Blood Volume in Clinical Shock. Ii. The Extent and Cause of Blood Volume Reduction in Traumatic, Hemorrhagic, and Burn Shock12

Abstract

found evidence of a direct relation between the severity of shock and the extent of the reduction in blood volume. This has been clearly demonstrated in recent experimental studies on traumatic and hemorrhagic shock in dogs (4, 5) in which blood volume was determined with more dependable methods. Within the past two years, there have also been reports of similar observations on cases of shock among civilians (6, 7, 8, and others).The aim of the present investigation was: (1) to determine more precisely the relation between the loss in blood volume and the severity of shock in man, in order to provide a sound basis for estimating the amount of blood needed for replacement after various types and degrees of injury; (2) to determine the cause of blood volume reduction in traumatic shock; and, (3) to test the view, held until recently by some investigators, that hemoconcentration is a criterion of shock. MATERIAL AND METHODSThe plasma volume was measured with T-1824 by extrapolation of a corrected time log-concentration curve as described in the preceding report (9) ; the total blood volume was calculated from the plasma volume and the arterial hematocrit. The serum protein concentration was determined by the falling drop (10) and refractometric.

Blood Volume in Clinical Shock. I. Mixing Time and Disappearance Rate of T-1824 in Normal Subjects and in Patients in Shock; Determination of Plasma Volume in Man From 10-Minute Sample12

“…This is in accord with recent reports that the hematocrit and plasma protein values are below normal before treatment in shock cases among civilian and war casualties (4,25). From our experience also it appears that in cases of skeletal trauma and hemorrhage, uncomplicated by exposure or dehydration, the initial determinations of hematocrit and plasma protein after the injury fall below the average normal values (3,10). Evidence of hemoconcentration has been observed only in the cases of burns and abdominal injuries, which, as noted above, provide the only clear instances of increased disappearance of dye.…”

“…The general plan was, (1) to make a systematic study of time-concentration curves of T-1824 in patients with various types of injuries and degrees of shock in order to evaluate the effect of shock on the time of mixing and disappearance rate of the dye, and to define the extent to which these factors influence the measurement of plasma volume in shock-like states; (2) to determine the extent and, if possible, the cause of blood volume reduction in human cases of shock. The results of the latter phase of the investigation are presented in a separate communication (10).…”

Blood Replacement

“…Since then especially the classic investigations of the English (GRANT and REEVE [553]) and of the American shock teams of World War II (BEECHER et al [114,115]; EMERSON [411]) and of the Korean War (ARTz et al [78]; HOWARD [730]) have shown that the main cause of hemorrhagic and traumatic shock [1090] is to be found in the reduction of the circulating BV [423], and that restoration of the BV by means of sufficient blood transfusion can relieve shock if the hypovolemic phase does not remain untreated for too long (survey in REEVE [1167]). …”

A mathematical model of the systemic circulatory system with logistically defined nervous system regulatory mechanisms

“…In the experiments reported in [28], recovery following haemorrhage occurred for a mean loss of 34.5% of total blood volume while a 43% blood loss was progressive. In [29,30], clinical signs of progressive shock occur with a blood loss in the range of 30 -40% of total blood volume. Consistent with these measured data, in the present simulation a 30% blood loss results in a minimum arterial pressure of 54 mmHg and, from figure 10, recovery is predicted.…”