Fenwal, Inc.

BACKGROUND: Platelet additive solutions (PASs) facilitate improved recovery of plasma and may reduce the severity and/or frequency of plasma‐associated transfusion reactions. Current apheresis platelet (PLT) PAS products contain approximately 30 to 40% residual plasma. In an effort to further decrease the residual plasma, two in vitro studies were conducted with PLTs suspended in 5% plasma and a reformulated PAS‐3, named PAS‐5, that contains additional salts, glucose, and bicarbonate.STUDY DESIGN AND METHODS: In Study 1, PLTs suspended in 5% plasma/95% PAS‐5 were prepared directly on a separator (Amicus, Fenwal, Inc.) without additional centrifugation or washing. In Study 2, a double unit of hyperconcentrated Amicus PLTs in plasma was collected, divided, and centrifuged to prepare a control unit in 100% plasma and a paired test unit in 5% plasma/95% PAS‐5. The in vitro properties of PLTs were assessed in both studies during 7‐day storage at 20 to 24°C with continuous agitation.RESULTS: In Study 1, PLT concentration, pH, mean PLT volume (MPV), HCO3‐, pCO2, pO2, lactate dehydrogenase, and hypotonic shock response (HSR) did not significantly change during storage. By Day 7, glucose levels and morphology scores modestly decreased (17.6 and 14.4%, respectively) and lactate levels modestly increased (to 7.2 mmol/L). In Study 2, MPV, pH, glucose, pO2, HSR, and morphology were comparable in control and test PLTs during 7‐day storage. Glucose consumption and lactate production were significantly less in test versus control PLTs (p ≤ 0.0015). Extent of shape change and %CD62P‐positive test PLTs were less than those of controls (p < 0.001).CONCLUSION: Apheresis PLTs suspended in 5% plasma/95% PAS‐5 maintained in vitro properties during 7‐day storage.

Many manufactured products have as their basic constituent agricultural, plastic, or metallic dusts.Elimination or reduction of dust-explosion hazards requires knowledge of the explosion characteristics of each specific dust.Laboratory techniques were developed in which dust is forced into a test vessel and distributed evenly; 1 sec. later the dust is ignited by an elec. spark.The history of the pressure surge is recorded and typical curves are given.Specific parameters studied are dust concentration, O required to support combustion, min. spark energy required, and temperatures of ignition of dust clouds and dust layers.

Explosions in a 1 × 100-ft. flare stack were examined by using 5% C3H8 in air from a 1000-gal. reservoir.Passage of the flame front was determined by ionization probes.The pressure profile of the duct was determined by strain-gage pressure transducers.Ignition of the gas mixture was by a 105-j. spark.The average flame velocity was 6-7 ft. for the first 36 ft. where ignition occurred in the open end of the tube (O gas flow).The terminal velocity approached Mach 1.At the 75-ft. point, the pressure was >24 psi.Structural damage indicated a possible peak of 150-200 psi.Tests made with the spark occurring 34 ft. upstream with a gas flow rate of 22 ft./sec. showed that 250 msec. elapsed before a buildup of damaging pressure at 84 ft. upstream.The last 30 ft. of duct ruptured.Explosion-suppression equipment in the duct was tested consisting of an elec. operated discharge extinguisher.About 1500 cc. of a halogenated extinguishing agent was dispersed up and down the tube (∼1 cc. of liquid/volume to be protected).Two extinguishers were sufficient to prevent an explosion in the stack (O flow).