Perioperative allogeneic blood transfusion does not cause adverse sequelae in patients with cancer: a meta-analysis of unconfounded studies

Long-Term Sustainability of a Quality Initiative Program on Transfusion Rates in Total Joint Arthroplasty: A Follow-Up Study

BACKGROUND

There are significant variations in transfusion rates among institutions performing total joint arthroplasty. We previously demonstrated that implementation of an educational program to increase awareness of the American Association of Blood Banks' transfusion guidelines led to an immediate decrease in transfusion rates at our facilities. It remained unclear how this initiative would endure over time. We report the long-term success and sustainability of this quality program.

METHODS

We reviewed the Michigan Arthroplasty Collaborative Quality Initiative data from 2012 through 2017 of all patients undergoing primary hip and knee arthroplasty at our institutions for preoperative and postoperative hemoglobin level, transfusion status, and number of units transfused and transfusions outside of protocol to identify changes surrounding our blood transfusion educational initiative. We calculated the transfusions prevented and cost implications over the course of the study.

RESULTS

We identified 6645 primary hip and knee arthroplasty patients. There was a significant decrease in transfusion rate and overall transfusions in each group when compared to pre-education values. Subgroup analysis of TKA and THA independently showed significant decreases in both transfusion rate and overall transfusions. Over the final 3 years of the study, only 2 patients were transfused outside of the American Association of Blood Banks protocol. We estimate prevention of 519 transfusions over the study period.

CONCLUSION

Application of this quality initiative was an effective means of identifying opportunities for quality improvement. The program was easily initiated, had significant early impact, and has been shown to be sustainable.

Long-lasting discussion: Adverse effects of intraoperative blood loss and allogeneic transfusion on prognosis of patients with gastric cancer

Gastrectomy with radical lymph node dissection is the most promising treatment avenue for patients with gastric cancer. However, this procedure sometimes induces excessive intraoperative blood loss and requires perioperative allogeneic blood transfusion. There are lasting discussions and controversies about whether intraoperative blood loss or perioperative blood transfusion has adverse effects on the prognosis in patients with gastric cancer. We reviewed laboratory and clinical evidence of these associations in patients with gastric cancer. A large amount of clinical evidence supports the correlation between excessive intraoperative blood loss and adverse effects on the prognosis. The laboratory evidence revealed three possible causes of such adverse effects: anti-tumor immunosuppression, unfavorable postoperative conditions, and peritoneal recurrence by spillage of cancer cells into the pelvis. Several systematic reviews and meta-analyses have suggested the adverse effects of perioperative blood transfusions on prognostic parameters such as all-cause mortality, recurrence, and postoperative complications. There are two possible causes of adverse effects of blood transfusions on the prognosis: Anti-tumor immunosuppression and patient-related confounding factors (e.g., preoperative anemia). These factors are associated with a worse prognosis and higher requirement for perioperative blood transfusions. Surgeons should make efforts to minimize intraoperative blood loss and transfusions during gastric cancer surgery to improve patients’ prognosis.

Allogeneic blood transfusion in 163 children with acute lymphocytic leukemia (a STROBE-compliant article)

Little research has been done about the effects of allogeneic blood transfusion (ABT) on the recurrence and prognosis in the cases with childhood acute lymphocytic leukemia (cALL). In order to provide a basis for clinical safe blood transfusion, the data of 163 cases with cALL were retrospectively analyzed to explore the issue.The data of 163 cases with cALL between 2006 and 2011 were retrospectively analyzed. According to the frequency of blood transfusion, the 163 cases were divided into 4 groups including non-transfusion group, 1 to 10-time transfusion group, 11 to 25-time transfusion group, and >25-time transfusion group. Survival rates were compared with Log-Rank test. Cox regression analysis was used in the effects of risk factors on recurrence and death.ABT was performed in 152 cases with cALL (93.25%). In low-risk and intermediate-and-high risk cALL, the survival rate significantly decreased in all transfusion groups compared with that in non-transfusion group (all P < .01). Cox regression analysis showed that >25-time transfusion was an independent prognosis index of recurrence (odds ratio [OR] = 3.015, 95% confidence interval [CI]: 1.368-6.646) and death (OR = 3.979, 95% CI: 1.930-8.207) in cALL.Frequency of ABT appears to affect the recurrence and death in cALL. We should be careful with blood transfusion and avoid unnecessary blood transfusion as far as possible in the cases with cALL.

Quality Initiative Programs Can Decrease Total Joint Arthroplasty Transfusion Rates-A Multicenter Study Using the MARCQI Total Joint Registry Database

BACKGROUND

The Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) noted wide variability between member hospitals in blood transfusion rates after primary total hip and knee arthroplasty (THA and TKA). Blood transfusion has substantial risks and accepted recommendations exist to guide transfusion practices. MARCQI began an initiative to decrease unnecessary transfusions by identifying/reporting outliers, discussing conservative transfusion practices, and recommending transfusion guidelines. There was a later recommendation to consider intraoperative use of tranexamic acid.

METHODS

All MARCQI-registered unilateral TKA and THA cases from the 28 member hospitals (pre-November 2013) were included. For 3 time periods (before November 13, 2013; November 13, 2013, to November 12, 2014; and after November 12, 2014), we calculated average risk and range of transfusion, transfusion with nadir hemoglobin >8 g/dL, mean length of stay, and 90-day risk of discharge to nursing home, readmission, deep infection, and emergency department visits.

RESULTS

For THA, risk and range of transfusion decreased over the 3 time periods: 12.6% (2.5%-36.2%), 7.6% (2.2%-23.8%), and 4.5% (0.7%-14.4%); for TKA, 6.3% (1.3%-15.6%), 3.1% (0%-12.5%), and 1.3% (0%-7.4%). Decreases were also noted for transfusion with a nadir hemoglobin >8 g/dL with a near elimination of "unnecessary" transfusions. There was no evidence of increase in length of stay, discharge to nursing home, readmission, deep infection, or emergency department visits.

CONCLUSION

A simple intervention can decrease unnecessary blood transfusions during and after elective primary unilateral THA or TKA. A collaborative registry can be used effectively to improve the quality of patient care and set a new benchmark for transfusion.

The Michigan Experience with Safety and Effectiveness of Tranexamic Acid Use in Hip and Knee Arthroplasty

BACKGROUND

The efficacy of tranexamic acid (TXA) in reducing blood loss and transfusion requirements in total hip and knee arthroplasty has been well established in small controlled clinical trials and meta-analyses. The purpose of the current study was to determine the risks and benefits of TXA use in routine orthopaedic surgical practice on the basis of data from a large, statewide arthroplasty registry.

