scholarly journals The Physiology of Dehydration Stress in the Land Crab, Cardisoma Carnifex: Respiration, Ionoregulation, Acid-Base Balance and Nitrogenous Waste Excretion

1986 ◽  
Vol 126 (1) ◽  
pp. 271-296 ◽  
Author(s):  
CHRIS M. WOOD ◽  
R. G. BOUTILIER ◽  
D. J. RANDALL
Keyword(s):  
Metabolic Alkalosis ◽  
Ammonia Excretion ◽  
French Polynesia ◽  
Strong Ion Difference ◽  
Acid Base Balance ◽  
Acid Base ◽  
Land Crab ◽  
Base Balance ◽  
Ion Shifts ◽  
Total Body

Air-breathing Cardisoma carnifex, collected in Moorea, French Polynesia, were held in fresh water similar in chemical composition to that in their burrows. Under control conditions, which allowed branchial chamber flushing but not ventilation of the medium, crabs demonstrated net Na+ and Cl− uptake, and ammonia, urea and base excretion (= acidic equivalent uptake). Throughout 192 h of water deprivation, crabs dehydrated slowly at a rate of 0.55 g H2O kg−1 h−1, eventually reaching a near lethal 18% loss of total body water. Increases in haemolymph osmolytes were quite variable (0–29%); electrolyte excretion was negligible. MOO2 and MCOCO2 both decreased by approximately 55%, maintaining an unusually low gas exchange ratio (R = 0.53), and suggesting general metabolic depression. There was no evidence of internal hypoxia as haemolymph lactate remained at hydrated levels and PaOO2 actually increased. The dominant acid-base response was a progressive metabolic alkalosis accompanied by a partially compensating rise in PaCOCO2. Alkalosis was probably caused by blockage of the normal aquatic excretion of base produced by the metabolism of this herbivore. Other possible causes were eliminated: i.e. alkalaemia due to contraction of the ECFV; entrainment via strong ion shifts; CaCO3 mobilization; and ammonia accumulation in the haemolymph. In the absence of water, net ammonia production and excretion both appeared to cease, and alternate end products (urea, uric acid) did not generally accumulate. Within 2h of rehydration, crabs regained more than half the lost water, MOO2 and MCOCO2 increased above control levels, and ammonia excretion and haemolymph concentration both exhibited a prolonged (56 h) 4- to 6-fold rise. At the same time, metabolic alkalosis was reversed in association with elevated net base excretion into the water; the latter was correlated with an increase in the strong ion difference (SID) flux ([Na+ + K+ + Ca2+ + Mg2+ - Cl−]). Note:

Impact of Continuous Veno-venous Hemofiltration on Acid-base Balance

2003 ◽  
Vol 26 (1) ◽  
pp. 19-25 ◽  
Author(s):  
J. Rocktäschel ◽  
H. Morimatsu ◽  
S. Uchino ◽  
C. Ronco ◽  
R. Bellomo
Keyword(s):  
Renal Failure ◽  
Acute Renal Failure ◽  
Metabolic Alkalosis ◽  
Base Excess ◽  
Strong Ion Difference ◽  
Acid Base Balance ◽  
Strong Ion Gap ◽  
Acid Base ◽  
Biophysical Analysis ◽  
Base Balance

Background Continuous veno-venous hemofiltration (CVVH) appears to have a significant and variable impact on acid-base balance. However, the pathogenesis of these acid-base effects remains poorly understood. The aim of this study was to understand the nature of acid-base changes in critically ill patients with acute renal failure during continuous veno-venous hemofiltration by applying quantitative methods of biophysical analysis (Stewart-Figge methodology). Methods We studied forty patients with ARF receiving CVVH in the intensive care unit. We retrieved the biochemical data from computerized records and conducted quantitative biophysical analysis. We measured serum Na+, K+, Mg2+, Cl-, HCO3-, phosphate, ionized Ca2+, albumin, lactate and arterial blood gases and calculated the following Stewart-Figge variables: Strong Ion Difference apparent (SIDa), Strong Ion Difference Effective (SIDe) and Strong Ion Gap (SIG). Results Before treatment, patients had mild acidemia (pH: 7.31) secondary to metabolic acidosis (bicarbonate: 19.8 mmol/L and base excess: −5.9 mEq/L). This acidosis was due to increased unmeasured anions (SIG: 12.3 mEq/L), hyperphosphatemia (1.86 mmol/L) and hyperlactatemia (2.08 mmol/L). It was attenuated by the alkalinizing effect of hypoalbuminemia (22.5 g/L). After commencing CVVH, the acidemia was corrected within 24 hours (pH 7.31 vs 7.41, p <0.0001). This correction was associated with a decreased strong ion gap (SIG) (12.3 vs. 8.8 mEq/L, p <0.0001), phosphate concentration (1.86 vs. 1.49 mmol/L, p <0.0001) and serum chloride concentration (102 vs. 98.5 mmol/L, p <0.0001). After 3 days of CVVH, however, patients developed alkalemia (pH: 7.46) secondary to metabolic alkalosis (bicarbonate: 29.8 mmol/L, base excess: 6.7 mEq/L). This alkalemia appeared secondary to a further decrease in SIG to 6.7 mEq/L (p <0.0001) and a further decrease in serum phosphate to 0.77 mmol/L (p <0.0001) in the setting of persistent hypoalbuminemia (21.0 g/L; p=0.56). Conclusions CVVH corrects metabolic acidosis in acute renal failure patients through its effect on unmeasured anions, phosphate and chloride. Such correction coupled with the effect of hypoalbuminemia, results in the development of a metabolic alkalosis after 72 hours of treatment.

