Abstract

BACKGROUND AND OBJECTIVES Transfusion-associated circulatory overload (TACO) is a major cause of severe transfusion-related morbidity. Transfusion of red blood cells (RBCs) has been shown to induce hydrostatic pressure overload. It is unclear which product-specific factors contribute. We set out to determine the effect of autologous RBC transfusion versus saline on pulmonary capillary wedge pressure (PCWP) change. MATERIALS AND METHODS In a randomized crossover trial, patients who had undergone coronary bypass surgery were allocated to treatment post-operatively in the intensive care unit with either an initial 300 ml autologous RBC transfusion (salvaged during surgery) or 300 ml saline infusion first, followed by the other. Primary outcome was the difference in PCWP change. Secondary outcome measures were the difference in extra-vascular lung water index (EVLWI) and pulmonary vascular permeability index (PVPI). RESULTS Change in PCWP was not higher after autologous RBC transfusion compared to saline (ΔPCWP 0.3 ± 0.4 vs. 0.1 ± 0.4 mmHg). ΔEVLWI and ΔPVPI were significantly decreased after autologous RBC transfusion compared to saline (ΔEVLWI -1.6 ± 0.6 vs. 0.2 ± 0.4, p = 0.02; ΔPVPI -0.3 ± 0.1 vs. 0.0 ± 0.1, p = 0.01). Haemodynamic variables and colloid osmotic pressure were not different for autologous RBC transfusion versus saline. CONCLUSION Transfusion of autologous RBCs did not result in a more profound increase in PCWP compared to saline. RBC transfusion resulted in a decrease of EVLWI and PVPI compared to saline. Our data suggest that transfusing autologous RBCs may lead to less pulmonary oedema compared to saline. Future studies with allogeneic RBCs are needed to investigate other factors that may mediate the increase of PCWP, resulting in TACO.

Abstract

BACKGROUND Current practice guidelines for red blood cell (RBC) transfusion in ICUs are based on haemoglobin threshold, without consideration of oxygen delivery or consumption. We aimed to evaluate an individual physiological threshold-guided by central venous oxygen saturation ScvO(2). METHODS In a randomised study in two French academic hospitals, 164 patients who were admitted to ICU after cardiac surgery with postoperative haemoglobin <9 g dl(-1) were randomised to receive a transfusion with one unit of RBCs (haemoglobin group) or transfusion only if the ScvO(2) was <70% (individualised group). The primary outcome was the number of subjects receiving at least one unit of RBCs. The secondary composite outcome was acute kidney injury, stroke, myocardial infarction, acute heart failure, mesenteric ischaemia, or in-hospital mortality. One- and 6-month mortality were evaluated during follow-up. RESULTS The primary outcome was observed for 80 of 80 subjects (100%) in the haemoglobin group and in 61 of 77 patients (79%) in the individualised group (absolute risk -21% [-32.0; -14.0]; P<0.001). There was no significant difference in the secondary outcome between the two groups. Follow-up showed a non-significant difference in mortality at 1 and 6 months. CONCLUSIONS An individualised strategy based on an central venous oxygen saturation threshold of 70% allows for a more restrictive red blood cell transfusion strategy with no incidence on postoperative morbidity or 6-month mortality. CLINICAL TRIAL REGISTRATION NCT02963883.

