Red Blood Cell Transfusion Practices Research Articles

Transfusion practice in hip arthroplasty – a nationwide study

The optimal transfusion strategy in hip arthroplasty remains controversial despite existing guidelines. The aim of this study was to evaluate the transfusion practice in patients undergoing primary total hip arthroplasty (THA) or revision total hip arthroplasty (RTHA) in Denmark. We performed a retrospective cohort study of all patients undergoing THA or RTHA in Denmark in 2008. Primary outcomes were intercentre variation in red blood cell (RBC) transfusion rates and the timing of transfusion related to surgery. Six thousand nine hundred thirty-two THA patients and 1132 RTHA patients were included for analysis of which 1674 (24%) THA and 689 (61%) RTHA patients received RBC transfusion. Of these, 47% of THA and 73% of RTHA patients received transfusion on the day of surgery. Transfusion rates between centres varied from 7 to 71% and between 26 and 85% in THA and RTHA patients, respectively. Patients receiving RBC transfusion had longer length of stay and for THA patients an increased odds-ratio (5·5) of death within 90 days. Despite established guidelines, RBC transfusion practice in hip arthroplasty remains highly variable between Danish hospitals. The effect of RBC transfusion on outcome after hip arthroplasty should be established in prospective randomized controlled trials.

Changes in Red Blood Cell Transfusion Practice During the Turn of the Millennium: A Retrospective Analysis of Adult Patients Undergoing Elective Open Abdominal Aortic Aneurysm Repair Using the Mayo Database

Conclusion: Change in transfusion practice, including the use of more autotransfusions and tolerance of lower perioperative hemoglobin levels, have not resulted in significant differences in perioperative morbidity or mortality in patients undergoing open abdominal aortic aneurysm (AAA) repair. Summary: The average cost of the transfusion of a red blood cell (RBC) unit is $153.68, and 14 million units of RBCs are transfused annually in the United States (Sullivan NT, et al. Transfusion 2007;47:385-94). Currently, there is also enthusiasm for reducing the number of transfused units because of reported increased morbidity and mortality with increased transfusions and reported increased infectious complications with increased transfusions. The authors sought to determine whether changes in transfusion practice during a two-decade study had any impact on perioperative morbidity and mortality in patients undergoing open elective AAA repair. The authors stratified patients undergoing open elective AAA repair into one of two transfusion-related groups. Early practice was defined as that between 1980 and 1982, and late practice was defined as between 2003 and 2006. Hemoglobin concentration and RBC transfusion were analyzed as continuous variables and compared between groups. Perioperative complications were compared, and data were age adjusted and analyses corrected for multiple comparisons. Patients in the late practice group compared with those in the early practice group had lower intraoperative (mean, 10 ± 1.4 vs 11.5 ± 1.5 g/dL), postoperative (mean, 11.9 ± 1.4 vs 13.4 ± 1.5 g/dL), and discharge hemoglobin levels (mean, 10.8 ± 1.2 vs. 12.5 ± 1.5 g/dL; P < .0001 for each variable). Fewer patients in the late practice group received intraoperative allogenic transfusions (46% vs 99%, P < .0001). There were also fewer total allogenic units transfused in the late practice group (mean, 1.7 vs 4.3, P < .0001). No patients in the early practice group had intraoperative autotransfusions, whereas intraoperative autotransfusions were used in 97% of the late practice patients (P < .0001). The incidence of perioperative morbidity and mortality was 40% (n = 119) in the late practice group and 35% (n = 106) in the early practice group (P = .27). Comment: RBC transfusion is associated with worse outcomes in cardiac surgery patients and in patients experiencing acute coronary syndrome (Murphy GJ, et al. Circulation 2007;116:2544-52; and Rao SV. JAMA 2004;292:1555-62). However, a randomized trial in critically ill patients comparing liberal vs conservative RBC transfusion found no difference in survival with the two treatment strategies (Hebert PC, et al. N Engl J Med 1999;340:409-47). The current study also found no difference in major morbidity or mortality in patients undergoing AAA repair with respect to a changing transfusion policy using more conservative thresholds for transfusion. However, the patients did no worse, and given the expense occurred with each unit transfused, a more conservative policy for patients undergoing open AAA repair is at least indicated financially if not medically.