METHODS

From April 18, 2013, to September 30, 2014, there were 23,236 primary total knee arthroplasty cases and 11,489 primary total hip arthroplasty cases completed and registered in the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI). We evaluated the association between TXA use and hemoglobin drop, transfusion, length of stay (LOS), venous thromboembolism (VTE), readmission, and cardiovascular events by fitting mixed-effects generalized linear and mixed-effects Cox models. We used inverse probability of treatment weighting to enhance causal inference.

RESULTS

For total hip arthroplasty, TXA use was associated with a smaller drop in hemoglobin (mean difference = -0.65 g/dL; 95% confidence interval [CI] = -0.60 to -0.71 g/dL), decreased odds of blood transfusion (odds ratio [OR] = 0.72; 95% CI = 0.60 to 0.86), and decreased readmissions (OR = 0.77; 95% CI = 0.64 to 0.93) compared with no TXA use. There was no effect on VTE (hazard ratio [HR] = 0.91; 95% CI = 0.62 to 1.33), LOS (incident rate ratio [IRR] = 1.00; 95% CI = 0.97 to 1.03), or cardiovascular events (OR = 0.85; 95% CI = 0.47 to 1.52). For total knee arthroplasty, TXA was associated with a smaller drop in hemoglobin (mean difference = -0.68 g/dL; 95% CI = -0.64 to -0.71 g/dL) and one-fourth the odds of blood transfusion (OR = 0.26; 95% CI = 0.21 to 0.31). There was an association with decreased risk of VTE within 90 days after surgery (HR = 0.56; 95% CI = 0.42 to 0.73), slightly decreased LOS (IRR = 0.93; 95% CI = 0.92 to 0.95), and no association with readmissions (OR = 0.90; 95% CI = 0.79 to 1.04) or cardiovascular events (OR = 1.12; 95% CI = 0.74 to 1.71).

CONCLUSIONS

In routine orthopaedic surgery practice, TXA use was associated with decreased blood loss and transfusion risk for both total knee and total hip arthroplasty, without evidence of increased risk of complications. TXA use was also associated with reduced risk of readmission among total hip arthroplasty patients and reduced risk of VTE among total knee arthroplasty patients, and did not have an adverse effect on cardiovascular complications in either group.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Evidence-based treatment of patients with rectal cancer

Rectal cancer is a worldwide disease whose incidence has increased significantly. Evidence-based medicine is a category of medicine that optimizes decision making by using evidence from well-designed and conducted research. Evidence-based medicine can be used to formulate a reasonable treatment plan for newly diagnosed rectal cancer patients. The current review focuses on the application of evidence-based treatment on patients with rectal cancer. The relationship between perioperative blood transfusion and recurrence of rectal cancer after surgery, the selection between minimally invasive laparoscopic surgery and traditional laparotomy, choice of chemotherapy for patients with rectal cancer prior to surgery, selection between stapled and hand-sewn methods for colorectal anastomosis during rectal cancer resection, and selection between temporary ileostomy and colostomy during the surgery were addressed. Laparoscopy is considered to have more advantages but is time-consuming and has high medical costs. In addition, laparoscopic rectal cancer radical resection is preferred to open surgery. In radical resection surgery, use of a stapling device for anastomosis can reduce postoperative anastomotic fistula, although patients should be informed of possible anastomotic stenosis.

The view from 10,000 procedures: technical tips and wisdom from master pancreatic surgeons to avoid hemorrhage during pancreaticoduodenectomy

Pancreaticoduodenectomy remains the exclusive technique for surgical resection of cancers located within both the pancreatic head and periampullary region. Amongst peri-procedural complications, hemorrhage is particularly problematic given that allogenic blood transfusions are known to increase the risk of infection, acute lung injury, cancer recurrence and overall 30-day morbidity and mortality rates. Because blood loss can be considered a modifiable factor that reflects surgical technique, rates of perioperative blood loss and transfusion have been advocated as robust quality indicators. We present a correspondence manuscript that outlines peri-procedural concepts detailing a successful pancreaticoduodenectomy with minimal hemorrhage. These tips were collated from master pancreatic surgeons throughout the globe who have performed over 10,000 cumulative pancreaticoduodenectomies. At risk scenarios for hemorrhage include dissections of the superior mesenteric – portal vein, gastroduodenal artery, and retroperitoneal soft tissue margin. General principles in limiting slow continuous hemorrhage that may accumulate into larger total case losses are also discussed. While many of the techniques and tips proposed by master pancreas surgeons are intuitive and straight forward, when taken as a collective they represent a significant contribution to improved outcomes associated with the pancreaticoduodenectomy over the past 100 years.

Long-term outcomes of an integrated transfusion reduction initiative in patients undergoing resection for colorectal cancer

BACKGROUND

Perioperative blood transfusion in patients with colorectal cancer has been associated with increased cost, morbidity, mortality, and decreased survival. Five years ago, a transfusion reduction initiative (TRI) was implemented. We sought to evaluate the 5-year effectiveness and patient outcomes before and after the TRI.

METHODS

Patients who underwent colorectal resection for adenocarcinomas before (January 2006 to October 2009) and after the TRI (November 2009 to December 2013) were reviewed.

RESULTS

A total of 484 patients were included; 267 and 217 patients were in the pre- and post-TRI groups, respectively. Decreased overall transfusion rates were sustained throughout the entire post-TRI era (17% vs 28%, P = .006). Three-year colorectal cancer disease-free survival rates were similar in the pre- and post-TRI eras at 85.3% (95% confidence interval [CI]: 79.9 to 89.3) and 81.6% (95% CI: 71.9 to 88.2), respectively. Three-year disease-free survival rate was lower in those receiving BTs vs those without BTs at 78.4% (95% CI: 65.7 to 86.8) vs 85.3% (95% CI: 80.4 to 89.1), respectively.

CONCLUSIONS

A TRI remains a safe, effective way to reduce blood utilization in colorectal cancer surgery.

Impact of peri-operative blood transfusion on the outcomes of patients undergoing radical cystectomy for urothelial carcinoma of the bladder

OBJECTIVE

To determine the association between peri-operative blood transfusion (PBT) and oncological outcomes in a large multi-institutional cohort of patients undergoing radical cystectomy (RC) for urothelial carcinoma of the bladder (UCB).

PATIENTS AND METHODS

We conducted a retrospective analysis of 2895 patients treated with RC for UCB. Univariable and multivariable Cox regression models were used to analyse the effect of PBT administration on disease recurrence, cancer-specific mortality, and any-cause mortality.