Abstract

BACKGROUND Acute Kidney Injury (AKI) adversely affects outcomes after cardiac surgery. A major mediator of AKI is the activation of leukocytes through exposure to the cardiopulmonary bypass circuit. We evaluate the use of leukodepletion filters throughout bypass to protect against post-operative AKI by removing activated leukocytes during cardiac surgery. METHODS This is a single-centre, double-blind, randomized controlled trial comparing the use of leukodepletion versus a standard arterial filter throughout bypass. Elective adult patients undergoing heart valve surgery with or without concomitant procedures were investigated. The primary clinical outcome measured was the development of AKI according to the KDIGO criteria. Secondary measures included biomarkers of renal tubular damage (urinary Retinol Binding Protein and Kidney Injury Molecule-1), glomerular kidney injury (urinary Micro Albumin and serum Cystatin C) and urinary Neutrophil Gelatinase Associated Lipocalin, as well as the length of hospital stay and quality of life measures through EQ-5D-5L questionnaires. RESULTS The ROLO trial randomized 64 participants with a rate of recruitment higher than anticipated (57% achieved, 40% anticipated). The incidence of AKI was greater in the leukodepletion filter group (44% versus 23%, risk difference 21, 95% CI - 2 to 44%). This clinical finding was supported by biomarker levels especially by a tendency toward glomerular insult at 48 h, demonstrated by a raised serum Cystatin C (mean difference 0.11, 95% CI 0.00 to 0.23, p = 0.068) in the leukodepleted group. There was however no clear association between the incidence or severity of AKI and length of hospital stay. On average, health related quality of life returned to pre-operative levels in both groups within 3 months of surgery. CONCLUSIONS Leukocyte depletion during cardiopulmonary bypass does not significantly reduce the incidence of AKI after valvular heart surgery. Other methods to ameliorate renal dysfunction after cardiac surgery need to be investigated. TRIAL REGISTRATION The trial was registered by the International Standard Randomized Controlled Trial Number Registry ISRCTN42121335 . Registered on the 18 February 2014. The trial was run by the Bristol Clinical Trials and Evaluation Unit. This trial was financially supported by the National Institute of Health Research (Research for Patient Benefit), award ID: PB-PG-0711-25,090.

Abstract

This study aimed to compare the effects of restrictive and liberal red blood cell (RBC) transfusion strategies on pediatric patients undergoing cardiac surgery, including cyanotic and non-cyanotic children. A literature search of the MEDLINE, EMBASE, PubMed, and the Cochrane Library database was conducted. Meta-analyses were carried out comparing restrictive and liberal transfusion strategies. Subgroup analyses were performed based on the basis of cyanotic status. Five randomized controlled trials with a total of 497 children were included. There was no significant difference in the risk of in-hospital mortality between the two transfusion strategies (risk ratio 1.21; 95% confidence interval 0.49 to 2.99; P = 0.68). The trial sequential analysis suggested that the current meta-analysis had an absence of evidence for in-hospital mortality, and the data were insufficient. Moreover, no significant differences existed between groups in terms of risk of infection, blood loss, duration of mechanical ventilation, pediatric intensive care unit (PICU) stay duration, or hospital stay duration. Cyanotic children treated with a liberal transfusion strategy had a shorter ventilator duration, but the transfusion strategy did not affect in-hospital mortality, infection, hospital stay, or PICU stay duration. On the basis of the available data, our analysis indicates that a liberal transfusion strategy did not lead to a better outcomes, but the data are extremely sparse, which highlights the need for clearer transfusion guidelines specific to this specific population.Trial registration number CRD42018102283.

Abstract

AIM: To characterize the association between diabetes and transfusion and clinical outcomes in cardiac surgery, and to evaluate whether restrictive transfusion thresholds are harmful in these patients. MATERIALS AND METHODS The multinational, open-label, randomized controlled TRICS-III trial assessed a restrictive transfusion strategy (hemoglobin [Hb] transfusion threshold <75 g/L) compared to a liberal strategy (Hb <95 g/L for operating room or ICU; or < 85 g/L for ward) in patients undergoing cardiac surgery on cardiopulmonary bypass with a moderate-to-high risk of death (EuroSCORE ≥6). Diabetes status was collected preoperatively. The primary composite outcome was all-cause death, stroke, myocardial infarction, and new-onset renal failure requiring dialysis at 6 months. Secondary outcomes included components of the composite outcome at 6 months, and transfusion and clinical outcomes at 28 days. RESULTS Of the 5092 patients analyzed, 1396 (27.4%) had diabetes (Restrictive: n = 679, Liberal n = 717). Patients with diabetes had more cardiovascular disease than patients without diabetes. Neither the presence of diabetes (OR [95%CI]1.10[0.93-1.31]) or the restrictive strategy increased the risk for the primary composite outcome (diabetes OR [95%CI]1.04[0.68-1.59] vs. no diabetes OR 1.02[0.85-1.22],p(interaction) = 0.92). In patients with versus without diabetes, a restrictive transfusion strategy was more effective at reducing red blood cell transfusion (diabetes OR [95%CI] 0.28[0.21-0.36]; no diabetes OR [95%CI] 0.40[0.35-0.47];p(interaction) = 0.04). CONCLUSIONS The presence of diabetes did not modify the effect of a restrictive transfusion strategy on the primary composite outcome, but improved its efficacy on red cell transfusion. Restrictive transfusion triggers are safe and effective in patients with diabetes undergoing cardiac surgery. This article is protected by copyright. All rights reserved.