Red blood cell transfusion practice in elective orthopedic surgery: a multicenter cohort study

The indications for red blood cell (RBC) transfusions remain unclear despite published guidelines. Our hypothesis was that the transfusion practice varies inside the Centre hospitalier de l'Université de Montréal (CHUM). A total of 701 charts of patients who underwent a knee or hip arthroplasty or prosthesis revision in three hospitals of the CHUM were reviewed. Demography, hemoglobin (Hb) concentrations, details on transfusions, and postoperative adverse events (AEs) were collected up until discharge. The primary outcome was the presence or absence of RBC transfusion. Secondary outcomes were the nadir Hb, number of units transfused, discharge Hb, blood losses, and postoperative AEs. The rate of postoperative transfusion was 29%. We found no significant difference between odds ratios of each site for sex, coronary artery disease, chronic heart failure, type of procedure, American Society of Anesthesiologists physical status, weight, height, body mass index, body surface area, and estimated blood volume. Overall, patients were transfused at a Hb between 75 and 80g/L. Eighty-five percent of postoperative transfusions could be predicted using only nadir Hb and adding patient characteristics did not substantially improve the model (86.1%). Discharge Hb was below 100g/L in 66% of patients. There was no difference among hospitals regarding the way RBC transfusions are used. Our data suggest that physicians mainly based their decision to transfuse on a single variable, the Hb concentration, with the use of a restrictive strategy. Future trials should focus on the optimal transfusion trigger to adopt in major orthopedic surgery.

Changes in Red Blood Cell Transfusion Practice during the Turn of the Millennium: A Retrospective Analysis of Adult Patients Undergoing Elective Open Abdominal Aortic Aneurysm Repair Using the Mayo Database

Significant changes in perioperative red blood cell (RBC) transfusion practice during the past two decades have been reported but similar data are not available for patients undergoing abdominal aortic aneurysm (AAA) surgery. Adult patients who had undergone primary, elective, open AAA repair were stratified into one of two transfusion-related groups: early practice (1980-1982) or late practice (2003-2006). RBC transfusion and hemoglobin concentration (Hb) were analyzed as a continuous variable and compared between groups with use of the rank sum test. Perioperative complications were compared between groups with Fisher's exact test. Data were age adjusted, and analyses were corrected for multiple comparisons. Compared with the early practice group, patients in the late practice group had significantly lower intraoperative (mean 10 +/- 1.4 vs. 11.5 +/- 1.5 g/dL), postoperative (11.9 +/- 1.4 vs. 13.4 +/- 1.5 g/dL), and discharge Hbs (mean 10.8 +/- 1.2 vs. 12.5 +/- 1.5 g/dL) (p < 0.0001 for each variable). Patients in the late practice group were significantly less likely to receive intraoperative allogenic transfusions (46% vs. 99%, p < 0.0001). Additionally, significantly fewer total allogenic units of RBCs per patient were transfused in the late practice group (mean 1.7 vs. 4.3, p < 0.0001). Intraoperative autotransfusions were used in 97% of the late practice patients but in none of the early practice patients (p < 0.0001). In the late practice group, 119 patients (40%) experienced a major perioperative morbidity or mortality event compared with 106 patients (35%) in the early practice group (p = 0.27). In this retrospective analysis, we observed significantly lower perioperative Hb, fewer allogenic RBC transfusions, and more autotransfusions in open AAA repairs done in 2003-2006 versus those done in 1980-1982. Additionally, late transfusion practice patients were older and had more comorbid diseases. Despite these observations, no significant differences in perioperative morbidity or mortality were observed between groups.

Red blood cell transfusion practices in acute lung injury: What do patient factors contribute?

Red blood cell transfusion practices in acute lung injury: What do patient factors contribute?

