Iran J Ped Education Article June 2007, Vol 17 (No 2), Pp:171-178

Clinical Approach to the Patient with Potential Acid- Base Disturbances

Farahnak Assadi*1, MD

1. Pediatric Nephrologist, Rush University Medical Center, Chicago, IL, USA

Received: 3/1/07; Accepted:7/4/07

Introduction • Renal failure = • Hepatic failure = respiratory alkalosis Patient can present with normal acid-base • Vomiting = metabolic alkalosis balance, a single disorder, or multiple • Diarrhea = metabolic acidosis combinations of two or three disorders. The pH • Thiazide and loop diuretics = metabolic can be estimated in a patient with a single alkalosis disturbance using the formulas which describe • Acetazolamide = metabolic acidosis predicted compensation. Situations which are often associated with Blood gas studies are required for diagnosis mixed disturbances include: and pH estimation when more than one • Pulmonary edema or asthma: Respiratory disturbance may be present or when the alkalosis followed by respiratory acidosis information is insufficient to allow diagnosis (as the condition worsens) and metabolic of a single disturbance with confidence (e.g., acidosis (lactic acidosis due to hypoxia). the patient is unable to give an adequate • Sepsis: Respiratory alkalosis and metabolic history). acidosis (lactic acidosis) The diagnostic approach to acid-base • Hepatorenal syndrome: Respiratory disorders utilizes information from the history alkalosis (liver failure) and metabolic and physical examination, venous blood acidosis (renal failure) laboratory studies, and arterial blood gas • Cardiopulmonary arrest: Respiratory studies in a stepwise fashion. acidosis (lack of pulmonary function) and metabolic acidosis (lactic acidosis due to Step 1. Identify potential processes in the tissue hypoperfusion) history, and recognizeArchive the situations that often of• Salicylate SID poisoning: Respiratory alkalosis are associated with mixed disturbances. (due to stimulation of respiratory system by Potential processes which can be identified in salicylate) and metabolic acidosis (due to the history include: salicylic acid) • Congestive hear failure = respiratory • Use of diuretics to treat right sided failure in alkalosis chronic lung disease: Metabolic alkalosis • Pneumonia = respiratory alkalosis (diuretics) and chronic respiratory acidosis (tachypnea) (chronic lung disease) • Obstructive airway disease = chronic respiratory acidosis

* Correspondence author. Address: Rush University Medical Center, 1725 West Harrison St, 718 Professional Bldg, Chicago, IL. USA E-mail: [email protected] www.SID.ir 172 Approach to the potential acid-base disturbance, F Assadi

• Vomiting in a patient with renal failure: If high, there is either metabolic alkalosis or Metabolic alkalosis plus metabolic acidosis chronic respiratory acidosis. Determine which fits better with the history and physical examination. Step 2. Review the physical examination for • Delta (): Is the AG increased clues to diagnoses. This is usually much less above normal (ie, >12-13 mEq/L)? productive than a good history. Clues include: • Tachypnea = respiratory alkalosis If no, a process which produces H+ in • Tetany (Chvostek or Trousseau sign) = low association with anions (lactate, Keto- ionized Ca concentration. Alkalosis lowers acidosis, etc) is not present. the ionized Ca concentration by increasing Ca binding to protein If yes, by definition there is present a • Hypotension = hypoperfusion with process that is producing acid (ie, H+ in metabolic acidosis from association with an anion). production. • Edema can indicate congestive heart failure If this AG is increased above normal, there which is often associated with respiratory should be concordance between the fall in alkalosis the HCO3 concentration and the increase in • Jaundice, ascites and tremor can indicate AG. If there is not concordance, several impending liver failure which is associated processes are present. with respiratory alkalosis As an example, a patient presents with diabetic ketoacidosis and the following set of is obtained: Na 140, Cl 102, K 5.1, Step 3. Review the laboratory data. Laboratory HCO3 10. The AG is 28 and it has increased by data provide information on organ function as 15-16 from a normal value of 12-13. The well as the electrolytes which provide specific HCO3 has fallen by 15 from a normal value of information relative to acid-base. 25. The concordance in the change in the First check the studies that indicate organ HCO3 and the AG is consistent with a simple function and provide potential diagnoses. disturbance of metabolic acidosis. • The BUN and indicate renal However, if the values were Na 140, Cl failure 108, K 5.1, HCO3 10, there is not concordance. • Liver enzyme tests indicate hepatic function The AG is 22, an increase of 10-11 above the • Positive blood cultures would confirm the normal while the HCO3 fell by 15. Therefore, presence of sepsis some process in addition to increased Next evaluate the electrolytes as follows: metabolic acid production is contributing to the fall in HCO3 without affecting the AG. This • HCO3 Concentration: Is the total CO2 (the could be respiratory alkalosis or it could be concentration) normal, non-AG metabolic acidosis (eg, from diarrhea) decreased orArchive increased?) ofboth conditions SID which lower the HCO3 If normal, either the patient has no acid- concentration but do not increase the AG. base disturbances or he has more than one (ie, a mixed or complex disturbance) each of which influences the HCO3 in a different Step 4. Assemble a tentative acid-base diag- direction. nosis using the information obtained with the history, physical examination and laboratory If low, there is either metabolic acidosis or data. respiratory alkalosis. Determine which fits • Simple disturbance: If all the data sources better with the history and physical are consistence with the presence of a single examination. disturbance, estimate the pH from the