Abstract

PURPOSE Blood transfusions are frequently administered in cardiac surgery. Despite a large number of published studies comparing a "restrictive" strategy with a "liberal" strategy, no clear consensus has emerged to guide blood transfusion practice in cardiac surgery patients. The purpose of this study was to identify, critically appraise, and summarize the evidence on the overall effect of restrictive transfusion strategies compared with liberal transfusion strategies on mortality, other clinical outcomes, and transfusion-related outcomes in adult patients undergoing cardiac surgery. SOURCE We searched MEDLINE (OvidSP), EMBASE (OvidSP) and Cochrane CENTRAL (Wiley) from inception to 1 December 2017 and queried clinical trial registries and conference proceedings for randomized-controlled trials of liberal vs restrictive transfusion strategies in cardiac surgery. PRINCIPAL FINDINGS From 7,908 citations, we included ten trials (9,101 patients) and eight companion publications. Overall, we found no significant difference in mortality between restrictive and liberal transfusion strategies (risk ratio [RR], 1.08; 95% confidence interval [CI], 0.76 to 1.54; I(2) = 33%; seven trials; 8,661 patients). The use of a restrictive transfusion strategy did not appear to adversely impact any of the secondary clinical outcomes. As expected, the proportion of patients who received red blood cells (RBCs) in the restrictive group was significantly lower than in the liberal group (RR, 0.68; 95% CI, 0.64 to 0.73; I(2) = 56%; 5 trials; 8,534 patients). Among transfused patients, a restrictive transfusion strategy was associated with fewer transfused RBC units per patient than a liberal transfusion strategy. CONCLUSIONS In adult patients undergoing cardiac surgery, a restrictive transfusion strategy reduces RBC transfusion without impacting mortality rate or the incidence of other perioperative complications. Nevertheless, further large trials in subgroups of patients, potentially of differing age, are needed to establish firm evidence to guide transfusion in cardiac surgery. TRIAL REGISTRATION PROSPERO (CRD42017071440); registered 20 April, 2018.

Abstract

BACKGROUND During vascular surgery, restricted red-cell transfusion reduces frontal lobe oxygen (ScO(2) ) saturation as determined by near-infrared spectroscopy. We evaluated whether inadequate increase in cardiac output (CO) following haemodilution explains reduction in ScO(2) . METHODS This is a post-hoc analysis of data from the Transfusion in Vascular surgery (TV) Trial where patients were randomised on haemoglobin drop below 9.7 g/dL to red-cell transfusion at haemoglobin below 8.0 (low-trigger) vs. 9.7 g/dL (high-trigger). Fluid administration was guided by optimising stroke volume. We compared mean intraoperative levels of CO, haemoglobin, oxygen delivery, and CO at nadir ScO(2) with linear regression adjusted for age, operation type and baseline. Data for forty-six patients randomised before end of surgery were included for analysis. RESULTS The low-trigger resulted in a 7.1% lower mean intraoperative haemoglobin level (mean difference, -0.74 g/dl; P<0.001) and reduced volume of red-cell transfused (median [inter-quartile range], 0 [0-300] vs. 450 ml [300-675]; P<0.001) compared with the high-trigger group. Mean CO during surgery was numerically 7.3% higher in the low-trigger compared with the high-trigger group (mean difference, 0.36 L/min; 95% confidence interval (CI.95), -0.05 to 0.78; P=0.092; n=42). At the nadir ScO(2) -level, CO was 11.9% higher in the low-trigger group (mean difference, 0.58 L/min; CI.95, 0.10 to 1.07; P=0.024). No change in oxygen delivery was detected between trial groups (MD, 1.39 dL(O2) /min; CI.95, -6.16 to 8.93; P=0.721). CONCLUSION Vascular surgical patients exposed to restrictive RBC transfusion elicit the expected increase in CO making it unlikely that their potentially limited cardiac capacity explains the associated ScO(2) decrease.

