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Adrogué HJ, Tucker BM, Madias NE. Clinical Approach to Assessing Acid-Base Status: Physiological vs Stewart. Adv Chronic Kidney Dis 2022; 29:343-354. [PMID: 36175072 DOI: 10.1053/j.ackd.2022.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 04/12/2022] [Accepted: 04/25/2022] [Indexed: 01/25/2023]
Abstract
Evaluation of acid-base status depends on accurate measurement of acid-base variables and their appropriate assessment. Currently, 3 approaches are utilized for assessing acid-base variables. The physiological or traditional approach, pioneered by Henderson and Van Slyke in the early 1900s, considers acids as H+ donors and bases as H+ acceptors. The acid-base status is conceived as resulting from the interaction of net H+ balance with body buffers and relies on the H2CO3/HCO3- buffer pair for its assessment. A second approach, developed by Astrup and Siggaard-Andersen in the late 1950s, is known as the base excess approach. Base excess was introduced as a measure of the metabolic component replacing plasma [HCO3-]. In the late 1970s, Stewart proposed a third approach that bears his name and is also referred to as the physicochemical approach. It postulates that the [H+] of body fluids reflects changes in the dissociation of water induced by the interplay of 3 independent variables-strong ion difference, total concentration of weak acids, and PCO2. Here we focus on the physiological approach and Stewart's approach examining their conceptual framework, practical application, as well as attributes and drawbacks. We conclude with our view about the optimal approach to assessing acid-base status.
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Affiliation(s)
- Horacio J Adrogué
- Department of Medicine, Section of Nephrology, Baylor College of Medicine, Houston, TX; Department of Medicine, Division of Nephrology, Houston Methodist Hospital, Houston, TX
| | - Bryan M Tucker
- Department of Medicine, Section of Nephrology, Baylor College of Medicine, Houston, TX; Department of Medicine, Division of Nephrology, Houston Methodist Hospital, Houston, TX
| | - Nicolaos E Madias
- Department of Medicine, Tufts University School of Medicine, Boston, MA; Department of Medicine, Division of Nephrology, St Elizabeth's Medical Center, Boston, MA.
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Adrogué HJ, Madias NE. Alkali Therapy for Respiratory Acidosis: A Medical Controversy. Am J Kidney Dis 2020; 75:265-271. [DOI: 10.1053/j.ajkd.2019.05.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/27/2019] [Indexed: 12/22/2022]
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González SB, Menga G, Raimondi GA, Tighiouart H, Adrogué HJ, Madias NE. Secondary Response to Chronic Respiratory Acidosis in Humans: A Prospective Study. Kidney Int Rep 2018; 3:1163-1170. [PMID: 30197983 PMCID: PMC6127438 DOI: 10.1016/j.ekir.2018.06.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 05/14/2018] [Accepted: 06/01/2018] [Indexed: 02/07/2023] Open
Abstract
Introduction The magnitude of the secondary response to chronic respiratory acidosis, that is, change in plasma bicarbonate concentration ([HCO3−]) per mm Hg change in arterial carbon dioxide tension (PaCO2), remains uncertain. Retrospective observations yielded Δ[HCO3−]/ΔPaCO2 slopes of 0.35 to 0.51 mEq/l per mm Hg, but all studies have methodologic flaws. Methods We studied prospectively 28 stable outpatients with steady-state chronic hypercapnia. Patients did not have other disorders and were not taking medications that could affect acid−base status. We obtained 2 measurements of arterial blood gases and plasma chemistries within a 10-day period. Results Steady-state PaCO2 ranged from 44.2 to 68.8 mm Hg. For the entire cohort, mean (± SD) steady-state plasma acid−base values were as follows: PaCO2, 52.8 ± 6.0 mm Hg; [HCO3−], 29.9 ± 3.0 mEq/l, and pH, 7.37 ± 0.02. Least-squares regression for steady-state [HCO3−] versus PaCO2 had a slope of 0.476 mEq/l per mm Hg (95% CI = 0.414–0.538, P < 0.01; r = 0.95) and that for steady-state pH versus PaCO2 had a slope of −0.0012 units per mm Hg (95% CI = −0.0021 to −0.0003, P = 0.01; r = −0.47). These data allowed estimation of the 95% prediction intervals for plasma [HCO3−] and pH at different levels of PaCO2 applicable to patients with steady-state chronic hypercapnia. Conclusion In steady-state chronic hypercapnia up to 70 mm Hg, the Δ[HCO3−]/ΔPaCO2 slope equaled 0.48 mEq/l per mm Hg, sufficient to maintain systemic acidity between the mid-normal range and mild acidemia. The estimated 95% prediction intervals enable differentiation between simple chronic respiratory acidosis and hypercapnia coexisting with additional acid−base disorders.