RESULTS

Patients' median (interquartile range [IQR]) age was 67 (60, 73) years and the median (IQR) follow-up was 36.1 (15, 84) months. Patients who received PBT were more likely to have advanced disease (P < 0.001), high grade tumours (P = 0.047) and nodal metastasis (P = 0.004). PBT was associated with a higher risk of disease recurrence (P = 0.003), cancer-specific mortality (P = 0.017), and any-cause mortality (P = 0.010) in univariable, but not multivariable, analyses (P > 0.05). In multivariable analyses, pathological tumour stage, pathological nodal stage, soft tissue surgical margin, lymphovascular invasion and administration of adjuvant chemotherapy were independent predictors of disease recurrence, cancer-specific mortality and any-cause mortality (all P values <0.002).

CONCLUSIONS

Patients with UCB who underwent RC and received PBT had a greater risk of disease recurrence, cancer-specific mortality and any-cause mortality in univariable, but not multivariable, analysis. Although the greater need for PBT with more advanced disease is probably caused by a number of factors, including surgical and cancer-related factors, the present analysis showed that the disease characteristics rather than need for PBT led to worse outcomes.

Trends and risk factors for transfusion in hepatopancreatobiliary surgery

INTRODUCTION

Patient-specific factors impacting the need for possible perioperative blood transfusions have not been examined in patients undergoing hepatopancreatobiliary (HPB) procedures. We sought to define the overall utilization of blood transfusions for HPB surgery stratified by procedure type, as well as identify patient-level risk factors for transfusion.

METHODS

Hepatic and pancreatic resections were selected from the 2005-2011 American College of Surgeons National Surgical Quality Improvement Program's public use files. Transfusion utilization, risk factors, temporal trends, and outcomes were assessed using regression models. Missing data were addressed using multiple imputation.

RESULTS

Twenty-six thousand eight hundred twenty-seven patients met the inclusion criteria. There were 16,953 pancreas cases (distal pancreatectomy (31.2%), pancreaticoduodenectomy (65.8%), total pancreatectomy (3.0%)), and 9,874 liver cases (wedge resection (60.0%), hemi-hepatectomy (30.1%), trisegmentectomy (9.9%)). Overall, 25.7% patients received a perioperative transfusion. Transfusion rates varied by operation type (hepatic wedge resection 18.7%, lobectomy 31.3%, trisegmentectomy 39.8%, distal pancreatectomy 19.8%, Whipple 28.7%, total pancreatectomy 43.6%, p < 0.001). On multivariate analysis, several patient-level factors were strongly associated with the risk of transfusion: preoperative hematocrit <36% (risk ratios (RR) 1.99, 95% CI 1.91-2.08), preoperative albumin <3.0 g/dL (RR 1.25, 95% CI 1.19-1.31), American Society of Anesthesiologists (ASA) class IV (RR 1.24, 95% CI 1.16-1.33), and anticoagulation/bleeding disorder (RR 1.26, 95% CI 1.15-1.38) (all p < 0.001). Patients with any one of these high-risk factors had an over twofold increased risk of perioperative transfusion (RR 2.31, 95% CI 2.21-2.40, p < 0.001).

CONCLUSION

There are large differences in the incidence of transfusion among patients undergoing HPB procedures. While the type of HPB procedure was associated with the risk of transfusion, patient-level factors-including preoperative hematocrit and albumin, ASA classification, and history of anticoagulation/bleeding disorder-were as important.

Perioperative blood transfusions do not impact overall and disease-free survival after curative rectal cancer resection: a propensity score analysis

OBJECTIVE

To assess the putative impact of perioperative blood transfusions on overall and disease-free survival in patients undergoing curative resection of stage I-III rectal cancer by applying propensity-scoring methods.

BACKGROUND

Whether perioperative blood transfusions negatively impact survival remains a matter of great debate.

METHODS

In a single-center study, 401 patients undergoing open curative resection of stage I-III rectal cancer between 1996 and 2008 were assessed. The median follow-up was 34.2 months. Patients who did and did not receive perioperative blood transfusions were compared using Cox regression and propensity score analyses.

RESULTS

Overall, 217 patients (54.1%) received blood transfusions. Patients' characteristics were highly biased concerning transfusions (propensity score 0.77±0.23 vs. 0.28±0.25; P<0.001). In unadjusted analysis, blood transfusions were associated with a 119% increased risk of mortality [hazard ratio (HR): 2.19, 95% confidence interval (CI): 1.34-3.57, P=0.001]. In propensity score-adjusted Cox regression (HR: 1.02, 95% CI: 0.65-1.58, P=0.970), blood transfusions did not increase the risk of overall survival. Similarly, in propensity score-adjusted Cox regression (HR: 0.86, 95% CI: 0.60-1.23, P=0.672), blood transfusions were not associated with an increased risk of recurrence.

CONCLUSIONS

This is the first propensity score-based analysis providing compelling evidence that worse oncological outcomes after curative rectal cancer resection in patients receiving perioperative blood transfusions are caused by the clinical circumstances requiring transfusions, not due to the blood transfusions themselves. Therefore, concerns about overall and disease-free survival should be no issue in the decision-making regarding perioperative blood transfusions in patients undergoing curative rectal cancer resection.

Transfusion immunomodulation or TRIM: What does it mean clinically?

Evidence from a variety of sources indicate that allogeneic blood transfusions can induce clinically significant immunosuppression, as well as other effects, in recipients. This clinical syndrome is generally referred to in the Transfusion Medicine literature as transfusion-associated immunomodulation, or TRIM. TRIM has been linked to an improved clinical outcome in the setting of renal allograft transplantation. Possible deleterious TRIM-associated effects include an increased rate of cancer recurrence and of post-operative bacterial infection. The recognition that TRIM can increase morbidity and mortality in allogeneically transfused individuals has become a major concern for those involved in Transfusion Medicine. However, based on available randomized controlled trials, whether TRIM predisposes recipients to increased risk for cancer recurrence and/or bacterial infection is still unproven. In contrast, data from experimental animal studies suggest that TRIM is an immunologically mediated biological effect, associated with the transfusion of allogeneic leukocytes; an effect, which can be completely ameliorated by the pre-storage leukoreduction of blood products. Relevantly, several (n = 5) recent large observational trials have provided important evidence for the existence of deleterious TRIM and related effects (mortality and organ dysfunction) of leukocyte-containing allogeneic cellular blood products. These latter data suggest that allogeneic blood product transfusions, containing leukocytes, are associated with an increased risk both for mortality, and organ dysfunction in recipients.

