Infusion Of Platelet-rich Plasma Research Articles

Different types of vasocontractile responses to noradrenaline in the presence of platelets with platelet activating factor.

Platelet activating factor (PAF) is known to produce a wide variety of hemodynamic effects. The present study was carried out with the aim of elucidating the mechanism of PAF action on vasoconstrictive response to noradrenaline (NA-R) in the presence of autologous platelets. NA-R was examined in isolated perfused arterial segments. PAF action through stimulation of platelets by noradrenaline (NA) was explored during infusion of platelet rich plasma (PRP) with PAF into the perfusion circuit. Consequently, it was revealed that PRP with PAF elicited an initially augmented response, followed by gradually attenuated responses under conditions of low doses of NA (in the range of 5 to 25 ng). However, the augmented responses were observed consistently under a higher dose of NA (50 ng). In addition, the gradually attenuated responses were reversed by adding tetrodotoxin, a Na-spike inhibitor. Thus, it is concluded that PAF action on NA-R through platelets may be related partly to neurotransmitters originating from perivascular autonomic depressant nerves stimulated by some neuroeffector agents.

Autologous Platelet-Rich Plasmapheresis

Preoperative platelet-rich plasmapheresis has been suggested as a means of reducing homologous blood transfusions in cardiac surgical patients. The current study evaluated this technique in patients undergoing repeat cardiac operations. Fifty-two patients undergoing repeat myocardial revascularization and/or valve replacement were evaluated in a prospective randomized controlled study design. Autologous platelet-rich plasma (PRP) was harvested after the induction of anesthesia in the experimental group. After reversal of heparin, each patient received his or her autologous plasma. Patients in the control group did not have plasmapheresis and received standard transfusion therapy if coagulation variables were abnormal and a coagulopathy was clinically evident. Routine coagulation tests, thromboelastography (TEG), perioperative bleeding, and transfusion requirements were compared in the two groups. Forty-four patients completed the study. A significantly larger volume of packed red blood cells (PRBCs) was transfused in the PRP group than in the control group (P = 0.03). Platelet and fresh frozen plasma (FFP) transfusions did not differ between the two groups. Mediastinal tube drainage did not differ between the two groups. During PRP infusion, 60% of the patients required treatment for moderate hypotension (mean arterial pressure [MAP] < 60 mm Hg). Only 16% of control patients required treatment for hypotension during the comparable time period (P < 0.05). No patient who completed the study returned to the operating room for postoperative bleeding. These data suggest that PRP did not reduce postby-pass bleeding or transfusion requirements in repeat cardiac surgical patients. Moreover, the incidence of hypotension during PRP reinfusion introduces a potential risk to the procedure in the absence of any obvious benefit.

Autologous Platelet-Rich Plasmapheresis

Preoperative platelet-rich plasmapheresis has been suggested as a means of reducing homologous blood transfusions in cardiac surgical patients. The current study evaluated this technique in patients undergoing repeat cardiac operations. Fifty-two patients undergoing repeat myocardial revascularization and/or valve replacement were evaluated in a prospective randomized controlled study design. Autologous platelet-rich plasma (PRP) was harvested after the induction of anesthesia in the experimental group. After reversal of heparin, each patient received his or her autologous plasma. Patients in the control group did not have plasmapheresis and received standard transfusion therapy if coagulation variables were abnormal and a coagulopathy was clinically evident. Routine coagulation tests, thromboelastography (TEG), perioperative bleeding, and transfusion requirements were compared in the two groups. Forty-four patients completed the study. A significantly larger volume of packed red blood cells (PRBCs) was transfused in the PRP group than in the control group (P = 0.03). Platelet and fresh frozen plasma (FFP) transfusions did not differ between the two groups. Mediastinal tube drainage did not differ between the two groups. During PRP infusion, 60% of the patients required treatment for moderate hypotension (mean arterial pressure [MAP] < 60 mm Hg). Only 16% of control patients required treatment for hypotension during the comparable time period (P < 0.05). No patient who completed the study returned to the operating room for postoperative bleeding. These data suggest that PRP did not reduce postbypass bleeding or transfusion requirements in repeat cardiac surgical patients. Moreover, the incidence of hypotension during PRP reinfusion introduces a potential risk to the procedure in the absence of any obvious benefit. (Anesth Analg 1995;81:229-35)

Autologous Platelet-Rich Plasmapheresis

Preoperative platelet-rich plasmapheresis has been suggested as a means of reducing homologous blood transfusions in cardiac surgical patients. The current study evaluated this technique in patients undergoing repeat cardiac operations. Fifty-two patients undergoing repeat myocardial revascularization and/or valve replacement were evaluated in a prospective randomized controlled study design. Autologous platelet-rich plasma (PRP) was harvested after the induction of anesthesia in the experimental group. After reversal of heparin, each patient received his or her autologous plasma. Patients in the control group did not have plasmapheresis and received standard transfusion therapy if coagulation variables were abnormal and a coagulopathy was clinically evident. Routine coagulation tests, thromboelastography (TEG), perioperative bleeding, and transfusion requirements were compared in the two groups. Forty-four patients completed the study. A significantly larger volume of packed red blood cells (PRBCs) was transfused in the PRP group than in the control group (P = 0.03). Platelet and fresh frozen plasma (FFP) transfusions did not differ between the two groups. Mediastinal tube drainage did not differ between the two groups. During PRP infusion, 60% of the patients required treatment for moderate hypotension (mean arterial pressure [MAP] < 60 mm Hg). Only 16% of control patients required treatment for hypotension during the comparable time period (P < 0.05). No patient who completed the study returned to the operating room for postoperative bleeding. These data suggest that PRP did not reduce postbypass bleeding or transfusion requirements in repeat cardiac surgical patients. Moreover, the incidence of hypotension during PRP reinfusion introduces a potential risk to the procedure in the absence of any obvious benefit.