Abstract

Moyamoya syndrome (MMS) in patients with sickle cell disease (SCD) accentuates the risk of recurrent strokes. Chronic transfusion therapy (CTT) is an excellent option for preventing recurrent strokes in most SCD patients. In SCD with MMS, CTT may fail as a long-term solution. Cerebral revascularization, in the form of EC-IC bypass, has been shown to prevent recurrent strokes in this cohort. We review the evolution of this paradigm shift in the management of SCD-associated MMS. A systematic review, adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analysis protocol, was conducted. Our primary objectives were: 1.) to study the evolution of cerebral revascularization techniques in management of MMS in SCD; and 2.) to analyze the impact of neurosurgical intervention in this high-risk population. Four patients with SCD-associated MMS, who underwent indirect cerebral revascularization at our institute were retrospectively reviewed. A summary of 13 articles chronicling the advent and subsequent evolution of cerebral revascularization as a viable treatment strategy for stroke prevention in SCD-associated MMS, is presented. Literature review suggests early detection and surgical intervention (in addition to CTT) could significantly reduce stroke recurrence and improve neuro-cognitive outcome. Our short series of 4 patients also had a good outcome and no recurrence of strokes post-operatively. Current literature emphasizes the use of a traditional standardized protocol for early identification (TCDs, selective MRA, and CTT). Early treatment and screening that involves early MR angiography and referral to neurosurgery for revascularization may be considered for this high-risk population.

Abstract

OBJECTIVE Long-term outcomes following surgical aortic valve replacement (AVR) are excellent. However, there is a significant early morbidity burden. Red cell transfusion is common in the perioperative period and deleterious effects of receiving a transfusion on early postoperative morbidity are well described in observational studies. This study aimed to assess the effect of transfusion on ischaemic or infective outcomes after aortic valve replacement. METHODS Data from 270 patients enrolled in the Manubrium-limited ministernotomy versus conventional sternotomy for aortic valve replacement (MAVRIC) randomised controlled trial was used to create two cohorts, patients that received red cell transfusions following AVR and those that did not. Propensity score matching was performed to limit the effect of confounding variables. Strict transfusion thresholds were maintained, with patients receiving a transfusion if haemoglobin concentration fell below 80 g/L, or if significant bleeding or haemodynamic instability occurred. The primary outcome was a composite of ischaemic event (myocardial infarction, permanent stroke, gut ischaemia or acute kidney injury) or serious infection (sepsis, endocarditis, respiratory tract or wound infection). Patients were followed for 12 weeks following surgery. RESULTS Sixty-three (63) of 270 patients received a red cell transfusion (23.3%). Transfused patients had significantly lower body mass index (BMI), a higher proportion of females, a lower preoperative haemoglobin and haematocrit, a higher EuroSCORE II score, worse renal function and were more likely to have undergone urgent surgery compared to the unadjusted control cohort. Once matched, there was no difference in the primary outcome between cohorts. There was a significantly increased length of hospital stay in the transfused group (median 7 days transfused, median 5 days not-transfused, p=0.001). CONCLUSIONS Red cell transfusion, using a transfusion threshold of 80 g/L, does not appear to be associated with adverse ischaemic or infective outcomes after aortic valve replacement.

Abstract

CLINICAL QUESTION Is transfusing red cell components using a restrictive transfusion threshold (Hb < 75 g L(-1) ) as safe as a liberal transfusion threshold (Hb < 95 g L(-1) in intensive care and < 85 g L(-1) outside intensive care) during and after cardiac surgery for adults at moderate to high risk of death? EVIDENCE FROM TRIAL In adults undergoing cardiac surgery who were at moderate to high risk for death, using a restrictive red-cell transfusion threshold was as safe as a liberal red cell transfusion threshold (composite outcome of death from any cause, myocardial infarction, stroke or new-onset renal failure with dialysis at 6 months after surgery).