The impact of suctioning RBCs from a simulated operative site on mechanical fragility and hemolysis

The impact of intra-operative cell salvage during open radical prostatectomy

Background

To examine the effect of intra-operative cell salvage (ICS) in open radical prostatectomy.

Methods

In this retrospective cohort study, all patients undergoing open radical prostatectomy for malignancy at our institution between 10/04/2013 and 10/04/2017 were enrolled. Patients were grouped and compared based on whether they received ICS. Primary outcomes were allogeneic transfusion rates, and disease recurrence. Secondary outcomes were complications and transfusion-related cost.

Results

Fifty-nine men were enrolled; 30 used no blood conservation technique, while 29 employed ICS. There were no significant differences between groups in age, pre- or post-operative haemoglobin, Charlson comorbidity index, operation duration or length of stay. Tumour characteristics were also similar between groups, including pre-operative prostate specific antigen, post-operative Gleason score, T-stage, nodal status and rates of margin positivity. Compared with controls, the ICS group had longer follow up (945 vs. 989 days; P=0.0016). The control and ICS groups were not significantly different in rates of tumour recurrence (6 vs. 3 patients; P=0.30) or complications (10 vs. 5 patients; P=0.16). While the proportion of patients receiving allogenic transfusion was similar (9 vs. 6 patients; P=0.41), fewer red blood products transfused (40 vs. 12 units) meant transfusion related costs were lower in ICS patients (AUD $47,666 vs. $37,429).

Conclusions

ICS reduced transfusion related costs, without affecting allogeneic transfusion rates, tumour recurrence or complication rates. These findings extend the literature supporting ICS in oncological surgery. Prospective randomised studies are needed to confirm the existing level III evidence.

Effect of ascorbic acid on storage of Greyhound erythrocytes

OBJECTIVE

To assess changes in biochemical and biophysical properties of canine RBCs during cold (1° to 6°C) storage in a licensed RBC additive solution (the RBC preservation solution designated AS-1) supplemented with ascorbic acid.

SAMPLE

Blood samples from 7 neutered male Greyhounds; all dogs had negative results when tested for dog erythrocyte antigen 1.1.

PROCEDURES

Blood was collected into citrate-phosphate-dextrose and stored in AS-1. Stored RBCs were supplemented with 7.1mM ascorbic acid or with saline (0.9% NaCl) solution (control samples). Several biochemical and biophysical properties of RBCs were measured, including percentage hemolysis, oxygen-hemoglobin equilibrium, and the kinetic rate constants for O2 dissociation, carbon monoxide association, and nitric oxide dioxygenation.

RESULTS

Greyhound RBCs stored in AS-1 supplemented with ascorbic acid did not have significantly decreased hemolysis, compared with results for the control samples, during the storage period.

CONCLUSIONS AND CLINICAL RELEVANCE

In this study, ascorbic acid did not reduce hemolysis during storage. Several changes in stored canine RBCs were identified as part of the hypothermic storage lesion.

Washing and filtering of cell-salvaged blood - does it make autotransfusion safer?

Autologous transfusion was first performed in the late 1800s, but it was not until the 1970s that devices were developed that enabled widespread adoption of the practice. Unwashed salvaged blood contains thrombogenic products, cell breakdown products and plasma proteins, and gross chemical, cellular and physical contaminants. Washing and filtering of salvaged blood is routinely performed to remove or reduce these elements. In this paper we review the clinical data supporting the need for washing and filtering of salvaged blood.

Changes in mechanical fragility and free hemoglobin levels after processing salvaged cardiopulmonary bypass circuit blood with a modified ultrafiltration device

Modified ultrafiltration (MUF) is available for the salvage of post-cardiopulmonary bypass circuit blood. This study evaluated the extent of hemolysis, the mechanical fragility index (MFI), and the amount of plasma free hemoglobin (PFHb) created after processing with the MUF device. Several RBC parameters were measured on pre- and post-MUF device processed samples of blood from 12 patients undergoing cardiac surgery. The MFI and total amount of PFHb did not change significantly between the pre- and post-processing samples: MFI, pre: .19 +/- .06 versus post: .19 +/- .06, p = .76; total amount of PFHb, pre: .24 +/- .21 g versus post: .20 +/- .12 g, p = .42. There was significantly more hemolysis in the post-processing samples compared with the pre-processing samples, .33 +/- .24% versus .96 +/- .48%, respectively, p < .001. Although percent hemolysis was increased following processing with the MUF device, the total amount of PFHb and RBC sublethal injury were not increased. The clinical significance of these findings needs to be determined.

Haemolysis and sublethal injury of RBCs after routine blood bank manipulations

OBJECTIVES

To determine the extent of RBC sublethal injury in male donor units as measured by both the mechanical fragility index (MFI) and percentage haemolysis after RBCs underwent leucoreduction (LR), irradiation (IRRAD), and washing.

BACKGROUND

RBCs frequently undergo post-collection processing to meet certain recipient's special needs. The extent of haemolysis and sublethal injury following these interventions has not been fully characterised.

METHODS

Eight to ten day old male, AS-5 RBCs underwent either LR, IRRAD or washing. A control group of male, AS-5 RBCs were unmanipulated. The MFI, percent haemolysis, and plasma free haemoglobin (PFHb) were measured immediately after manipulation and, for a series of irradiated RBCs, 28 days after irradiation (IRRAD28).

RESULTS

The MFI of the washed units was significantly higher than unmanipulated, LR, IRRAD, IRRAD28 units (P < 0·0001). The percent haemolysis was highest in the IRRAD28 units (1·4%) followed by the washed units (0·74%); the other three units demonstrated significantly less haemolysis (P < 0·0001). The largest mean total amount of PFHb per unit was found in the IRRAD28 units (500·5 mg/unit) followed by the washed units (149·8 mg/unit); the mean total amount of PFHb in the three other types of units was significantly less than that found in both the IRRAD28 and washed units (P at least < 0·001).

CONCLUSION

There is a significant quantity of PFHb in IRRAD28 RBC units, and potentially in washed allogeneic RBC units. Clinical correlation is required to determine if this quantity of PFHb and the transfusion of potentially fragile RBCs causes adverse events.