l62 



OPERATIVE TECHNIQUE. 



irrigations. In human surgery steam of boiling water has recently 

 been used with good effect for checking uterine bleeding. 



Most styptics combine rapidly with the blood, and form with it a 

 clot which adheres to the wound and closes the injured vessel. Some 

 act by causing contraction of the vessel and surrounding tissues. 

 Among those formerly employed were oak bark powder, tannin, 

 mineral acids and their salts, alum, nitrate of silver, acetic acid, 

 creosote, carbolic acid, alcohol, oil of turpentine, etc. Perchloride of 

 iron in the form of liq. ferri perchlor. diluted with three parts of water 

 was often used to moisten tampons which were applied to the bleeding 



spot. Among the most useful are 

 mixtures of alcohol and water and 

 carbolic or sublimate solutions, but 

 under any circumstances styptics are 

 only of use in dealing with capillaries 

 and small vessels. In human surgery, 

 a light brown powder, consisting of 

 the soft hairs from the stem of an 

 East Indian tree fern {Cibotiinn Cnm- 

 niinghii), is used externally. To 

 check bleeding resulting from internal 

 injuries, extract of ergot {Sccalc cor- 

 nniitni) has also been used with suc- 

 cess. More recently it has been 

 largely replaced by extractum hydras- 

 tis Canadensis (golden seal). In 

 operative wounds all powerful styptics 

 prevent healing by first intention owing 

 to their caustic effect on the wound 

 surfaces.' 



We may now consider mechanical 

 methods of dealing with haimorrhage. 

 As a pre\'entive, especially when 

 operating on limbs, the application of a tourniquet (Fig. i86) or one or 

 another form of Esmarch's bandage is the means usually employed. 



In the horse the most primitive method consists in passing a loop 

 of stout cord or webbing around the limb and tightening it by the 

 rotation of a stout stick slipped through it. The pressure thus exercised 

 on the vessels checks circulation, and haemorrhage during operation is 

 virtually ////, while owing to compression of the nerves sensation 

 below the ligature is dulled and the pain of operation greatly 

 diminished. 



Fig. 1 86. — The tourniquet. 



