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Preoperative hemoglobin and perioperative blood transfusion in major head and neck surgery: a systematic review and meta-analysis
Ali, M., Dort, J. C., Sauro, K. M.
Journal of Otolaryngology - Head & Neck Surgery = Le Journal D'oto-Rhino-Laryngologie Et De Chirurgie Cervico-Faciale. 2023;52(1):3
Abstract
BACKGROUND There is a growing concern with inappropriate, excessive perioperative blood transfusions. Understanding the influence of low preoperative hemoglobin (Hgb) on perioperative blood transfusion (PBT) in head and neck cancer (HNC) surgery with free flap reconstruction may help guide clinical practice to reduce inappropriate treatment among these patients. The objective is to synthesize evidence regarding the association between preoperative Hgb and PBT among major HNC free flap surgeries. METHODS Terms and synonyms for HNC surgical procedures, Hgb and PBT were used to search MEDLINE, Embase, CINAHL, Cochrane Central Register of Controlled Trials and Cochrane Database of Reviews from inception to February 2020. Reference lists of included full texts and studies reporting the preoperative Hgb, anemia or hematocrit (exposure) and the PBT (outcome) in major HNC surgery with free flap reconstruction were eligible. Studies examining esophageal, thyroid and parathyroid neoplasms were excluded; as were case reports, case series (n < 20), editorials, reviews, perspectives, viewpoints and responses. Two independent, blinded reviewers screened titles, abstracts and full texts in duplicate. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses was followed. A random-effects model was used to pool reported data. The primary outcome was the proportion of patients who had a PBT. Subgroup analysis examined sources of heterogeneity for perioperative predictors of PBT (age, sex, flap type, flap site and preoperative Hgb). We also examined mean preoperative Hgb in the PBT and no PBT groups. RESULTS Patients with low preoperative Hgb were transfused more than those with normal Hgb (47.62%, 95% CI = 41.19-54.06, I(2) = 0.00% and 13.92%, 95% CI = 10.19-17.65, I(2) = 20.69%, respectively). None of the predictor variables explained PBT. The overall pooled mean preoperative Hgb was 12.96 g/dL (95% CI = 11.33-14.59, I(2) = 0.00%) and was 13.58 g/dL (95% CI = 11.95-15.21, I(2) = 0.00%) in the no PBT group and 12.05 g/dL (95% CI = 10.01 to 14.09, I(2) = 0.00%) in the PBT group. CONCLUSIONS The heterogeneity between studies, especially around the trigger for PBT, highlights the need for additional research to guide clinical practice of preoperative Hgb related to PBT to enhance patient outcomes and improve healthcare stewardship.
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Red Blood Cell Transfusion Guided by Hemoglobin Only or Integrating Perfusion Markers in Patients Undergoing Cardiac Surgery: A Systematic Review and Meta-Analysis With Trial Sequential Analysis
Putaggio, A., Tigano, S., Caruso, A., La Via, L., Sanfilippo, F.