Comparison of pooled risk estimates for adverse effects from different observational study designs: methodological overview

BACKGROUND

A diverse range of study designs (e.g. case-control or cohort) are used in the evaluation of adverse effects. We aimed to ascertain whether the risk estimates from meta-analyses of case-control studies differ from that of other study designs.

METHODS

Searches were carried out in 10 databases in addition to reference checking, contacting experts, and handsearching key journals and conference proceedings. Studies were included where a pooled relative measure of an adverse effect (odds ratio or risk ratio) from case-control studies could be directly compared with the pooled estimate for the same adverse effect arising from other types of observational studies.

RESULTS

We included 82 meta-analyses. Pooled estimates of harm from the different study designs had 95% confidence intervals that overlapped in 78/82 instances (95%). Of the 23 cases of discrepant findings (significant harm identified in meta-analysis of one type of study design, but not with the other study design), 16 (70%) stemmed from significantly elevated pooled estimates from case-control studies. There was associated evidence of funnel plot asymmetry consistent with higher risk estimates from case-control studies. On average, cohort or cross-sectional studies yielded pooled odds ratios 0.94 (95% CI 0.88-1.00) times lower than that from case-control studies.

INTERPRETATION

Empirical evidence from this overview indicates that meta-analysis of case-control studies tend to give slightly higher estimates of harm as compared to meta-analyses of other observational studies. However it is impossible to rule out potential confounding from differences in drug dose, duration and populations when comparing between study designs.

Prognostic effect of blood transfusion in children with acute lymphoblastic leukemia

Background

Most children with acute lymphoblastic leukemia (ALL) receive blood transfusions. Transfusions may affect ALL outcomes through transfusion-related immunomodulation (TRIM).

Methods

We analyzed overall survival (OS) and event-free survival (EFS) in relation to leukocyte reduced and irradiated (LR/IRR) blood products transfused during the induction phase in 136 children with ALL. Hazard ratios (HRs) for death and relapse were estimated through Cox regression analysis.

Results

One hundred and twenty patients (89%) were transfused with packed red blood cells (PRBCs) and 79 (58%) with single donor platelets (SDPs). The median number of transfusions was 2 (interquartile range [IQR]=1-3 events) and 1 (IQR=0-3 events) for PRBCs and SDPs, respectively. Patients who had white blood cell (WBC) count >50,000×10⁹/L, were classified as high risk according to the high National Cancer Institute criteria, displayed a T cell phenotype, or were minimal residual disease-positive at end of induction were more likely to receive >3 transfusions during induction (P=0.001, 0.002, 0.03, and 0.01, respectively). In univariate analysis, PRBC, SDP, and fresh frozen plasma transfusions did not have any significant association with relapse or death. For PRBC transfusions, the HRs for EFS and OS were 1.02 (95% CI, 0.85-1.24; P=0. 76) and 1.03 (95% CI, 0.83-1.27; P=0.76), respectively. For SDP transfusions, HRs were 1.03 (95% CI, 0.90-1.18; P=0.64) and 0.98 (95% CI, 0.80-1.20; P=0.87) for EFS and OS, respectively.

Conclusion

LR/IRR blood products may not confer a TRIM effect in childhood ALL and are unlikely to affect outcome.

Systematic review of methods used in meta-analyses where a primary outcome is an adverse or unintended event

BACKGROUND

Adverse consequences of medical interventions are a source of concern, but clinical trials may lack power to detect elevated rates of such events, while observational studies have inherent limitations. Meta-analysis allows the combination of individual studies, which can increase power and provide stronger evidence relating to adverse events. However, meta-analysis of adverse events has associated methodological challenges. The aim of this study was to systematically identify and review the methodology used in meta-analyses where a primary outcome is an adverse or unintended event, following a therapeutic intervention.

METHODS

Using a collection of reviews identified previously, 166 references including a meta-analysis were selected for review. At least one of the primary outcomes in each review was an adverse or unintended event. The nature of the intervention, source of funding, number of individual meta-analyses performed, number of primary studies included in the review, and use of meta-analytic methods were all recorded. Specific areas of interest relating to the methods used included the choice of outcome metric, methods of dealing with sparse events, heterogeneity, publication bias and use of individual patient data.

RESULTS

The 166 included reviews were published between 1994 and 2006. Interventions included drugs and surgery among other interventions. Many of the references being reviewed included multiple meta-analyses with 44.6% (74/166) including more than ten. Randomised trials only were included in 42.2% of meta-analyses (70/166), observational studies only in 33.7% (56/166) and a mix of observational studies and trials in 15.7% (26/166). Sparse data, in the form of zero events in one or both arms where the outcome was a count of events, was found in 64 reviews of two-arm studies, of which 41 (64.1%) had zero events in both arms.

CONCLUSIONS

Meta-analyses of adverse events data are common and useful in terms of increasing the power to detect an association with an intervention, especially when the events are infrequent. However, with regard to existing meta-analyses, a wide variety of different methods have been employed, often with no evident rationale for using a particular approach. More specifically, the approach to dealing with zero events varies, and guidelines on this issue would be desirable.

Impact of blood transfusions on survival and recurrence in colorectal cancer surgery

The aim of our study was to evaluate the prognostic significance of blood transfusion on recurrence and survival in patients undergoing curative resections for colorectal cancer. Retrospective analysis of prospectively collected data of patients after elective resections for colorectal cancer between January 2001 and December 2009 was undertaken. The main endpoint was overall survival, disease-free survival, and recurrence rate. These data were evaluated in relation to blood transfusion (group A, no blood transfusion; group B, one to two blood transfusions; group C, three and more blood transfusions). A total of 583 patients met the criteria for inclusion in the study. Of these, 132 (22.6 %) patients received blood transfusion in the perioperative period. There were 83 (14.2 %) patients who received one or two blood transfusions and 49 (8.4 %) patients who required three or more transfusions. Patients with three or more transfusions had a significantly worse 5-year overall survival, disease-free survival, and increased incidence of distant recurrences in comparison with the group without transfusion or the group with one or two transfusions. Multivariate analysis showed that the application of three or more blood transfusions is an independent risk factor for overall survival (P = 0.001; HR 2.158; 95 % CI 1.370-3.398), disease-free survival (P < 0.001; HR 2.514; 95 % CI 1.648-3.836), and the incidence of distant recurrence (P < 0.001; HR 2.902; 95 % CI 1.616-5.212). Application of three or more blood transfusions in patients operated for colorectal carcinoma is an adverse prognostic factor. Indications for blood transfusion should be carefully considered not only with regard to the risk of early complications, but also because of the possibility of compromising long-term results.