Variability on red blood cell transfusion practices among Brazilian neonatal intensive care units

Guidelines for red blood cell (RBC) transfusions exist; however, transfusion practices vary among centers. This study aimed to analyze transfusion practices and the impact of patients and institutional characteristics on the indications of RBC transfusions in preterm infants. RBC transfusion practices were investigated in a multicenter prospective cohort of preterm infants with a birth weight of less than 1500 g born at eight public university neonatal intensive care units of the Brazilian Network on Neonatal Research. Variables associated with any RBC transfusions were analyzed by logistic regression analysis. Of 952 very-low-birth-weight infants, 532 (55.9%) received at least one RBC transfusion. The percentages of transfused neonates were 48.9, 54.5, 56.0, 61.2, 56.3, 47.8, 75.4, and 44.7%, respectively, for Centers 1 through 8. The number of transfusions during the first 28 days of life was higher in Center 4 and 7 than in other centers. After 28 days, the number of transfusions decreased, except for Center 7. Multivariate logistic regression analysis showed higher likelihood of transfusion in infants with late onset sepsis (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.8-4.4), intraventricular hemorrhage (OR, 9.4; 95% CI, 3.3-26.8), intubation at birth (OR, 1.7; 95% CI, 1.0-2.8), need for umbilical catheter (OR, 2.4; 95% CI, 1.3-4.4), days on mechanical ventilation (OR, 1.1; 95% CI, 1.0-1.2), oxygen therapy (OR, 1.1; 95% CI, 1.0-1.1), parenteral nutrition (OR, 1.1; 95% CI, 1.0-1.1), and birth center (p < 0.001). The need of RBC transfusions in very-low-birth-weight preterm infants was associated with clinical conditions and birth center. The distribution of the number of transfusions during hospital stay may be used as a measure of neonatal care quality.

Anemia and blood transfusion practices in the critically ill: A prospective cohort review

Nearly 75% of critically ill patients develop anemia in the intensive care unit (ICU). Anemia can be treated with red blood cell (RBC) transfusions, although evidence suggests that lower hemoglobin levels are tolerated in the critically ill. Despite such recommendations, variation exists in clinical practice. A prospective cohort was assessed for anemia and RBC transfusion practices in 100 consecutive adults admitted to our General Systems ICU. The prevalence of anemia in this cohort was 98%. Mean blood loss via phlebotomy was 25+/-10.3 mL per patient per day. The RBC transfusion rate for the ICU stay was 40%, increasing to 70% in patients whose ICU stay was >7 days. The mean pretransfusion level of hemoglobin was 7.35+/-0.47 mg/dL for the total cohort, and 8.2+/-0.65 mg/dL for those with a history of cardiovascular disease. Anemia was common in this critically ill cohort, with hemoglobin levels continuing to drop with ICU stay. Pretransfusion hemoglobin levels were lower than reported by others, yet the RBC transfusion rate was comparable. There was no association between anemia and phlebotomy practices in our ICU.

Red blood cell transfusion practices in acute lung injury: What do patient factors contribute?*

To describe red blood cell (RBC) transfusion practices and evaluate the association between patient-related factors and pretransfusion hemoglobin concentration in acute lung injury (ALI). Secondary analysis of prospectively collected data. Nine intensive care units (ICUs) in three teaching hospitals in Baltimore, MD. Two hundred forty-nine consecutive patients with ALI requiring mechanical ventilation. None. Simple and multiple linear regression analyses were used to evaluate the association between the nadir hemoglobin concentration on the day of initial RBC transfusion and 20 patient-level demographic, clinical and ICU treatment factors as well as ICU type. Of 249 patients with ALI, 47% received an RBC transfusion in the ICU without evidence of active hemorrhage or acute cardiac ischemia. The mean (sd) nadir hemoglobin on the day of first transfusion was 7.7 (1.1) g/dL with 67%, 36%, 15%, and 5% of patients transfused at >7, >8, >9, and >10 g/dL, respectively. Transfused patients received a mean (sd) of 5 (6) RBC units from ALI diagnosis to ICU discharge. Prehospital use of iron or erythropoietin and platelet transfusion in the ICU were independently associated with lower pretransfusion hemoglobin concentrations. No patient factors were associated with higher hemoglobin concentrations. Admission to a surgical (vs. medical) ICU was independently associated with a 0.6 g/dL (95% confidence interval 0.1-1.1 g/dL) higher pretransfusion hemoglobin. Patients with ALI commonly receive RBC transfusions in the ICU. The pretransfusion hemoglobin observed in our study was lower than earlier studies, but a restrictive strategy was not universally adopted. Patient factors do not explain the gap between clinical trial evidence and routine transfusion practices. Future studies should further explore ICU- and physician-related factors as a source of variability in transfusion practice.

