Cardiopulmonary bypass in a rat model may shorten the lifespan of stored red blood cells by activating caspase-3.

BACKGROUND: Red blood cell transfusion is required for many types of surgery against cardiovascular disease, and the function of transfused cells appears to decline over time. The present study examined whether transfusion also reduces red blood cell lifespan in a rat model. MATERIAL AND METHODS: Bypass in rats were established by connecting a roll pump to the femoral artery and vein. Then FITC-labeled stored red blood cells from rats were transfused in the animals, and the cells in circulation were counted after transfusion. In separate experiments, stored red blood cells were incubated with bypass plasma in vitro, and the effects of incubation were assessed on cell morphology, redox activity, ATP level, caspase-3 activity, and phosphatidylserine exposure on the cell surface. These in vivo and in vitro experiments were also performed after pretreating the stored red blood cells with the caspase-3 inhibitor Z-DEVD-FMK. RESULTS: Bypass significantly decreased the number of circulating FITC-labeled stored red blood cells and increased the proportions of monocytes, neutrophils and splenic macrophages that had phagocytosed the red blood cells. In vitro, bypass plasma altered the morphology of red blood cells and increased oxidative stress, caspase-3 activity and phosphatidylserine exposure, while decreasing ATP level. Pretreating stored red blood cells with Z-DEVD-FMK attenuated the effects of bypass on caspase-3 activity, but not oxidative stress, in stored red blood cells. DISCUSSION: Bypass appears to shorten the lifespan of stored red blood cells, at least in part by activating caspase-3 in the cells.

Red blood cells are damaged by intraoperative blood salvage via Ca2+-dependent and -independent mechanisms.

AIMS: Intraoperative blood salvage (IBS) is associated with shortened lifespan of red blood cells (RBCs). This study aims to examine how salvaged RBCs are compromised during IBS. MAIN METHODS: Thirty patients who underwent vertebra surgery with IBS were included in the study. To examine possible mechanisms of IBS-induced injury, both fresh and salvaged RBCs from each patient were mixed with plasma, the Ca2+ ionophore ionomycin or mannitol-adenine-phosphate (MAP) solution (n = 10 patients per condition). Binding of Fluo-3 and/or Annexin V by RBCs was measured. KEY FINDINGS: The percentage of Fluo-3-binding RBCs in salvaged samples was 2.83 ±â€¯0.76%, which increased to 15.34 ±â€¯5.99% after 48-h incubation in plasma. These percentages were significantly higher than those observed with fresh RBCs (P < 0.01). Ionomycin dose-dependently increased the percentage of Fluo-3-binding RBCs in salvaged samples, while MAP solution decreased it. Incubating salvaged RBCs in plasma for 48 h increased the percentage of Fluo-3-positive spherocytes from 0.8 ±â€¯0.6% to 11.35 ±â€¯3.96%, and this increase was blocked by MAP solution. Ionomycin increased the percentage of RBCs binding both Fluo-3 and Annexin V, while MAP decreased this percentage. The percentage of Annexin V-binding RBCs was also higher in salvaged samples than in fresh samples, but this percentage was unaffected by either ionomycin or MAP solution. SIGNIFICANCE: Our results suggest that IBS induces a postponed RBC damage by inducing spherocyte formation, which likely reflects Ca2+ entry induced by energy exhaustion, as well as by exposing phosphatidylserine on the RBC surface, which likely occurs via Ca2+ entry and via Ca2+-independent pathways.

Intraoperative blood salvage may shorten the lifespan of red blood cells within 3 days postoperatively: A pilot study.

BACKGROUND: Intraoperative blood salvage (IBS) recovers most lost blood, and is widely used in the clinic. It is unclear why IBS does not reduce long-term postoperative requirements for red blood cells (RBCs), and 1 possibility is that IBS affects RBC lifespan. METHODS: Prospectively enrolled patients who underwent spine, pelvic, or femur surgery not involving allogeneic RBC transfusion were grouped based on whether they received IBS or not. Volumes of blood lost and of RBCs salvaged during surgery were recorded. Total blood cell counts, levels of plasma-free hemoglobin, and CD235a-positive granulocytes were determined perioperatively. RESULTS: Although intraoperative blood loss was higher in the IBS group (n = 45) than in the non-IBS group (n = 52) (P < .001), hemoglobin levels were similar between groups (P = .125) at the end of surgery. Hemoglobin levels increased in non-IBS patients (4 ±â€Š11 g/L), but decreased in IBS patients (-7 ±â€Š12 g/L) over the first 3 postoperative days. Nadir hemoglobin levels after surgery were higher in the non-IBS group (107 ±â€Š12 g/L) than in the IBS group (91 ±â€Š12 g/L). Salvaged RBC volume correlated with hemoglobin decrease (r = 0.422, P = .004). In multivariate analysis, salvaged RBC volume was an independent risk factor for hemoglobin decrease (adjusted odds ratio 1.002, 95% confidence interval 1.001-1.004, P = .008). Flow cytometry showed the numbers of CD235a-positive granulocytes after surgery to be higher in the IBS group than in the non-IBS group (P < .05). CONCLUSION: IBS may shorten the lifespan of RBCs by triggering their engulfment upon re-infusion (China Clinical Trial Registry ChiCTR-OCH-14005140).

Risk Factors for the Postoperative Transfusion of Allogeneic Blood in Orthopedics Patients With Intraoperative Blood Salvage: A Retrospective Cohort Study.

