Cell salvage for minimising perioperative allogeneic blood transfusion in adults undergoing elective surgery.

BACKGROUND: Concerns regarding the safety and availability of transfused donor blood have prompted research into a range of techniques to minimise allogeneic transfusion requirements. Cell salvage (CS) describes the recovery of blood from the surgical field, either during or after surgery, for reinfusion back to the patient. OBJECTIVES: To examine the effectiveness of CS in minimising perioperative allogeneic red blood cell transfusion and on other clinical outcomes in adults undergoing elective or non-urgent surgery. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, three other databases and two clinical trials registers for randomised controlled trials (RCTs) and systematic reviews from 2009 (date of previous search) to 19 January 2023, without restrictions on language or publication status. SELECTION CRITERIA: We included RCTs assessing the use of CS compared to no CS in adults (participants aged 18 or over, or using the study's definition of adult) undergoing elective (non-urgent) surgery only. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. MAIN RESULTS: We included 106 RCTs, incorporating data from 14,528 participants, reported in studies conducted in 24 countries. Results were published between 1978 and 2021. We analysed all data according to a single comparison: CS versus no CS. We separated analyses by type of surgery. The certainty of the evidence varied from very low certainty to high certainty. Reasons for downgrading the certainty included imprecision (small sample sizes below the optimal information size required to detect a difference, and wide confidence intervals), inconsistency (high statistical heterogeneity), and risk of bias (high risk from domains including sequence generation, blinding, and baseline imbalances). Aggregate analysis (all surgeries combined: primary outcome only) Very low-certainty evidence means we are uncertain if there is a reduction in the risk of allogeneic transfusion with CS (risk ratio (RR) 0.65, 95% confidence interval (CI) 0.59 to 0.72; 82 RCTs, 12,520 participants). Cancer: 2 RCTs (79 participants) Very low-certainty evidence means we are uncertain whether there is a difference for mortality, blood loss, infection, or deep vein thrombosis (DVT). There were no analysable data reported for the remaining outcomes. Cardiovascular (vascular): 6 RCTs (384 participants) Very low- to low-certainty evidence means we are uncertain whether there is a difference for most outcomes. No data were reported for major adverse cardiovascular events (MACE). Cardiovascular (no bypass): 6 RCTs (372 participants) Moderate-certainty evidence suggests there is probably a reduction in risk of allogeneic transfusion with CS (RR 0.82, 95% CI 0.69 to 0.97; 3 RCTs, 169 participants). Very low- to low-certainty evidence means we are uncertain whether there is a difference for volume transfused, blood loss, mortality, re-operation for bleeding, infection, wound complication, myocardial infarction (MI), stroke, and hospital length of stay (LOS). There were no analysable data reported for thrombosis, DVT, pulmonary embolism (PE), and MACE. Cardiovascular (with bypass): 29 RCTs (2936 participants) Low-certainty evidence suggests there may be a reduction in the risk of allogeneic transfusion with CS, and suggests there may be no difference in risk of infection and hospital LOS. Very low- to moderate-certainty evidence means we are uncertain whether there is a reduction in volume transfused because of CS, or if there is any difference for mortality, blood loss, re-operation for bleeding, wound complication, thrombosis, DVT, PE, MACE, and MI, and probably no difference in risk of stroke. Obstetrics: 1 RCT (1356 participants) High-certainty evidence shows there is no difference between groups for mean volume of allogeneic blood transfused (mean difference (MD) -0.02 units, 95% CI -0.08 to 0.04; 1 RCT, 1349 participants). Low-certainty evidence suggests there may be no difference for risk of allogeneic transfusion. There were no analysable data reported for the remaining outcomes. Orthopaedic (hip only): 17 RCTs (2055 participants) Very low-certainty evidence means we are uncertain if CS reduces the risk of allogeneic transfusion, and the volume transfused, or if there is any difference between groups for mortality, blood loss, re-operation for bleeding, infection, wound complication, prosthetic joint infection (PJI), thrombosis, DVT, PE, stroke, and hospital LOS. There were no analysable data reported for MACE and MI. Orthopaedic (knee only): 26 RCTs (2568 participants) Very low- to low-certainty evidence means we are uncertain if CS reduces the risk of allogeneic transfusion, and the volume transfused, and whether there is a difference for blood loss, re-operation for bleeding, infection, wound complication, PJI, DVT, PE, MI, MACE, stroke, and hospital LOS. There were no analysable data reported for mortality and thrombosis. Orthopaedic (spine only): 6 RCTs (404 participants) Moderate-certainty evidence suggests there is probably a reduction in the need for allogeneic transfusion with CS (RR 0.44, 95% CI 0.31 to 0.63; 3 RCTs, 194 participants). Very low- to moderate-certainty evidence suggests there may be no difference for volume transfused, blood loss, infection, wound complication, and PE. There were no analysable data reported for mortality, re-operation for bleeding, PJI, thrombosis, DVT, MACE, MI, stroke, and hospital LOS. Orthopaedic (mixed): 14 RCTs (4374 participants) Very low- to low-certainty evidence means we are uncertain if there is a reduction in the need for allogeneic transfusion with CS, or if there is any difference between groups for volume transfused, mortality, blood loss, infection, wound complication, PJI, thrombosis, DVT, MI, and hospital LOS. There were no analysable data reported for re-operation for bleeding, MACE, and stroke. AUTHORS' CONCLUSIONS: In some types of elective surgery, cell salvage may reduce the need for and volume of allogeneic transfusion, alongside evidence of no difference in adverse events, when compared to no cell salvage. Further research is required to establish why other surgeries show no benefit from CS, through further analysis of the current evidence. More large RCTs in under-reported specialities are needed to expand the evidence base for exploring the impact of CS

