimate the risk of adverse outcomes with blood transfusions. Statistical heterogeneity was assessed by considering the I(2) statistic.

RESULTS

Nineteen studies that included 2,258,711 patients with more than 54,000 transfusion events were identified (prevalence of blood transfusion 2.3%). Crude mortality rate was 6,435 of 50,979 (12.6%, 8 studies) in patients who received a blood transfusion and 27,061 of 2,266,111 (1.2%, 8 studies) in the remaining patients. Crude MACE rates were 17.4% (8,439 of 48,518) in patients who had a blood transfusion and 3.1% (68,062 of 2,212,730) in the remaining cohort. Meta-analysis demonstrated that blood transfusion was independently associated with an increase in mortality (odds ratio: 3.02, 95% confidence interval: 2.16 to 4.21, I(2) = 91%) and MACE (odds ratio: 3.15, 95% confidence interval: 2.59 to 3.82, I(2) = 81%). Similar observations were recorded in studies that adjusted for baseline hematocrit, anemia, and bleeding.

CONCLUSIONS

Blood transfusion is independently associated with increased risk of mortality and MACE events. Clinicians should minimize the risk for periprocedural transfusion by using available bleeding-avoidance strategies and avoiding liberal transfusion practices.

Aeromedical evacuation of combat patients by military critical care air transport teams with a lower hemoglobin threshold approach is safe

BACKGROUND

Military critical care air transport teams (CCATT) evacuate critically ill and injured patients out of theater for tertiary treatment. Teams are led by a physician, nurse, and respiratory technician. Current aeromedical guidelines require a hemoglobin (Hgb) of 9 g/dL or greater to evacuate; however, civilians report that an Hgb of 8 g/dL or less is safe in critically ill patients. This study aimed to compare postflight short-term and 30-day patient outcomes for CCATT patients evacuated out of theater with an Hgb of 8 g/dL or less with those with an Hgb of greater than 8 g/dL.

METHODS

We conducted a retrospective record review of all traumatically injured patients evacuated from theater by CCATT between March 2007 and December 2011. We recorded demographics, injury descriptions, vital signs, laboratory values, adverse events, and disposition at 30 days. Patients were separated into those with a preflight Hgb of 8 g/dL or less versus those with greater than 8 g/dL. Continuous data were analyzed using Student's t tests or Wilcoxon tests and reported as mean ± SD. χ or Fisher's exact tests were performed. Stepwise, multifactorial logistic regression models were used. Statistical significance was considered with p < 0.05.

RESULTS

Of 1,252 patients, 1,033 had a preflight Hgb of greater than 8 and 219 had an Hgb of 8 or less. Age, sex proportions, vitals, laboratory values, and Injury Severity Score (ISS; 24±13) were similar. The group with 8 or less had more blast injuries (68% vs. 76%, p = 0.01). No associations were identified between preflight Hgb levels and adverse outcomes. Disposition at 30 days was similar. We also compared preflight Hgb greater than 7 versus 7 or less (n = 1,212 vs. 45). Those with an Hgb greater than 7 had a greater incidence of hospitalization at 30 days (77% vs. 67%, p = 0.04). The group with an Hgb of 7 or less had more subjects discharged home or returning to duty (10% vs. 21%, p = 0.04).

CONCLUSION

Evacuating CCATT patients with an Hgb of 8 or less had similar adverse outcomes and mortality at 30 days compared with those with an Hgb greater than 8. Patients with an Hgb of 7 or less had higher rates of hospital discharge and decreased incidence of hospitalization at 30 days.

LEVEL OF EVIDENCE

Prognostic/epidemiologic study, level III.

Can old dogs learn new "transfusion requirements in critical care": a survey of packed red blood cell transfusion practices among members of The American Association for the Surgery of Trauma

BACKGROUND

The objective of this study was to characterize variations in packed red blood cell (PRBC) transfusion practices in critically ill patients and to identify which factors influence such practices. We hypothesized that significant variation in transfusion triggers exists among acute care surgeons.

METHODS

A survey of PRBC transfusion practices was administered to the American Association for the Surgery of Trauma members. The scenarios examined hemoglobin thresholds for which participants would transfuse PRBCs.