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Affiliation(s)
- Silvia B González
- Department of Pulmonology and Clinical Laboratory, Hospital María Ferrer, Buenos Aires, Argentina
| | - Guillermo Menga
- Department of Pulmonology and Clinical Laboratory, Hospital María Ferrer, Buenos Aires, Argentina
| | - Guillermo A Raimondi
- Department of Pulmonology, Instituto de Investigaciones Neurológicas Raúl Carrea (FLENI), Buenos Aires, Argentina
| | - Hocine Tighiouart
- Institute for Clinical Research and Health Policy Studies, Tufts Medical Center, Boston, Massachusetts, USA.,Tufts Clinical and Translational Science Institute, Tufts University, Boston, Massachusetts, USA
| | - Horacio J Adrogué
- Department of Medicine, Baylor College of Medicine, Houston, Texas, USA.,Department of Medicine, Houston Methodist Hospital, Harris Health, Houston, Texas, USA.,Renal Section, Veterans Affairs Medical Center, Houston, Texas, USA
| | - Nicolaos E Madias
- Department of Medicine, Tufts University School of Medicine, Boston, Massachusetts, USA.,Department of Medicine, Division of Nephrology, St. Elizabeth's Medical Center, Boston, Massachusetts, USA
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Adrogué HJ, Madias NE. Assessing Acid-Base Status: Physiologic Versus Physicochemical Approach. Am J Kidney Dis 2016; 68:793-802. [PMID: 27590096 DOI: 10.1053/j.ajkd.2016.04.023] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 04/08/2016] [Indexed: 11/11/2022]
Abstract
The physiologic approach has long been used in assessing acid-base status. This approach considers acids as hydrogen ion donors and bases as hydrogen ion acceptors and the acid-base status of the organism as reflecting the interaction of net hydrogen ion balance with body buffers. In the physiologic approach, the carbonic acid/bicarbonate buffer pair is used for assessing acid-base status and blood pH is determined by carbonic acid (ie, Paco2) and serum bicarbonate levels. More recently, the physicochemical approach was introduced, which has gained popularity, particularly among intensivists and anesthesiologists. This approach posits that the acid-base status of body fluids is determined by changes in the dissociation of water that are driven by the interplay of 3 independent variables: the sum of strong (fully dissociated) cation concentrations minus the sum of strong anion concentrations (strong ion difference); the total concentration of weak acids; and Paco2. These 3 independent variables mechanistically determine both hydrogen ion concentration and bicarbonate concentration of body fluids, which are considered as dependent variables. Our experience indicates that the average practitioner is familiar with only one of these approaches and knows very little, if any, about the other approach. In the present Acid-Base and Electrolyte Teaching Case, we attempt to bridge this knowledge gap by contrasting the physiologic and physicochemical approaches to assessing acid-base status. We first outline the essential features, advantages, and limitations of each of the 2 approaches and then apply each approach to the same patient presentation. We conclude with our view about the optimal approach.
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Affiliation(s)
- Horacio J Adrogué
- Department of Medicine, Baylor College of Medicine, Houston, TX; Department of Medicine, Methodist Hospital, Houston, TX; Renal Section, Veterans Affairs Medical Center, Houston, TX
| | - Nicolaos E Madias
- Department of Medicine, Tufts University School of Medicine, Boston, MA; Division of Nephrology, Department of Medicine, St. Elizabeth's Medical Center, Boston, MA.
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5
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Abstract
Metabolic alkalosis is a common acid-base disturbance in critically ill patients. In this review we discuss the approach to diagnosis and management of this disorder; particular emphasis is given to the causes most com monly responsible for alkalosis in critical care medicine. We present rules for (1) identifying the presence of metabolic alkalosis, ( 2 ) determining whether the disor der is simple or complicated by a second acid-base dis turbance, and (3) determining the cause: The causes are subdivided into three major groups: Chloride-respon sive, chloride-resistant, and alkali administration. The pathogenesis of each type of alkalosis is discussed sep arately, although we stress that more than one cause may be responsible in critically ill patients. The patho logical consequences of metabolic alkalosis and ap proaches to treatment are reviewed. The major issues relating to the critically ill patient are (1) identification and removal of exogenous sources of alkali, (2) iden tification and minimization of HCl losses or selective NaCl losses, and (3) maneuvers to reduce serum HCO 3 concentration without producing extracellular fluid volume overload.
