126 BACTERIOLOGICAL DIAGNOSIS. 



LUMBAR PUNCTURE. 



Fluid may be removed from the spinal meninges for 

 a bacteriological or other examination by means of 

 Quincke's lumbar puncture. The information furnished 

 by this means is often of very great value ; in fact Osier 

 says that " during the past ten years no single measure 

 of greater value in diagnosis has been introduced." 

 The process is simple, easy, and entirely devoid of 

 danger, and can be carried out without an anaesthetic. 



Requisites. i. A suitable needle. In children the 

 spinal meninges will be reached at a depth of 3-4 centi- 

 metres (roughly i-i| inches) while in adults the depth 

 may be twice as great. The needle should not be less 

 than i\ inches long for an infant and 4 inches for an 

 adult, and should be sharp and strong. An antitoxin 

 needle will answer every purpose. Aspiration is un- 

 necessary, and no syringe is required. 



2. Materials for disinfection of the patient's skin and 

 (if cultures are to be taken) the hands of the operator. 

 Hot water, soap, alcohol, ether, perchloride lotion (i in 

 1000). 



3. Apparatus for boiling the needle in a dilute solu- 

 tion of washing soda.* 



4. Spray for local anaesthesia. (If used). 



5. A test-tube sterilised by dry heat and plugged 

 with dry cotton- wool. 



6. If cultures are to be taken the tubes of medium 

 should be inoculated at the time of the operation if 



* If possible the needle should be sterilised by dry heat previous 

 to the operation and kept in a tube plugged at both ends with 

 cotton-wool as in the method recommended for the collection of 

 blood for bacteriological examination. 



