Lumbar puncture resulting in a bloody spinal fluid occurs not infrequently in general practice and may happen occasionally to the most experienced physician. There are times when a second puncture is inadvisable or refused; yet the Lange test would prove of material aid in making a diagnosis. The following experiments, 214 in number, were undertaken in an attempt to find a way to utilize these contaminated fluids.
In order to produce, experimentally, conditions comparable to those encountered in clinical practice, the patient's blood was added in increasing amount to his own spinal fluid. The maximum amount of blood added was 5 cmm. of blood to 1 cc. of spinal fluid. This produced a fluid definitely pink and corresponding macroscopically to the most contaminated fluid received in the laboratory. A red cell count made on this mixture averaged about 25,000 cells per cubic millimeter of blood.
Normal spinal fluids were used