scholarly journals Comparative analysis of acid-base balance in patients with severe sepsis and septic shock: traditional approach vs. physicochemical approach

2019 ◽  
Vol 67 (4) ◽  
pp. 441-446
Author(s):  
José Diaztagle Diaztagle-Fernández ◽  
Ingrid Juliana Moreno-Ladino ◽  
Jorge Alfredo Morcillo-Muñoz ◽  
Andrés Felipe Morcillo-Muñoz ◽  
Luis Alejandro Marcelo-Pinilla ◽  
...  
Keyword(s):  
Severe Sepsis ◽  
Metabolic Alkalosis ◽  
Traditional Approach ◽  
Strong Ion Difference ◽  
Acid Base Balance ◽  
Physicochemical Model ◽  
Acid Base ◽  
Base Balance ◽  
Diagnostic Approaches ◽  
Sepsis And Septic Shock

Introduction: The evaluation of metabolism and the diagnostic classification of acid-base disorders has generated great controversy. Acid-base balance (ABB) is approached by means of the physicochemical and Henderson’s models.Objective: To compare two diagnostic approaches to ABB in patients with severe sepsis.Materials and methods: Prospective, descriptive study conducted in patients with severe sepsis. ABB was analyzed within the first 24 hours. The diagnosis was compared according to each model and the causes of the disorders were compared according to the physicochemical model.Results: 38 patients were included in the study, of which 21 (55%) were women; the mean age was 49 years, the median APACHE II, 13.28, and the mortality at 28 days, 24.3%. The traditional approach identified 8 patients with normal ABB, 20 with metabolic acidosis, and 10 with other disorders. Based on the physicochemical model, all subjects had acidosis and metabolic alkalosis. Increased strong ion difference (SID) was the most frequently observed disorder.Conclusion: The physicochemical model was useful to diagnose more patients with acid-base disorders. According to these results, all cases presented with acidosis and metabolic alkalosis; the most frequent proposed mechanism of acidosis was elevated SID. The nature of these disorders and their clinical relevance is yet to be established.

Influence of plasma bicarbonate concentration and pH on citrate excretion

1964 ◽  
Vol 206 (4) ◽  
pp. 875-882 ◽  
Author(s):  
David P. Simpson
Keyword(s):  
Linear Relationship ◽  
Metabolic Alkalosis ◽  
High Plasma ◽  
Alkaline Ph ◽  
Acid Base Balance ◽  
Bicarbonate Concentration ◽  
Acid Base ◽  
Plasma Bicarbonate ◽  
Close Relationship ◽  
Base Balance

Citrate excretion has been studied in dogs under various conditions of acid-base balance in order to determine which factors are responsible for the increased citrate clearance present in metabolic alkalosis. A close relationship, significantly modified by systemic pH, was found between plasma bicarbonate concentration and citrate clearance. In the presence of an alkaline plasma pH, there was a linear relationship between changes in plasma bicarbonate concentration and changes in citrate clearance. Other experiments also demonstrated the influence of plasma bicarbonate concentration on citrate clearance at alkaline pH. Under acidotic conditions citrate clearances were low and changes in plasma bicarbonate concentration had little effect on citrate excretion. A change in plasma pH from an acidotic to an alkalotic state, with a constant plasma bicarbonate concentration, produced an increase in citrate clearance. Thus the coexistence in metabolic alkalosis of high plasma bicarbonate concentration and high plasma pH results in a markedly increased citrate clearance.