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Affiliation(s)
- Jeffrey M. Rimmer
- Department of Medicine, University of Vermont Col lege of Medicine, Burlington, VT
| | - F. John Gennari
- Department of Medicine, University of Vermont Col lege of Medicine, Burlington, VT
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6
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Schiavo A, Renis M, Polverino M, Iannuzzi A, Polverino F. Acid-base balance, serum electrolytes and need for non-invasive ventilation in patients with hypercapnic acute exacerbation of chronic obstructive pulmonary disease admitted to an internal medicine ward. Multidiscip Respir Med 2016; 11:23. [PMID: 27226896 PMCID: PMC4879756 DOI: 10.1186/s40248-016-0063-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 04/29/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hypoventilation produces or worsens respiratory acidosis in patients with hypercapnia due to acute exacerbations of chronic obstructive pulmonary disease (AECOPD). In these patients acid-base and hydroelectrolite balance are closely related. Aim of the present study was to evaluate acid-base and hydroelectrolite alterations in these subjects and the effect of non-invasive ventilation and pharmacological treatment. METHODS We retrospectively analysed 110 patients consecutively admitted to the Internal Medicine ward of Cava de' Tirreni Hospital for acute exacerbation of hypercapnic chronic obstructive pulmonary disease. On admission all patients received oxygen with a Venturi mask to maintain arterial oxygen saturation at least >90 %, and received appropriate pharmacological treatment. Non-Invasive Ventilation (NIV) was started when, despite optimal therapy, patients had severe dyspnea, increased work of breathing and respiratory acidosis. Based on Arterial Blood Gas (ABG) data, we divided the 110 patients in 3 groups: A = 51 patients with compensated respiratory acidosis; B = 36 patients with respiratory acidosis + metabolic alkalosis; and C = 23 patients with respiratory acidosis + metabolic acidosis. 55 patients received only conventional therapy and 55 had conventional therapy plus NIV. RESULTS The use of NIV support was lower in the patients belonging to group B than in those belonging to group A and C (25 %, vs 47 % and 96 % respectively; p < 0.01). A statistically significant association was found between pCO2 values and serum chloride concentrations both in the entire cohort and in the three separate groups. CONCLUSIONS Our study shows that in hypercapnic respiratory acidosis due to AECOPD, differently from previous studies, the metabolic alkalosis is not a negative prognostic factor neither determines greater NIV support need, whereas the metabolic acidosis in addition to respiratory acidosis is an unfavourable element, since it determines an increased need of NIV and invasive mechanical ventilation support.
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Affiliation(s)
- Alfonso Schiavo
- Division of Internal Medicine, Cava de' Tirreni Hospital, University of Salerno, Cava de' Tirreni, SA, Italy
| | - Maurizio Renis
- Division of Internal Medicine, Cava de' Tirreni Hospital, University of Salerno, Cava de' Tirreni, SA, Italy
| | - Mario Polverino
- Division of Pulmonary Medicine, Scafati Hospital, Salerno, Italy
| | | | - Francesca Polverino
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA USA
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Abstract
The concept of homeostasis has been inextricably linked to the function of the kidneys for more than a century when it was recognized that the kidneys had the ability to maintain the "internal milieu" and allow organisms the "physiologic freedom" to move into varying environments and take in varying diets and fluids. Early ingenious, albeit rudimentary, experiments unlocked a wealth of secrets on the mechanisms involved in the formation of urine and renal handling of the gamut of electrolytes, as well as that of water, acid, and protein. Recent scientific advances have confirmed these prescient postulates such that the modern clinician is the beneficiary of a rich understanding of the nephron and the kidney's critical role in homeostasis down to the molecular level. This review summarizes those early achievements and provides a framework and introduction for the new CJASN series on renal physiology.
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Affiliation(s)
- Melanie P Hoenig
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Mark L Zeidel
- Division of Nephrology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
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Wang Z, Fang M, Yu H, Wei CC, Luo Z. Experimental and Modeling Study of Trace CO2 Removal in a Hollow-Fiber Membrane Contactor, Using CO2-Loaded Monoethanolamine. Ind Eng Chem Res 2013. [DOI: 10.1021/ie402264k] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Zhen Wang
- State
Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, People’s Republic of China
- CSIRO Energy Centre, Mayfield West, 2304, Australia
| | - Mengxiang Fang
- State
Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, People’s Republic of China
| | - Hai Yu
- CSIRO Energy Centre, Mayfield West, 2304, Australia
| | | | - Zhongyang Luo
- State
Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, People’s Republic of China
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9
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Lee JM, Kim C, Kim YJ, Shin SH, Lee J, Sohn JA, Sohn SH, Choi GY, Lee JA, Park HW, Choi CW, Kim EK, Kim HS, Kim BI, Choi JH. The Time When the Metabolic Compensation for Hypercapnia Begin to Occur in Very Low Birth Weight Infants. NEONATAL MEDICINE 2013. [DOI: 10.5385/nm.2013.20.1.42] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Affiliation(s)
- Jae Myoung Lee
- Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Curie Kim
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Yoon Ju Kim
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Seung Han Shin
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Juyoung Lee
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Jin A Sohn
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Se Hyung Sohn
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Ga Young Choi
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Jin A Lee
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Hye Won Park
- Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Chang Won Choi
- Department of Pediatrics, Seoul National University Bundang Hospital, Seongnam, Korea
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Ee-Kyung Kim
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Han-Suk Kim
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Beyong Il Kim
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
| | - Jung-Hwan Choi
- Department of Pediatrics, Seoul National University Medical College, Seoul, Korea
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10
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Aronson PS, Giebisch G. Effects of pH on potassium: new explanations for old observations. J Am Soc Nephrol 2011. [PMID: 21980112 DOI: 10.1681/asn.20111040414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Maintenance of extracellular K(+) concentration within a narrow range is vital for numerous cell functions, particularly electrical excitability of heart and muscle. Potassium homeostasis during intermittent ingestion of K(+) involves rapid redistribution of K(+) into the intracellular space to minimize increases in extracellular K(+) concentration, and ultimate elimination of the K(+) load by renal excretion. Recent years have seen great progress in identifying the transporters and channels involved in renal and extrarenal K(+) homeostasis. Here we apply these advances in molecular physiology to understand how acid-base disturbances affect serum potassium.