Journal of cardiothoracic and vascular anesthesia. 2023
Abstract
OBJECTIVE Strategies for red blood cell (RBC) transfusion in patients undergoing cardiac surgery have been traditionally anchored to hemoglobin (Hb) targets. A more physiologic approach would consider markers of organ hypoperfusion. DESIGN The authors conducted a systematic review and meta-analysis with trial sequential analysis of randomized controlled trials (RCTs). SETTING Cardiac surgery. PARTICIPANTS Adult patients. INTERVENTION RBC transfusion targeting only Hb levels compared with strategies combining Hb values with markers of organ hypoperfusion. MEASUREMENTS AND MAIN RESULTS Primary outcomes were the number of RBC units transfused, the number of patients transfused at least once, and the average number of transfusions. Secondary outcomes were postoperative complications, intensive care (ICU) and hospital lengths of stay, and mortality. Only 2 RCTs were included (n = 257 patients), and both used central venous oxygen saturation (ScvO(2)) as a marker of organ hypoperfusion (cut-off: <70% or ≤65%). A transfusion protocol combining Hb and ScvO(2) reduced the overall number of RBC units transfused (risk ratio [RR]: 1.57 [1.33-1.85]; p < 0.0001, I(2) = 0%), and the number of patients transfused at least once (RR: 1.33 [1.16-1.53]; p < 0.0001, I(2) = 41%), but not the average number of transfusions (mean difference [MD]: 0.18 [-0.11 to 0.47]; p = 0.24, I(2) = 66%), with moderate certainty of evidence. Mortality (RR: 1.29, [0.29-5.77]; p = 0.73, I(2) = 0%), ICU length-of-stay (MD: -0.06 [-0.58 to 0.46]; p = 0.81, I(2) = 0%), hospital length-of-stay (MD: -0.05 [-1.49 to 1.39];p = 0.95, I(2) = 0%), and all postoperative complications were not affected. CONCLUSIONS In adult patients undergoing cardiac surgery, a restrictive protocol integrating Hb values with a marker of organ hypoperfusion (ScvO(2)) reduces the number of RBC units transfused and the number of patients transfused at least once without apparent signals of harm. These findings were preliminary and warrant further multicentric research.
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Prevention of cardiac surgery-associated acute kidney injury: a systematic review and meta-analysis of non-pharmacological interventions
Hariri, G., Collet, L., Duarte, L., Martin, G. L., Resche-Rigon, M., Lebreton, G., Bouglé, A., Dechartres, A.
Critical care (London, England). 2023;27(1):354
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Editor's Choice
Abstract
BACKGROUND Cardiac surgery-associated acute kidney injury (CSA-AKI) is frequent. While two network meta-analyses assessed the impact of pharmacological interventions to prevent CSA-AKI, none focused on non-pharmacological interventions. We aim to assess the effectiveness of non-pharmacological interventions to reduce the incidence of CSA-AKI. METHODS We searched PubMed, Embase, Central and clinical trial registries from January 1, 2004 (first consensus definition of AKI) to July 1, 2023. Additionally, we conducted manual screening of abstracts of major anesthesia and intensive care conferences over the last 5 years and reference lists of relevant studies. We selected all randomized controlled trials (RCTs) assessing a non-pharmacological intervention to reduce the incidence of CSA-AKI, without language restriction. We excluded RCTs of heart transplantation or involving a pediatric population. The primary outcome variable was CSA-AKI. Two reviewers independently identified trials, extracted data and assessed risk of bias. Random-effects meta-analyses were conducted to calculate risk ratios (RRs) with 95% confidence intervals (CIs). We used the Grading of Recommendations Assessment, Development, and Evaluation to assess the quality of evidence. RESULTS We included 86 trials (25,855 patients) evaluating 10 non-pharmacological interventions to reduce the incidence of CSA-AKI. No intervention had high-quality evidence to reduce CSA-AKI. Two interventions were associated with a significant reduction in CSA-AKI incidence, with moderate quality of evidence: goal-directed perfusion (RR, 0.55 [95% CI 0.40-0.76], I(2) = 0%; P(het) = 0.44) and remote ischemic preconditioning (RR, 0.86 [0.78-0.95]; I(2) = 23%; P(het) = 0.07). Pulsatile flow during cardiopulmonary bypass was associated with a significant reduction in CSA-AKI incidence but with very low quality of evidence (RR = 0.69 [0.48; 0.99]; I(2) = 53%; P(het) < 0.01). We found high quality of evidence for lack of effect of restrictive transfusion strategy (RR, 1.02 [95% CI 0.92; 1.12; P(het) = 0.67; I(2) = 3%) and tight glycemic control (RR, 0.86 [95% CI 0.55; 1.35]; P(het) = 0.25; I(2) = 26%). CONCLUSIONS Two non-pharmacological interventions are likely to reduce CSA-AKI incidence, with moderate quality of evidence: goal-directed perfusion and remote ischemic preconditioning.
