Red blood cell recovery and reinfusion

Estimating surgical blood loss: A review of current strategies in various clinical settings

The estimation of surgical blood loss is routinely performed during and after surgical procedures and has morbidity and mortality implications related to the risk of under- and over-resuscitation. The strategies for estimating surgical blood loss include visual estimation, the gravimetric method, the colorimetric method, formula-based methods, and other techniques (e.g., cell salvage). Currently, visual estimation continues to be the most widely used technique. In addition, unique considerations exist when these techniques are applied to various clinical settings such as massive transfusion, cardiac surgery, and obstetrics. Ultimately, when using estimated surgical blood loss to guide perioperative fluid management and transfusion thresholds, it is also important to mitigate the risks associated with resuscitation by targeting a goal-directed fluid therapy approach by utilizing markers of fluid-responsiveness to optimize stroke volume (cardiac output) and delivery of oxygen.

Bipolar Fusionless Versus Standard Fusion Surgery in Neuromuscular Scoliosis: A Two-center Comparative Study

STUDY DESIGN

Nonrandomized controlled cohort.

OBJECTIVE

To compare early results between bipolar fusionless construct (BFC) and single posterior fusion (SPF) surgery in neuromuscular scoliosis (NMS).

BACKGROUND

Surgical treatments for NMS have traditionally been characterized by high complication rates. A mini-invasive BFC was developed to reduce these risks while maintaining adequate curve reduction. There is, however, a current lack of studies comparing clinical and radiologic perioperative outcomes between both techniques.

METHODS

All patients surgically treated for NMS with to-pelvis construct between 2011 and 2021 at 2 centers were included and divided into 2 groups according to the surgical technique (BFC or SPF). Gender, age, main deformity region, etiology, preoperative and postoperative main curve magnitude and pelvic obliquity, surgery time, estimated blood loss and transfusion rates, length of hospital stay, the magnitude of main curve and pelvic obliquity correction, and early complications were compared. Quantitative data were compared through ANOVA or Mann-Whitney test. Analysis of qualitative outcomes was performed through Fisher exact test and logistic regressions. Kruskal-Wallis test was used to compare complications between groups.

RESULTS

Eighty-nine NMS patients were included: 48 in the SPF group and 41 in the BFC group. Surgery time (203 vs. 241 min), rate (32 vs. 52%) and severity of complications, unplanned returns to the operating room (15 vs. 39%), estimated blood loss (179 vs. 364 cc), and transfusion rates (27 vs. 73%) were lower in the BFC group ( P <0.05). There were no significant differences in age, maturity stage, preoperative curve magnitude, preoperative pelvic obliquity and postoperative curve, and pelvic obliquity correction between groups.

CONCLUSIONS

BFC may be a safer and less invasive option for NMS surgical treatment, resulting in similar curve corrections while significantly decreasing the number and severity of complications as well as intraoperative blood loss when compared with SPF.

LEVEL OF EVIDENCE

Level -lll.

How do I perform cell salvage during vaginal obstetric hemorrhage?

BACKGROUND

Obstetric hemorrhage is a leading cause of preventable maternal mortality. To combat this, obstetric organizations worldwide recommend consideration of autotransfusion during severe peripartum bleeding to minimize allogenic transfusion. Current guidelines for autotransfusion in obstetrics are limited to patients undergoing cesarean birth. At present, women experiencing vaginal obstetric hemorrhage are excluded from many obstetric autotransfusion protocols. However, emerging data suggest that autotransfusion of vaginally shed blood is both safe and feasible in the obstetric patient population.

METHODS AND MATERIALS

In this review, we will provide an overview of the current literature surrounding cell salvage of vaginally send blood and a detailed outline of our institution's blood collection protocol.

RESULTS

Recent data suggests autotransfusion of vaginally shed blood is both safe and effective.

DISCUSSION

Implementation of autotransfusion technology into the delivery room is a critical next step for the advancement of transfusion medicine in obstetrics. This review provides an overview of the data surrounding autotransfusion of vaginally shed blood during maternal hemorrhage and describes practical suggestions for how it can be effectively implemented into routine practice.

Dynamic changes in clot formation determined using thromboelastometry after reinfusion of unwashed anticoagulated cell-salvaged whole blood in total hip arthroplasty

BACKGROUND

Cell salvage is a key part of patient blood management. Different techniques are available for salvaging blood. A new intra-operative autotransfusion filter system became available for reinfusion of unwashed whole blood. Concern exists regarding whether this technique induces coagulation disturbances, offsetting the benefits of the reinfusion of autologous blood. This study was designed to investigate the content of intra-operatively salvaged filtered blood and its impact after reinfusion on clot formation in patients undergoing primary hip arthroplasty.

MATERIALS AND METHODS

Twenty-five patients scheduled for primary total hip arthroplasty were enrolled in the study. Cell salvage was performed using a new intra-operative autotransfusion filter system. Before surgery and within 1 hour of reinfusion of 300 mL or more of salvaged whole blood, blood samples were taken to assess clot formation by thromboelastometry and standard laboratory-based coagulation profiling. Cytokine content of the salvaged blood was assessed by enzyme-linked immunosorbent assays.