Gastric tube reconstruction reduces postoperative gastroesophageal reflux in adenocarcinoma of esophagogastric junction

BACKGROUND

The anastomosis of gastric remnant to esophagus after proximal gastrectomy is the traditional surgical treatment procedure for patients with types II and III adenocarcinoma of esophagogastric junction. However, the postoperative complications such as gastroesophageal reflux are frequent.

AIMS

To assess the outcome of the intraperitoneal anastomosis of the reconstructed gastric tube to esophagus after proximal gastrectomy for types II and III adenocarcinoma of esophagogastric junction.

METHODS

Seventy-six consecutive patients with preoperative diagnosis of type II or type III adenocarcinoma of esophagogastric junction were recruited. Forty-one patients had the traditional anastomosis of gastric remnant to esophagus and 35 patients underwent an anastomosis of esophagus to a gastric tube that was constructed from the gastric remnant after proximal gastrectomy.

RESULTS

Twenty-three (56.1%) versus 12 (28.6%) patients (p = 0.016) complained various discomforts and/or were diagnosed with complications in the traditional group and gastric tube group, respectively, although there were no significant differences between the two groups in demographic data and pathological characteristics. Fourteen (34.1%) versus five (14.3%) patients (p = 0.046) complained of heartburn or acid regurgitation and nine (22.0%) versus two (5.7%) patients (p = 0.045) were confirmed reflux esophagitis in the traditional group and the gastric tube group, respectively.

CONCLUSIONS

The intraperitoneal anastomosis of the reconstructed gastric tube to esophagus demonstrates less complaints of gastroesophageal reflux and reflux esophagitis than the traditional anastomosis of gastric remnant to esophagus in the surgical treatment of types II and III adenocarcinoma of esophagogastric junction in 1-year follow-up.

Skin and soft tissue infections in patients with solid tumours

BACKGROUND

Skin and soft tissue infections (SSTIs) in cancer patients represent a diagnostic challenge, as etiologic diagnosis is often missing, and clinical assessment of severity is difficult. Few studies have described (SSTIs) in patients with solid tumours (STs).

PATIENTS AND METHODS

Records of patients with ST and SSTI, cared for at the University Hospital of Heraklion, from 2002 to 2006 were retrospectively studied. Results. A total of 81 episodes of SSTIs, occurring in 71 patients with ST, have been evaluated. Their median age was 65 years (34-82). The most common underlying malignancy was breast cancer in 17 patients (24%). Most episodes (89%) occurred in nonneutropenics. Cellulitis/erysipelas was the most common clinical presentation (56; 69%). Bacterial cultures were possible in 29 (36%) patients. All patients received antimicrobial therapy, while in 17 episodes (21%) an incision and drainage was required. Treatment failure occurred in 20 episodes (25%). Five patients (7%) died due to sepsis. None was neutropenic. Severe sepsis on admission (P = 0.002) and prior blood transfusion (P = 0.043) were independent predictors of treatment failure.

CONCLUSION

SSTIs can be life threatening among patients with ST. Early diagnosis and appropriate treatment are of the utmost importance, since sepsis was proven a significant factor of unfavourable outcome.

Surgery: a stressful business

Over the years the surgical stress response and the efforts to modify it have been the subject of a great deal of research. Most recently this has led to the development of 'enhanced recovery' programmes which are revolutionizing perioperative patient care across the UK.

Meta-analyses of adverse effects data derived from randomised controlled trials as compared to observational studies: methodological overview

BACKGROUND

There is considerable debate as to the relative merits of using randomised controlled trial (RCT) data as opposed to observational data in systematic reviews of adverse effects. This meta-analysis of meta-analyses aimed to assess the level of agreement or disagreement in the estimates of harm derived from meta-analysis of RCTs as compared to meta-analysis of observational studies.

METHODS AND FINDINGS

Searches were carried out in ten databases in addition to reference checking, contacting experts, citation searches, and hand-searching key journals, conference proceedings, and Web sites. Studies were included where a pooled relative measure of an adverse effect (odds ratio or risk ratio) from RCTs could be directly compared, using the ratio of odds ratios, with the pooled estimate for the same adverse effect arising from observational studies. Nineteen studies, yielding 58 meta-analyses, were identified for inclusion. The pooled ratio of odds ratios of RCTs compared to observational studies was estimated to be 1.03 (95% confidence interval 0.93-1.15). There was less discrepancy with larger studies. The symmetric funnel plot suggests that there is no consistent difference between risk estimates from meta-analysis of RCT data and those from meta-analysis of observational studies. In almost all instances, the estimates of harm from meta-analyses of the different study designs had 95% confidence intervals that overlapped (54/58, 93%). In terms of statistical significance, in nearly two-thirds (37/58, 64%), the results agreed (both studies showing a significant increase or significant decrease or both showing no significant difference). In only one meta-analysis about one adverse effect was there opposing statistical significance.

CONCLUSIONS

Empirical evidence from this overview indicates that there is no difference on average in the risk estimate of adverse effects of an intervention derived from meta-analyses of RCTs and meta-analyses of observational studies. This suggests that systematic reviews of adverse effects should not be restricted to specific study types. Please see later in the article for the Editors' Summary.

Peri-operative blood transfusion and operative time are quality indicators for pancreatoduodenectomy

BACKGROUND

Minimization of blood loss during pancreatoduodenectomy requires careful surgical technique and specific preventative measures. Therefore, red blood cell (RBC) transfusions and operative time are potential surgical quality indicators. The aim of the present study was to compare peri-operative RBC transfusion and operative time with 30-day morbidity/mortality after pancreatoduodenectomy.

METHODS

All pancreatoduodenectomies (2005 to 2008) were identified using the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP). RBC transfusions and operative time were correlated with 30-day morbidity/mortality.

RESULTS

Pancreatoduodenectomy was completed in 4817 patients. RBC transfusions were given to 1559 (32%) patients (1-35 units). Overall morbidity and mortality rates were 37% and 3.0%, respectively. Overall 30-day morbidity increased in a stepwise manner with the number of RBC transfusions (R = 0.69, P < 0.01). Although RBC transfusions and operative times were not statistically linked (P = 0.87), longer operative times were linearly associated with increased 30-day morbidity (R = 0.79, P < 0.001) and mortality (R = 0.65, P < 0.01). Patients who were not transfused also displayed less morbidity (33%) and mortality (1.9%) (P < 0.05).