RESULTS

A hemoglobin threshold of less than or equal to 7 g/dL was adopted by 45% of respondents in gastrointestinal bleeding, 75% in penetrating trauma, 66% in sepsis, and 62% in blunt trauma. Acute care surgeons modified their transfusion trigger significantly in the majority of the modifications of these scenarios, often inappropriately so.

CONCLUSIONS

This study documents continued evidence-practice gaps and wide variations in the PRBC transfusion practices of acute care surgeons. Numerous clinical factors altered such patterns despite a lack of supporting evidence (for or against).

Trends in red blood cell transfusion and 30-day mortality among hospitalized patients

BACKGROUND

Blood conservation strategies have been shown to be effective in decreasing red blood cell (RBC) utilization in specific patient groups. However, few data exist describing the extent of RBC transfusion reduction or their impact on transfusion practice and mortality in a diverse inpatient population.

STUDY DESIGN AND METHODS

We conducted a retrospective cohort study using comprehensive electronic medical record data from 21 medical facilities in Kaiser Permanente Northern California. We examined unadjusted and risk-adjusted RBC transfusion and 30-day mortality coincident with implementation of RBC conservation strategies.

RESULTS

The inpatient study cohort included 391,958 patients who experienced 685,753 hospitalizations. From 2009 to 2013, the incidence of RBC transfusion decreased from 14.0% to 10.8% of hospitalizations; this change coincided with a decline in pretransfusion hemoglobin (Hb) levels from 8.1 to 7.6 g/dL. Decreased RBC utilization affected broad groups of admission diagnoses and was most pronounced in patients with a nadir Hb level between 8 and 9 g/dL (n = 73,057; 50.8% to 19.3%). During the study period, the standard deviation of risk-adjusted RBC transfusion incidence across hospitals decreased by 44% (p < 0.001). Thirty-day mortality did not change significantly with declines in RBC utilization in patient groups previously studied in clinical trials nor in other subgroups.

CONCLUSIONS

After the implementation of blood conservation strategies, RBC transfusion incidence and pretransfusion Hb levels decreased broadly across medical and surgical patients. Variation in RBC transfusion incidence across hospitals decreased from 2010 to 2013. Consistent with clinical trial data, more restrictive transfusion practice did not appear to impact 30-day mortality.

Economic considerations on transfusion medicine and patient blood management

In times of escalating health-care cost, it is of great importance to carefully assess the cost-effectiveness and appropriateness of the most resource-consuming health interventions. A long-standing and common clinical practice that has been underestimated in cost and overestimated in effectiveness is the transfusion of allogeneic blood products. Studies show that this intervention comes with largely underestimated service cost and unacceptably high utilisation variability for matched patients, thus adding billions of unnecessary dollars to the health-care expenditure each year. Moreover, a large and increasing body of literature points to a dose-dependent increase of morbidity and mortality and adverse long-term outcomes associated with transfusion whereas published evidence for benefit is extremely limited. This means that transfusion may be a generator for increased hospital stay and possible re-admissions, resulting in additional billions in unnecessary expenditure for the health system. In contrast to this, there are evidence-based and cost-effective treatment options available to pre-empt and reduce allogeneic transfusions. The patient-specific rather than a product-centred application of these multiple modalities is termed patient blood management (PBM). From a health-economic perspective, the expeditious implementation of PBM programmes is clearly indicated. Both patients and payers could benefit from this concept that has recently been endorsed through the World Health Assembly resolution WHA63.12.

Is single-unit blood transfusion bad post-coronary artery bypass surgery?

OBJECTIVES

Publications in the surgical literature are very consistent in their conclusions that blood is dangerous with regard to in-hospital mortality, morbidity and long-term survival. Blood is frequently used as a volume expander while simultaneously increasing the haematocrit. We investigated the effects of a single-unit blood transfusion on long-term survival post-cardiac surgery in isolated coronary artery bypass grafting patients.

METHODS

A prospective single-institution cardiac surgery database was analysed involving 4615 patients. Univariate, multivariate stepwise Cox regression analysis and propensity matching were performed to identify whether a single-unit blood transfusion was detrimental to long-term survival.