Red blood cell transfusions in acute paediatrics

Red blood cell (RBC) transfusions should usually be given only to restore or maintain oxygen delivery to vital organs and tissues. Medical history has clearly documented the importance of blood...

Changes in red blood cell transfusion practice during the past two decades: a retrospective analysis, with the Mayo database, of adult patients undergoing major spine surgery

Others have reported significant changes in red blood cell (RBC) transfusion practice during the past two decades during knee, hip, prostate, and carotid surgery. Similar data for patients undergoing major spine surgery, however, are not available. After institutional review board approval, adult patients undergoing elective major spine surgery were stratified into one of two transfusion-related groups: 1) 1980 to 1985 (i.e., before human immunodeficiency virus screening, early practice group; n = 699) or 2) 1995 to 2000 (i.e., late practice group; n = 610). Patients in the late practice group were older, had greater numbers of preoperative coexisting diseases (e.g., hypertension, cardiac dysrhythmias, coronary artery disease, prior myocardial infarction, diabetes mellitus, renal disease, cerebrovascular disease, and asthma), and were exposed to longer operations (p < 0.01 for each variable). Over time, allogeneic RBC administration significantly decreased, whereas autologous and intraoperative autotransfusion significantly increased. Compared to the early practice group, all perioperative Hb concentrations were significantly lower than the late practice group, yet no significant difference in major morbidity or mortality was observed between groups. In this retrospective analysis, significantly lower acceptable perioperative Hb concentrations were observed in older patients having substantially worse baseline comorbidity and exposed to longer major spine operations, without significant change in the incidence of perioperative morbidity or mortality.

Red blood cell transfusion practices amongst Canadian anesthesiologists: a survey

To assess red blood cell transfusion practices among Canadian anesthesiologists.A survey depicting three realistic clinical scenarios of elective surgical procedures with different risks of bleeding was administered to all Canadian practicing members (n = 2,100) of the Canadian Anesthesiologists' Society. Respondents were requested to choose hemoglobin thresholds for which they would transfuse red blood cells under various conditions within each scenario.We obtained a response rate of 47% (719/1,512). Transfusion thresholds differed significantly between baseline scenarios. A threshold above 70 g x L(-1) was chosen by 48% of respondents in the general surgery scenario compared to 56% in the orthopedic surgery scenario and 79% in the vascular surgery scenario (P < 0.001). A history of coronary artery disease was associated with a transfusion threshold >or= 100 g x L(-1) in a significant proportion of respondents ranging from 20% in the orthopedic surgery scenario to 31% in the general surgery scenario and to 49% in the vascular surgery scenario (P < 0.001). Conversely, changing the patient's age from 60 to 20 yr resulted in the adoption of a transfusion threshold <or= 60 g x L(-1) by > 30% of respondents in two scenarios (P < 0.001). The year of respondent graduation was strongly associated with these findings.There was significant variation in transfusion practices among Canadian anesthesiologists. The type of surgical procedure, patient's age and a history of coronary artery disease influenced reported transfusion threshold. Practice variation in specific subgroups would support the need for further research to identify optimal transfusion thresholds.

Survey of Red Blood Cell Transfusion Practices in Medically Ill Patients.