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Affiliation(s)
- Peter S Aronson
- Section of Nephrology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8029, USA.
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11
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Aronson PS, Giebisch G. Effects of pH on potassium: new explanations for old observations. J Am Soc Nephrol 2011; 22:1981-9. [PMID: 21980112 DOI: 10.1681/asn.2011040414] [Citation(s) in RCA: 135] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Maintenance of extracellular K(+) concentration within a narrow range is vital for numerous cell functions, particularly electrical excitability of heart and muscle. Potassium homeostasis during intermittent ingestion of K(+) involves rapid redistribution of K(+) into the intracellular space to minimize increases in extracellular K(+) concentration, and ultimate elimination of the K(+) load by renal excretion. Recent years have seen great progress in identifying the transporters and channels involved in renal and extrarenal K(+) homeostasis. Here we apply these advances in molecular physiology to understand how acid-base disturbances affect serum potassium.
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Affiliation(s)
- Peter S Aronson
- Section of Nephrology, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8029, USA.
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12
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Severinghaus JW. Siggaard-Andersen and the “Great Trans-Atlantic Acid-Base Debate”. Scandinavian Journal of Clinical and Laboratory Investigation 2011. [DOI: 10.1080/00365519309090685] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Adrogué HJ, Madias NE. Secondary responses to altered acid-base status: the rules of engagement. J Am Soc Nephrol 2010; 21:920-3. [PMID: 20431042 DOI: 10.1681/asn.2009121211] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Each of the four canonical acid-base disorders expresses as a primary change in carbon dioxide tension or plasma bicarbonate concentration followed by a secondary response in the countervailing variable. Quantified empirically, these secondary responses are directional and proportional to the primary changes, run a variable time course, and tend to minimize the impact on body acidity engendered by the primary changes. Absence of an appropriate secondary response denotes the coexistence of an additional acid-base disorder. Here we address the expected magnitude of the secondary response to each cardinal acid-base disorder in humans and offer caveats for judging the appropriateness of each secondary response.
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Affiliation(s)
- Horacio J Adrogué
- Department of Medicine, Baylor College of Medicine, Houston, Texas, USA
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15
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Crosby A, Talbot NP, Balanos GM, Donoghue S, Fatemian M, Robbins PA. Respiratory effects in humans of a 5-day elevation of end-tidal PCO2 by 8 Torr. J Appl Physiol (1985) 2003; 95:1947-54. [PMID: 14555667 DOI: 10.1152/japplphysiol.00548.2003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aims of this study were to determine 1) whether ventilatory adaptation occurred over a 5-day exposure to a constant elevation in end-tidal Pco2 and 2) whether such an exposure altered the sensitivity of the chemoreflexes to acute hypoxia and hypercapnia. Ten healthy human subjects were studied over a period of 13 days. Their ventilation, chemoreflex sensitivities, and acid-base status were measured daily before, during, and after 5 days of elevated end-tidal Pco2 at 8 Torr above normal. There was no major adaptation of ventilation during the 5 days of hypercapnic exposure. There was an increase in ventilatory chemosensitivity to acute hypoxia (from 1.35 ± 0.08 to 1.70 ± 0.07 l/min/%; P < 0.01) but no change in ventilatory chemosensitivity to acute hypercapnia. There was a degree of compensatory metabolic alkalosis. The results do not support the hypothesis that the ventilatory adaptation to chronic hypercapnia would be much greater with constant elevation of alveolar Pco2 than with constant elevation of inspired Pco2, as has been used in previous studies and in which the feedback loop between ventilation and alveolar Pco2 is left intact.
