Editorial Type:
Physiology

Effects of acute dilutional hyponatremia on acid-base changes and electrolyte concentrations in rats with bilateral renal pedicle ligation

Kate Hopper Department of Veterinary Surgery and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616.

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 BVSc, PhD
and
Steve C. Haskins Department of Veterinary Surgery and Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616.

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 DVM
DOI:
https://doi.org/10.2460/ajvr.71.8.967
Volume/Issue:
Volume 71: Issue 8
Online Publication Date:
01 Aug 2010
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Abstract

Objective—To describe the effects of increasing the extracellular fluid (ECF) volume by approximately 20% on acid-base changes and electrolyte concentrations in anesthetized rats.

Animals—18 adult male Sprague-Dawley rats.

Procedures—Rats were assigned to a control group (n = 6 rats) and a treatment group (12). All rats were anesthetized, and instrumentation and bilateral renal pedicle ligation were performed. The treatment group was infused IV with sterile water throughout a 30-minute period. Acid-base variables and concentrations of electrolytes, lactate, albumin, phosphorus, and hemoglobin were measured before (baseline) and 30 and 60 minutes after onset of infusion. Anion gap, strong ion difference, strong ion gap, and contributions of sodium, chloride, albumin, phosphorus, and lactate concentrations to base excess were calculated at each time point.

Results—Infusion of sterile water led to an increase in ECF volume of approximately 18%. This had no effect on acid-base balance, compared with that in control rats. Infusion of sterile water caused a significant decrease in sodium, chloride, ionized calcium, lactate, and albumin concentrations, compared with concentrations in the control group. Anion gap and calculated effects of sodium, chloride, albumin, and lactate concentrations on base excess at 60 minutes differed significantly between infused and control rats.

Conclusions and Clinical Relevance—Infusion of sterile water did not cause clinically relevant dilutional acidosis. The acidotic impact of water administration was offset by generation of new bicarbonate via carbonic acid equilibration and intracellular buffering in combination with the alkalotic effects of decreases in albumin, phosphorus, and lactate concentrations.

Abstract

Objective—To describe the effects of increasing the extracellular fluid (ECF) volume by approximately 20% on acid-base changes and electrolyte concentrations in anesthetized rats.

Animals—18 adult male Sprague-Dawley rats.

Procedures—Rats were assigned to a control group (n = 6 rats) and a treatment group (12). All rats were anesthetized, and instrumentation and bilateral renal pedicle ligation were performed. The treatment group was infused IV with sterile water throughout a 30-minute period. Acid-base variables and concentrations of electrolytes, lactate, albumin, phosphorus, and hemoglobin were measured before (baseline) and 30 and 60 minutes after onset of infusion. Anion gap, strong ion difference, strong ion gap, and contributions of sodium, chloride, albumin, phosphorus, and lactate concentrations to base excess were calculated at each time point.

Results—Infusion of sterile water led to an increase in ECF volume of approximately 18%. This had no effect on acid-base balance, compared with that in control rats. Infusion of sterile water caused a significant decrease in sodium, chloride, ionized calcium, lactate, and albumin concentrations, compared with concentrations in the control group. Anion gap and calculated effects of sodium, chloride, albumin, and lactate concentrations on base excess at 60 minutes differed significantly between infused and control rats.

Conclusions and Clinical Relevance—Infusion of sterile water did not cause clinically relevant dilutional acidosis. The acidotic impact of water administration was offset by generation of new bicarbonate via carbonic acid equilibration and intracellular buffering in combination with the alkalotic effects of decreases in albumin, phosphorus, and lactate concentrations.

Contributor Notes

Supported by a grant (No. 03-04-F) from the Center for Companion Animal Health at the University of California-Davis.

Address correspondence to Dr. Hopper (khopper@ucdavis.edu).
Cover American Journal of Veterinary Research
American Journal of Veterinary Research
Publication Date:
01 Aug 2010
  • 1.

    Peters JPVan Slyke DD. Changes in the acid-base balance caused by drugs and hormones. In: gQuantitative clinical chemistry. Baltimore: The Williams & Wilkins Co, 1931;971–972.

    • Search Google Scholar
    • Export Citation
  • 2.

    Garella SChang BSKahn SI. Dilution acidosis and contraction alkalosis: review of a concept. Kidney Int 1975;8:279–283.

  • 3.

    Fencl VRossing TH. Acid-base disorders in critical care medicine. Annu Rev Med 1989;40:17–29.

  • 4.

    Haskins SCHopper KRezende ML. The acid-base impact of free water removal from, and addition to, plasma. J Lab Clin Med 2006;147:114–120.

  • 5.