PICO Summary
Population
Adult patients undergoing cardiac surgery such as coronary artery bypass grafting and/or valve surgery (86 randomised controlled trials (RCTs) n= 25,855).
Intervention
Non-pharmacological interventions to reduce the incidence of cardiac surgery-associated acute kidney injury (CSA-AKI): Goal directed perfusion (GDP), pulsatile flow during cardiopulmonary bypass (CPB), minimally invasive extracorporeal circulation (MECC), epidural analgesia, remote ischemic preconditioning (RIPc), tight glycemic control, kidney disease improving global outcomes care bundle, hyperoxia during CPB, restrictive transfusion strategy, high target arterial pressure.
Comparison
Usual care.
Outcome
No intervention had high-quality evidence to reduce CSA-AKI. From the included studies, the most frequent intervention was RIPc (31 RCTs, n= 7,738), MECC, (14 RCTs, n= 1,617) and pulsatile blood flow during CPB (10 RCTs, n= 1,993). Three interventions were associated with a significantly reduced risk of CSA-AKI: GDP, RIPc and pulsatile flow during CPB.
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Outcomes following perioperative red blood cell transfusion in patients undergoing elective major abdominal surgery: a systematic review and meta-analysis
Morris, F. J. D., Fung, Y. L., Craswell, A., Chew, M. S.
British journal of anaesthesia. 2023
Abstract
BACKGROUND Perioperative red blood cell transfusion is a double-edged sword for surgical patients. While transfusion of red cells can increase oxygen delivery by increasing haemoglobin levels, its impact on short- and long-term postoperative outcomes, particularly in patients undergoing elective major abdominal surgery, is unclear. METHODS We conducted a systematic review and meta-analysis on the effect of perioperative blood transfusions on postoperative outcomes in elective major abdominal surgery. PubMed, Cochrane, and Scopus databases were searched for studies with data collected between January 1, 2000 and June 6, 2020. The primary outcome was short-term mortality, including all-cause 30-day or in-hospital mortality. Secondary outcomes included long-term all-cause mortality, any morbidity, infectious complications, overall survival, and recurrence-free survival. No randomised controlled trials were found. Thirty-nine observational studies were identified, of which 37 were included in the meta-analysis. RESULTS Perioperative blood transfusion was associated with short-term all-cause mortality (odds ratio [OR] 2.72, 95% confidence interval [CI] 1.89-3.91, P<0.001), long-term all-cause mortality (hazard ratio 1.35, 95% CI 1.09-1.67, P=0.007), any morbidity (OR 2.18, 95% CI 1.81-2.64, P<0.001), and infectious complications (OR 1.90, 95% CI 1.60-2.26, P<0.001). Perioperative blood transfusion remained associated with short-term mortality in the sensitivity analysis after excluding studies that did not control for preoperative anaemia (OR 2.27, 95% CI 1.59-3.24, P<0.001). CONCLUSIONS Perioperative blood transfusion in patients undergoing elective major abdominal surgery is associated with poorer short- and long-term postoperative outcomes. This highlights the need to implement patient blood management strategies to manage and preserve the patient's own blood and reduce the need for red blood cell transfusion. TRIAL REGISTRATION PROSPERO (CRD42021254360).