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Affiliation(s)
- Alexi Crosby
- University Laboratory of Physiology, University of Oxford, Oxford OX1 3PT, United Kingdom
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Bégin P, Grassino A. Chronic alveolar hypoventilation helps to maintain the inspiratory muscle effort of COPD patients within sustainable limits. Chest 2000; 117:271S-3S. [PMID: 10843947 DOI: 10.1378/chest.117.5_suppl_1.271s] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Affiliation(s)
- P Bégin
- Complexe hospitalier de la Sagamie, Quebec, PQ, Canada
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Schlichtig R, Grogono AW, Severinghaus JW. Human PaCO2 and standard base excess compensation for acid-base imbalance. Crit Care Med 1998; 26:1173-9. [PMID: 9671365 DOI: 10.1097/00003246-199807000-00015] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Renal and respiratory acid-base regulation systems interact with each other, one compensating (partially) for a primary defect of the other. Most investigators striving to typify compensations for abnormal acid-base balance have reported their findings in terms of arterial pH, PaCO2, and/or HCO3-. However, pH and HCO3- are both altered by both respiratory and metabolic changes. We sought to simplify these relations by expressing them in terms of standard base excess (SBE in mM), which quantifies the metabolic balance and is independent of PaCO2. DESIGN Meta-analysis. SETTING Historical synthesis developed via the Internet. PATIENTS Arterial pH, PaCO2, and/or HCO3- data sets were obtained from 21 published reports of patients considered to have purely acute or chronic metabolic or respiratory acid-base problems. INTERVENTIONS We used the same data to compute the typical compensatory responses to imbalances of SBE and PaCO2. Relations were expressed as difference (delta) from normal values for PaCO2 (40 torr [5.3 kPa]) and SBE (0 mM). MEASUREMENTS AND MAIN RESULTS The data of patient compensatory changes conformed to the following equations, as well as to the traditional PaCO2 vs. HCO3- or H+ vs. PaCO2 equations: Metabolic change responding to change in PaCO2: Acute deltaSBE = 0 x deltaPaCO2, hence: SBE = 0, Chronic deltaSBE = 0.4 x deltaPaCO2. Respiratory change responding to change in SBE: Acidosis deltaPaCO2 = 1.0 x deltaSBE, Alkalosis deltaPaCO2 = 0.6 x deltaSBE. CONCLUSION Data reported by many investigators over the past 35 yrs on typical, expected, or "normal" human compensation for acid-base imbalance may be expressed in terms of the independent variables: PaCO2 (respiratory) and SBE (metabolic).
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Affiliation(s)
- R Schlichtig
- Department of Research and Development, Pittsburgh Veterans Affairs Medical Center, PA, USA
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18
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Abstract
This article discusses flow diagrams and tables intended to provide a systematic approach to the rapid laboratory differential diagnosis of acid-base disorders in the emergency department.
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Affiliation(s)
- M Fulop
- Department of Medicine, Albert Einstein College of Medicine and Jacobi Medical Center, Bronx, New York, USA
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19
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Abstract
The practice of internal medicine involves daily exposure to abnormalities of acid-base balance. A wide variety of disease states either predispose patients to develop these conditions or lead to the use of medications that alter renal, gastrointestinal, or pulmonary function and secondarily alter acid-base balance. In addition, primary acid-base disease follows specific forms of renal tubular dysfunction (renal tubular acidosis). We review the acid-base physiologic functions of the kidney and gastrointestinal tract and the current understanding of acid-base pathophysiologic conditions. This includes a review of whole animal and renal tubular physiologic characteristics and a discussion of the current knowledge of the molecular biology of acid-base transport. We stress an approach to diagnosis that relies on knowledge of acid-base physiologic function, and we include discussion of the appropriate treatment of each disorder considered. Finally, we include a discussion of the effects of acidosis and alkalosis on human physiologic functions.
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Affiliation(s)
- M E Laski
- Texas Tech University Health Sciences Center, Section of General Internal Medicine, Lubbock, USA
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21
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Levesque PR. Acid-base balance controversy. Total-body carbon dioxide titration. J Clin Monit Comput 1991; 7:277-9. [PMID: 1890453 DOI: 10.1007/bf01619276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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22
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Krapf R, Beeler I, Hertner D, Hulter HN. Chronic respiratory alkalosis. The effect of sustained hyperventilation on renal regulation of acid-base equilibrium. N Engl J Med 1991; 324:1394-401. [PMID: 1902283 DOI: 10.1056/nejm199105163242003] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND In normal subjects, chronic hyperventilation lowers plasma bicarbonate concentration, primarily by inhibiting the urinary excretion of net acid. The quantitative relation between reduced arterial carbon dioxide tension (PaCO2) and the plasma bicarbonate concentration in the chronic steady state has not been studied in humans, however, and the laboratory criteria for the diagnosis of chronic respiratory alkalosis therefore remain undefined. We wished to provide such reference data for clinical use. Moreover, because chronic hyperventilation paradoxically lowers blood pH still further in dogs with metabolic acidosis, we desired to study the effect of chronic hypocapnia on the plasma bicarbonate concentration (and blood pH) in normal human subjects in whom acidosis had been induced with ammonium chloride. METHODS Under metabolic-balance conditions, we used altitude-induced hypobaric hypoxia to produce chronic hypocapnia in nine normal young men, five of whom received ammonium chloride daily to cause metabolic acidosis (the mean [+/- SE] steady-state plasma bicarbonate level in these five was 12.0 +/- 0.5 mmol per liter). RESULTS For each decrease of 1 mm Hg (0.13 kPa) in the PaCO2, the plasma bicarbonate concentration decreased by 0.41 mmol per liter in the subjects who started with a normal plasma bicarbonate concentration and by 0.42 mmol per liter in the subjects with acidosis. In contrast to the findings in previous studies of dogs, hypocapnia increased blood pH similarly in both groups; the blood hydrogen ion concentration decreased by about 0.4 nmol per liter for every decrease of 1 mm Hg (0.13 kPa) in PaCO2. CONCLUSIONS These results provide reference data for the diagnosis of chronic respiratory alkalosis in humans. Although chronic hypocapnia decreased plasma bicarbonate levels similarly in normal subjects with acidosis and without acidosis, the percent reduction in PaCO2 was always greater than the corresponding percent reduction in the plasma bicarbonate concentration. Therefore, as was not true of the response in dogs, the subjects' blood pH always increased with hyperventilation, regardless of the initial plasma bicarbonate concentration.