Platelet function, coagulation tests, and cardiopulmonary bypass

Platelet function and blood coagulation were studied and correlated with the post-operative red blood cell (RBC) loss in 41 patients that underwent cardiopulmonary bypass surgery. Before and after surgery, whole blood platelet aggregation and secretion were tested with different agonists, and the platelet count, prothrombin time, and activated partial thromboplastin time measured simultaneously. Post-operatively, RBC loss in chest fluid was also calculated. Platelet aggregation and secretion with different agonists (except with ristocetin and adenosine diphosphate (ADP)) were decreased significantly after protamine and platelet-rich plasma administration. There were no significant differences in aggregation and secretion immediately after cardiopulmonary bypass compared with after platelet-rich plasma administration With ADP, adenosine triphosphate (ATP) release was decreased significantly after the platelet-rich plasma infusion compared with post-protamine. Platelet count decreased significantly during surgery and remained low after platelet-rich plasma infusion. The clotting times were increased significantly after surgery, and after platelet-rich plasma infusion, the prothrombin time decreased significantly relative to the post-protamine value, the activated partial thromboplastin time being essentially unchanged. Postoperatively, the total volume of RBC collected after 36 h was 158 +/- 13 ml and there was no significant correlation with the above parameters. We conclude that pre-operative or intra-operative whole blood lumi-aggregometry is not a predictor of post-operative blood loss in patients receiving platelet-rich plasma intra-operatively.

Effets du plasma riche en plaquettes sur l'hémostase et le besoin transfusionnel en chirurgie vasculaire

• Objective : To assess the effect of intraoperative autologous platelet-rich plasma (PRP) transfusion on haemostasis, blood loss and blood requirements during vascular surgery. • Study design : Randomized clinical trial. • Patients : Twenty patients undergoing elective abdominal infrarenal aortic aneurysmectomy, using autologous transfusion techniques (predonation programme and/or preoperative normovolaemic haemodilution and/or intraoperative use of a cell-saver), were randomly allocated either into the PRP group (n = 10) or the Control group (n = 10). • Method : In patients of PRP group, 10 mL·kg −1 of PRP were obtained over 40 to 50 min, prior to induction of anaesthesia, and compensated simultaneously with an equivalent amount of hydroxyethyl starch. Each PRP unit was transfused to its donor after aortic declamping. Blood samples were obtained before induction, before incision, at wound closing and at the end of PRP unit transfusion for determination of biological variables. • Results : The PRP units transfused in the patients of PRP group contained 755 ± 117 mL of plasma with a platelet count of 62 ± 31 G·L −1. The intra and postoperative blood losses were similar in both groups (1622 ± 758 and 233 ± 322 mL respectively in PRP group vs 1890 ± 1331 and 291 ± 303 mL respectively in Control group). In both groups, three patients required an additional transfusion of homologous blood. The results of biological tests (haematocrit, platelet and white cell counts, prothrombine time, aPTT, thrombine time, fibrinogen, D-dimers, proteins, calcium) were also similar between groups at the various times of sampling. The reinfusion of the PRP unit did not increase the platelet count. • Conclusions : This study demonstrates that intraoperative infusion of autologous PRP does not decrease blood loss and homologous transfusion requirements in patients undergoing elective abdominal infrarenal aortic aneurysmectomy. This result can be related to the relatively moderate enrichment in platelets obtained with the centrifugation speed used in this study.

Infusion of autologous platelet rich plasma does not reduce blood loss and product use after coronary artery bypass: A prospective, randomized, blinded study

