scholarly journals THE CARBON DIOXIDE TENSION AND ACID-BASE BALANCE OF JEJUNAL SECRETIONS IN MAN

1942 ◽  
Vol 142 (2) ◽  
pp. 893-904 ◽  
Author(s):  
Lemuel C. McGee ◽  
A. Baird Hastings
PEDIATRICS ◽  
1950 ◽  
Vol 6 (5) ◽  
pp. 753-771
Author(s):  
HELEN S. REARDON ◽  
BRUCE D. GRAHAM ◽  
JAMES L. WILSON ◽  
MARY L. BAUMANN ◽  
MAKEPEACE U. TSAO ◽  
...  

A study of the acid base balance of arterial blood in 92 premature infants, aged 1 to 65 days and 1.1 kg. to 2.3 kg. in weight, has been presented. The temporal artery blood was analyzed for pH, plasma CO2 content, chloride, total protein, total base. Alveolar carbon dioxide tension (pCO2) and "R" were calculated. Acid base analyses on the femoral artery blood of 16 adolescent well boys were used as controls. The study reveals the following salient facts: There is a wide variation in the blood chemical findings between normal, well premature infants. In addition, repeat determinations upon the same infants revealed a more labile blood chemical picture than is found in older infants or adults. No premature infant had all fractions of the acid base balance within the adult normal range. The mean values for pH, CO2 content and protein were reduced in premature infants, while the mean values for total base, chloride, phosphate and "R" were elevated as compared to the values for the adult controls. The mean value for carbon dioxide tension was normal. Sixty-seven per cent of the premature infants had the chemical findings of an uncompensated metabolic acidosis; 13% had a normal pH and CO2 content; 10% had a respiratory acidosis, 7% had a respiratory alkalosis and 3% were unclassified. There was no statistical correlation of acid base values to birth weight or age or weight at the time of chemical sampling. There was no difference of acid base values in infants who had been transfused by blood or plasma and those infants who had never been given blood or plasma transfusions. By clinical examination alone, the nature of the acid base variations could not be anticipated in what we generally consider as well premature infants. There was no correlation between the variations of the acid base disturbance and the prognosis for life in these babies. The fact that most premature infants have an increased hydrogen ion concentration and an unstable acid base balance may be additional reasons why premature babies so easily develop severe acidosis when any stress occurs, whether it is improper feeding, infection, etc. The cause of the acidosis in premature infants has not been established. The theory that premature infants have a partial anaerobic metabolism with a decreased production of carbon dioxide is tenable but not established.


1957 ◽  
Vol 191 (2) ◽  
pp. 384-387 ◽  
Author(s):  
Billy James Williamson ◽  
Smith Freeman

The effects of acute disturbances in acid-base balance on renal cation excretion were studied in dogs. Special attention was given to the excretory mechanism for calcium. Four different states were produced experimentally: respiratory acidosis, metabolic acidosis, metabolic alkalosis and compensated metabolic alkalosis. Additional experiments were carried out in normal and alkalotic animals subjected to calcium loading. Calcium reabsorption was found to vary directly with the filtered load of calcium. The increased excretion of calcium in acidosis appears to be due to an increase in filtered calcium. The percentage of reabsorption of filtered calcium was 98–99% in normal and acidotic dogs, but decreased to approximately 90% in animals made acutely alkalotic. However, the relative loss of water to calcium in the urine in acute alkalosis was decreased, resulting in an elevated renal threshold of retention of calcium in metabolic alkalosis. Data are included on the behavior of inorganic phosphate in the various states studied. Elevated carbon dioxide tension was associated with phosphate mobilization from the tissues regardless of whether or not the carbon dioxide excess was compensated for by extra alkali.


1984 ◽  
Vol 25 (5) ◽  
pp. 830-837 ◽  
Author(s):  
Juan P. Bosch ◽  
Sheldon Glabman ◽  
George Moutoussis ◽  
Mario Belledonne ◽  
Beat von Albertini ◽  
...  

1995 ◽  
Vol 198 (12) ◽  
pp. 2423-2430 ◽  
Author(s):  
M Nikinmaa ◽  
S Airaksinen ◽  
L V Virkki

Haemoglobin function within lamprey erythrocytes offers a unique solution to gas transport among vertebrates. Lamprey haemoglobin within intact erythrocytes is in oligomer/monomer equilibrium and has an oxygen affinity similar to that of haemoglobin in other active fishes. The cooperativity of oxygen binding, which is reduced at low pH values, the effect of protons and the effect of the concentration of haemoglobin on its oxygen affinity are all due to dissociation/association reactions of the haemoglobin molecules. The permeability of the lamprey red cell membrane to acid and base equivalents is very low, and plasma bicarbonate cannot therefore be dehydrated to carbon dioxide to any significant extent during the residence time of blood in the gills. This potential limitation on carbon dioxide excretion is overcome, however, by the high intraerythrocytic pH and the marked oxygenation-linked pH changes in the erythrocyte, which are due to the large Haldane effect of the haemoglobin. Owing to the relative impermeability of the erythrocyte membrane to acid equivalents, intraerythrocytic haemoglobin cannot take part in the acid-base buffering of the extracellular compartment. As a consequence, extracellular acid loads cause marked fluctuations in plasma pH.


