22O MANUAL OF BACTERIOLOGY. 



is .6 per cent, sodium chloride, prepared roughly by adding 

 a teaspoonful of salt to the pint of water. This solution 

 may be sterilized by boiling for half an hour on three con- 

 secutive days. It does not injure tissue, and may be freely 

 used in operations for irrigating. It has no germicidal or 

 antiseptic properties. 



Accident wounds are generally lacerated or contused and may con- 

 tain pathogenic bacteria. They should be promptly and carefully 

 cleansed with sterile salt solution, wiped with sterile gauze and if 

 necessary scrubbed vigorously with sterile soap and brush to remove 

 all infectious dirt. When there is any doubt of this being accomplished 

 it is better to dress such wounds wide open, filled with sterile gauze, 

 for forty-eight hours 'or more. Retained blood clots form a good 

 medium for the development of bacteria so that drainage for a day or 

 two is safer in doubtful cases. 



Infected wounds. There is no known method for promptly sterilizing 

 infected wounds without destroying tissue. An infected wound, if 

 the infection be not too deep, may be sterilized by cauterizing with pure 

 carbolic acid. 



Care must be exercised in the application of antiseptic solutions in 

 infected wounds for the antiseptic rarely penetrates as deeply into the 

 tissues as the bacteria are found, therefore, further necrosis of tissue 

 and mechanical cleanliness are about all they accomplish. 



After-treatment of wounds. Close attention to details is important in 

 the technique of a first dressing after an operation. All instruments, 

 irrigating fluids, bowls, basins, etc., are to be sterilized. When the 

 dressing is removed the skin surrounding the wound should be cleansed 

 by washing with salt solution or peroxide of hydrogen. The sutures 

 or drainage should be removed with sterile forceps, and fresh sterile 

 dressings applied. If a wound is found infected, all accumulations of 

 blood-clot, pus, etc., should be gently and carefully washed out, and 

 free drainage provided. In the care of infected wounds careful attention 

 must be paid to maintaining mechanical cleanliness and avoiding 

 infection with some organism which may not be already present. 



It should be borne in mind that anything that tends to depress a 

 patient's resisting powers encourages infection ; such as prolonged 

 exposure to cold during an operation, loss of blood and infliction of a 

 great degree of surgical shock. 