Prior nonblinded studies have suggested dramatic hemostatic effects and decreased plasma after cardiopulmonary bypass. Platelet rich plasma (8 to 10 ml/kg total body weight) was obtained (Haemonetics Plasma Saver; Haemonetics Corp., Natick, Mass.) from 51 patients undergoing primary coronary artery bypass grafting before heparinization. After double-blinded randomization, the platelet rich plasma was reinfused immediately in the control group or after heparin reversal in the treatment group. Homologous blood product usage, blood loss, and the surgeon's intraoperative subjective assessment of coagulation were evaluated. Additionally, thromboelastography, prothrombin time, partial thromboplastin time, activated clotting time, fibrinogen, platelet counts, and hematocrit values were evaluated before the operation, after heparin reversal, after infusion of platelet rich plasma or control solution, and 2 hours after infusion. The surgeon's subjective assessment of coagulation was not different between control and treatment groups (p = 0.78). According to specific predetermined transfusion guidelines, no statistically significant differences were found in the use of whole blood (p = 0.07), packed red blood cells (p = 0.62), platelets (p = 0.11), total units of blood products (p = 0.45), or in the percentage of patients receiving transfusions (control group 70%, treatment group 71%, p = 0.97). Cumulative amount of blood shed through the chest tube was not significantly different between the groups at any interval but tended toward significance at 4, 6, and 12 hours (p = 0.09, 0.07, and 0.09). The prothrombin time immediately after reinfusion of platelet rich plasma was significantly lower in the treatment group (p = 0.03), but all other laboratory studies were similar at each time interval. Infusion of platelet rich plasma after cardiopulmonary bypass in patients having uncomplicated primary coronary artery bypass grafting has minimal effects on the surgeon's assessment of coagulation, total transfusion requirements, mediastinal drainage, and laboratory studies of coagulation.

Prostaglandins released from the isolated perfused arterial segment and vasocontractile response--influence of plasma constituents and platelets

In the present study, relationship between each level of PGE, TX B2 and 6-keto-PGF1 alpha in the effluent perfusate and vasocontractile response to noradrenaline (NA-R) was examined using the isolated perfused arterial segment of a rabbit ear. The following results were obtained. 1. NA-R was significantly augmented under the conditions infusing either platelet poor plasma (PPP) or platelet rich plasma (PRP), when compared with the control one during perfusion of modified normal Krebs solution (N-R) alone. 2. During PPP infusion, PGE level alone and during PRP infusion, both PGE and TX B2 levels showed significant increment in comparison with the each control ones during perfusion of N-R, respectively. 6-keto-PGF1 alpha level was significantly altered under the conditions infusing neither PPP nor PRP. 3. There was the positively significant correlation between delta NA-R and delta (TX B2/PGE ratio), which represent the difference between the control value during perfusion of N-R and the one during infusion of either PPP or PRP, respectively. From the results obtained, it seems possible to draw the conclusion that the augmentation in NA-R induced by PPP or PRP relates, at least in part, to the secondary alteration of PGE and prostanoids metabolism in the arterial preparation.

Role of platelets in maintenance of pulmonary vascular permeability to protein.

We examined the role of platelets in maintenance of pulmonary vascular integrity by inducing thrombocytopenia in sheep using antiplatelet serum (APS). A causal relationship between thrombocytopenia and increase in pulmonary vascular permeability was established by platelet repletion using platelet-rich plasma (PRP). Sheep were chronically instrumented and lung lymph fistulas prepared to monitor pulmonary lymph flow (Qlym). A balloon catheter was positioned in the left atrium to assess pulmonary vascular permeability to protein after raising the left atrial pressure (Pla). Thrombocytopenia was maintained for 3 days by daily intramuscular APS injections. Platelet count decreased from 460,000 +/- 77,000 to 16,000 +/- 4,000 platelets/microliters, without significant changes in the leukocyte count and hematocrit. Studies were made in three groups: 1) control sheep having a normal platelet count; 2) thrombocytopenic sheep; and 3) PRP-infused thrombocytopenic sheep. Elevation in Pla in control sheep increased pulmonary transvascular protein clearance (CL) to 12.1 +/- 2.1 ml/h, whereas the same Pla elevation in thrombocytopenia increased CL to 24.1 +/- 4.0 ml/h, indicating an increase in pulmonary vascular permeability to protein in thrombocytopenic animals. Infusion of PRP restored normal permeability, since it prevented the increase in CL. In studies using cultured bovine pulmonary artery endothelial monolayers, transendothelial permeability of 125I-labeled albumin was reduced 50 and 95%, respectively, when 2.5 X 10(7) or 5 X 10(7) platelets were added onto endothelial monolayers. However, addition of 5 X 10(6) platelets or 5 X 10(7) red blood cells did not reduce endothelial monolayer albumin permeability.(ABSTRACT TRUNCATED AT 250 WORDS)

Parturition in the Thoroughbred Mare

The use of autologous blood processing tools including platelet-rich plasma (PRP) devices is increasingly widespread in veterinary medicine. In equine reproduction, a number of studies have explored the effects of intrauterine infusion of PRP on persistent mating-induced endometritis. Artificial insemination with thawed frozen semen incites an intrauterine inflammatory response and we sought to extend the applications of intrauterine PRP to normal mares being inseminated with frozen semen. We investigated a subset of our normal breeding population to observe the clinical effects of prebreeding intrauterine infusion of PRP and plasma followed by insemination with frozen semen. Eighteen mares were treated after failure to achieve pregnancy after one breeding cycle of artificial insemination with frozen semen. Breeding management was performed in a routine manner, and each mare was bred to the same stallion as the previous cycle. Autologous PRP was prepared using a commercial platelet isolation device; PRP was diluted with Platelet-poor Plasma, and intrauterine infusion was performed 12–48 hours before artificial insemination. This case series represents an initial investigation into the clinical effects of intrauterine PRP and plasma infused before insemination with thawed frozen semen in a population of clinically normal mares.