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Affiliation(s)
- R Krapf
- Department of Medicine, Insel University Hospital, Berne, Switzerland
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Lee SM. Clinical indices to predict simple and mixed acid-base disturbances. Med Hypotheses 1989; 30:211-5. [PMID: 2689850 DOI: 10.1016/0306-9877(89)90063-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We propose that in any acid-base disturbance there is a predictable mathematical relationship between the changes in the individual serum anionic concentrations of chloride, bicarbonate and the unmeasured anion gap. Two indices were developed, from the ratios of the changes in these anionic concentrations, that are useful in predicting the presence of an acid-base disturbance. Based on recent experimental evidence we determined the mathematical values of these 2 indices, alpha and beta, in 17 acid-base disturbances. By utilizing the paired values of these indices, the 17 disturbances including simple, metabolic plus respiratory and triple disorders were subcategorized into 7 groups. It is suggested that the use of these indices will facilitate the diagnosis of complicated mixed acid-base disorders.
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Javaheri S, Kazemi H. Metabolic alkalosis and hypoventilation in humans. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1987; 136:1011-6. [PMID: 3116894 DOI: 10.1164/ajrccm/136.4.1011] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- S Javaheri
- Pulmonary Division, Veterans Administration Medical Center, Cincinnati, OH 45220
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25
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Skaredoff MN. A computerized system for rapid interpretation of acid/base disorders. INTERNATIONAL JOURNAL OF BIO-MEDICAL COMPUTING 1986; 18:229-38. [PMID: 3087888 DOI: 10.1016/0020-7101(86)90019-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Rapid and correct interpretation of arterial blood gas results is necessary in the operating room or intensive care unit. However, manual calculation and interpretation is tedious and prone to error. A computer system consisting of two programs written in BASIC has been created to address these problems. The program uses a series of decisions to arrive at a conclusion. Data generated by the Interpreter may be used by a subsequent program, the Manager, in determining ventilation parameters.
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Schreck DM, Zacharias D, Grunau CF. Diagnosis of complex acid-base disorders: physician performance versus the microcomputer. Ann Emerg Med 1986; 15:164-70. [PMID: 3511785 DOI: 10.1016/s0196-0644(86)80013-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Patients with acid-base disturbances that are often complex frequently present to the emergency department. The sometimes hectic nature of the ED can preclude the appropriate quantitative analysis required by these disorders, especially when mixed disturbances are present. A computer program using generally accepted acid-base and electrolyte formulae was developed for use on the Apple II+ or IBM-PC microcomputer. Each of a series of 35 acid-base disturbances incorporating single, double, and triple disorders was correctly identified by the computer in less than 45 seconds. Problem sets based on the same 35 disturbances were presented to 21 physician-subjects at various levels of training from the emergency medicine, internal medicine, pediatrics, surgery, and family practice specialties. Although the physicians were given unlimited time and the necessary formulae to reach a diagnosis, they were requested to perform their analyses in the same fashion used in the ED. Although times varied widely, no physician spent more than five minutes on any problem. The physician correct response rates were 86%, 49%, and 17% for single, double, and triple disorders, respectively. The primary disorder correct response rate was 89% for double disorders and 94% for triple disorders. The primary and secondary disorder correct response rate was 58% for triple disorders. The data suggest that the microcomputer may be beneficial in the rapid assessment of complex disorders.