Although red cell transfusion is a relatively common treatment used in medically ill patients, much is not known about clinical determinants used to guide its use. A cross-sectional self-administered survey was used to assess the red blood cell transfusion practices of academic medical internists, subspecialty physicians and internal medicine residents who practice on the Medical Teaching Unit (MTU) at the Queen Elizabeth II Health Sciences Center, Halifax, Nova Scotia. We evaluated transfusion thresholds before transfusion and the number of red cell units ordered for four clinical scenarios: chronic obstructive pulmonary disease (COPD), coronary artery disease (CAD), gastrointestinal bleeding and delirium. Clinical characteristics were varied to further clarify clinical determinants of transfusion. The response rate among the forty-nine medical internists and subspecialty physicians was 59%. Among internal medicine residents the response rate was 100% (n=14). The primary area of practice for the majority of respondents was general internal medicine. Most staff physicians attended on the MTU for greater than four weeks. Baseline hemoglobin transfusion thresholds averaged from 75.6 +/− 9.8 g/L in a patient with acute delirium to 91.4 +/− 11.4 g/L in the gastrointestinal bleeding scenario. Range of baseline hemoglobin transfusion thresholds within scenarios was as wide as 60 to 120 g/L. Between the four scenarios, baseline hemoglobin transfusion thresholds differed significantly (p<0.03) except between the CAD and gastrointestinal bleeding scenarios. Clinical factors age and gender did not significantly (p>0.05) alter hemoglobin transfusion thresholds in the CAD and delirium scenarios, but were significant (p<0.02) modifiers of hemoglobin transfusion thresholds along with oxygen saturation, lactic acidosis, hemodynamic stability, requirement for urgent surgery, and chronic surgery in all other scenarios. Comparing staff physicians and internal medicine residents, there was no significant difference between the two groups for baseline hemoglobin transfusion thresholds. In conclusion, among physicians caring for medically ill patients, there is significant variation in red blood cell transfusion practices. Consistent with research in the critical care setting, pre-transfusion hemoglobin, along with other clinical factors, continues to be an important determinant of red cell transfusion.

Morbid Risks of Unnecessary Red Blood Cell Transfusion in Stable Coronary Artery Bypass Graft Patients.

The persistent variability in red blood cell transfusion practice in coronary artery bypass graft (CABG) patients, despite established guidelines, suggests inappropriate use. Our objective was to determine the impact of postoperative red blood cell (RBC) transfusion in entirely stable CABG patients. We investigated a cohort of 940 stable CABG patients from the 5,065 patients enrolled in the Multicenter Study of Perioperative Ischemia Epidemiology II (EPI II) Study with (1) low to moderate risk profile; (2) postoperative hemoglobin levels ≥ 10 g/dL; (3) minimal postoperative blood loss, and (4) no evidence of any morbid event on the day of surgery. RBC transfusion was assessed during the first 24 postoperative hours and multiorgan outcomes as well as markers of resource utilization from postoperative day one to hospital discharge. Transfused patients (N =190, 20.2 %) were more likely to suffer myocardial infarction (OR, 1.89; 95 % CI, 1.08 to 3.29; P = 0.02); renal dysfunction (OR, 3.35; 95 % CI, 1.01 to 11.1; P = 0.04); renal failure requiring dialysis (OR, 4.01; 95 % CI, 0.99 to 16.2; P = 0.05); and/or harvest site wound infection (OR, 5.45; 95 % CI, 1.87 to 15.9; P = 0.001). RBC transfusion was shown to be an independent predictor of composite morbidity outcome, cardiac morbidity, and harvest site wound infection in multivariate analysis. In transfused patients, the mean duration of hospitalization was increased by 2.5 days (14.4 days vs. 11.9 days; P < 0.001). In CABG patients with low to moderate mortality risk profiles, adequate hemoglobin values and low bleeding rates, postoperative RBC transfusion is associated with an increased risk for cardiac, renal and infectious morbidity, as well as increased health care expenses, without any detectable benefit.

Transfusion management strategies: a survey of practicing pediatric hematology/oncology specialists.

Little is known about the criteria used by pediatric oncologists for the transfusion of red blood cells and platelets to pediatric oncology patients. Data regarding red blood cell and platelet transfusion practices were collected with an internet-based survey of physician members of the American Society for Pediatric Hematology/Oncology (ASPH/O). Respondents were asked to define platelet and red blood cell transfusion thresholds in a variety of clinical scenarios, and to describe criteria for dealing with cytomegalovirus (CMV) transmission from blood products, platelet dosing strategies, and prevention of RhD alloimmunization. The overall response rate was 31.4% (264 of 841). Of the respondents, 76% indicated that their institution had defined criteria for acceptable transfusion practice; of these respondents, 114 (57%) indicated that there were special guidelines for pediatric oncology patients. Examination of the distribution of threshold platelet counts and hemoglobin levels that would prompt transfusion indicated a wide range of transfusion practice in commonly encountered clinical scenarios. Similar variability in practice was evident in platelet dosing strategies, CMV prevention strategies, and in the use of anti-D in RhD-negative patients who received RhD-positive platelets. This current survey demonstrates that transfusion practices vary widely among pediatric hematology/oncology specialists and that prospective clinical trials may be necessary to determine optimal criteria for blood product support in pediatric oncology patients.