DISCUSSION

Peri-operative RBC transfusion after pancreatoduodenectomy is linearly associated with 30-day morbidity. Longer operative time also correlates with increased morbidity and mortality. Therefore, blood transfusions and prolonged operative time should be considered quality indicators for pancreatoduodenectomy.

Allogeneic blood transfusion in patients in Dukes B stage of colorectal cancer

The aim of this study is to evaluate influence of allogeneic blood transfusion on prognosis in patients in Dukes B stage of colorectal cancer. All patients with colorectal cancer who were admitted at our Department of Surgery between January 2000 and December 2004 were analyzed. One hundred fifty-one patients who fulfilled inclusion criteria were enrolled in further evaluation. B stage according to Dukes classification and curative resection were inclusion criteria. Exclusion criteria were polyposis syndromes, nonpolyposis syndromes, inflammatory bowel disease, autoimmune disease and previous blood transfusion. Patients were divided into two groups: Group 1 received ≤ 3 units of allogeneic blood transfusion and group 2 received >3 units of allogeneic blood transfusion. "Cutoff" value of 3 units of blood was defined according to our results and literature data. Follow-up was 5 year. There was no statistical difference between these groups in local recurrence (χ(2) = 0.009, P > 0.05) and distant metastasis (χ(2) = 0.44, P > 0.05). Also, the Kaplan-Meier survival curves were calculated, and long-rank test did not show a survival difference between these two groups (log rank = 0.075, P > 0.05). Postoperative complications are significantly more frequent in Group 2 (χ(2) = 4.67, P < 0.05). Multivariate logistic regression analysis confirmed that intraoperative blood transfusion more than three units had independent influence on local recurrence. Postoperative transfusion more than 3 units was statistically independent prognostic factor for metastasis and mortality. Overall transfusion less than 3 units of allogeneic blood does not influence the outcome of patients in Dukes B stage of colorectal cancer.

Blood loss in surgical oncology: neglected quality indicator?

Quality indicators can be defined as "specific and measurable elements of practice that can be used to assess the quality of care". Surgical blood loss is one of the most significant perioperative predictors of patient outcome. Blood loss is a modifiable quality indicator for oncologic cancer surgery. Surgical oncologists need to alter their surgical technique to promote bloodless surgery and decrease the variability in reported blood loss and rates of blood transfusion.

The impact of perioperative blood transfusion on clinical outcomes in colorectal surgery

Colorectal cancer is the second-leading cause of cancer-related death in the US. The prognosis of advanced colorectal cancer remains poor in spite of the advances obtained in recent years with new therapeutic agents, new approaches in surgical procedures and new diagnostic methods. Currently, colorectal cancer is the second most common cancer in Europe both in terms of incidence and mortality. Approximately 90% of all cancer deaths arise from the metastatic dissemination of primary tumors. It is a matter of vital importance whether perioperative blood transfusion promotes tumor recurrence and morbidity. This paper reviews the relevant medical literature published in English language on the theoretical background, methodological problems, results, as well as the possible clinical impact of blood transfusions in colorectal surgery with well-controlled trials. Searches were last update August 2007.

Autologous versus allogeneic transfusions: no difference in perioperative outcome after partial hepatectomy. Autologous transfusion on hepatectomy outcome

Blood transfusion is often necessary in patients undergoing liver resection. Because of the risks associated with allogeneic blood products, preoperative autologous blood donation has been advocated, but its benefit with respect to perioperative outcome remains unclear. This study compares perioperative outcome in patients transfused only with autologous blood to a matched cohort receiving only allogeneic blood. All patients subjected to hepatic resection and given only perioperative autologous red cell transfusions were identified from a prospective database of 2,123 patients and reviewed retrospectively. This group was matched to patients transfused only with a comparable number of allogeneic red cell units and to a control group that received no blood products. All patients in the autologous or allogeneic group received either 1 or 2 U. Matching was based on age, comorbidity, extent of hepatic resection, and estimated blood loss. Matched pair analysis was performed using the paired t test, McNemar and Stuart-Maxwell tests. From December 1991 to May 2003, 124 patients undergoing hepatic resection received perioperative autologous blood only, for which optimal matching was possible in 104. The groups were similar with respect to age, comorbidities, and blood loss; the proportions receiving preoperative chemotherapy, requiring a major resection (>or=3 segments) or a complex procedure (concomitant major procedure in addition to the principal hepatic resection) were also similar. There were no differences between the autologous and allogeneic groups in length of hospitalization, complications, and operative mortality. In patients undergoing hepatic resection, autologous blood transfusion did not demonstrably improve perioperative outcome when compared to a matched cohort of patients receiving a similar number of allogeneic units.

The intention-to-treat principle in clinical trials and meta-analyses of leukoreduced blood transfusions in surgical patients

BACKGROUND

The scientific method requires that only experiments actually and correctly performed be used to draw conclusions. The intention-to-treat principle requires that all patients, even those not or improperly treated, be included. In clinical trials and meta-analyses investigating leukoreduced blood transfusions to reduce postoperative infections, the intention-to-treat principle and the scientific method have been variably applied.

STUDY DESIGN AND METHODS

Clinical trials and meta-analyses were retrieved from the literature, and their scientific and statistical methods were assessed. A meta-analysis emphasizing the scientific method was created, restricted to patients who actually received transfusions, given that patients who did not receive transfusions cannot benefit from leukoreduction.

RESULTS

Nine clinical trials and 11 meta-analyses were identified. In 2 of the trials and all but 1 of the meta-analyses, conclusions were based on data that included many (>10%) patients who had been randomly assigned but not received a transfusion or data not derived from investigative results. Limiting the meta-analysis to patients who actually received transfusions (n = 3093), demonstrated that leukoreduced transfusions significantly reduced the odds of postoperative infection (summary odds ratio, 0.522; 95% confidence interval, 0.332-0.821; p = 0.005).

CONCLUSION

When data restricted to patients receiving transfusions are analyzed, and no data absent from the actual investigations are introduced, leukoreduced transfusions substantially and significantly reduce the odds of postoperative infection by approximately 50 percent. These results demonstrate the importance of including only scientifically valid data in clinical trials and meta-analyses. The intention-to-treat principle should never lead to inclusion of data not actually derived from experimental results.

Transfusion therapy in the critically ill

Blood transfusion remains an important part of treatment in critically ill patients. While the known infectious risks continue to decrease, concerns remain about the effects of allogeneic blood on the immune system. Some patients tolerate anemia much better than others; the optimal hemoglobin level, however, is difficult to define in any individual patient.