The difference in potential harms between whole blood and component blood transfusion in major bleeding: A rapid systematic review and meta-analysis of RCTs

Our aim was to assess whether there is a difference in outcomes of potential &ldquo;all-cause&rdquo; harm in the transfusion of whole blood (WB) compared to blood components (BC) for any bleeding patient regardless of age or clinical condition. We searched multiple electronic databases using a pre-defined search strategy from inception to 2nd&nbsp;March 2021. 1 reviewer screened, extracted, and analysed data, with verification by a second reviewer of all decisions. We used Cochrane ROB1 and GRADE to assess the quality of the evidence. We used predefined subgroups of trauma and non-trauma studies in the analysis. We included six RCTs (618 participants) which compared WB and BC&nbsp;transfusion therapy&nbsp;in major bleeding, one trauma trial (n&nbsp;=&nbsp;107), and 5 surgical trials (non-trauma) (n&nbsp;=&nbsp;511). We GRADED evidence as very-low for all outcomes (downgraded for high and unclear risk of bias, small sample size, and wide confidence intervals around the estimate). Our primary outcome (all-cause mortality at 24-hours and 30-days) was reported in 3 out of 6 included trials. There was no evidence of a difference in mortality of WB compared to BC therapy (very-low certainty evidence). There may be a benefit of WB therapy compared to BC therapy in the non-trauma subgroup, with a reduction in the duration of oxygen dependence (1 study;&nbsp;n&nbsp;=&nbsp;60; mean difference 5.9 fewer hours [95% Confidence Interval [CI] -10.83, &ndash;0.99] in WB group), and a reduction in hospital stay (1 study,&nbsp;n&nbsp;=&nbsp;64, median difference 6 fewer days in WB group) (very-low certainty evidence). For the remaining outcomes (organ injury,&nbsp;mechanical ventilation&nbsp;and intensive care unit requirement, infection, arterial/venous thrombotic events, and haemolytic transfusion reaction) there was no difference between WB and BC therapy (wide CI, crossing line of no effect), though many of these outcomes were based on small single studies (very-low certainty evidence). In conclusion, there appears to be little to no difference in harms between WB and BC therapy, based on small studies with very low certainty of the evidence. Further large trials are required to establish the overall safety of WB compared to BC, and to assess differences between trauma and non-trauma patients.</p

Timing of induction of labour in the prevention of prolonged pregnancy: Systematic review with meta‐analysis

Objective To update the systematic review which informed the National Institute for Health and Care Excellence guideline “Inducing Labour” (NG207), including additional data and analyses, and comparison with a recent individual patient data analysis of 41- versus 42-week induction. Search Strategy Multiple database search (including Cochrane Central Register of Controlled Trials, MEDLINE, and Embase) from inception to 10th September 2021 for randomised controlled trials (RCTs) comparing different induction timing in uncomplicated singleton pregnancies. Data Collection and Analysis One reviewer screened, extracted, analysed, and assessed the quality/certainty of the evidence (using ROB1 and GRADE), with second reviewer verification. Main Results Five week-to-week comparisons, and one overall comparison (induction vs. delayed induction, 20 RCTs, n = 15 725 pregnant women) for assessment of predefined subgroups. Most data were for 41 versus 42 weeks and 39 versus 41 weeks: 10 times as many participants as the other week-to-week comparisons. There was evidence of an effect at 41 versus 42 weeks (five RCTs, n = 5819) in favour of 41-week induction: fewer perinatal deaths and neonatal intensive care unit admissions (low-to-moderate certainty of the evidence); there was no evidence of an effect in either direction for the remaining outcomes (very-low to moderate certainty). There was no evidence of an effect for outcomes reported for: 40 versus 42 weeks (three RCTs, n = 668, very-low to low certainty); 39 versus 42 weeks (three RCTs, n = 1103, very-low to moderate certainty); 39 versus 41 weeks (four RCTs, n = 7101, very-low to low certainty); and 41/42 versus 43/44 weeks (four RCTs, n = 954, very-low to low certainty). Conclusion The evidence supports offering induction at 41 + 0 weeks compared to 42 + 0 weeks to reduce adverse perinatal and obstetric outcomes. Practioners points 1. Evidence supports offering induction at 41 + 0 weeks compared to 42 + 0 weeks to reduce adverse perinatal outcomes in uncomplicated singleton pregnancies. 2. Other week-to-week comparisons require more data for all outcomes. 3. More data is needed for all week-to-week comparisons for women at potentially higher risk for adverse outcomes: black, Asian, and minority ethnic groups, higher body mass index (30+), older (35+ years), and women who conceived using artificial reproductive technology