Hemoglobin-Oxygen Equilibrium in Cystic Fibrosis

PEDIATRICS ◽  
1977 ◽  
Vol 59 (6) ◽  
pp. 919-926
Author(s):  
Amnon Rosenthal ◽  
Kon Taik Khaw ◽  
Harry Shwachman

A study of 35 patients with cystic fibrosis demonstrated that increasing severity of pulmonary involvement was associated with a mild but definite increase in erythrocyte 2,3-diphosphoglycerate (2,3-DPG) and a decrease in hemoglobin affinity for oxygen. The predominant regulators of 2,3-DPG were blood pH, cardiac output, and systemic oxygen transport. No significant relationship was observed between erythrocyte 2,3-DPG content and arterial oxygen tension. Hypophosphatemia may have prevented a greater increase in erythrocyte 2,3-DPG content. The inadequate increase in 2,3-DPG and consequent insufficient change in hemoglobin-oxygen affinity, coupled with an insufficient compensatory erythrocytic response, may adversely affect tissue oxygenation in patients with severe cystic fibrosis.

PEDIATRICS ◽  
1977 ◽  
Vol 59 (4) ◽  
pp. 588-594
Author(s):  
Amnon Rosenthal ◽  
Lawrence N. Button ◽  
Kon Taik Khaw

Simultaneous red blood cell (RBC) and plasma volume determinations were obtained in 16 patients with cystic fibrosis (CF) and moderately severe pulmonary involvement. Hypervolemia with an increase in both RBC and plasma volumes was observed. Changes in blood volume were marked when values were indexed by weight but less significant when indexed by height. Decreasing systemic arterial oxygen saturation was associated with a progressive increase in RBC mass, hematocrit value, and hemoglobin level and a decrease in mean corpuscular hemoglobin concentration. RBC and total blood volumes were highest in patients with cor pulmonale and congestive heart failure. However, the compensatory polycythemic response in patients with CF was inadequate when compared with the response to hypoxemia in patients with cyanotic congenital heart disease. The insufficient oxygen-carrying capacity may compromise tissue oxygen delivery and necessitate treatment.


1992 ◽  
Vol 1 (2) ◽  
pp. 53-60 ◽  
Author(s):  
CH Clark ◽  
G Gutierrez

BACKGROUND: Monitoring the adequacy of tissue oxygenation is an important goal in the care of the critically ill patient. Global alterations in tissue oxygenation are inferred from changes in systemic oxygen transport (defined as the product of cardiac output and arterial oxygen content) and total oxygen consumption. These parameters, however, cannot measure the level of oxygenation of specific tissue beds, in particular those that are first affected by hypoxia, such as the gastrointestinal tract and the kidneys. DISCUSSION: Gastrointestinal tonometry is a new method for measuring the partial pressure of carbon dioxide of the gastrointestinal mucosa. This information can be used in conjunction with the arterial blood bicarbonate to calculate the pH of the mucosa. Mucosal acidosis correlates well with the onset of anaerobic metabolism in response to hypoxia or sepsis. This review discusses the basic principles of tonometry, the results of experimental and clinical studies, and the practical aspects related to the implementation and use of tonometers in patients in the critical care unit. CONCLUSION: Gastrointestinal tonometry is a relatively noninvasive device that appears capable of measuring metabolic changes produced by hypoxia. Because of the sensitive nature of the gastrointestinal mucosa, these changes often occur well in advance of other, more common, indices of hypoxia. The use of the tonometer may become a routine procedure in the overall monitoring of critically ill patients.


Blood ◽  
1983 ◽  
Vol 61 (5) ◽  
pp. 920-924 ◽  
Author(s):  
NA Noble ◽  
CA Jansen ◽  
PW Nathanielsz ◽  
KR Tanaka

Abstract The tenfold increase in red cell 2,3-diphosphoglycerate (DPG) concentration that occurs during the first 5 days of life in lambs is an important adaptation to extrauterine life. In lambs, DPG reduces hemoglobin oxygen affinity by the Bohr effect. Our data on 10 neonatal lambs suggest that the biochemical mechanism underlying this DPG increase involves the following: (1) a rise in plasma glucose from 40 to 100 mg/dl in the first 48 hr of life, which allows for increased glucose consumption in the highly glucose-permeable neonatal RBC; (2) a transitory rise in blood pH begins at birth, peaks at about 20 hr, and falls slightly; (3) the pH increase coincides with a threefold increase in RBC fructose-1,6-diphosphate (FDP) concentration due, we believe, to pH activation of phosphofructokinase; (4) glycolytic intermediates after the glyceraldehyde-3-phosphate dehydrogenase (GAPD) step do not rise in the first 24 hr of life, possibly due to insufficient inorganic phosphate (Pi), a substrate of GAPD; (5) plasma Pi increases from about 7 mg/dl at birth to 11 mg/dl at 72 hr, activates the GAPD, and FDP levels decline; and (6) the in vitro activity of the DPG synthetic enzyme, DPG mutase, is increased 12-fold in neonatal compared to adult RBC. We conclude that the postnatal rise in DPG is explained at least in part by the sequential effects of these metabolic changes.


Vox Sanguinis ◽  
1978 ◽  
Vol 34 (2) ◽  
pp. 111-127 ◽  
Author(s):  
J.C. Bakker ◽  
Ernest Beutler ◽  
John A. Collins ◽  
R. Ben Dawson ◽  
Lars Garby ◽  
...  