Red blood cell transfusion and ventilator-associated pneumonia: A potential link?

To determine the relationship between packed red blood cell transfusion practice and the development of ventilator-associated pneumonia (VAP). Secondary analysis of a multicentered, prospective observational study of transfusion practice in intensive care units in the United States. A total of 284 intensive care units in the United States were studied from August 2000 to April 2001. Patients without pneumonia at intensive care unit admission and who then required at least 48 hrs of mechanical ventilation were considered at risk for VAP. VAP was diagnosed based on prospectively defined clinical criteria and represented the primary study end point. Late-onset VAP (VAP arising after > or =5 days of mechanical ventilation) represented a secondary end point. Transfusions given during the intensive care unit stay and before the onset of VAP were tracked prospectively. Of 4,892 subjects in the original cohort, 1,518 received mechanical ventilation of > or =48 hrs and did not have preexisting pneumonia. VAP was diagnosed in 311 (20.5%) patients. Multivariate analysis revealed that transfusion independently increased the risk for VAP (odds ratio, 1.89; 95% confidence interval [CI], 1.33-2.68). Other factors increasing the risk for VAP included male sex (odds ratio, 1.54; 95% CI, 1.15-2.07), admission after trauma (odds ratio, 1.68; 95% CI, 1.15-2.47), use of continuous sedation (odds ratio, 1.43; 95% CI, 1.07-1.92), and type of nutritional support (e.g., early enteral nutrition: odds ratio, 2.65; 95% CI, 1.93-3.63; total parenteral nutrition: odds ratio, 3.27; 95% CI, 2.24-4.75). The effect of transfusion on late-onset VAP was more pronounced (odds ratio, 2.16; 95% CI, 1.27-3.66) and demonstrated a positive dose-response relationship (p =.0223 for trend test). Transfusion of packed red blood cells increases the risk of developing VAP. Avoiding the unnecessary use of packed red blood cell transfusions may decrease the occurrence of VAP.

A survey of physicians' attitudes toward blood transfusion in patients undergoing cesarean section

ObjectiveThis study was undertaken to evaluate the attitude of anesthesiologists and gynecologists to the use of blood during cesarean section operation and, on the basis of the results, to ascertain the need for improvement of current transfusion guidelines. Study designA scenario-based survey was performed. ResultsThe response rate was 94% (327/347) among anesthesiologists and 91% (355/391) among gynecologists. The majority of responders selected a hemoglobin threshold ranging from 7.5 to 8.5 g/dL (62%). Threshold hemoglobin concentration differed significantly (P<.001) between anesthesiologists (median, 7.5 g/dL) and gynecologists (median, 8 g/dL). At that threshold, 56% of anesthesiologists compared with 86% of gynecologists administered 2 units of blood (P<.05). When transfusing packed cells, most practitioners would give 2 units regardless of the transfusion threshold. ConclusionOur findings demonstrate differing approaches to current transfusion protocols. Transfusion consensus recommendations should be improved and unified to enhance red blood cell transfusion practices for relatively young and healthy patients undergoing anesthesia and surgery.

Review of the clinical practice literature on patient characteristics associated with perioperative allogeneic red blood cell transfusion.