    Rosenbaum BJMakoff DLMaxwell MH. Acid-base and electrolyte changes induced by acute isotonic saline infusion in the nephrectomized dog. J Lab Clin Med 1969;74:427–435.

    • Search Google Scholar
    • Export Citation
  • 6.

    Constable PD. Hyperchloremic acidosis: the classic example of strong ion acidosis. Anesth Analg 2003;96:919–922.

  • 7.

    Kellum JA. Determinants of plasma acid-base balance. Crit Care Clin 2005;21:329–346.

  • 8.

    Stewart PA. Modern quantitative acid base chemistry. Can J Physiol Pharmacol 1983;61:1444–1461.

  • 9.

    Siggaard Andersen O. The acid-base status of the blood. Scand J Clin Lab Invest 1963;15:1–134.

  • 10.

    Corey HE. Stewart and beyond: new models of acid-base balance. Kidney Int 2003;64:777–787.

  • 11.

    de Morais HSA. A nontraditional approach to acid base disorders. In: DiBartola SP, ed. Fluid therapy in small animal practice. Philadelphia: WB Saunders Co, 1992;297–320.

    • Search Google Scholar
    • Export Citation
  • 12.

    Fencl VLeith DE. Stewart's quantitative acid-base chemistry: applications in biology and medicine. Respir Physiol 1993;91:1–16.

  • 13.

    Masoro EJSiegel PD. Carbonic acid and the bicarbonate acid buffer system. In: gAcid-base regulation: its physiology, pathophysiology and the interpretation of blood-gas analysis. 2nd ed. Philadelphia: WB Saunders Co, 1977;41–61.

    • Search Google Scholar
    • Export Citation
  • 14.

    Rossing THMaffeo NFencl V. Acid-base effects of altering plasma protein concentration in human blood in vitro. J Appl Physiol 1986;61:2260–2265.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15.

    Story DAMorimatsu HBellomo R. Strong ions, weak acids and base excess: a simplified Fencl-Stewart approach to clinical acid-base disorders. Br J Anaesth 2005;92:54–60.

    • Search Google Scholar
    • Export Citation
  • 16.

    Rose DBPost TW. The total body water and the plasma sodium concentration. In: Clinical physiology of acid base and electrolyte disorders. 5th ed. New York: McGraw-Hill, 2001;241–257.

    • Search Google Scholar
    • Export Citation
  • 17.

    Thomas MARice HBWeinstock D, et al.Effect of aging on food intake and body composition in rats. Physiol Behav 2002;76:487–500.

  • 18.

    Kim do JPark SHSheen MR, et al.Comparison of experimental lung injury from acute renal failure with injury due to sepsis. Respiration 2006;73:815–824.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 19.

    Lumb AB. Changes in the carbon dioxide tension. In: Nunn's applied respiratory physiology. 6th ed. Philadelphia: Elsevier, 2005;460–470.

    • Search Google Scholar
    • Export Citation
  • 20.

    Rampton DSRamsay DJ. The effects of pentobarbitone anesthesia on the volume and composition of the extracellular fluid of dogs. J Physiol 1974;237:521–533.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 21.

    Asano SKato EYamauchi M, et al.The mechanism of the acidosis caused by infusion of saline solution. Lancet 1966;1:1245–1246.

  • 22.

    Bruegger DJacob MScheingraber S, et al.Changes in acid base balance following bolus infusion of 20% albumin solution in humans. Intensive Care Med 2005;31:1123–1127.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 23.

    Garella STzamaloukas AHChazan JA. Effect of isotonic volume expansion on extracellular bicarbonate stores in normal dogs. Am J Physiol 1973;225:628–636.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 24.

    Liskaser FJBellomo RHayhoe M, et al.Role of pump prime in the etiology and pathogenesis of cardiopulmonary bypass—associated acidosis. Anesthesiology 2000;93:1170–1173.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 25.

    Makoff DLDa Silva JARosenbaum BJ, et al.Hypertonic expansion: acid-base and electrolyte changes. Am J Physiol 1970;218:1201–1207.

  • 26.

    Mathes DDMorell RCRohr MS. Dilutional acidosis: is it a real clinical entity? Anesthesiology 1997;86:501–503.

  • 27.

    Rehm MOrth VScheingraber S, et al.Acid-base changes caused by 5% albumin versus 6% hydroxyethyl starch solution in patients undergoing acute normovolemic hemodilution. Anesthesiology 2000;93:1174–1183.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 28.

    Scheingraber SRehm MSehmisch C, et al.Rapid saline infusion produces hyperchloremic acidosis in patients undergoing gynecologic surgery. Anesthesiology 1999;90:1265–1270.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 29.

    Shires GTHolman J. Dilution acidosis. Ann Intern Med 1948;28:557–559.