Transfusion in the intensive care unit: strategies under scrutiny

The transfusion of blood products continues to be an important technique for resuscitating patients in intensive care settings. A number of provocative studies have been published in the past year which examine the transfusion of blood products and alternatives. The Transfusion Requirements in Critical Care (TRICC) trial clearly established the safety of a restrictive transfusion strategy, thereby suggesting that physicians could easily minimize exposure to allogeneic red blood cells by lowering their transfusion threshold. The crystalloids versus colloids debate was also fueled by a number of studies this past year, specifically a meta-analysis which reported a 4% increase in absolute risk of mortality associated with resuscitation therapy using colloids. A recent study demonstrated that erythropoietin is a promising therapy in the intensive care. We can anticipate the results of a trial, currently underway, for further evidence of the use of smaller doses of erythropoietin in the ICU setting.

Randomisation to protect against selection bias in healthcare trials

BACKGROUND

Randomised trials use the play of chance to assign participants to comparison groups. The unpredictability of the process, if not subverted, should prevent systematic differences between comparison groups (selection bias), provided that a sufficient number of people are randomised.

OBJECTIVES

To assess the effects of randomisation and concealment of allocation on the results of healthcare trials.

SEARCH STRATEGY

We searched the Cochrane Methodology Register, MEDLINE, SciSearch, reference lists up to August 2000 and used personal communication.

SELECTION CRITERIA

Cohorts of trials, systematic reviews or meta-analyses of healthcare interventions that compared outcomes or prognostic factors for one of the following comparisons: randomised versus non-randomised trials, randomised trials with adequately versus inadequately concealed allocation, or high versus low quality trials where selection bias could not be separated from other sources of bias.

DATA COLLECTION AND ANALYSIS

One of us went through all of the citations in the Cochrane Methodology Register and accumulated reference lists. Studies that appeared to meet the inclusion criteria were retrieved and assessed independently by two of the reviewers. The methodological quality of included studies was appraised and information extracted by one of us and checked by a second. Tabular summaries of the results were prepared for each comparison and the results across studies were assessed qualitatively to identify common trends or discrepancies.

MAIN RESULTS

We identified 32 studies including over 3000 trials. Twenty-two studies compared randomised versus non-randomised trials, three compared adequately versus inadequately concealed allocation, and nine compared high versus low quality trials (some studies included more than one comparison). Five studies were of high methodological quality. In 15 of the 22 studies that compared randomised and non-randomised trials of the same intervention, important differences were found in the estimates of effect. Some of these differences were due to a poorer prognosis in the control groups in the non-randomised trials. The results of the other seven studies that compared randomised and non-randomised trials across different interventions are less clear. Comparisons of adequately and inadequately concealed allocation in randomised trials of the same intervention provided high quality evidence that concealment can be crucial in achieving similar treatment groups and, therefore, unbiased estimates of treatment effects. Studies with inadequate concealment tended to overestimate treatment effects. Comparisons of high and low quality trials of the same intervention have found important differences in estimates of effect, but it is not possible to determine the extent to which these differences can be attributed to randomisation or concealment of allocation. Omitting comparisons between randomised trials and non-randomised trials using historical controls did not substantially alter the results or conclusions of our review.

AUTHORS' CONCLUSIONS

On average, non-randomised trials and randomised trials with inadequate concealment of allocation tend to result in larger estimates of effect than randomised trials with adequately concealed allocation. However, it is not generally possible to predict the magnitude, or even the direction, of possible selection biases and consequent distortions of treatment effects.

Universal Leukocyte Reduction of Transfused Red Cells Does Not Provide Benefit to Patients Undergoing Cardiac Surgery

OBJECTIVE

A policy of universal leukocyte reduction of the blood supply in Finland was implemented at the beginning of 2003. The aim of the present evaluation was to determine the potential role of leukocyte-reduced red blood cells in decreasing postoperative infections.

DESIGN

A retrospective cohort study.

SETTING

A major university clinic.

PARTICIPANTS

Consecutive patients undergoing cardiac surgery during the years 2002 and 2003.

INTERVENTIONS

Transfused patients received either buffy-coat-depleted red blood cells before leukocyte reduction (n = 782) or leukocyte-reduced red blood cells after leukocyte reduction (n = 632).

MEASUREMENTS AND MAIN RESULTS

The evaluated outcome parameters were culture-proven postoperative infections, 90-day mortality, and length of stay in the intensive care unit. The percentage of patients transfused with red blood cells (56% v 53%, p = 0.16) and amounts of transfused red blood cells (4.3 +/- 6.7 [3.0] units v 4.3 +/- 6.6 [2.0] units, means +/- standard deviation [median], p = 0.48) were comparable between the study groups (buffy-coat-depleted group and leukocyte-reduced group, respectively). The 90-day mortality (6.6% v 6.3%, p = 0.28), the length of intensive care stay (3.6 +/- 4.7 [2.0] days v 4.3 +/- 7.1 [2.0] days, p = 0.34), and the number of patients with culture-proven infections (8.8% v 10.9%, p = 0.19) were unchanged after universal leukocyte reduction. In multivariate comparisons, the leukocyte reduction was not associated with culture-proven postoperative infections and 90-day mortality.

CONCLUSION

No beneficial effect of the universal leukocyte reduction in cardiac surgery was found for culture-positive infection rates, 90-day mortality, or length of intensive care stay.

Release of PMN elastase, TGF-β1 and neopterin during blood storage; unfiltered versus filtered blood

Release of inflammatory mediators from blood cells during prestorage leukocyte filtration may result in recipient immune suppression. To investigate the effects of prestorage leukocyte filtration on the quality of blood components, twenty-four blood units were collected from healthy donors and randomised into 3 groups. Eight units were stored as whole blood, eight units were separated into plasma, red blood cells (RBC) and buffy coat and eight units were collected and filtered through the ASAHI RZ 2000 leukocyte filter and separated into plasma and RBC. The units were stored for 35 days. Samples were collected weekly for analyses of polymorphonuclear elastase (PMN elastase), transforming growth factor-beta1 (TGF-beta1) and neopterin. PMN elastase and neopterin increased during storage of whole blood and RBC. From the beginning and throughout storage, PMN elastase was increased in filtered plasma as compared with unfiltered plasma. Filtration per se did not influence the neopterin concentration in plasma or RBC. TGF-beta1 increased in plasma and RBC during storage. In filtered plasma, an elevation of the TGF-beta1 concentration was observed from the start of storage. The TGF-beta1 levels were higher in filtered plasma compared with unfiltered plasma. Prestorage leukocyte filtration increased the release of PMN elastase and TGF-beta1 in plasma and RBC.