1980 ◽  
Vol 59 (2) ◽  
pp. 143-145 ◽  
Author(s):  
G. Severini ◽  
A. Giuliani ◽  
D. Maffi ◽  
N. Cerulli

1. The relationship between erythrocyte 2,3-diphosphoglycerate (2,3-DPG) and changes in blood pH and in oxygen affinity were studied in six patients treated with two dialysis techniques: conventional haemodialysis and ultrafiltration followed by conventional haemodialysis. 2. The decrease in erythrocyte 2,3-diphosphoglycerate and increase in pH after conventional haemodialysis may significantly increase the affinity of haemoglobin for oxygen and consequently result in inadequate oxygenation of tissue. 3. Ultrafiltration followed by conventional haemodialysis, on the contrary, is more beneficial for oxygenation of tissue and post-dialysis symptoms may be reduced.


Blood ◽  
1983 ◽  
Vol 61 (5) ◽  
pp. 920-924 ◽  
Author(s):  
NA Noble ◽  
CA Jansen ◽  
PW Nathanielsz ◽  
KR Tanaka

The tenfold increase in red cell 2,3-diphosphoglycerate (DPG) concentration that occurs during the first 5 days of life in lambs is an important adaptation to extrauterine life. In lambs, DPG reduces hemoglobin oxygen affinity by the Bohr effect. Our data on 10 neonatal lambs suggest that the biochemical mechanism underlying this DPG increase involves the following: (1) a rise in plasma glucose from 40 to 100 mg/dl in the first 48 hr of life, which allows for increased glucose consumption in the highly glucose-permeable neonatal RBC; (2) a transitory rise in blood pH begins at birth, peaks at about 20 hr, and falls slightly; (3) the pH increase coincides with a threefold increase in RBC fructose-1,6-diphosphate (FDP) concentration due, we believe, to pH activation of phosphofructokinase; (4) glycolytic intermediates after the glyceraldehyde-3-phosphate dehydrogenase (GAPD) step do not rise in the first 24 hr of life, possibly due to insufficient inorganic phosphate (Pi), a substrate of GAPD; (5) plasma Pi increases from about 7 mg/dl at birth to 11 mg/dl at 72 hr, activates the GAPD, and FDP levels decline; and (6) the in vitro activity of the DPG synthetic enzyme, DPG mutase, is increased 12-fold in neonatal compared to adult RBC. We conclude that the postnatal rise in DPG is explained at least in part by the sequential effects of these metabolic changes.


1981 ◽  
Vol 51 (4) ◽  
pp. 864-870 ◽  
Author(s):  
B. K. Ross ◽  
M. P. Hlastala

The importance of hemoglobin-oxygen affinity (HOA) in affecting skeletal muscle oxygen consumption (VO2) was reevaluated using an isolated canine gracilis muscle. HOA of the blood [normal O2 half-saturation pressure of hemoglobin (P50) = 30 Torr] was increased by refrigerated storage (P50 = 22 Torr), incubation in sodium metabisulfite (P50 = 24 Torr), or in sodium cyanate (P50 = 14 Torr). Stored blood caused a significant fall in VO2 to 80% of control, with no change in venous O2 partial pressure (PvO2), substantiating previous studies. However, in contrast, blood incubated in sodium metabisulfite or sodium cyanate resulted in no impairment of VO2, with a fall in PvO2 in the latter case indicating that a critical PvO2 did not cause the reduction in VO2 with stored blood. To substantiate further the lack of existence of a critical PO2, fresh and increased HOA blood was perfused at constant flow rates and varying arterial oxygen saturations. Stored blood showed a marked reduction in VO2 as compared with normal blood over a wide range of saturations. However, carbamylated blood VO2 was identical to fresh blood VO2 values. The data suggest that the position of the oxygen dissociation curve may not be as important as originally thought in determining skeletal muscle oxygen delivery. The drop in VO2 caused by perfusion with stored blood is due to some other factor unrelated to HOA.


PEDIATRICS ◽  
1977 ◽  
Vol 60 (3) ◽  
pp. 372-377
Author(s):  
William K. Lau ◽  
Lowell S. Young ◽  
Alan B. Osher ◽  
Richard R. Dooley

Amikacin, a new semisynthetic aminoglycoside antibiotic with activity against Pseudomonas aeruginosa, was used to treat 22 acute exacerbations of chronic pulmonary infections in 18 patients with cystic fibrosis. Patients ranged from 5 to 32 years of age and had mucoid P. aeruginosa isolated from sputum. The amikacin dose was usually 7.5 mg/kg every eight hours but was increased to 10 mg/kg and/or carbenicillin was added in selected cases depending on clinical course. Although P. aeruginosa was not eliminated from our patients' sputum except in two cases, there was a good clinical response in 19 of 22 courses. Significant improvement in chest x-ray films, spirometry, or arterial oxygen tension was documented in 11 of 17 courses. One instance of serum creatinine level elevation could not be attributed to this antibiotic. Two patients showed minimal (15 dB) unilateral high-frequency hearing loss on serial audiograms. Activity against many gentamicin-resistant strains and high blood levels are among the attractive properties of amikacin. Amikacin is clinically effective in treating Pseudomonas-associated pulmonary infections complicating cystic fibrosis.


PEDIATRICS ◽  
1972 ◽  
Vol 50 (2) ◽  
pp. 291-298
Author(s):  
Andre Lamarre ◽  
Bernard J. Reilly ◽  
A. Charles Bryan ◽  
Henry Levison

We studied gas exchange in 19 children with cystic fibrosis in whom measurement of lung volumes, flow rates and airway conductance, diffusing capacity and mixing efficiency were normal. A significant decrease in arterial oxygen tension was found together with a significant increase in alveolar-arterial difference for oxygen and physiologic dead space/tidal volume ratio. These findings are consistent with evidence that early in cystic fibrosis the site of obstruction is in the small airways. It is also suggested from these data that blood gas abnormalities occur before other parameters of lung function become abnormal.


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