There is evidence to suggest that there exists considerable variation in red blood cell (RBC) transfusion practices, especially in the surgical specialties. This is in large part related to difficulties in defining specific transfusion threshold criteria, given that there is no minimum acceptable hemoglobin threshold concentration and there is variability in assigning importance to patient factors. The purpose of this study is to identify patient-related factors that might be associated with the need for allogeneic RBC transfusion in surgical patients. We systematically identified, selected, and reviewed all observational or interventional studies describing patient-specific or related variables associated with the need for allogeneic RBC transfusion in the surgical patient population. We also evaluated the methodological characteristics of the individual studies. Sixty-two studies met our inclusion criteria and were analyzed for this review. Most of these studies were conducted in patients undergoing cardiac surgery (n = 30) and orthopedic surgery (n = 16). Decreased preoperative red cell reserve was most frequently associated with RBC transfusions, being identified as a significant variable in 46 studies. The other factors commonly associated with transfusion were advancing age (n = 28), female gender (n = 21), and small body size (n = 14). Only 2 studies attempted to prospectively validate a predictive model for RBC transfusion based on the variables identified. This systematic review shows that preoperative anemia, advancing age, female gender, and small body size are often associated with perioperative allogeneic RBC transfusion. However, the retrospective nature of most of the studies and the small sample sizes make it difficult to formulate a clinically useful prediction rules regarding allogeneic RBC transfusion. Ongoing research in designing large prospective cohort studies evaluating transfusion patterns are needed to further elucidate how patient characteristics impact the transfusion threshold.

Review of the clinical practice literature on patient characteristics associated with perioperative allogeneic red blood cell transfusion

There is evidence to suggest that there exists considerable variation in red blood cell (RBC) transfusion practices, especially in the surgical specialties. This is in large part related to difficulties in defining specific transfusion threshold criteria, given that there is no minimum acceptable hemoglobin threshold concentration and there is variability in assigning importance to patient factors. The purpose of this study is to identify patient-related factors that might be associated with the need for allogeneic RBC transfusion in surgical patients. We systematically identified, selected, and reviewed all observational or interventional studies describing patient-specific or related variables associated with the need for allogeneic RBC transfusion in the surgical patient population. We also evaluated the methodological characteristics of the individual studies. Sixty-two studies met our inclusion criteria and were analyzed for this review. Most of these studies were conducted in patients undergoing cardiac surgery (n = 30) and orthopedic surgery (n = 16.) Decreased preoperative red cell reserve was most frequently associated with RBC transfusions, being identified as a significant variable in 46 studies. The other factors commonly associated with transfusion were advancing age (n = 28), female gender (n = 21), and small body size (n = 14). Only 2 studies attempted to prospectively validate a predictive model for RBC transfusion based on the variables identified. This systematic review shows that preoperative anemia, advancing age, female gender, and small body size are often associated with perioperative allogeneic RBC transfusion. However, the retrospective nature of most of the studies and the small sample sizes make it difficult to formulate a clinically useful prediction rules regarding allogeneic RBC transfusion. Ongoing research in designing large prospective cohort studies evaluating transfusion patterns are needed to further elucidate how patient characteristics impact the transfusion threshold.

Survey on transfusion practices of pediatric intensivists.

To describe the red blood cell transfusion practices of pediatric intensivists. Cross-sectional self-administered survey. Pediatric intensive care units. Academic pediatric intensivists. None. Scenario-based survey among English- or French-speaking intensivists from Canada, France, Belgium, or Switzerland, working in tertiary-care pediatric intensive care units. Respondents were asked to report their decisions regarding transfusion practice with respect to four scenarios: cases of bronchiolitis, septic shock, trauma, and the postoperative care of a patient with Fallot's tetrad. The response rate was 71% (163 of 230). The overall baseline hemoglobin transfusion threshold that would have prompted intensivists to transfuse a patient ranged from 7 to 13 g/dL (70-130 g/L) within almost all scenarios. There was a significant difference between scenarios of the average baseline hemoglobin transfusion thresholds (p < .0001). A low Pao2, a high blood lactate concentration, a high Pediatric Risk of Mortality score, active gastric bleeding, emergency surgery, and age (2 wks) were important determinants of red blood cell transfusion, whereas none of the respondents' personal characteristics were. The average volume of packed red blood cells transfused in the four scenarios did not differ significantly. This survey documented a significant variation in transfusion practice patterns among pediatric critical care practitioners with respect to the threshold hemoglobin concentration for red blood cell transfusion. The volume of packed red blood cells given was not adjusted to the hemoglobin concentration.

Red Blood Cell Transfusion Practice in Gynecology and Obstetrics in a Primary Care Hospital

Red Blood Cell Transfusion Practice in Gynecology and Obstetrics in a Primary Care Hospital