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Severinghaus JW, Astrup PB. History of blood gas analysis. II. pH and acid-base balance measurements. J Clin Monit Comput 1985; 1:259-77. [PMID: 3913750 DOI: 10.1007/bf02832819] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Electrometric measurement of the hydrogen ion concentration was discovered by Wilhelm Ostwald in Leipzig about 1890 and described thermodynamically by his student Walther Nernst, using the van't Hoff concept of osmotic pressure as a kind of gas pressure, and the Arrhenius concept of ionization of acids, both of which had been formalized in 1887. Hasselbalch, after adapting the pH nomenclature of Sørensen to the carbonic-acid mass equation of Henderson, made the first actual blood pH measurements (with a hydrogen electrode) and proposed that metabolic acid-base imbalance be quantified as the "reduced" pH of blood after equilibration to a carbon dioxide tension (PCO2) of 40 mm Hg. This good idea, coming 40 years before simple blood pH measurements at 37 degrees C became widely available, was never adopted. Instead, Van Slyke developed a concept of acid-base chemistry that depended on measuring plasma CO2 content with his manometric apparatus, a standard method until the 1960s, when it was displaced by the three-electrode method of blood gas analysis. The 1952 polio epidemic in Copenhagen stimulated Astrup to develop a glass electrode in which pH could be measured in blood at 37 degrees C before and after equilibration with known PCO2. He introduced the interpolative measurement of PCO2 and bicarbonate level (later base excess) using only pH measurements and, with Siggaard-Andersen, developed clinical acid-base chemistry. Controversy arose when blood base excess was noted to be altered by acute changes in PCO2 and when abnormalities of base excess were called metabolic acidosis or alkalosis, even when they represented compensation for respiratory abnormalities in PCO2. In the 1970s it became clear that "in-vivo" or "extracellular fluid" base excess (measured at an average extracellular fluid hemoglobin concentration of 5 g) eliminated the error caused by acute changes in PCO2. Base excess is now almost universally used as the index of nonrespiratory acid-base imbalance.
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Bar-Ilan A, Marder J. The effects of the inhibition of the renal carbonic anhydrase on the blood acid-base status in hypercapnic rats. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. A, COMPARATIVE PHYSIOLOGY 1985; 81:121-6. [PMID: 2859945 DOI: 10.1016/0300-9629(85)90277-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Arterial blood acid-base status was measured in unanesthetized rats treated with benzolamide (a selective renal carbonic anhydrase inhibitor). These measurements were carried out in rats exposed to different levels of CO2 in air (0-10% CO2) for periods of up to 6 hr. In untreated rats the whole body buffer value showed a continuous increase and after 6 hr of exposure to hypercapnia its value was twice that measured initially. On the other hand, the whole body buffer value of benzolamide treated rats did not change during the 6 hr of exposure to hypercapnia. The whole body buffer value of normal rats, measured after 6 hr of hypercapnia is similar to that reported for chronic (3-5 days) hypercapnia in the normal dog. The whole body buffer value in benzolamide treated rats was similar to that reported for the normal dog and man, during acute CO2 exposures. It is suggested that mechanisms involving the renal carbonic anhydrase are responsible for the significant, rapid changes in the whole body buffer value that take place during the initial phase of acute exposure to CO2 in the rat. This may represent a mechanism of adaptation to burrow hypercapnic conditions.
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Bernauer J, Bender HJ, Hartung HJ, Osswald PM. Graphic presentation of blood gas data. INTERNATIONAL JOURNAL OF CLINICAL MONITORING AND COMPUTING 1984; 1:93-5. [PMID: 6549597 DOI: 10.1007/bf01872747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Marieb NJ. Metabolie Care of the Head and Neck Surgical Patient. Otolaryngol Clin North Am 1981. [DOI: 10.1016/s0030-6665(20)32264-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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LASKER NORMAN. Blood Gases, pH, and Acid–Base Balance. Clin Biochem 1981. [DOI: 10.1016/b978-0-12-657101-1.50011-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
Both respiratory acidosis and respiratory alkalosis are most likely to occur in combination with some metabolic acid-base disturbance, particularly in the hospitalized patient. After a review of the pulmonary and renal cellular events involved in these complex electrolyte imbalances, principles of diagnosis and treatment are illustrated by means of clinically representative cases.
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Gabel RA. Algorithms for calculating and correcting blood-gas and acid-base variables. RESPIRATION PHYSIOLOGY 1980; 42:211-32. [PMID: 6784207 DOI: 10.1016/0034-5687(80)90116-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
This is a review of the origins, derivations, and 'fidelity' of available equations for correcting PO2, PCO2, and pH for temperature, and for estimating blood-gas and acid-base variables from measured values: 1. Oxygen saturation (SO2) from PO2, PCO2, pH, and body temperature (T). 2. Oxygen concentration (CO2) from SO2, PO2, and hemoglobin concentration (Hb). 3. Base excess (BE) from pH, PCO2, and Hb. 4. 'In vivo BE' (BE3) from pH and PCO2. 5. 'Compensated BE3' (BEC) from PCO2. 6. Bicarbonate ([HCO3-]) and carbon dioxide concentrations (CCO2) from pH and PCO2. PHysiologic considerations are emphasized, with mathematical background when it contributes to understanding. Algorithms are variously compared with their graphic counterparts, with the data from which they were derived, and with each other.