  • 30.

    Skellett SMayer ADurward A, et al.Chasing the base deficit: hyperchloremic acidosis following 0.9% saline fluid resuscitation. Arch Dis Child 2000;83:514–516.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 31.

    Waters JHBernstein CA. Dilutional acidosis following hetastarch or albumin in healthy volunteers. Anesthesiology 2000;93:1184–1187.

  • 32.

    Waters JHGottlieb ASchoenwald P, et al.Normal saline versus lactated ringer's solution for intraoperative fluid management in patients undergoing abdominal aortic aneurysm repair: an outcome study. Anesth Analg 2001;93:817–822.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 33.

    Wilkes NJWoolf RMutch M, et al.The effects of balanced versus saline-based hetastarch and crystalloid solutions ion acid-base and electrolyte status and gastric mucosal perfusion in elderly surgical patients. Anesth Analg 2001;93:811–816.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 34.

    Watson PD. Modeling the effects of proteins on pH in plasma. J Appl Physiol 1999;86:1421–1427.

  • 35.

    Swan RCPitts RF. Neutralization of infused acid by nephrectomized dogs. J Clin Invest 1955;34:205–212.

  • 36.

    Singh MSandhir RKiran R. In vitro effects of organophosphate pesticides on rat erythrocytes. Indian J Exp Biol 2004;42:292–296.

  • 37.

    Kurtz IKraut JAOrnekian V, et al.Acid base analysis: a critique of the Stewart and bicarbonate centered approaches. Am J Physiol Renal Physiol 2008;294:F1009–F1031.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 38.

    Pankow JF. The proton balance, electroneutrality and mass balance equations. In: Aquatic chemistry concepts. Chelsea, Mich: Lewis Publishers, 1991;61–68.

    • Search Google Scholar
    • Export Citation
  • 39.

    Snoeyink VLJenkins D. Acid base chemistry. In: Water chemistry. New York: John Wiley & Sons, 1980;86–195.

  • 40.

    Corey HE. The anion gap (AG): studies in the nephrotic syndrome and diabetic ketoacidosis (DKA). J Lab Clin Med 2006;147:121–125.

  • 41.

    Morgan TJ. Clinical review: the meaning of acid-base abnormalities in the intensive care unit—effects of fluid administration. Crit Care 2005;9:204–211.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 42.

    Story DAMorimatsu HBellomo R. Hyperchloremic acidosis in the critically ill: one of the strong-ion acidosis? Anesth Analg 2006;103:144–148.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 43.

    Hamill-Ruth RJ. Dilutional acidosis: a matter of perspective. Crit Care Med 1999;27:2296–2297.

  • 44.

    Morgan TJVenkatesh BHall J. Crystalloid strong ion difference determines metabolic acid-base change during acute normovolemic haemodilution. Intensive Care Med 2004;30:1432–1437.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 45.

    Figge JRossing THFencl V. The role of serum proteins in acidbase equilibria. J Lab Clin Med 1991;117:453–467.

  • 46.

    Kellum JA. Determinants of blood pH in health and disease. Crit Care 2000;4:6–14.

  • 47.

    Moviat Mvan Haren Fvan der Hoeven H. Conventional or physiochemical approach to intensive care unit patients with metabolic acidosis. Crit Care 2003;7:R41–R45.

    • Search Google Scholar
    • Export Citation
  • 48.

    Kaplan LJKellum JA. Initial pH, base deficit, lactate, anion gap, strong ion difference, and strong ion gap predict outcome from major vascular injury. Crit Care Med 2004;32:1120–1124.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 49.

    Story DAPoustie SBellomo R. Estimating unmeasured anions in critically ill patients: anion-gap, base-deficit and strongiongap. Anaesthesia 2002;57:1109–1114.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 50.

    Fencl VJabor AKazda A, et al.Diagnosis of metabolic acidbase disturbances in critically ill patients. Am J Respir Crit Care Med 2000;162:2246–2251.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 51.

    Dubin AMenises MMMaseviscius FD, et al.Comparison of three different methods of evaluation of metabolic acid base disorders. Crit Care Med 2007;35:1264–1270.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 52.

    Wilkes P. Hypoproteinemia, strong-ion difference and acid-base status in critically ill patients. J Appl Physiol 1998;84:1740–1748.

  • 53.

    Fall PJSzerlip HM. Lactic acidosis: from sour milk to septic shock. Intensive Care Med 2005;20:255–271.

  • 54.

    Robergs RAGhiasvand FParker D. Biochemistry of exerciseinduced metabolic acidosis. Am J Physiol Regul Integr Comp Physiol 2004;287:R502–R516.

    • Crossref
    • Search Google Scholar
    • Export Citation

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