Evaluation of blood components exposed to coated arterial filters in extracorporeal circuits.

BACKGROUND: Biocompatible surfaces play an important role in the inflammatory response during cardiopulmonary bypass (CBP), with the arterial filter contributing a large surface area of the circuit. Different filter-coating materials designed to improve blood-filter biocompatibility are currently used in CPB circuits. This study evaluates eight biocompatible coatings used for arterial filters and their effects on blood components during circulation. METHODS: Arterial filters were randomly assigned in eight independent heparin-bonded tubing loops and perfused by a single swine (n=8). Arterial blood was routed simultaneously, but separately, into each circuit and circulated for 30 minutes at 37 degrees C. Blood samples were drawn for CBC, ACT, and TAT III measurements at baseline, post-heparinization and post-circulation. At study completion, filters were imaged using multiphoton microscopy. RESULTS: RBC, platelet, and WBC counts, and TAT III complex were all decreased after 30 minutes of circulation; however, WBC count was the only parameter that showed statistically significant differences between the filters. Circulating WBC reduction ranged from 6% (Carmeda and Trillium) to 41% (Terumo-X-coating) with corresponding microscopic confirmation of increased WBC entrapment. CONCLUSION: All eight filter coatings altered the blood components to varying degrees. Selection of the most effective filter, in conjunction with a heparin-bonded circuit for CPB, may decrease the intraoperative foreign-surface activation of blood cells.

Use of a large bore syringe creates significantly fewer high intensity transient signals (HITS) into a cardiopulmonary bypass system than a small bore syringe.

INTRODUCTION: High intensity transient signals (HITS) have been reported to occur following perfusionist intervention during cardiac surgery. This study investigates the relationship of the syringe bore, injection rate, and HITS created. METHODS: Syringes (10 mL) with a male luer-lock connection (Large Bore) and Abboject 'jet syringes' with a 20 GA needle and male luer-lock connector (Small Bore) were filled with 10 mL of 0.9 N saline. A perfusionist was randomly assigned a set of four similar syringes followed by the other syringe bore. Each of the four syringes was injected into an in vitro saline-primed cardiopulmonary bypass (CPB) system over 5, 10, 15, or 20 sec. Sixteen randomizations of small and large bore syringes were completed at the four injection times (128 injections). HITS in the CPB arterial line were detected with transcranial Doppler (TCD) probes, were recorded for the 2 min following the injection, and were counted independently off-line by two reviewers. RESULTS: The use of a large bore syringe compared to a small bore syringe created significantly fewer HITS (29 +/- 6 versus 145 +/- 17 [mean +/- SEM], p<0.001) introduced into the CPB arterial line. Injection over a longer time produced significantly fewer HITS than shorter injection times (p<0.001). CONCLUSION: Significantly fewer HITS are introduced into the CPB system by using standard syringes and slower injection time.

In vitro effects of poly-N-acetyl glucosamine on the activation of platelets in platelet-rich plasma with and without red blood cells.

BACKGROUND: This study was performed to assess the effect of poly-N-acetyl glucosamine fiber slurry on plasma clotting proteins, platelets, and red blood cells in the clotting of the blood. METHODS: Citrate phosphate dextrose whole blood was stored at 22degreesC for 48 hours to prepare platelet-poor plasma, platelet-rich plasma (PRP), and PRP plus red blood cells with hematocrit values of 20%, 35%, and 45% with and without an equal volume of poly-N-acetyl glucosamine fibers (1 mg/mL 0.9% NaCl). RESULTS: Thromboelastogram data show that poly-N-acetyl glucosamine fibers (p-GlcNAc) significantly reduced the R time in platelet-poor plasma, PRP, and PRP supplemented with red blood cells. Poly-N-acetyl glucosamine fibers increased, but not significantly, Annexin V and factor X binding to platelets, platelet microparticles, and red blood cell Annexin V binding. Poly-N-acetyl glucosamine fibers increased the production of thromboxane B2 by PRP. CONCLUSION: Poly-N-acetyl glucosamine slurry activates platelets.

The in vitro quality of red blood cells frozen with 40 percent (wt/vol) glycerol at -80 degrees C for 14 years, deglycerolized with the Haemonetics ACP 215, and stored at 4 degrees C in additive solution-1 or additive solution-3 for up to 3 weeks.

BACKGROUND: Red blood cells (RBCs) frozen with 40 percent (wt/vol) glycerol, stored at -80 degrees C (mean temperature; range, -65 to -90 degrees C) for 14 years, deglycerolized in the Haemonetics automated cell processor (ACP) 215 with the 325-mL disposable bowl, and stored at 4 degrees C in additive solution (AS)-1 or AS-3 for 21 days were evaluated. STUDY DESIGN AND METHODS: A total of 106 units of citrate phosphate dextrose adenine-1 RBCs were frozen with 40 percent (wt/vol) glycerol in the original 800-mL polyvinylchloride plastic bag and stored in corrugated cardboard boxes at -80 degrees C for 14 years. The thawed units were deglycerolized with the ACP 215 with a 325-mL disposable bowl and stored in AS-1 or AS-3 at 4 degrees C for 21 days. RESULTS: The freeze-thaw recovery value was 94 +/- 4 percent (mean +/- SD), the freeze-thaw-wash recovery value was 80 +/- 7 percent, and there was no breakage. Thirty-eight units were processed as 19 pairs. Two units of ABO-matched units were thawed, pooled, divided equally into two units, and deglycerolized. One unit was stored in AS-1 and the other in AS-3 at 4 degrees C for 21 days. Units stored in AS-1 exhibited significantly greater hemolysis than those stored in AS-3. CONCLUSIONS: Acceptable results were achieved when RBCs frozen at -80 degrees C for 14 years were deglycerolized in the ACP 215. Deglycerolized RBCs in AS-1 exhibited significantly higher hemolysis than those in AS-3 after storage at 4 degrees C for 7 to 21 days.