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The effect of different timing of blood transfusion on oncological outcomes of patients undergoing radical cystectomy for bladder cancer: a systematic review and meta-analysis
Ma, S. Y., An, Y., Sun, J. X., Xu, M. Y., Liu, C. Q., Xu, J. Z., Zhong, X. Y., Zeng, N., He, H. D., Xia, Q. D., et al
Frontiers in oncology. 2023;13:1223592
Abstract
HIGHLIGHTS This meta-analysis and systematic review aim to analyze the association between BT and oncological outcomes of patients undergoing RC for bladder cancer, and tries to find out whether the timing of blood transfusion could also have an effect on this relationship. A total of 20 retrospective studies from online databases and other sources are identified and enrolled in this study. The results show that BT administration during RC operation or perioperative period is significantly associated with worse oncological outcomes including ACM, CSM and DR. BACKGROUND Bladder cancer is one of the most common urological malignancies. Radical cystectomy (RC) remains the main treatment for localized muscle-invasive bladder cancer (MIBC) or high-grade non-muscle-invasive bladder cancer (NMIBC). In the process of RC, the administration of blood transfusion (BT) is sometimes needed, however, it may cause transfusion-related complications or lead to worse oncological outcomes. This meta-analysis and systematic review aims to give a comprehensive insight into the association between BT and oncological outcomes of patients undergoing RC, and tries to find out whether the timing of blood transfusion could also have an impact on this association. METHODS This systematic review and meta-analysis were carried out according to the PRISMA 2020 reporting guideline. We have searched four bibliographic databases including PubMed (Medline), EMBASE, Cochrane Library, and Web of Science with no language limitation. Studies investigating the association between BT and oncological outcomes of patients undergoing RC are identified and included in this research from inception through March 20, 2023. This research calculates the pooled hazard ratios (pHR) and 95% confidence intervals (95% CI) of all-cause mortality (ACM), cancer-specific mortality (CSM) and disease recurrence (DR) using Random Effects models or Fixed Effects models. Subgroup analyses stratified by parameters such as timing of transfusion are also conducted. This meta-analysis was registered with PROSPERO, CRD42022381656. RESULTS A total of 20 retrospective studies from online databases and other sources are identified and enrolled in this study. Results show that blood transfusion significantly increased the risks for ACM (HR = 1.33, 95% CI: 1.23-1.44), CSM (HR = 1.25, 95% CI: 1.15 - 1.35) and DR (HR = 1.26, 95% CI: 1.15 - 1.38). However, when stratified by the timing of BT, we find that only intraoperative and perioperative transfusion significantly increased in risks for worse prognosis, while postoperative transfusion raised none of the risks of ACM (HR = 1.26, 95% CI: 0.92-1.73), CSM (HR = 1.08, 95% CI: 0.93-1.26) nor DR (HR = 1.08, 95% CI: 0.90-1.29) significantly. CONCLUSION BT administration during RC operation or perioperative period is significantly associated with worse oncological outcomes including ACM, CSM and DR. Clinicians should consider carefully when deciding to administrate BT to patients undergoing RC and carry out according to current guidelines.
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Effects of perioperative blood transfusion in gastric cancer patients undergoing gastrectomy: A systematic review and meta-analysis
Wang W, Zhao L, Niu P, Zhang X, Luan X, Zhao D, Chen Y
Frontiers in surgery. 2022;9:1011005
Abstract
BACKGROUND The short-term and long-term effects of perioperative blood transfusion (PBT) on patients with gastric cancer are still intriguing. This systematic review and meta-analysis aimed to investigate the effects of blood transfusion on clinical outcomes in patients with gastric cancer undergoing gastrectomy. METHODS We searched PubMed, Web of Science, Embase, and The Cochrane Library on December 31th 2021. The main outcomes were overall survival (OS), disease-free survival (DFS), disease-specific survival (DFS), and postoperative complications. A fixed or random-effects model was used to calculate the hazard ratio (HR) with 95% confidence intervals (CIs). RESULTS Fifty-one studies with a total of 41,864 patients were included for this review and meta-analysis. Compared with patients who did not receive blood transfusions (NPBT), PBT was associated with worse 5-year OS (HR = 2.39 [95%CI: 2.00, 2.84]; p < 0.001; Multivariate HR = 1.43 [95%CI: 1.24, 1.63]; p < 0. 001), worse 5-year DFS (HR = 2.26 [95%CI: 1.68, 3.05]; p < 0.001; Multivariate HR = 1.45 [95%CI: 1.16, 1.82]; p < 0. 001), and worse 5-year DSS (HR = 2. 23 [95%CI: 1.35, 3.70]; p < 0.001; Multivariate HR = 1.24 [95%CI: 0.96, 1.60]; p < 0.001). Moreover, The PBT group showed a higher incidence of postoperative complications [OR = 2.30 (95%CI:1.78, 2. 97); p < 0.001] than that in the NPBT group, especially grade III-V complications, according to the Clavien-Dindo classification. [OR = 2.50 (95%CI:1.71, 3.63); p < 0.001]. CONCLUSION In patients who underwent gastrectomy, PBT was associated with negative survival effects (OS, DFS, DSS) and a higher incidence of perioperative complications. However, more research was expected to further explore the impact of PBT. Meanwhile, strict blood transfusion management should be implemented to minimize the use of PBT.
