Rapid controlled thawing of fresh‐frozen plasma in a modified microwave oven

Abstract

A microwave oven was specifically modified to permit rapid thawing of fresh-frozen plasma (FFP) by using a rotating disc with a temperature sensor to hold the plasma bag. This modification makes it possible to mix the FFP continuously during thawing, and automatically shuts the oven off when the plasma reaches 21.degree. C. Comparisons were made between FFP thawed in the modified microwave oven and FFP thawed conventionally in a 37.degree. C waterbath. The following tests were done: total protein, albumin and Ig concentrations; plasma fibrinogen, factor VIII and factor IX activities; protein electrophoresis, albumin aggregation, hemolytic complement activity, and plasma particle count and size. In no case was there a significant difference between plasma thawed in the microwave oven compared with that thawed in the waterbath. Microwave thawing was reliable and rapid; all units of FFP thawed in less than 6 min, and the thawed plasma did not vary by more than 6.degree. C from the preselected final temperature of 21.degree. C. Controlled thawing of FFP in a microwave oven specifically designed for this purpose apparently is an effective and reliable method and has many advantages over conventional thawing of FFP.