Much attention has been given in the past to the study of changes in the blood produced by hemorrhage. Considerably less study has been devoted to changes in body fluid resulting from ether anesthesia, though such findings as elevation of blood sugar, increase in hydrogen ion concentration of the blood, and reduction in plasma bicarbonate, have been well established. The present work presents measurements of changes in quantity, as well as concentration, of certain components of body fluid as found in 16 patients subjected to the traumatizing factors of major surgical operations and to ether anesthesia. The time chosen for obtaining data to compare with the preoperative normal values was just at the end of operation, while the patient was still anesthetized. None of the patients studied showed evidence of more than mild shock or anoxemia during the study period.
METHODSOn the morning of operation, before administration of preanesthetic drugs, the fasting patient was weighed. Determinations were then made of plasma volume, body fluid "available for solution of thiocyanate" (1), hematocrit, plasma protein, serum protein and serum albumin. In addition, serum nonprotein nitrogen and serum sodium, potassium, chloride, and bicarbonate were measured. These determinations were repeated at the end of operation while the patient was still anesthetized and before parenteral fluid had been given. In most instances blood loss during operation was measured, using the method of Gatch and Little (2).Plasma volume was determined by the technic devel-