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Transfusion Guidelines in Brain Tumor Surgery: A Systematic Review and Critical Summary of Currently Available Evidence
Rail B, Hicks WH, Oduguwa E, Barrie U, Pernik MN, Montgomery E, Tao J, Kenfack YJ, Mofor P, Adeyemo E, et al
World neurosurgery. 2022
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Editor's Choice
Abstract
OBJECTIVE Red blood cell (RBC) transfusion is commonly indicated in brain tumor surgery due to risk of blood loss. Current transfusion guidelines are based on evidence derived from critically ill patients and may not be optimal for brain tumor surgeries. Our study is the first to synthesize available evidence to suggest RBC transfusion thresholds in brain tumor patients undergoing surgery. METHODS A systematic review was conducted using PubMed, EMBASE, and Google Scholar databases in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines to critically assess RBC transfusion thresholds in adult patients with brain tumors and complications secondary to transfusion following blood loss in the operating room (OR) or the perioperative period. RESULTS Seven (7) articles meeting our search criteria were reviewed. Brain tumor patients who received blood transfusions were older, had greater rates of ASA class 3 or 4, and presented with increased number of comorbidities including diabetes, hypertension, and cardiovascular diseases. In addition, transfused patients had a prolonged surgical time. Transfusions were associated with multiple postoperative major and minor complications, including longer hospital length of stay (LOS), increased return to the OR, and elevated 30-day mortality. Analysis of transfusion thresholds showed that a restrictive hemoglobin (Hb) threshold of 8 g/dL is safe in patients, as evidenced by a reduction in LOS, mortality, and complications (Level C Class IIa). CONCLUSIONS A restrictive Hb threshold of 8 g/dL appears to be safe and minimizes potential complications of transfusion in brain tumor patients. LEVEL OF EVIDENCE Class C Level IIa.
PICO Summary
Population
Brain tumor patients undergoing surgery (7 studies).
Intervention
Systematic review assessing red blood cell transfusion thresholds.
Comparison
Outcome
Patients who received blood transfusions were older, had greater rates of American Society of Anesthesiologists class 3 or 4, and presented with increased number of comorbidities including diabetes, hypertension, and cardiovascular diseases. Transfused patients had a prolonged surgical time. Transfusions were associated with multiple postoperative major and minor complications, including longer hospital length of stay (LOS), increased return to the operating room, and elevated 30-day mortality. Analysis of transfusion thresholds showed that a restrictive haemoglobin (Hb) threshold of 8 g/dL was safe in patients, as evidenced by a reduction in LOS, mortality, and complications.