RESULTS

Following reinfusion of 460 mL (median) of salvaged blood, thromboelastometry showed normal clot formation and did not indicate a coagulopathy. Clotting time, clot formation time, maximum firmness and maximum lysis all remained within the normal range. Standard laboratory coagulation tests were also normal in all patients before surgery and after reinfusion. Although monocyte chemoattractant protein-1 levels were higher than normal, all other measured cytokines were either undetectable or within the normal range. No adverse events were seen following cell salvage.

DISCUSSION

Reinfusion of unwashed salvaged whole blood did not alter clot formation in our patients. The results add to the knowledge about this approach and contribute to the growing body of evidence regarding the lack of adverse events when reinfusing unwashed shed blood in major orthopaedic procedures.

Retrospective analysis of community hospital red blood cell recovery procedures: improved utilization needed for effectiveness

BACKGROUND

Perioperative blood recovery (PBR) is an important component of patient blood management. We analyzed our experience providing PBR for community hospitals to determine procedure types and clinical variables associated with efficacy and cost-effectiveness.

STUDY DESIGN AND METHODS

PBR cases (>25,000) from January 2008 through December 2012 were analyzed. For each procedure type, the median number of returned red blood cell units (rRBCs) and ratio of cases with at least 1 to less than 1 rRBC unit were calculated. Clinical predictors of rRBC were identified by linear and logistic regression.

RESULTS

The overall median rRBC was 0.29 units despite median estimated blood loss (EBL) of 350 mL. Only three of 31 common procedure types had ≥1:<1 rRBC ratios near to or higher than 1. In nine of 31 common procedure types, at least 50% of cases had no rRBC return. Linear regression demonstrated significant association of rRBCs with increased EBL, longer operative duration, surgeon, PBR device type (autoLog vs. CS5), and decreasing age. EBL, autoLog use, high surgeon case volume, vascular procedures, and emergent versus elective procedures associated with higher odds of at least 1 rRBC.

CONCLUSION

Discrepancy between rRBC and EBL and high percentages of cases with no rRBC suggests that PBR technique and case selection need optimization. Identification of procedure types and variables associated with PBR efficacy (≥1 rRBC) should improve utilization of PBR. Association of autoLog use with higher rRBC warrants further investigation.

The introduction of intra-operative cell salvage in obstetric clinical practice: a review of the available evidence

Intra-operative blood salvage is common practice in many surgical specialties but its safety is questioned with concerns about the risks of contamination of recovered blood with amniotic fluid and of maternal-foetal alloimmunization. However, the role of cell salvage as a blood-saving measure in this clinical setting is progressively acquiring relevance thanks to the growing body of evidence regarding its quality and safety. Modern cell savers remove most particulate contaminants and leukodepletion filtering of salvaged blood prior to transfusion adds further safety to this technique. Amniotic fluid embolism is no longer regarded as an embolic disease and the contamination of the salvaged blood by foetal Rh-mismatched red blood cells can be dealt with using anti-D immunoglobulin; ABO incompatibility tends to be a minor problem since ABO antigens are not fully developed at birth. Maternal alloimmunization can be caused also by other foetal red cell antigens, but it should also be noted that the risk of alloimmunization of the mother from allogeneic transfusion may be even greater. Therefore the use of cell savers in obstetric clinical practice should be considered in patients at high risk for haemorrhage or in cases where allogeneic blood transfusion is difficult or impossible.

Hemolysis and red blood cell mechanical fragility in shed blood after total knee arthroplasty

BACKGROUND

There are several options for the salvage of postoperative shed red blood cells (RBCs). This study compared the characteristics of the returned RBCs collected using two different devices: one that washes and one that does not wash the collected RBCs.

STUDY DESIGN AND METHODS

Forty patients undergoing first-time total knee arthroplasty consented to participate. Twenty patients were operated on by a surgeon who routinely uses a device that does not wash the shed RBCs (unwashed group), the other 20 patients were operated on by surgeons who routinely use a device that washes and concentrates the collected RBCs (washed group). A small quantity of postprocessing RBCs were collected immediately before reinfusion and the amount of plasma-free hemoglobin (PFHb), and the mechanical fragility index (MFI) of the returned RBCs were determined.

RESULTS

The patients in both groups were well matched for age, sex, and length of stay. The mean percent hemolysis of the returned RBCs was not different between the unwashed and washed groups (1.22±0.30 vs. 1.24±0.42, p=0.895), while the mean total amount of returned PFHb was not different (0.51±0.12 g vs. 0.55±0.35 g, p<0.615). The ratio of total PFHb:total returned Hb was significantly lower for the washed group (0.0087±0.0023 vs. 0.0035±0.0011, p<0.0001). The MFI was higher in the washed group (1.71±0.55 vs. 0.53±0.42, p<0.001).

CONCLUSIONS

The washing device returned more Hb to the patients relative to the amount of free Hb.