Robert W. Winters

Metabolic Acidosis Resulting from Intravenous Alimentation Mixtures Containing Synthetic Amino Acids

Abstract Hyperchloremic metabolic acidosis was observed in 11 infants receiving total parenteral nutrition containing mixtures of synthetic L-amino acids. The observed acidosis was not due to excessive gastrointestinal or renal losses of base as judged by the stool undetermined anion content and the urinary net acid excretion, nor was it due to infusion of preformed hydrogen ion as judged by the titratable acidity of the synthetic amino acid mixtures. Instead, the synthetic amino acid mixtures contain an excess of cationic amino acids in relation to anionic amino acids or other organic anions. Metabolism of these cationic amino acids results in a net excess of hydrogen ion, explaining the observed acidosis.

Quantitative Displacement of Acid-Base Equilibrium in Metabolic Acidosis

Excerpt Metabolic acidosis is commonly encountered in a variety of disorders, all of which are characterized either by the gain of strong acid or by loss of bicarbonate from the extracellular fluid...

Contraction Alkalosis After Diuresis of Edematous Patients with Ethacrynic Acid

Excerpt Systemic alkalosis has been observed (1) after diuresis of patients with ethacrynic acid, a new potent oral diuretic. In the present study, metabolic balance studies were performed on four ...

Carbohydrate Metabolism in Experimental Salicylism.

Summary Fasting rats given large doses of sodium salicylate fail to deposit liver glycogen even when they are given a major stimulus for such deposition in the form of Compound F. Yet such animals continue to break down body protein at an accelerated rate as judged by the nitrogen balances. The level of muscle glycogen salicylate-treated rats is reduced and this effect is countered by concurrent treatment with Compound F. The significance of these findings is briefly discussed.

Influence of Body Composition on the In Vivo Response to Acute Hypercapnia

Extract: Changes in the acid-base status of blood in vivo have been investigated in anesthetized, nephrectomized, artificially ventilated dogs during acute hypercapnia before and after induced changes in body composition. The experiments were designed to study factors influencing the redistribution of bicarbonate generated by buffers in the blood compartments and the interstitial fluid volume.The first series of experiments was designed to determine the best linear fit to data collected in vivo in dogs with acute steady state hypercapnia (the so-called in vivo CO2 equilibration curve). Three groups were studied: a control group, a group with expanded extracellular fluid (ECF), and a group with expanded blood volume. A linear relation was found between pH-log Pco2 and [H+]-Pco2, the correlation coefficients being 0.98 for both pairs of variables in all three groups. The pH-log Pco2 coordinate system was adopted. The linear relation between pH and log Pco2 allows the slope (Δlog Pco2 ΔpH) of the in vivo CO2 equilibration curve to be determined by measuring only two points on the line.In the second series of experiments, the slope of the in vivo CO2 equilibration curve was determined before and after body composition was altered so that each dog served as his own control. Six groups of dogs were studied: group 1 (six dogs) was control and had no change in body composition; groups 2 and 3 (six dogs each), ECF volume was increased by infusing 100 and 200 ml/kg, respectively, of a mock ECF solution; group 4 (eight dogs), blood volume was increased by infusing 50 ml/kg fresh, heparinized whole blood; group 5 (eight dogs), hemoglobin concentration was decreased by replacing blood with plasma; and group 6 (four dogs), hemoglobin concentration was increased by infusing 25–30 ml/kg packed erythrocytes. Statistical analysis of the changes in slopes caused by these changes in body composition (Table V) showed the following results: slope increased significantly as plasma bicarbonate concentration fell; slope decreased significantly as ECF volume increased; slope increased significantly as blood volume increased; slope did not change significantly with acute changes in hemoglobin concentration.Speculation: This study indicates that the slope of the in vivo CO2 equilibration curve is dependent upon certain variables of body composition, especially the volume of the extracellular fluid (ECF) and blood. Thus, correct interpretation of blood acid-base data in acute hypercapnia must take account of the redistribution of bicarbonate as a function of the body composition. For example, an infant born prematurely presenting.

Osmotic Effects of Infusion of THAM

Extract: Changes in plasma osmolality as well as in extracellular fluid (ECF) space following infusion of THAM or NaHCO3 to anesthetized, nephrectomized dogs have been used to compare the osmotic effects of the two agents. Groups of five to six dogs received (per kg body weight) 10 millimoles THAM (pH 7.3), 10 millimoles THAM (pH 8.5), 5 millimoles NaHCO3, 10 millimoles NaHCO3 or 5 millimoles NaCl, while a control group of five dogs received no infusion. Increases in plasma osmolality and 36Cl space (ECF) were greater following infusion of THAM (pH 7.3 or pH 8.5) than after infusion of either NaHCO3 or NaCl. Specifically, the osmotic effects of THAM, as judged from increases in osmolality of the body fluids and in 36Cl space, were much greater than those of a 5-millimole dose of NaHCO3, which produced an equivalent rise in plasma bicarbonate, and were even greater than those of an equimolar dose of NaHCO3 (10 millimoles/kg). Furthermore, the increase in concentration of plasma bicarbonate produced by this dose of NaHCO3 was much greater than that produced by THAM. Although theoretical considerations have predicted that the osmotic effects of THAM would be as great or greater than those of NaHCO3, this is the first experimental documentation.Speculation: The results reported herein provide further evidence for the view that THAM is not superior to NaHCO3 for treatment of clinical acid-base disturbances.

Clinical and physiological consequences of total parenteral nutrition in the pediatric patient

Pediatricians share a long common historical tradition with their surgical colleagues in a concern for the provision of effective parenteral nutrition to patients in whom an adequate flow of enteral nutrients cannot be maintained. In the pediatric patient the problem is even more complicated than in adults, since in the former the nutritional requirements for normal growth and development are superimposed upon those for maintenance.

Net acid balance (NAB) in metabolic acidosis

In previous studies from this laboratory the principles for the determination of the balance (intake minus output) of non-carbonic, non-metabolizable, non-metabolized acid (net acid) have been validated and applied to healthy, growing infants. To determine NAB requires the independent measurement of all components of net acid intake (sulfuric and organic acid production plus net acid generated by skeletal mineralization minus net base intake) and net acid output (renal net acid excretion).In the present study NAB was determined over 3–8 day balance periods in 11 infants developing (n = 3) or recovering from (n = 8) diarrhea, ileostomy, renal or late metabolic acidosis. Four studies on infants having no significant change in acid-base status over the period of study served as controls. MAB was significantly positive during the development of acidosis and negative during recovery. A close (r > 0.9) linear relationship was found between NAB (mEq/kg) and the measured change in blood base excess (Δ BE, mEq/l) over the period of study such that the virtual volume of retained net base or acid approximated 50% of the body weight suggesting considerable involvement of non-ECF buffers. To our knowledge this study represents the first complete quantitative measurement of the total magnitude and the separate components of net base retained (during recovery) or net acid retained (during development) in metabolic acidosis.