SURGICAL HEMOSTASIA. 527 



1st. Refrigerants. — The agents included in this class act 

 almost exclusively by depriving the parts upon which they are 

 applied of their heat, and ia producing a certain excitation upon 

 the vaso-motor nerves, followed by a toxic contraction of the mus- 

 cular fibres of the vessels, and the diminution, or sometimes the 

 complete arrest, of the bloody flow. Their action is principally 

 efficacious on vessels of small cahbre, such as the capUlaries. 



Cold water, snow, cracked ice, and the very volatile Uquids, as 

 ether, chloroform, and freezing mixtures, fiU an important place in 

 this category. In veterinary surgery, cold water, being the sim- 

 plest, the most accessible and abundant, and the easiest to apply, 

 heads the hst. It is used in the form of douches, baths, lotions 

 and injections, or by means of compresses, pads, or cushions of 

 oakum laid upon the seat of hemorrhage. The saline mixtures, 

 and the snow or cracked ice, are placed in cloths, bags or blad- 

 ders, but their action -must be watched in order to obviate the 

 possibility of congelation and mortification of the tissues, quite a 

 possible result of excessive refrigeration. 



Eefrigerants are generally considered as fooning the least ef- 

 fective of hemostatics, but their facility of appHcation has brought 

 them into common use. They are principally indicated against 

 external capillary bleeding, or that which escapes from a small 

 vessel, but would generally prove insufficient against a hemor- 

 rhage from a large vessel. They may, however, prove advanta^ 

 geous against some internal hemorrhages, which, though they 

 may be controllable by other direct means, yet can be reached by 

 the water without difficulty or danger, and act directly or by con- 

 tinuity in producing the necessary contraction. In this manner, 

 injections into the nasal cavities, or the uterus, or rectum are 

 often efficacious in arresting a hemorrhagic flow suddenly occur- 

 ring. But in any case, refrigerants should be applied with care, 

 and their effect watched. If they are allowed to remain too long 

 in place, or the temperature be too low, they may induce an in- 

 flammatory reaction and local gangrene, or produce other dan- 

 gerous general effects upon the internal economy. On the other 

 hand, if imperfectly applied, and without a sufficient degree of 

 cold, their action, already weak, will become a mere useless nega- 

 tion, if not worse. Between these two extremes there is a middle 

 course, which the competent surgeon wiU be able to observe by 

 exercising his discretion, and an appeal to his own experience. 



