Stanley Lang

Early response of plasma volume, red cell mass and plasma proteins to massive hemorrhage.

Summary 1) The chromium 51 red cell tagged dilution method is valid for measuring red cell mass in the presence of hypovolemic shock as no difference was found in red cell mass measured in tourniquet shocked animals when 15, 30 and 60 minutes were allowed for mixing of tagged cells, or between these values and those of control animals. 2) The response of blood volume compartments and plasma proteins to acute withdrawal of 50% of circulating blood volume has been determined at 2, 4, and 8 hours after hemorrhage. Plasma volume is restored to 100% of the control within 4 hours and is 108% at 8 hours post-hemorrhage. Despite the elevated plasma volume, total blood volume remains well below the control, due to persistent red cell mass deficit. Changes in hematocrit inversely reflect plasma volume changes. Plasma protein concentration is restored to 87% of control by 8 hours. Protein replacement seems to occur in 2 stages. An immediate response is evident within the first 2 hours and a delayed response begins at 4 hours after blood withdrawal and extends over a 48 hour period.

Response of Acutely Starved and Chronically Undernourished Rats to Saline Therapy Following Tourniquet Shock.

Summary Experiments were performed to ascertain possible differences in survival following tourniquet trauma and saline infusion therapy between rats chronically undernourished to 77.4-80.3%, and those acutely starved to 77-80% of initial body weight. It has been demonstrated that there is a significantly higher percentage of survival when chronically undernourished rats are infused with 7 ml normal saline solution/100 g body weight following an otherwise lethal tourniquet trauma. Acutely starved rats are not protected by this level of replacement, but do show 75% survival when infused at level of 15 ml saline solution/100 g body weight.

Influence of Mixing Time on Determination of Red Cell Volume in Normal and Shocked Rats

Summary Determinations of red cell volume using radiochromium 51 tagged red cells have been made in normal and tourniquet shocked rats using varied mixing times. Red cell volume determinations were significantly reproducible in the normal rat using mixing times of from 5 to 30 minutes. A 15 minute mixing time in the tourniquet shocked rats allowed significantly reproducible determinations of the red cell volume.

Comparison of Normal and Buffered Saline Solution for Fluid Replacement Following Tourniquet Shock.

Summary 1. Simultaneous comparison was made of therapeutic effectiveness of isotonic NaCl and saline-bicarbonate solutions when used in treatment of an otherwise lethal tourniquet trauma. The method of treatment allowed slow constant intravenous infusion of therapeutic solutions over period of greatest loss of fluid from circulating volume into traumatized extremities. The solutions were equally effective in increasing survival rate over that of untreated, traumatized controls. 2. Both solutions produced the same alteration in serum electrolyte concentration, i.e., elevation of serum Cl values. The lowered CO2 combining power of untreated control was not appreciably altered in the treatment groups.

Oxygen consumption in the rat during prolonged, acute starvation.

Summary Hypothyroid, hyperthyroid and euthyroid rats were subjected to acute starvation to extremis. Their oxygen consumption was measured daily. All groups showed an approximately equivalent early depression of oxygen consumption which is independent of the absolute level of the initial oxygen consumption.