Impact of blood transfusions on recurrence and survival after rectal cancer surgery

PURPOSE

This study was designed to determine whether type or number of blood units transfused affected short-term and long-term outcome in patients undergoing surgery for rectal cancer. The number of perioperative blood units is associated with postoperative mortality and overall survival by some authors. In addition, allogenic perioperative blood transfusion has been postulated to produce host immunosuppression and has been reported to result in adverse outcome in patients with colorectal cancer. Autologous blood transfusion might improve results compared with allogenic transfusion.

METHODS

Clinical outcome for 597 patients undergoing surgery for rectal cancer was analyzed according to their transfusion status. Results for type (autologous or allogenic) and number of blood units transfused were recorded.

RESULTS

Blood transfusion was associated with increased postoperative mortality at 60 days. Patients who received > 3 units had a postoperative mortality of 6 percent compared with 1 percent for patients who received 1 to 3 units and 0 percent for patients who did not require transfusions. No difference was found between patients who received autologous or allogenic blood. Blood transfusions were also associated with impaired overall survival in a univariate analysis, but this finding was not confirmed in the multivariate analysis. The number or type of blood units transfused did not influence oncologic results. Local recurrence rates, distant metastases rates, and disease-free survival were not influenced by transfusion in our patients.

CONCLUSIONS

Increased numbers of blood units were associated with postoperative mortality. However, there is no reason, with respect to cancer recurrence or disease-free survival, to use a program of transfusion with autologous blood in patients undergoing surgery for rectal cancer.

[Use of blood products in patients treated surgically for stage I non-small cell lung cancer]

OBJECTIVE

Retrospective study on the relation between the use of blood products and survival rates in patients treated surgically for stage I non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

The study included 856 patients who underwent surgical resection from 1969 to 2000 for stage I NSCLC, classified histologically according to the current guidelines of the Spanish Society of Pulmonary and Thoracic Surgery (SEPAR). Patients who died in the postoperative period were excluded from the study. A series of clinicopathological variables were recorded, including the perioperative use or not of blood products. Descriptive, univariate, and multivariate statistical analyses were performed. Follow up concluded in December of 2003.

RESULTS

One hundred twenty-five patients (14.6%) underwent a perioperative transfusion. A significant association was found between the use of blood products and tumor size (P<.001), pneumectomy (P<.001), and cell type (P<.05). The respective 2, 5, and 10-year survival rates were 78%, 63%, and 54% for the nontransfusion group, and 73%, 59%, and 46% for the transfusion group. Both survival curves were compared and no significant differences were found (P=.23). Multivariate regression analysis included tumor size, patient age, and histologic cell type (squamous cell carcinoma or not); no relation between transfusion and survival was found.

CONCLUSIONS

In our series, we found no difference in survival rates for patients with stage I NSCLC after perioperative blood transfusion.

Blood conservation in the critically ill patient

This review focuses on transfusion practice in the critically ill.

Evaluating meta-analyses in the general surgical literature: a critical appraisal

OBJECTIVE

To assess the methodologic quality of meta-analyses of general surgery topics published in peer-reviewed journals.

SUMMARY BACKGROUND DATA

Systematic reviews and meta-analysis are used to seek, summarize, and interpret primary studies on a given topic. Accordingly, systematic reviews and meta-analyses of high-quality primary studies may be the highest level of evidence for issues of prevention and treatment in evidence-based medicine. However, not all published meta-analyses are rigorously performed.

METHODS

We searched MEDLINE (from January 1, 1997, to September 1, 2002) and reference lists and solicited general surgery specialists to identify relevant meta-analyses. Inclusion criteria were use of meta-analytic methods to pool the results of primary studies in general surgery on issues of diagnosis, causation, prognosis, or treatment. Our search strategies identified 487 potentially relevant articles. After excluding articles based on a priori criteria, 51 meta-analyses fulfilled eligibility criteria. In duplicate and independently, 2 reviewers assessed the quality of these meta-analyses using a 10-item index called the Overview Quality Assessment Questionnaire.

RESULTS

Overall concordance between 2 independent reviewers was good (interobserver agreement 81%, and a kappa of 0.62 (95% CI 0.55-0.69). Of 51 relevant articles, 38 were published in surgical journals. Most studies had major methodologic flaws (median score of 3.3, scale of 1-7). Factors associated with low overall scientific quality included the absence of any prior meta-analyses publications by authors and meta-analyses produced by surgical department members without external collaboration.

CONCLUSIONS

This critical appraisal of meta-analyses published in the general surgery literature demonstrates frequent methodologic flaws. The quality of these reports limits the validity of the findings and the inferences that can be made about the primary studies reviewed. To improve the quality of future meta-analyses, we recommend following guidelines for the optimal conduct and reporting of meta-analyses in general surgery.

Anemia, allogenic blood transfusion, and immunomodulation in the critically ill

Anemia and allogenic RBC transfusions are exceedingly common among critically ill patients. Multiple pathologic mechanisms contribute to the genesis of anemia in these patients. Emerging risks associated with allogenic RBC transfusions including the transmission of newer infectious agents and immune modulation predisposing the patient to infections requires reevaluation of current transfusion strategies. Recent data have suggested that a restrictive transfusion practice is associated with reduced morbidity and mortality during critical illness, with the possible exception of acute coronary syndromes. In this article, we review the immune-modulatory role of allogenic RBC transfusions in critically ill patients.

Evaluating the role of quality assessment of primary studies in systematic reviews of cancer practice guidelines

BACKGROUND

The purpose of this study was to evaluate the role of study quality assessment of primary studies in cancer practice guidelines.

METHODS

Reliable and valid study quality assessment scales were sought and applied to published reports of trials included in systematic reviews of cancer guidelines. Sensitivity analyses were performed to evaluate the relationship between quality scores and pooled odds ratios (OR) for mortality and need for blood transfusion.

RESULTS

Results found that that whether trials were classified as high or low quality depended on the scale used to assess them. Although the results of the sensitivity analyses found some variation in the ORs observed, the confidence intervals (CIs) of the pooled effects from each of the analyses of high quality trials overlapped with the CI of the pooled odds of all trials. Quality score was not predictive of pooled ORs studied here.

CONCLUSIONS

Had sensitivity analyses based on study quality been conducted prospectively, it is highly unlikely that different conclusions would have been found or that different clinical recommendations would have emerged in the guidelines.