RESULTS

Univariate analysis revealed that blood was significantly associated with a reduced long-term survival even with a single-unit transfused, P = 0.0001. Cox multivariate regression analysis identified age, ejection fraction, preoperative dialysis, logistic EuroSCORE, postoperative CKMB, blood transfusion, urgent operative status and atrial fibrillation as significant factors determining long-term survival. When the Cox regression was repeated with patients who received no blood or only one unit of blood, transfusion was not a risk factor for long-term survival. An interaction analysis revealed that blood transfusion was significantly interacting with preoperative haemoglobin levels, P = 0.02. Propensity analysis demonstrated that a single-unit transfusion is not associated with a detrimental long-term survival, P = 0.3.

CONCLUSIONS

Cox regression and propensity matching both indicate that a single-unit transfusion is not a significant cause of reduced long-term survival. Preoperative anaemia is a significant confounding factor. Despite demonstrating the negligible risks of a single-unit blood transfusion, we are not advocating liberal transfusion and would recommend changing from a double-unit to a single-unit transfusion policy. We speculate that blood is not bad, but that the underlying reason that it is given might be.

Circulação extracorpórea e complicações no período pós-operatório imediato de cirurgias cardíacas

OBJETIVO: Comparar a frequência de complicações apresentadas pelos pacientes, durante o pós-operatório imediato (POI), de cirurgias cardíacas de acordo com o tempo de circulação extra-corpórea (CEC). MÉTODOS: Estudo de natureza quantitativa, descritivo e correlacional com 83 pacientes adultos divididos em dois grupos de acordo com o tempo de CEC. RESULTADOS: Do total de pacientes, 44 (53%) tiveram o tempo de duração da CEC de até 85 minutos e 39 (47 %) tiveram o tempo acima de 85 minutos. As complicações foram comuns para ambos os grupos, sendo as mais frequentes dor e oligúria. No entanto, hemotórax, pneumotórax e infarto agudo do miocárdio ocorreram apenas no grupo com maior tempo de CEC. CONCLUSÃO: A maioria das complicações ocorridas no POI apresentou frequencia semelhante para os pacientes, independente do tempo de CEC.

Red blood cell transfusion in the critically ill patient

Red blood cell (RBC) transfusion is a common intervention in intensive care unit (ICU) patients. Anemia is frequent in this population and is associated with poor outcomes, especially in patients with ischemic heart disease. Although blood transfusions are generally given to improve tissue oxygenation, they do not systematically increase oxygen consumption and effects on oxygen delivery are not always very impressive. Blood transfusion may be lifesaving in some circumstances, but many studies have reported increased morbidity and mortality in transfused patients. This review focuses on some important aspects of RBC transfusion in the ICU, including physiologic considerations, a brief description of serious infectious and noninfectious hazards of transfusion, and the effects of RBC storage lesions. Emphasis is placed on the importance of personalizing blood transfusion according to physiological endpoints rather than arbitrary thresholds.

Management of late postoperative complications of bariatric surgery

Background

The prevalence of obesity is increasing worldwide and the past decade has witnessed an exponential rise in the number of bariatric operations performed. As a consequence, an increasing number of patients are presenting to non-specialist units with complications following bariatric procedures. This article outlines the management of the most common late postoperative complications that are likely to present to the general surgeon.

Methods

A search was conducted for late postoperative complications after bariatric surgery using PubMed, Embase, OVID and Google search engines, and combinations of the terms bariatric surgery, gastric bypass, gastric banding or sleeve gastrectomy, and late or delayed complications. Only studies with follow-up longer than 6 months were included.

Results

The most common long-term complications after gastric banding include band slippage and erosion. Deflation or removal of the band is often required. Internal hernia, adhesions and anastomotic stenosis are common causes of intestinal obstruction after gastric bypass surgery. Hepatobiliary complications pose a particular challenge because of the altered anatomy. Functional disorders such as reflux and dumping, and nutritional deficiencies are common and should be differentiated from conditions that require urgent investigations and timely surgical intervention.