The purpose of this study is to explore the risk factors affecting the postoperative transfusion of allogeneic blood in patients undergoing orthopedics surgery with intraoperative blood salvage (IBS). A retrospective study of 279 patients undergoing orthopedic surgeries with IBS from May 2013 to May 2015 was enrolled. The binary logistic regression was used to find out the risk factors associated with postoperative transfusion of allogeneic blood in orthopedics patients with IBS, and then receiver operating characteristic (ROC) curve was drawn to determine the optimal threshold of the regression model.Single factor analysis showed that age, American Society of Anesthesiologists (ASA) grade, preoperative hemoglobin, operation time, received autologous blood, the laying time of autologous blood, bleeding volume, and postoperative drainage volume had significant effects on postoperative allogeneic blood transfusion.In binary logistic regression analysis, the independent factors predicting orthopedic patients with IBS need to transfuse allogeneic blood after surgeries were age (odds ratio [OR] = 0.415, P = 0.006), ASA grade (OR = 2.393, P = 0.035), preoperative hemoglobin (OR = 0.532, P = 0.022), and postoperative drainage volume (OR = 4.279, P = 0.000). The area under ROC curve was 0.79 and the predicted accuracy rate of the model was 81.58%.After operation, the orthopedic patients with IBS still have a high allogeneic blood transfusion rate, and IBS is not a perfect blood protection method. The logistic regression model of our study provides a reliable prediction for postoperative transfusion of allogeneic blood in orthopedic patients with IBS, which have a certain reference value.

Pyruvate effects on red blood cells during in vitro cardiopulmonary bypass with dogs' blood.

To investigate the effects of pyruvate (Pyr) on adenosine triphosphate (ATP), endothelial nitric oxide synthase (eNOS), and nitric oxide (NO) in red blood cells (RBCs) during the cardiopulmonary bypass procedure (CPB), blood, 500 mL, was collected from each of 10 healthy dogs (weight 12-18 kg). The blood was divided into two parts (250 mL each) and randomly assigned into the control group (Group C, n = 10) or the Pyr group (Group P, n = 10). The blood was commingled with an equal volume of 0.9% NaCl and pyruvated isotonic solution (Pyr 50 mM) in the extracorporeal circuit in the two groups, respectively. The CPB procedure was fixed at 120 min, and the transferring flow was 4 L/min. Contents of ATP in RBCs, eNOS activities, and NO productions in plasma were measured before CPB and during CPB at 30, 60, 90, and 120 min in both groups. The ATP level, eNOS activity, and NO production were not different prior to CPB between the two groups. A decline of ATP levels was shown in both groups but remained significantly higher in Group P than in Group C at the same time points during in vitro CPB (P < 0.01). Values of eNOS and NO were significantly increased in Group C but markedly reduced in Group P during CPB, compared with pre-CPB (P < 0.01). The CPB procedure significantly damaged dogs' RBCs in the ATP level, eNOS activity, and NO production, in vitro, but Pyr effectively protected RBCs in these functions during CPB. Pyr would be clinically protective for RBCs during CPB.

[Effect of Shenfu injection on the erythrocyte immune function of patients undergoing cardiopulmonary bypass].

OBJECTIVE: To observe the effect of Shenfu Injection (SFI) on erythrocyte immunity function of patients undergoing cardiopulmonary bypass (CPB). METHODS: Twenty patients scheduled for valve replacement were randomly assigned to two groups, i.e. , the SFI group and the control group, 10 in each. SFI 1 mL/kg was intravenously dripped before induction of anesthesia and SFI 1 mL/kg administered in priming solution in the SFI group, while only normal saline was given to those in the control group. Venous blood samples (5 mL) were collected before induction of anesthesia (T1), 30 min CPB (T2), immediate by the end of CPB (T3), and postoperative 24 h (T4) respectively in all groups. The levels of the rosette rate of RBC-C3b receptor (RBC-C3bRR), the rosette rate of RBC-immune complex (RBC-ICR), plasma malondialdehyde (MDA), free hemoglobin (FHB), and interleukin-6 (IL-6) were detected. RESULTS: There was no significant difference in the levels of RBC-C3bRR, RBC-ICR, plasma MDA, FHB, and IL-6 at T1 in both groups (P > 0.05). RBC-C3bRR at the rest time points was lower in the two groups than before induction of anesthesia. There was no statistical difference in FHB or IL-6 between T4 and T1 in the SFI group. The levels of RBC-ICR, MDA, FHB, and IL-6 increased in the two groups more than before induction of anesthesia at T2-4 ( P < 0.05). Besides, the RBC-C3b RR was lower, and levels of RBC-ICR, MDA, FHB, and IL-6 higher in the control group than in the SFI group, showing significant difference (P <0.05). CONCLUSION: SFI could decrease the generation of inflammatory mediators during CPB, improve the erythrocyte immune function of patients during CPB, and reduce the risk of postoperative infection.

Enantioselctive syntheses of sulfur analogues of flavan-3-Ols.

The first enantioselective syntheses of sulfur flavan-3-ol analogues 1-8 have been accomplished, whereby the oxygen atom of the pyran ring has been replaced by a sulfur atom. The key steps were: (a) Pd(0) catalyzed introduction of -S t-butyl group, (b) Sharpless enantioselective dihydroxylation of the alkene, (c) acid catalyzed ring closure to produce the thiopyran ring, and (d) removal of benzyl groups using N,N-dimethylaniline and AlCl(3). The compounds were isolated in high chemical and optical purity.