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bicarbonate concentration using the modified Normal Compensation Henderson Hasselbach equation as follows: The following equations are used to evaluate H+= 24 pCO : HCO . To convert H into pH 2 3 the appropriateness of compensation for a use the equation listed below: single acid-base disorder. + Δ10 nEq/L increment in H =Δ0.10 fall in Acute respiratory acidosis: ΔHCO3=0.1 ΔpCO2 pH The plasma HCO3 concentration rises by (every 0.1 fall in pH is equivalent to a 10 1mEq/L for every 10 mmHg elevation in the + nEq/L rise in plasma H concentration): pCO2 pH H+ (nEq/L) • Acute respiratory Alkalosis: ΔHCO = 0.2 7.40 = 40 3 ΔpCO : The plasma HCO concentration 7.30 = 50 2 3 falls by 2 mEq/L for every 10 mmHg 7.20 = 60 decline in the pCO . 7.10 = 70 2 Blood gases are not necessary unless there is • Chronic respiratory acidosis: Δ HCO3= likely to be a marked change in pH. 0.3 ΔpCO2: The plasma HCO3 concent- ration rises by 3 mEq/L for every 10 mmHg • Complex disturbance: If the data suggest elevation in the pCO2. that there is more than one disturbance • Chronic respiratory alkalosis: Δ HCO3= present, the pH can not be estimated. It is 0.4 ΔpCO2: The plasma HCO3 concen- necessary to measure the pH to corroborate tration falls by 4 mEq/L for every 10 mmHg the diagnoses present and to determine decline in the pCO2. treatment for the abnormal pH. • Metabolic acidosis: Δ pCO2= 1.2Δ HCO3: Mistakes can be made in the laboratory. The results in a Always ensure the blood gas data are correct 1.2 mmHg fall in the pCO2 for every 1 (ie, fit the Henderson Hasselbach equation mEq/L reduction in HCO3 before using the information). If the data are concentration. correct, are they consistent with normal • Metabolic alkalosis: Δ pCO2= 0.6 Δ compensation of a simple disturbance? If yes, HCO3: The respiratory compensation the process is complete. If no, why? When you results in an increase in pCO2 of 0.6 mmHg are happy with the validity of the pH and the for every 1 mEq/L elevation in serum HCO3 diagnosis, complete a treatment plan. concentration.

ACID-BASE DISTURBANCES CLINICAL QUIZ 1. A 12-year Archiveold female is brought to the ofWhat do SIDyou estimate her arterial pH to be? Emergency Room because of increasing A. 7.20-7.24 weakness. She had been having low grade B. 7.25-7.29 fever and severe diarrhea for four days. C. 7.30-7.34 Laboratory studies reveal sodium 140 mEq/L, D. 7.40-7.44 potassium 2.4 mEq/L, chloride 115 mEq/L, E. 7.45-7.49 bicarbonate 15 mEq/L, BUN 21 mg/dL, The correct answer is C. The acid-base creatinine 1.5 mg/dL, 88 mg/dL, diagnosis is uncomplicated hyperchloremic 10.0 mg/dL, phosphate 3.5 mg/dL, acidosis due to severe diarrhea. This would magnesium 1.8 mg/dL, and allow you to estimate her pCO from Winter’s 284 mosmol/kg. 2 formula which applies only when simple

