The history of 0.9% saline.

BACKGROUND & AIMS We aimed to trace the historical origins of 0.9% saline, how it came to be used so commonly today, and to consider whether its continued use can be justified. METHODS We searched the Medline, Science Citation Index, ScienceDirect and Google databases using the key words saline, physiological, salt solution, sodium chloride, 0.9%, intravenous, injection, fluid, cholera, resuscitation, parenteral, history, historical and origins. RESULTS The use of 0.9% saline is believed to have originated during the cholera pandemic that swept across Europe in 1831. However, an examination of the composition of the fluids used by the pioneering physicians of that era reveals solutions that bear no resemblance to 0.9% or so-called 'normal' saline which appears to have very little scientific or historical basis for its routine use, except for Hamburger's in vitro studies of red cell lysis. CONCLUSIONS The currently used 0.9% saline solution is without convincing historical basis. Given that the composition of 0.9% sodium chloride is dissimilar to most solutions used in the past, and is in no way 'normal' or 'physiological', our current practice may be based on historical fallacy and misconception.