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Madias NE, Adrogué HJ, Horowitz GL, Cohen JJ, Schwartz WB. A redefinition of normal acid-base equilibrium in man: carbon dioxide tension as a key determinant of normal plasma bicarbonate concentration. Kidney Int 1979; 16:612-8. [PMID: 44886 DOI: 10.1038/ki.1979.171] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
It has been shown recently that normal acid-base equilibrium in the dog is characterized by a strong positive correlation between plasma bicarbonate concentration and PCO2. The present study was undertaken to examine the possibility that a similar relationship between normal levels of PCO2 and plasma bicarbonate might be present in man. The results indicate that values for bicarbonate within the normal range are highly dependent upon the prevailing level of PCO2 ([HCO3-] = 0.36 PaVCO2 + 10.4; r = 0.73). Thus, approximately 50% of the normal variance in bicarbonate concentration is explained simply by the variance in PCO2. The joint confidence region for bicarbonate concentration and PCO2, that can be derived from these data provides a new and more rigorous definition of normal acid-base equilibrium in man.
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Abstract
Patients with respiratory failure should be approached in a systematic way, with emphasis both in diagnosis and treatment on arterial blood gases. The intelligent assessment of oxygenation, ventilation and acid-base balance, based on physiologic principles, can make the management of these patients very rewarding. The physiologic principles outlined here should be well understood by anyone entrusted with the care of these patients. They provide the cornerstone of diagnosis and management, and will remain valid long after current clinical dogma has been revised.
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Worthley LI. A diagram to facilitate the understanding and therapy of mixed acid base disorders. Anaesth Intensive Care 1976; 4:245-53. [PMID: 9841 DOI: 10.1177/0310057x7600400313] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A diagram based on in-vivo relationships between arterial hydrogen ion activity (H+) and carbon dioxide tension (PCO2) in primary abnormalities of acid base homeostasis is presented. It is designed to facilitate the interpretation of pH data by including the 95% confidence limits described in patients with simple metabolic and respiratory acid base disorders. These bands have been formulated from observation of simple acid base abnormalities and indicate the appropriate respiratory or renal compensatory response to the primary pH defect. A plot which falls outside these limits therefore indicates the presence of a mixed acid base disorder. The diagram presents a physiological approach to clinical disorders of pH regulation demonstrating maintenance of intra-cellular fluid homeostasis during primary extracellular fluid disturbances. Diagnostic and therapeutic advantages are further illustrated and discussed in six case reports.
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Abstract
The use of the Henderson-Hasselbalch equation and the relationships between bicarbonate levels and the pCO2 or carbonic acid concentration in evaluating acid-base abnormalities are explained. The etiology, pathophysiology, diagnosis and treatment of respiratory alkalosis and acidosis and metabolic alkalosis and acidosis are discussed. The results of laboratory tests should be examined in relation to the patient's condition and consistency with other laboratory tests. Therapy is directed at correcting the underlying problems and, secondarily, at correcting the numbers. Patients respond primarily to rate of change and not absolute numbers. Therefore, problems should be corrected at approximately the rate they develop. Treatment should be guided by continued patient observation and serial laboratory studies.
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Greenham LW, Peacock DB. Letter: Geographical distribution of multiple sclerosis. Lancet 1975; 1:106. [PMID: 45996 DOI: 10.1016/s0140-6736(75)91114-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Honda Y, Miyamura M, Nakano E. Serial observations of arterial and mixed-venous blood gases after step change in ventilation. Pflugers Arch 1975; 353:123-38. [PMID: 1167666 DOI: 10.1007/bf00599873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
In 22 dogs, subjected to a step change in ventilation, serial changes in blood gas composition and lactate and pyruvate concentrations of arterial as well as mixed venous blood were studied. The change of PaCO2 was approximately 20 mm Hg both in hypo- and hyperventilation. During hypoventilation the difference in various forms of CO2 between arterial and mixed venous blood showed first a downward shift and then gradually increased, whereas during hyperventilation they progressively increased and reached a constant level within 10-20 min. This difference was assumed to be mainly due to more efficient CO2 elimination through lung ventilation in hyperventilation as compared with CO2 accumulation from tissue metabolism in hypoventilation. In vivo buffer slopes for CO2 during hypoventilation were about half those in vitro, whereas during hyperventilation both slopes were approximately the same. In vivo arterial buffer slope was higher during hypoventilation and lower during hyperventilation as compared to that of mixed venous blood in the respective state of ventilation.
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Kettel LJ. The management of acute ventilatory failure in chronic obstructive lung disease. Med Clin North Am 1973; 57:781-92. [PMID: 4573471 DOI: 10.1016/s0025-7125(16)32275-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Rastegar A, Thier SO. Physiologic consequences and bodily adaptations to hyper- and hypocapnia. Chest 1972; 62:Suppl:28S-34S. [PMID: 5049518 DOI: 10.1016/s0012-3692(15)30347-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Goldring RM, Turino GM, Heinemann HO. Respiratory-renal adjustments in chronic hypercapnia in man. Extracellular bicarbonate concentration and the regulation of ventilation. Am J Med 1971; 51:772-84. [PMID: 5129545 DOI: 10.1016/0002-9343(71)90305-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Siggaard-Andersen O. An acid-base chart for arterial blood with normal and pathophysiological reference areas. Scand J Clin Lab Invest 1971; 27:239-45. [PMID: 5581186 DOI: 10.3109/00365517109080214] [Citation(s) in RCA: 135] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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