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(uncomplicated) metabolic acidosis is present: Would you like to draw a blood gas? ΔpCO2 =1.2 x ΔHCO3 or 12 mmHg. Thus, the A. Yes, I believe one is indicated predicted pCO2 compensation would be 28 B. No, I do not believe it is necessary mmHg, the difference between normal pCO2 The correct answer is A. A blood gas is and the expected fall in pCO2 [normal pCO2 indicated in this case. This is because you (40)] – [ΔpCO2 (12)]. The pH can then be cannot be sure that there is only one acid-base calculated with the modiefied Henderson- disturbance present when there is no history + Hasselbach equation: H = 24 x pCO2 : HCO3. available and thus you cannot predict the pH. The value obtained is 45 nEq/L, which is equivalent to a pH of 35.0 (every 0.1 fall in pH 3. An arterial blood gas was obtained which is equivalent to a 10 nEq/L rise in plasma H+ revealed: pH 7.20; pCO 16 mmHg; HCO - 15 concentration): 2 3 mEq/L; pO2 110 mmHg. + Δ10 nEq/L increment in H = Δ 0.10 fall in What is the acid-base diagnosis? pH A. Metabolic acidosis + pH H (nEq/L) B. Metabolic acidosis plus metabolic 7.40 = 40 alkalosis 7.30 = 50 C. Metabolic acidosis plus respiratory 7.20 = 60 acidosis 7.10 = 70 D. Metabolic acidosis plus respiratory The point of this exercise is to remind you that alkalosis the principal indication for a blood gas is the E. Metabolic acidosis plus metabolic inability to estimate pH when there are alkalosis plus respiratory acidosis multiple acid-base abnormalities present or The correct answer is D. This is anion gap when you cannot be sure that there is only one (AG) metabolic acidosis in a patient without abnormality present. signs suggestive of hepatic coma. Laboratory studies on venous blood reveal an increased - 2. An 18-year old boy is brought to the ER in a anion AG and a reduced HCO3 compatible coma. There is no other history available. with AG metabolic acidosis. The fall in the Physical examination revealed a thin, non- bicarbonate concentration (-18) is close to the icteric Caucasian female in coma. The patient change in the AG (+17) suggesting that another is comatose without focal neurological signs, acid-base process is not present. The blood gas Temp is 37ºC; BP 136/88 mmHg; pulse 98; data are compatible with metabolic acidosis respiratory rate 24/min; weight 70 kg; length and inappropriate respiratory compensation as 170 cm. The chest is clear without rales or determined by Winter’s formula discussed rhonchi. The heart rate is regular; there are no earlier. extra sounds or murmurs. The abdomen is soft. Mild hepatosplenomegaly is present without 4. What is the likely cause of the anion gap jaundice or ascites. No other masses are metabolic acidosis in this patient? palpable. BowelArchive sounds are present. Mild ofA. AlcoholicSID ketoacidosis kyphosis is noted. Extremities are free of B. Idiopathic or primary lactic acidosis rashes or edema. Laboratory studies reveal C. Toxic ingestion (, ethylene sodium 140 mEq/L, potassium 5.5 mEq/L, glycol) - chloride 106 mEq/L, HCO3 6.6 mEq/L, BUN D. Renal failure 30 mg/dL, creatinine 0.8 mg/dL, glucose 95 E. Starvation ketoacidosis mg/dL, calcium 9.0 mg/dL, phosphate 2.9 The correct answer is C. The potential causes mg/dL, magnesium 1.7 mg/dL, plasma of AG metabolic acidosis include: starvation osmolality 340 mosmo/kg, and serum ketones ketoacidosis, alcoholic ketoacidosis, methanol 1+. intoxication, intoxication, lactic acidosis, inborn error of , and