PEDIATRICS ◽  
1955 ◽  
Vol 16 (6) ◽  
pp. 908-908
Author(s):  
HENRY B. BULL

This is the latest edition of a well-known textbook on clinical biochemistry designed essentially for use by advanced medical students and by practicing physicians. There are 12 chapters beginning with the metabolism of carbohydrates, lipids, proteins and nucleic acids and continuing through the metabolism of iron, sulfur, iodine, etc. There are chapters on electrolytes, water and acid-base balance and on oxygen and carbon dioxide transport. There is a lengthy and impressive section on endocrine function followed by a short summary of the vitamins.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
John (Ken) Leypoldt ◽  
Joerg Kurz ◽  
Jorge Echeverri ◽  
Markus Storr ◽  
Kai Harenski

Abstract Background and Aims Critically ill acute kidney injury (AKI) patients may require treatment by extracorporeal carbon dioxide removal (ECCO2R) devices to allow protective or ultraprotective mechanical ventilation and avoid hypercapnic acidosis. Continuous venovenous hemofiltration (CVVH) and ECCO2R devices can be arranged in series to form a single extracorporeal circuit; such a circuit has been proposed to be optimal, based carbon dioxide removal efficacy, if the ECCO2R device is placed proximal to the CVVH device (Allardet-Servent et al, Crit Care Med 43:2570-2581, 2015). Method We developed a mathematical model of whole-body, acid-base balance during extracorporeal therapy using in-series ECCO2R and CVVH devices for treatment of mechanically ventilated AKI patients. Equilibrium acid-base chemistry in blood was assumed as reported previously (Rees and Andreassen, Crit Rev Biomed Eng 33:209-264, 2005). Published clinical data from Allardet-Servent et al of mechanically ventilated (6 mL/kg predicted body weight or PBW) AKI patients treated by CVVH without ECCO2R were used to adjust model parameters to fit plasma levels of arterial partial pressure of carbon dioxide (PaCO2) and arterial plasma bicarbonate concentration ([HCO3]). The effects of applying ECCO2R at an unchanged tidal volume and a reduced tidal volume (4 mL/kg PBW) on PaCO2 and [HCO3] were then simulated assuming carbon dioxide removal rates from the ECCO2R device measured in the clinical study (91 mL of CO2/min when ECCO2R was proximal and 72 mL of CO2/min when CVVH was proximal). Results Agreement of model predictions with the clinical data was good, and model predictions were relatively independent of the in-series position of the devices (see Table). Total carbon dioxide removal from the CVVH device via ultrafiltration predicted by the model was lower after applying ECCO2R at both the unchanged tidal volume (25 mL of CO2/min when ECCO2R was proximal and 39 mL of CO2/min when CVVH was proximal) and the reduced tidal volume (30 mL of CO2/min when ECCO2R was proximal and 44 mL of CO2/min when CVVH was proximal). The reduced removal of total carbon dioxide via ultrafiltration when ECCO2R was proximal resulted from the lower total carbon dioxide concentration in blood entering the CVVH device. Thus, independent of the in-series position of the devices, the magnitude of this difference in total carbon dioxide removal by the CVVH device (14 mL of CO2/min) approximately cancels out the relative greater efficacy of the ECCO2R device (19 mL of CO2/min). Conclusion The described mathematical model has quantitative accuracy. It suggests that overall acid-base balance when using ECCO2R and CVVH devices in a single, combined extracorporeal circuit will be similar, independent of their in-series position.


1989 ◽  
Vol 67 (8) ◽  
pp. 2065-2073 ◽  
Author(s):  
George K. Iwama ◽  
James C. McGeer ◽  
Mark P. Pawluk

Some physiological aspects of five fish anaesthetics in rainbow trout were investigated. The effects of benzocaine, 2-phenoxyethanol, MS-222 (Sandoz), metomidate, and carbon dioxide gas (CO2) on acid–base regulation, hematocrit, blood gases, and cortisol and adrenaline concentrations were determined in resting rainbow trout fitted with chronic catheters in the dorsal aorta. A severe hypoxia developed with the cessation of breathing in deep anaesthesia. This was accompanied by a rise in blood [Formula: see text] and adrenaline concentration, and a fall in blood pH. Blood bicarbonate concentrations remained unchanged and cortisol concentrations declined with time. There was a transient increase in hematocrit coinciding with the increase in adrenaline concentrations.


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