This rapid review was conducted in accordance with the methodological guidelines of the Cochrane Rapid Reviews Methods Group (RRMG) to ensure rigor and transparency throughout the evidence synthesis process [3]. Rapid reviews are a streamlined form of systematic review designed to deliver timely evidence by employing methodological shortcuts which expedite the processes of identifying, selecting, extracting, and synthesizing data to address urgent or emerging healthcare issues [4]. These strategies aim to accelerate the review process while minimizing the risk of bias and maintaining acceptable methodological quality [4].

The rapid review format was adopted not only for reasons of methodological feasibility, but also the need to provide timely evidence to inform policy decisions. Specifically, this review was commissioned to support the Brazilian Ministry of Health in its evaluation of the clinical effectiveness of intraoperative blood recovery in surgical patients at risk of requiring transfusion support, with the aim of guiding evidence-informed decisions regarding its potential implementation within the national healthcare system.

The protocol of this review was registered in advance on the Open Science Framework (OSF) platform (https://doi.org/10.17605/OSF.IO/4G9WY).

This review addressed the following research question: What is the effectiveness of intraoperative blood recovery in surgical patients at risk of requiring transfusion support? The question was developed using the PICOS framework. The population consisted of surgical patients considered at risk of needing transfusion support. The intervention under analysis was intraoperative blood recovery. The comparator was either allogeneic blood transfusion or no comparator. The primary outcomes of interest were the effectiveness of the intervention and the need for transfusion. Secondary outcomes included associated costs, and hospital indicators, such as length of hospitalization, infection rate, mortality, and readmission. The type of surgical procedure and patient profile were considered study characteristics. Eligible study designs included systematic reviews with or without meta-analysis, published from 2004 onwards, as well as randomized controlled trials, non-randomized clinical trials, and observational studies.

A literature search was conducted on October 2, 2024 of the following electronic databases: PubMed, Virtual Health Library (VHL), and the Cochrane Library. Controlled vocabularies from each database were combined with relevant synonyms and keywords to formulate the search queries. The complete search strategies, with the included keywords, are detailed in Appendix 1.

The methodological shortcuts taken were to limit the review to studies published in Portuguese, English or Spanish. The title and abstract screening stage of the review process was conducted by pairs of reviewers working independently. Assessments of the eligibility, data extraction, and quality appraisal were performed independently by reviewers, and any discrepancies were resolved by consensus.

After duplicate records were removed using Mendeley software, the remaining citations were imported into the Rayyan platform for the title and abstract screening phase. To ensure consistency among reviewers in applying the inclusion and exclusion criteria, a calibration exercise was conducted using a sample of studies.

Data were extracted independently by four reviewers using a standardized Excel spreadsheet. The data collected included the study reference (title, authors, publication year), objective, design, application context (such as emergency or elective surgery), characteristics of the intraoperative blood recovery method, patient characteristics, the surgical procedures where the method was applied, and the outcomes reported. These outcomes included the clinical effectiveness of the intervention, the total number and mean volume of transfusions in the intervention and control groups, associated costs, healthcare utilization metrics, and the reported benefits or limitations of the method.

The methodological quality of the included studies was assessed by one reviewer and checked by a second reviewer. The AMSTAR 2 tool was used for systematic reviews and the Joanna Briggs Institute critical appraisal tools were applied for all other study designs [5].

Across most surgical contexts, intraoperative blood recovery demonstrated potential to reduce the need for allogeneic blood transfusion [2,6–9,11,16,17,20,28,29,31–34,37–42,45,48–53]. The most consistent evidence of effectiveness was observed in orthopedic procedures, particularly spinal and joint replacement surgeries [2,7,16,17,20,49–51], obstetric interventions at high risk of hemorrhage [8,32–34,37,38], gastrointestinal resections [39,40,53], and pediatric cardiac surgeries [7]. These settings demonstrated reductions in transfusion volume, transfusion rates, or both, particularly in studies using combined multimodal blood management strategies, such as acute normovolemic hemodilution or the use of tranexamic acid.

In cardiac surgery, the results were heterogeneous. While some studies reported a moderate reduction in exposure to allogeneic blood products, especially in off-pump coronary artery bypass grafting (OPCABG) [6], others reported no significant differences, especially in complex procedures involving cardiopulmonary bypass [2]. Similarly, in vascular [2] and thoracic surgeries [46], studies were inconclusive regarding the effectiveness of cell salvage, likely due to variability in surgical complexity and baseline blood loss.