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Transfusion Guidelines in Adult Spine Surgery: A Systematic Review and Critical Summary of Currently Available Evidence
Barrie U, Youssef CA, Pernik MN, Adeyemo E, Elguindy M, Johnson ZD, Ahmadieh TYE, Akbik OS, Bagley CA, Aoun SG
The spine journal : official journal of the North American Spine Society. 2021
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Editor's Choice
Abstract
BACKGROUND CONTEXT Red blood cell transfusion can be associated with complications in medical and surgical patients. Acute anemia in ambulatory patients undergoing surgery can also impede wound healing and independent self-care. Current transfusion threshold guidelines are still based on evidence derived from critically-ill intensive care unit medical patients and may not apply to spine surgery candidates. PURPOSE We aimed to provide the reader with a synthesis of the best available evidence to recommend transfusion trigger thresholds and guidelines in adult patients undergoing spine surgery. STUDY DESIGN/SETTING This is a systematic review. OUTCOME MEASURES Physiological measure: Blood transfusion thresholds and associated posttransfusion complications (morbidity, mortality, length of stay, infections, etc…) of the published articles. PATIENT SAMPLE Adult spine surgery patients. METHODS A systematic review of the literature using the PubMed, Google Scholar, and Web of Science electronic databases was made according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Focus was set on papers discussing thresholds for blood transfusion in adult surgical spine patients, as well as complications associated with transfusion after acute surgical blood loss in the operating room or postoperative period. Publications discussing pediatric cases, blood type analyses, blood loss prevention strategies and protocols, systematic reviews and letters to the editor were excluded. RESULTS A total of 22 articles fitting our search criteria were reviewed. Patients who received blood transfusion in these studies were older, of female gender, had more severe comorbidities except for smoking, and had prolonged surgical time. Blood transfusion was associated with multiple adverse postoperative complications, including a higher rate of superficial or deep surgical site infections, sepsis, urinary and pulmonary infections, cardiovascular complications, return to the operating room, and increased postoperative length of stay and 30-day readmission. Analysis of transfusion thresholds from these studies showed that a pre-operative hemoglobin (Hb) of > 13 g/dL, and an intraoperative and post-operative Hb nadir above 9 and 8 g/dL, respectively, were associated with better outcomes and fewer wound infections than lower thresholds (Level B Class III). Additionally, it was generally recommended to transfuse autologous blood that was < 28 days old, if possible, with a limit of 2 to 3 units to minimize patient morbidity and mortality. CONCLUSION Blood transfusion thresholds in surgical patients may be specialty-specific and different than those used for critically-ill medical patients. For adult spine surgery patients, red blood cell transfusion should be avoided if Hb numbers remain > 9 and 8 g/dL in the intraoperative and direct post-operative periods, respectively.
PICO Summary
Population
Adult spine surgery patients (22 studies).
Intervention
Systematic review of studies on recommended thresholds for blood transfusion, and its associated complications.
Comparison
Outcome
Patients who received blood transfusion in the studies reviewed were older, female, had more severe comorbidities except for smoking, and had prolonged surgical time. Blood transfusion was associated with multiple adverse postoperative complications, including a higher rate of superficial or deep surgical site infections, sepsis, urinary and pulmonary infections, cardiovascular complications, return to the operating room, and increased postoperative length of stay and 30-day readmission. Analysis of transfusion thresholds showed that a pre-operative haemoglobin (Hb) of > 13 g/dL, and an intraoperative and post-operative Hb nadir above 9 and 8 g/dL, respectively, were associated with better outcomes and fewer wound infections than lower thresholds. Additionally, it was generally recommended to transfuse autologous blood that was < 28 days old, if possible, with a limit of 2 to 3 units to minimize patient morbidity and mortality.
