合理使用血液和血液成分.ppt

* * * * * * * * * * * * * * * * * * * * * * * * * * * * Platelets are derived via several different techniques. Following the manual collection of a unit (450-500 mL) of whole blood, the unit may be separated into its components by centrifugation. In the US, the first spin is a “soft spin”, and platelet –rich plasma is expressed off the red cells. This is subjected to a second, harder spin, and all but 50-60 mL of platelet-poor plasma is expressed off the concentrated platelet button. In Europe, platelets are commonly produced by first producing a buffy coat; the second spin then separates red cells from the platelets. The number of platelets in a unit derived from a single whole blood donation is clinically inadequate for all but neonates. Usually before issuance from the Transfusion Service lab, or sometimes at the bedside, a pool of 4-6 units is created to provide a therapeutic dose of platelets. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * Platelets are derived via several different techniques. Following the manual collection of a unit (450-500 mL) of whole blood, the unit may be separated into its components by centrifugation. In the US, the first spin is a “soft spin”, and platelet –rich plasma is expressed off the red cells. This is subjected to a second, harder spin, and all but 50-60 mL of platelet-poor plasma is expressed off the concentrated platelet button. In Europe, platelets are commonly produced by first producing a buffy coat; the second spin then separates red cells from the platelets. The number of platelets in a unit derived from a single whole blood donation is clinically inadequate for all but neonates. Usually before issuance from the Transfusion Service lab, or sometimes at the bedside, a pool of 4-6 units is created to provide a therapeutic dose of platelets. NEED FOR TRANSFUSION CONSULTATIONS Wide variety of blood products Variable level of expertis