Wang et al. [6] reported a 37% reduction in allogeneic transfusions and a 40% decrease in red blood cell use in cardiac surgeries. Similarly, Meybohm et al. [7] observed a 29% overall reduction in exposure to allogeneic blood products across surgical procedures, with a 45% decrease specifically in vascular surgeries.

In complex cardiovascular surgeries, Amanvermez et al. [9] found lower transfusion volumes (200 mL vs. 600 mL in controls). In orthopedics, Wong et al. [50] observed mean reinfusion volumes of 168.6 ± 89.3 mL (intraoperative) and 272.2 ± 104.2 mL (postoperative), while Herd et al. [51] reported 0.4 units per patient in the intervention group versus 3.5 in controls. In oncology surgery, studies reported a mean recovery of 1.21 red blood cell units per procedure. In obstetrics, a reduced need for allogeneic red blood cells and plasma was reported. Reinfused autologous blood volumes ranged from 300 mL [33] to 508.92 mL [38], and intraoperative cell salvage was associated with higher postpartum hemoglobin levels.

The use of cell salvage in oncologic surgery remains controversial particularly due to concerns about the reinfusion of malignant cells. Despite recent advances in leukocyte depletion filters, the results have been mixed. Some studies have demonstrated reduced transfusion needs without compromising oncological outcomes [26,27], while others have raised concerns about potential tumor recurrence in selected cancer types [25].

In urologic surgeries, cell salvage appeared effective in reducing transfusion needs in prostatectomies and nephrectomies, particularly in cases involving moderate to high blood loss [28,31,54]. However, the benefit was less clear in cystectomy procedures, where findings were inconsistent across studies [30].

The safety profile of cell salvage was generally favorable across most surgical domains. Adverse events directly attributed to the technique were rare. Some studies reported reductions in postoperative infection [2,7,8,26], reoperation due to bleeding [26,27,29], or length of hospital stay [32,34,37,53], though these findings were not consistent across all populations or surgical types. In pediatric and oncologic contexts, specific concerns persisted, such as potential immunologic complications or recurrence risk, although no robust evidence has confirmed these risks [7,25].

In cardiac surgery, Luque-Oliveros et al. [11] reported a lower incidence of postoperative fever in the intraoperative cell salvage group (15%) compared to controls (25%), suggesting a potential benefit in reducing the inflammatory response.

Regarding safety, only the studies by Nunes et al. [55] and Wang et al. [32] reported the absence of complications related to cell salvage use, such as embolism and coagulopathy; other studies did not assess or report on these parameters.

Mortality rates also did not differ significantly in cardiac surgery [2], spine surgery [7], cystectomy [30], gastrointestinal surgery [53], vascular surgery [7], transplantation after one year [41], and trauma surgery [47]. Overall, intraoperative cell salvage appears safe, but does not significantly influence mortality based on current data.

Sixteen studies evaluated the cost of intraoperative cell salvage compared to allogeneic transfusion, with mixed results: eight reported lower costs associated with intraoperative cell salvage [9,20,28,31,37,39,43,54], three demonstrated significantly higher costs [6,18,56], and five yielded inconclusive or neutral results [7,35,47,48,57].

Higher costs were observed primarily in studies conducted in Turkey and China involving orthopedic and cardiac surgeries. These increases were attributed to consumables (e.g., collection bags, filters), the need for additional personnel to operate the device, and extended intraoperative setup requirements. Wang et al. [32] reported that, compared with standard allogeneic transfusion, intraoperative cell salvage incurred consistently higher costs across all subgroups, with mean costs ranging from US$ 281.7 to US$ 439.2, depending on the extent of resource utilization. Similarly, Başaran et al. [18] and Bilgil et al. [56] found significantly higher perioperative transfusion costs in intraoperative cell salvage groups, largely due to resource-intensive implementation.

In contrast, eight studies conducted in countries including Brazil, Saudi Arabia, Australia, and the USA, identified cost savings from intraoperative cell salvage. These were largely due to reductions in allogeneic transfusion requirements, often by 1.4 to 1.5 units per patient. Amanvermez et al. [9] and Rajendran et al. [39] reported statistically significant cost reductions from intraoperative cell salvage, particularly in cardiac and gastrointestinal surgeries.

Five studies, mostly from the UK and South Africa, reported inconclusive results. These included randomized controlled trials and systematic reviews, which found either small, non-significant differences or variable outcomes, depending on the analytical approach (e.g., intention-to-treat vs. per protocol). Meybohm et al. [7] concluded that there is insufficient evidence to establish a consistent cost-effectiveness profile for intraoperative cell salvage.