Conclusion

The immediate management of bariatric patients presenting with complications outside the immediate postoperative period requires adherence to basic surgical principles. Accurate diagnosis often relies on high-quality contrast and cross-sectional imaging, and effective surgical intervention necessitates a broad understanding of the altered anatomy, advanced surgical skills and liaison with specialists in the field when necessary.

Patient factors associated with transfusion practices in Veterans Affairs intensive care units: implications for further research

PURPOSE

We sought to describe how patient characteristics influence the frequency of red blood cell (RBC) transfusions among critically ill patients after taking into account hemoglobin (Hgb) level.

METHODS

This was a retrospective cohort study using secondary analysis of administrative data of Veterans Affairs intensive care unit (ICU) admissions. The outcome of interest was RBC transfusion during the first 30 days of ICU admission. Besides Hgb level, explanatory variables included demographics, admission-related information, comorbid conditions, ICU admission diagnosis, and selected laboratory test results. Logistic regression modeling quantified associations between explanatory variables and transfusion.

RESULTS

For 259 281 ICU admissions from 2001 to 2005, the overall incidence of RBC transfusion was 12.5%. Increased age, male gender, admission for acute myocardial infarction (AMI), and comorbid heart disease were independently associated with transfusion. Compared with admission for reference diagnoses, transfusions were more likely for admissions for AMI, unstable angina, and congestive heart failure only at Hgb levels below 11, 9, and 6 g/dL, respectively.

CONCLUSIONS

Intensive care unit patients admitted for AMI, unstable angina, and congestive heart-failure had higher likelihood of receiving RBC transfusions below specific Hgb levels varying from 6 to 11 g/dL. Further research is needed to determine how these transfusion practices influence outcomes.

Blood transfusion after pediatric cardiac surgery is associated with prolonged hospital stay

BACKGROUND

Red blood cell transfusion is associated with morbidity and mortality among adults undergoing cardiac surgery. We aimed to evaluate the association of transfusion with morbidity among pediatric cardiac surgical patients.

METHODS

Patients discharged after cardiac surgery in 2003 were retrospectively reviewed. The red blood cell volume administered during the first 48 postoperative hours was used to classify patients into nonexposure, low exposure (≤15 mL/kg), or high exposure (>15 mL/kg) groups. Cox proportional hazards modeling was used to evaluate the association of red blood cell exposure to length of hospital stay (LOS).

RESULTS

Of 802 discharges, 371 patients (46.2%) required blood transfusion. Demographic differences between the transfusion exposure groups included age, weight, prematurity, and noncardiac structural abnormalities (all p<0.001). Distribution of Risk Adjusted Classification for Congenital Heart Surgery, version 1 (RACHS-1) categories, intraoperative support times, and postoperative Pediatric Risk of Mortality Score, Version III (PRISM-III) scores varied among the exposure groups (p<0.001). Median duration of mechanical ventilation (34 hours [0 to 493] versus 27 hours [0 to 621] versus 16 hours [0 to 375]), incidence of infection (21 [14%] versus 29 [13%] versus 17 [4%]), and acute kidney injury (25 [17%] versus 29 [13%] versus 34 [8%]) were highest in the high transfusion exposure group when compared with the low or nontransfusion groups (all p<0.001). In a multivariable Cox proportional hazards model, both the low transfusion group (adjusted hazard ratio [HR] 0.80, 95% confidence interval [CI]: 0.66 to 0.97, p=0.02) and high transfusion group (adjusted HR 0.66, 95% CI: 0.53 to 0.82, p<0.001) were associated with increased LOS. In subgroup analyses, both low transfusion (adjusted HR 0.81, 95% CI: 0.65 to 1.00, p=0.05) and high transfusion (adjusted HR 0.65, 95% CI: 0.49 to 0.87, p=0.004) in the biventricular group but not in the single ventricle group was associated with increased LOS.

CONCLUSIONS

Blood transfusion is associated with prolonged hospitalization of children after cardiac surgery, with biventricular patients at highest risk for increased LOS. Future studies are necessary to explore this association and refine transfusion practices.

Transfusion practice in the intensive care unit: a 10-year analysis

BACKGROUND

Clinical guidelines recommend a restrictive transfusion strategy in nonhemorrhaging critically ill patients.

