STANDARDIZATION OF HEMORRHAGIC SHOCK IN THE DOG

Abstract

A method of producing hemorrhagic shock in dogs is outlined in which the severity of shock is gauged by means of stress indices. For a period of reduced blood volume the plasma bicarbonate content (m[image]/l.) was plotted vs. time (min.) and the area enclosed by such a plot and a line drawn at 10 m[image]/l. was utilized as a measure of the degree of stress. Areas so obtained, having the dimensions of millimole min., were called stress indices The mortality rate in a series of 6 dogs with stress indices in the range of 0 to 420 was 17% while that in an equal number of dogs having stress indices ranging from 420 to 840 was 67%. Comparison of the avg results obtained on a series of 17 dogs having stress indices between 420 and 840 (severe stress) with a 2d series of 16 dogs having stress indices between 0 and 420 (moderate stress) shows that during the periods of reduced blood volume the animals of the former group withstand less blood loss, respire more rapidly, have less cardiac acceleration and show less hyperglycemia. Further, dogs subjected to severe stress show greater increases in whole blood lactate and plasma inorganic phosphate, and a greater depression in plasma bi-* carbonate and whole pH than those subjected to moderate stress. Both groups of animals show an early fall in hematocrit followed by a later rise, this rise being more pronounced in the dogs with stress indices between 0 and 420. The reduction in blood pressure and in plasma protein concn. and the elevation in whole blood pyruvate are not significantly different in the 2 groups.