Perspectives of clinical osmometry.

Several clinical applications of osmometry have been reviewed. Questions remain concerning the clinical acceptance that osmometry will achieve in veterinary medicine. Many practices may not be able to justify the purchase of an osmometer; however, osmometers are available at most medical centers and clinical laboratories. In an era when serum chemistry profiles are being used more frequently, it may prove that serum osmolatity will be requested more frequently. Determination of osmolality is a simple, rapid, and inexpensive test that has potential in screening for disorders of body fluids. Several research laboratories utilize osmometry routinely in screening for potential fluid or electrolyte inbalances. When coupled with glucose, blood urea nitrogen, and electrolyte values, a comparison of calculated and measured osmolality allows further clinical interpretations. Differences may exist between calculated and measured osmolality. In some instances, determination of calculated osmolality alone may lead to erroneous conclusions concerning the true status of body fluids. Specialized intensive care practices should certainly consider the value of osmometry in monitoring patients undergoing extensive fluid therapy. Last, but not least, osmometry does provide the best measure of renal concentrating ability and is of particular value in evaluation of polyuric and proteinuric patients.