Biological Effects of Blood Loss: Implications for Sampling Volumes and Techniques * Commentary: H. Richard Adams

The purpose of this paper is to review the literature on the effects of acute and chronic blood loss and techniques of blood sampling in laboratory animals. When possible, recommendations regarding limits on single and multiple blood samplings in laboratory animals are offered. Although blood sampling is a common laboratory procedure, it is nonetheless problematic, especially for techniques that attempt to set up protocols for chronic blood taking. In a letter to The American Journal of Physiology, Giner et al. (1987) announced their failure to reproduce an experimental protocol on rats that involved repeated blood sampling by means of an arterial catheter described in an earlier article in the same publication (Burt et al., 1980). Giner and associates attempted the described procedure on eight rats with no success. They then modified the technique by increasing the heparin concentrations, by using larger catheters, by flushing the cannula frequently, and finally by using a Teflon cannula. They succeeded in obtaining blood samples, but not without causing renal or intestinal infarctions and ischemia to the hind limbs. According to the authors, "after three months of work in attempting to emulate Burt's work and the death of a large number of rats, we were left with an excellent model for arterial embolism." Giner's letter highlights a problem basic to many vascular sampling techniques: their successful execution requires considerable skill. The difference between one experimenter's success with a technique