STUDY DESIGN AND METHODS

We conducted a retrospective observational study of 3533 single-admission patients, without evidence of acute coronary syndromes, hemorrhage, or hemoglobinopathy admitted to the medical intensive care unit (MICU) of a large, academic medical center.

RESULTS

MICU admission hemoglobin (Hb) level did not change significantly over the study period. The proportion of transfused patients decreased from 31.0% in 1997 to 1998 to 18.0% in 2006 to 2007 (p<0.001). Among patients receiving transfusion, the mean pretransfusion Hb level decreased over time from 7.9±1.3 to 7.3±1.3g/dL (p<0.001). These changes in practice were not accounted for by differences in patient characteristics. The mean nadir Hb level in nontransfused patients decreased from 11.2±2.2g/dL in 1997 to 1999 to 10.4±2.3g/dL in 2006 to 2007 (p<0.001). The mean number of units per patient transfused decreased during this time from 4.3±4.7 to 3.0±3.8 units (p<0.001). The proportion of transfused patients who were transfused at a Hb level of less than 7.0g/dL increased by an estimated absolute increment of 3.2% (95% CI, 2.1%-4.3%) per interval (p<0.001), and the proportion of single-unit transfusions during the first transfusion episode increased by 1.4% per interval (95% CI, 0.2 to 2.6%; p=0.03) from 40.2% in 1997 to 1998 to 53.1% in 2006 to 2007.

CONCLUSIONS

Between 1997 and 2007, important and sustained changes have occurred in our MICU physician transfusion practices, with overall reductions in the proportion of patients transfused, mean pretransfusion Hb level, and nadir Hb level in patients who were not transfused.

[Is there still a role for recombinant erythropoietin in the management of anaemia of critical illness?]

There is a high prevalence of anaemia among patients admitted to the intensive care unit (ICU), and it may have a negative effect on patient's outcome. The most common treatment for anaemia in the ICU patient is allogeneic blood transfusion (ABT), yet it has been found to be a risk factor associated with an increased risk of morbidity and mortality in critical care patients. As a reduction of erythropoietin secretion and action is observed in most ICU patients, the administration of (rHuEPO) has emerged as a therapeutic option. Unfortunately, the results from different studies show that rHuEPO treatment results in a small reduction of ABT requirements when "restrictive" transfusion criteria are applied, which has only been supported by three of the studies. Yet this did not result in a decreased mortality rate, except for patients with a diagnosis on admission of trauma in two studies, even though one study reported a dose-dependent increase of thrombotic vascular events among patients without thromboprophylaxis. Altogether, clinical data suggest a role for rHuEPO in the treatment of anaemia in trauma patients, especially in those sustaining neurotrauma, whereas for non-trauma patients without an approved indication, rHuEPO administration is an expensive approach, does not seem to improve outcome, and might result in serious adverse effects. Consequently, more basic and clinical studies are required to ascertain which patients are more likely to benefit from these treatments, as well as to identify the optimal doses and administration schedules, and iron administration.

Investigator-led clinical research consortia: the Canadian Critical Care Trials Group

Advances in the care of critically ill patients are dependent upon rigorous clinical research undertaken to characterize natural history and risk factors, and determine optimal approaches to the management of the diseases of the critically ill patient. The Canadian Critical Care Trials Group (CCCTG) was formed in 1989 to foster such research. It has grown to become a national, multidisciplinary organization with more than 100 members, and more than 3 dozen active research programs. Its members have been highly successful in obtaining funding for, completing, and publishing well-designed studies that have informed international practice in areas such as transfusion, stress ulcer prophylaxis, long term outcomes from acute respiratory distress syndrome, diagnosis and management of infection in the intensive care unit, and end-of-life care. In the process, the CCCTG has developed a highly effective culture of scientific mentoring, and has served as a model for investigator-led critical care research groups around the world. This review summarizes the history, activities, approaches, and challenges of the CCCTG, in the conviction that investigator-led groups such as ours represent the future of intensive care unit-based research.

Transfusion practice and outcomes in non-ST-segment elevation acute coronary syndromes

OBJECTIVES

To describe the association between transfusion and outcomes as a function of nadir hematocrit (HCT) in patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS).

