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.

Abstract

Postoperative pancreatic fistula (POPF) is a major source of morbidity following pancreatic resection. Surgically placed drains under suction or gravity are routinely used to help mitigate the complications associated with POPF. Controversy exists as to whether one of these drain management strategies is superior. The objective was to identify and compare the incidence of POPF, adverse events, and resource utilization associated with passive gravity (PG) versus active suction (AS) drainage following pancreatic resection. MEDLINE, EMBASE, CINAHL, and Cochrane Library databases were searched from inception to May 18, 2020. Outcomes of interest included POPF, post-pancreatectomy hemorrhage (PPH), surgical site infection (SSI), other major morbidity, and resource utilization. Descriptive qualitative and pooled quantitative meta-analyses were performed. One randomized control trial and five cohort studies involving 10 663 patients were included. Meta-analysis found no difference in the odds of developing POPF between AS and PG (p = 0.78). There were no differences in other endpoints including PPH (p = 0.58), SSI (wound p = 0.21, organ space p = 0.05), major morbidity (p = 0.71), or resource utilization (p = 0.72). The risk of POPF or other adverse outcomes is not impacted by drain management following pancreatic resection. Based on current evidence, a suggestion cannot be made to support the use of one drain over another at this time. There is a trend toward increased intra-abdominal wound infections with AS drains (p = 0.05) that merits further investigation.

Abstract

OBJECTIVES The objective of this work was to carry out a systematic review of clinical practice guidelines (CPGs) pertaining to intraoperative red blood cell (RBC) transfusions, in terms of indications, decision-making, and supporting evidence base. SUMMARY BACKGROUND DATA Red blood cell (RBC) transfusions are common during surgery and there is evidence of wide variability in practice. METHODS Major electronic databases (MEDLINE, EMBASE, and CINAHL), guideline clearinghouses and Google Scholar were systematically searched from inception to January 2019 for CPGs pertaining to indications for intraoperative RBC transfusion. Eligible guidelines were retrieved and their quality assessed using AGREE II. Relevant recommendations were abstracted and synthesized to allow for a comparison between guidelines. RESULTS Ten guidelines published between 1992 and 2018 provided indications for intraoperative transfusions. No guideline addressed intraoperative transfusion decision-making as its primary focus. Six guidelines provided criteria for transfusion based on hemoglobin (range 6.0-10.0 g/dL) or hematocrit (<30%) triggers. In the absence of objective transfusion rules, CPGs recommended considering other parameters such as blood loss (n = 7), signs of end organ ischemia (n = 5), and hemodynamics (n = 4). Evidence supporting intraoperative recommendations was extrapolated primarily from the non-operative setting. There was wide variability in the quality of included guidelines based on AGREE II scores. CONCLUSION This review has identified several clinical practice guidelines providing recommendations for intraoperative transfusion. The existing guidelines were noted to be highly variable in their recommendations and to lack a sufficient evidence base from the intraoperative setting. This represents a major knowledge gap in the literature.

Abstract

BACKGROUND Major liver resection is associated with blood loss and transfusion. Observational data suggest that hypovolaemic phlebotomy can reduce these risks. This feasibility RCT compared hypovolaemic phlebotomy with the standard of care, to inform a future multicentre trial. METHODS Patients undergoing major liver resections were enrolled between June 2016 and January 2018. Randomization was done during surgery and the surgeons were blinded to the group allocation. For hypovolaemic phlebotomy, 7-10 ml per kg whole blood was removed, without intravenous fluid replacement. Co-primary outcomes were feasibility and estimated blood loss (EBL). RESULTS A total of 62 patients were randomized to hypovolaemic phlebotomy (31) or standard care (31), at a rate of 3.1 patients per month, thus meeting the co-primary feasibility endpoint. The median EBL difference was -111 ml (P = 0.456). Among patients at high risk of transfusion, the median EBL difference was -448 ml (P = 0.069). Secondary feasibility endpoints were met: enrolment, blinding and target phlebotomy (mean(s.d.) 7.6(1.9) ml per kg). Blinded surgeons perceived that parenchymal resection was easier with hypovolaemic phlebotomy than standard care (16 of 31 versus 10 of 31 respectively), and guessed that hypovolaemic phlebotomy was being used with an accuracy of 65 per cent (20 of 31). There was no significant difference in overall complications (10 of 31 versus 15 of 31 patients), major complications or transfusion. Among those at high risk, transfusion was required in two of 15 versus three of nine patients (P = 0.326). CONCLUSION Endpoints were met successfully, but no difference in EBL was found in this feasibility study. A multicentre trial (PRICE-2) powered to identify a difference in perioperative blood transfusion is justified. Registration number: NCT02548910 ( http://www.clinicaltrials.gov).

Abstract

BACKGROUND Hypovolemic phlebotomy (HP) is a novel intervention that involves intraoperative removal of whole blood (7-10 mL/kg) without volume replacement. The subsequent central venous pressure (CVP) reduction is hypothesized to decrease blood loss and the need for blood transfusion. The objective was to conduct a systematic assessment of the safety and efficacy of HP on blood loss and transfusion in the liver surgery literature. METHODS MEDLINE, EMBASE, and Cochrane Library databases were searched. Outcomes of interest included blood loss, allogenic red blood cell transfusion, postoperative adverse events, and CVP change. A qualitative synthesis and meta-analysis were performed as appropriate. RESULTS Four cohort studies, one case series, and three randomized controlled trials involving 2255 patients were included. Meta-analysis of studies involving liver resections for any indication (n = 6) found no difference in transfusion (OR 0.38, p = 0.12) or incidence of adverse events with HP compared to non-use. Pooling of studies involving liver resections for an underlying pathology (n = 4) revealed HP was associated with significant reduction in transfusion (OR 0.25, p = 0.03) but no differences in blood loss (-173 mL, p = 0.17). CONCLUSION This review suggests HP is safe and associated with decreased transfusion in patients undergoing liver surgery. It supports further investigation.