Nitrogen excretion in germ-free and conventional chickens: effects of an alkali load

1978 ◽  
Vol 39 (1) ◽  
pp. 99-104 ◽  
Author(s):  
J. Okumura ◽  
D. Hewitt ◽  
Marie E. Coates
Keyword(s):  
Amino Acids ◽  
Uric Acid ◽  
Ammonia Excretion ◽  
Nitrogen Excretion ◽  
Acid Base Balance ◽  
Acid Base ◽  
Total N ◽  
Germ Free ◽  
Base Balance ◽  
Micro Organisms

1. Groups of three colostomized germ-free (GF) and conventional (CV) chickens aged 4 months were maintained for successive periods of 8 d on a diet containing 200 g casein/kg without and with sodium bicarbonate at the rate of 20 mmol/d and a nitrogen-free diet without and with NaHCO3at 9 mmol/d. Urine and faeces were collected during the last 3 d of each period.2. Total N, uric acid- and ammonia-N were determined in urine and total N in faeces. Amino acids were measured in hydrolysates of faeces collected during the periods when no NaHCO3was included in the diets.3. The CV birds excreted more N on the casein diets but less on the N-free diets than did their GF counterparts, the differences being mainly shown in the urine.4. On both diets hydrolysates of the faeces of CV birds contained smaller amounts of amino acids. On the N-free diet the proportions (g/160 g N) of serine, proline and threonine were reduced, suggesting some conservation of endogenous N by micro-organisms, and the proportions of histidine, alanine, lysine and methionine increased, possibly through microbial synthesis; on the casein diet, proportions of most amino acids were less, probably because bacterial deamination had occurred.5. Urinary excretion of total N, uric acid and ammonia was much greater on the casein than on the N-free diets. Inclusion of NaHCO3caused a sharp fall in urinary ammonia on both diets and in both environments.6. It was concluded that the level of dietary protein and the regulation of acid-base balance have more effect than microbial activity on the urinary ammonia excretion.

Acid-base balance and renal function following total body perfusion

1962 ◽  
Vol 61 (2) ◽  
pp. 287-288
Author(s):  
James G. Calene ◽  
William H. Weidman ◽  
Khalil G. Wakim ◽  
John W. Rosevear ◽  
John W. Kirklin ◽  
...  
Keyword(s):  
Renal Function ◽  
Acid Base Balance ◽  
Acid Base ◽  
Base Balance ◽  
Total Body

Renal regulation of acid-base balance in the bullfrog

1961 ◽  
Vol 201 (6) ◽  
pp. 980-986 ◽  
Author(s):  
Hisato Yoshimura ◽  
Masateru Yata ◽  
Minoru Yuasa ◽  
Robert A. Wolbach
Keyword(s):  
Carbonic Anhydrase ◽  
Ammonia Excretion ◽  
Respiratory Acidosis ◽  
Acid Base Balance ◽  
Acid Base ◽  
Urinary Ph ◽  
Base Balance ◽  
Chloride Excretion ◽  
Acid Load ◽  
Renal Carbonic Anhydrase

Renal mechanisms for the maintenance of acid-base balance were studied in the normal bullfrog, during metabolic and respiratory acidosis, and after carbonic anhydrase inhibition. Following intravenous administration of 0.3–12 mmole HCl/ kg, as 0.1 n HCl, urinary pH (initially pH 6.3–7.7) did not change significantly. However, urinary ammonia excretion increased more than twofold, and within 3–5 days the cumulative increase was equivalent to the acid load given. Despite the increased ammonia excretion, chloride excretion did not increase after acid loading. In both normal and acidotic bullfrogs ammonia excretion was correlated with an increase in urinary pH. Respiratory acidosis in the small frog, Rana limnocharis, produced by exposure to 6.4% CO2 in air, induced neither urinary acidification nor increased ammonia excretion; both urinary sodium and bicarbonate excretion increased. When renal carbonic anhydrase was inhibited by acetazoleamide injection, urine flow, sodium excretion, and bicarbonate excretion increased markedly, urinary pH increased slightly, and urinary ammonia excretion remained unchanged. These renal responses to acidosis are compared with those of the acidotic dog.

Effect of acetazolamide on citrate excretion in the dog

1964 ◽  
Vol 206 (4) ◽  
pp. 883-886 ◽  
Author(s):  
David P. Simpson
Keyword(s):  
Metabolic Alkalosis ◽  
Acid Base Balance ◽  
Acid Base ◽  
Marked Rise ◽  
Before And After ◽  
Base Balance

Clearance measurements were made on dogs in order to study the mechanism of the effect of acetazolamide on citrate excretion. Induction of metabolic alkalosis resulted in a marked rise in citrate clearance despite treatment with acetazolamide. Measurement of citrate clearances in alkalotic animals before and after acetazolamide infusion showed either no change or an increase in citrate clearance. No evidence was found that acetazolamide decreases citrate excretion when acidosis is prevented. These results are consistent with the hypothesis that changes in citrate clearance after acetazolamide administration are entirely secondary to changes in acid-base balance.

Sign in / Sign up

Export Citation Format

Share Document