BACKGROUND

The adverse outcomes associated with transfusion in NSTE ACS is uncertain and may vary by nadir HCT of the transfused.

METHODS

Using data from 44242 patients with NSTE ACS in 400 US hospitals in the CRUSADE initiative (January 2004-December 2005), we describe blood transfusion as a function of nadir HCT and associated outcomes across nadir HCT groups (<or=24%, 24.1%-27%, 27.1%-30%, >30%). We further explore patient and process variation across hospital quartiles defined by transfusion use.

RESULTS

Overall, 22.2% of patients with NSTE ACS are anemic and 10.4% receive a blood transfusion during their care. Likelihood of transfusion rose from 1% when nadir HCT was >30% to 70% when nadir HCT was <or=24%. The threshold for transfusion is a median nadir HCT of 25.7% (interquartile range 23.8%-27.5%). Although nadir HCT of transfused remains constant across quartiles of transfusion use, occurrence of bleeding increases. Inhospital mortality is higher in lower nadir HCT groups. In those with a nadir HCT of <or=24%, transfusion tended to have a beneficial impact on mortality (HCT <or=24% adjusted odds ratio [OR] 0.68 [0.45-1.02]). In the median range where transfusion occurs, transfusion had a neutral impact on mortality (HCT 24%-27% adjusted OR 1.01 [0.79-1.30]). Although rare, those transfused with nadir HCT of 27% to 30% (adjusted OR 1.18 [0.92-1.50]) or HCT of >30% (adjusted OR 3.47 [2.30-5.23]) had higher mortality.

CONCLUSION

Anemia and transfusion are common in the care of NSTE ACS. The observed association between transfusion and adverse outcomes is neutral in the nadir HCT range where transfusions are most often given and trends strongly to benefit when nadir HCT is <or=24%. Although reassuring, randomized trials are needed to confirm the safety of transfusion in NSTE ACS. In the meantime, avoiding the need for transfusion is the best approach.

A survey of Canadian intensivists' resuscitation practices in early septic shock

Introduction

Recent evidence suggests that early, aggressive resuscitation in patients with septic shock reduces mortality. The objective of this survey was to characterize reported resuscitation practices of Canadian physicians caring for adult critically ill patients with early septic shock.

Methods

A scenario-based self-administered national survey was sent out to Canadian critical care physicians. One hypothetical scenario was developed to obtain information on several aspects of resuscitation in early septic shock, including monitoring and resuscitation end-points, fluid administration, red blood cell transfusion triggers, and use of inotropes. The sampling frame was physician members of Canadian national and provincial critical care societies.

Results

The survey response rate was 232 out of 355 (65.3%). Medicine was the most common primary specialty (60.0%), most respondents had practiced for 6 to 10 years (30.0%), and 82.0% were male. The following monitoring devices/parameters were reported as used/measured 'often' or 'always' by at least 89% of respondents: oxygen saturation (100%), Foley catheters (100%), arterial blood pressure lines (96.6%), telemetry (94.3%), and central venous pressure (89.2%). Continuous monitoring of central venous oxygen saturation was employed 'often' or 'always' by 9.8% of respondents. The two most commonly cited resuscitation end-points were urine output (96.5%) and blood pressure (91.8%). Over half of respondents used normal saline (84.5%), Ringers lactate (52.2%), and pentastarch (51.3%) 'often' or 'always' for early fluid resuscitation. In contrast, 5% and 25% albumin solutions were cited as used 'often' or 'always' by 3.9% and 1.3% of respondents, respectively. Compared with internists, surgeons and anesthesiologists (odds ratio (95% confidence interval): 9.8 (2.9 to 32.7) and 3.8 (1.7 to 8.7), respectively) reported greater use of Ringers lactate. In the setting of a low central venous oxygen saturation, 52.5% of respondents reported use of inotropic support 'often' or 'always'. Only 7.6% of physicians stated they would use a red blood cell transfusion trigger of 100 g/l to optimize oxygen delivery further.

Conclusion

Our survey results suggest that there is substantial practice variation in the resuscitation of adult patients with early septic shock. More randomized trials are needed to determine the optimal approach.