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Impact of perioperative blood transfusions on oncologic outcomes after radical cystectomy: A systematic review and meta-analysis of comparative studies
Uysal D, Egen L, Grilli M, Wessels F, Lenhart M, Michel MS, Kriegmair MC, Kowalewski KF
Surgical oncology. 2021;38:101592
Abstract
This study aimed at systematically analyzing and evaluating the impact of perioperative blood transfusions (PBT) on oncologic outcomes of patients undergoing radical cystectomy for bladder cancer. This systematic review follows the recommendations of the Cochrane Handbook for Systematic Reviews and Interventions and was conducted in line with the PRISMA statement and the AMSTAR II criteria. A comprehensive database search was performed based on the PICO criteria. Two independent reviewers performed all screening steps and quality assessment. Risk of bias and certainty in evidence were assessed with the Newcastle Ottawa Scale for non-randomized trials and the GRADE approach. Of 1123 identified studies 20 were eligible for qualitative analysis and 15 for quantitative analysis reporting on 21,915 patients. Receiving a PBT was associated with an increased risk of all-cause mortality (hazard ratio (HR) [95% confidence interval (CI)]: 1.29 [1.18, 1.40]; p < 0.001), cancer-specific mortality (HR [CI]: 1.27 [1.15; 1.41]; p < 0.001) and disease recurrence (HR [CI]: 1.22 [1.12; 1.34]; p < 0.001). Subgroup analysis of transfusion timing revealed a significantly increased risk of mortality with intraoperative or combined intra- and postoperative transfusions compared to postoperative transfusion only for all three outcomes (p < 0.001). Leukocyte-depletion was associated with increased all-cause mortality, but not cancer-specific mortality. The administration of PBT negatively impacts oncological outcomes after radical cystectomy. Therefore, careful treatment indication and strict adherence to transfusion guidelines is encouraged in order to avoid adverse effects during the perioperative course.
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A Systematic Review and Meta-analysis of Randomized Controlled Trials Comparing Intraoperative Red Blood Cell Transfusion Strategies
Lenet T, Baker L, Park L, Vered M, Zahrai A, Shorr R, Davis A, McIsaac DI, Tinmouth A, Fergusson DA, et al
Annals of surgery. 2021
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Editor's Choice
Abstract
OBJECTIVE The objective of this work was to carry out a meta-analysis of RCTs comparing intraoperative RBC transfusion strategies to determine their impact on postoperative morbidity, mortality, and blood product use. SUMMARY OF BACKGROUND DATA RBC transfusions are common in surgery and associated with widespread variability despite adjustment for casemix. Evidence-based recommendations guiding RBC transfusion in the operative setting are limited. METHODS The search strategy was adapted from a previous Cochrane Review. Electronic databases were searched from January 2016 to February 2021. Included studies from the previous Cochrane Review were considered for eligibility from before 2016. RCTs comparing intraoperative transfusion strategies were considered for inclusion. Co-primary outcomes were 30-day mortality and morbidity. Secondary outcomes included intraoperative and perioperative RBC transfusion. Meta-analysis was carried out using random-effects models. RESULTS Fourteen trials (8641 patients) were included. One cardiac surgery trial accounted for 56% of patients. There was no difference in 30-day mortality [relative risk (RR) 0.96, 95% confidence interval (CI) 0.71-1.29] and pooled postoperative morbidity among the studied outcomes when comparing restrictive and liberal protocols. Two trials reported worse composite outcomes with restrictive triggers. Intraoperative (RR 0.53, 95% CI 0.43-0.64) and perioperative (RR 0.70, 95% CI 0.62-0.79) blood transfusions were significantly lower in the restrictive group compared to the liberal group. CONCLUSIONS Intraoperative restrictive transfusion strategies decreased perioperative transfusions without added postoperative morbidity and mortality in 12/14 trials. Two trials reported worse outcomes. Given trial design and generalizability limitations, uncertainty remains regarding the safety of broad application of restrictive transfusion triggers in the operating room. Trials specifically designed to address intraoperative transfusions are urgently needed.
PICO Summary
Population
Adult patients undergoing surgery (14 studies, n= 8,641).
Intervention
Restrictive blood transfusion strategy.
Comparison
Liberal blood transfusion strategy.
Outcome
There was no difference in 30-day mortality relative risk (RR) 0.96, and pooled postoperative morbidity among the studied outcomes when comparing restrictive and liberal protocols. Two trials reported worse composite outcomes with restrictive triggers. Intraoperative (RR 0.53) and perioperative (RR 0.70) blood transfusions were significantly lower in the restrictive group compared to the liberal group.