Hemoglobin and Effect of Transfusion

In limb injuries, after blood loss there is usually a fairly rapid dilution of blood, first with protein-free or protein-poor fluid, but later chiefly 

Transfusions of dilute plasma or of blood rarely alter the plasma protein concentration by more than 0.5 g/100 ml. The greater part of the diluent in both rapidly leaves the circulation (G19). 

In cases of trauma, Flear and Clarke (F2) found that the nitrogen released by the breakdown of transfused red cells is not excreted but is available to the rest of the body. The experiments of Whipple, Miller, and Robscheit-Robbins (W12) indicate that when undernourished anemic dogs are fed protein it is preferentially utilized for synthesis of hemoglobin. It seems likely that this is the case in the anemia of trauma. 

Flear and Clarke (F2) have obtained the impression of improved convalescence after major injury when blood transfusions adequate to prevent the anemia are given. When this has been achieved, and in the absence of major complications, they have not seen the lengthy early stages of convalescence described by Moore and Bail (M14). Such clinical impressions suggest that when there has been generous replacement of blood loss incurred by injury and its treatment, the metabolic picture may be modified. They have not usually found the retention of sodium, chloride, and water in the transfused cases after the first 24 hours, though in nontransfused cases the amounts and period over which they were retained were of the same order as those reported by others to follow surgery. 

The differences between the transfused and nontransfused cases observed by Flear and Clarke (F2) appeared to be related to the adequacy of the circulating red cell mass and the total blood volume during the early stages after injury and its treatment. They suggest that blood loss and an adequate circulating blood volume are major etiologic factors of posttraumatic metabolic changes. The concept of a fixed pattern of response to injury involves an oversimplified approach and may lead to 

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