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renal failure. Blood ketones are only trace D. Mixed metabolic and respiratory alkalosis positive and the serum creatinine is normal. E. Mixed metabolic alkalosis and acidosis However, the measured serum osmolality is The correct answer is D. This is an example considerably higher than the calculated of primary metabolic alkalosis plus primary osmolality (340 vs. 296 mosmol/kg). respiratory acidosis. The history of vomiting The presence of an is consistent suggests the presence of metabolic alkalosis. with toxic ingestion with a substance such as The pulmonary embolus suggests that there alcohol, methanol or ethylene glycol which may be superimposed acute respiratory produce acidosis by interfering with alkalosis. Laboratory studies reveal an metabolism and in part by producing lactic increased BUN to creatinine ratio consistent acidosis. with volume contraction. The bicarbonate is increased and the AG is normal consistent with 5. A 19-year old boy presents to the ER with metabolic alkalosis without metabolic acidosis. severe vomiting and the recent onset of chest Blood gas values show a markedly increased pain. The patient has a history of peptic ulcer pH with an increased HCO3 and a low pCO2 disease. Vomiting began 48 hours ago and confirming the presence of both metabolic continued until the present time without alkalosis and respiratory alkalosis. improvement. Fifteen minutes before arriving in the ER, the patient developed the sudden 7. A 16-year old women is seen for a routine onset of left sided pleuric chest pain, shortness examination. The history is basically non- of breath and hemptysis. Physical exam revealing and she has no current complains. revealed a tachypneic male in acute distress She denies taking any medications now but with a respiratory rate of 30/min and does admit to using diet pills in the past. She complaining of chest pain. The remainder of also relates that her potassium has been low on the examination was normal. Lab data several occasions in the past. Physical exam revealed, sodium 140 mEq/l, potassium 3.0 revealed a thin Caucasian female in no acute or mEq/L, chloride 92 mEq/L, CO2 36 mEq/L, chronic distress. Tem 37ºC; BP 116/80 mmHg; BUN 30 mg/dL, creatinine 1.3 mg/dL, calcium pulse 78 beats/min; respiratory rate16/min; 10.0 mg/dL, phosphate 3.5 mg/dL, blood weight 49 kg, Ht 162 cm. The heart is regular; ketones negative, glucose 90 mg/dL and there are no extra sounds or murmurs. The plasma osmolaity 280 mosoml/kg. The chest x- lungs are clear without rales or rhonchi, ray showed marked pleural effusion on the left abdomen is soft without palpable masses. pleural chest with the left lower lobe infiltrate. Bowel sounds are present. There is no edema. Would you like to draw a blood gas? Neurological exam is intact. Laboratory data A. No revealed sodium 136 mEq/L, chloride 95 B. Yes mEq/L, potassium 3.0 mEq/L, CO2 32 mEq/L, BUN 15 mg/dL, creatinine 1.1 mg/dL, calcium The correct answer is B. Yes, this is because 10.0 mg/dL, phosphate 3.6 mg/dL, magnesium the history suggests that more than one acid- 1.7 mg/dL and albumin 4.6 g/dL. base disturbanceArchive may be present and you of SID Would you like to draw a blood gas? cannot therefore predict the arterial pH. A. Yes B. No 6. The blood gas revealed a pH of 7.69 with a The correct answer is B. A blood gas is not pCO2 of 30 mmHg, a HCO3 of 35 mEq/l and a necessary in this case. There is sufficient pO2 of 75 mmHg. information in the history and laboratory data What is the acid-base diagnosis? to make a diagnosis of a single acid-base A. Simple metabolic alkalosis disturbance. This allows prediction of the B. Respiratory alkalosis arterial pH from Winter’s formula for that C. Respiratory acidosis disturbance and a blood gas is not necessary.

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8. What is the acid-base diagnosis and which there are no extra sounds or murmurs. The studies would help with the differential chest is clear without rales or rhonchi. The diagnosis of this condition? (Select all that abdomen is soft. No palpable masses. Bowel apply) sounds are present. There is no edema. Several A. Respiratory alkalosis ecchymoses are apparent over his trunk and B. Metabolic acidosis limbs. Laboratory data revealed serum sodium C. Metabolic alkalosis 140 mEq/L, chloride 108 mEq/L, potassium D. Respiratory acidosis 3.8 mEq/L, HCO3 13 mEq/L, BUN 14 mg/dL, E. Measurement of urinary creatinine 1.2 mg/dL, glucose 96 mg/dL; blood F. Urinary diuretic screen ketones 2+; calcium 10.0 mg/dL, phosphate 3.5 G. Measurement of urinary chloride mg/dL, magnesium 1.8 mg/dL and albumin 4.0 excretion g/dL and plasma osmolality 284 mosmol/kg. The correct answers are C, F and G. This is Would you like a blood gas? a case of metabolic alkalosis. The history A. Yes reveals that hypokalemia might be present. B. No Diet pills are often diuretics which may cause a The correct answer is A. The blood gas metabolic alkalosis. determination is indicated in this case. The Laboratory data reveal an increased presence or absence of more than one bicarbonate, a normal AG, and hypokalemia disturbance cannot be determined in the associated with renal K wasting and metabolic absence of an adequate history. In addition, alkalosis due to diuretics or upper GI losses there is a discrepancy between the increase in (vomiting). Rarely the etiology is one of the the AG and the fall in the serum bicarbonate inherited salt-wasting nephropathies (Bartter’s level. syndrome or Gitelman’s syndrome). Urinary Cl excretion helps to distinguish between 10. A blood gas was obtained and revealed the diuretics and vomiting as causes of metabolic following: pH 7.4, pCO2 20; HCO3 12; pO2 alkalosis. Vomiting is associated with ECF 105 volume depletion, chloride depletion and a What is the acid-base diagnosis? (Select all urinary Cl excretion less than 15 MEq/L. In that apply) contrast, urinary Cl excretion is usually greater A. Metabolic acidosis than 40 mEq/L in conditions associated with B. Metabolic alkalosis Bartter’s syndrome, Gittleman’s syndrome, C. Respiratory acidosis hyperaldosteronism or use of diuretics. D. Respiratory alkalosis Surreptitious diuretic abuse can be confirmed The correct answers are A and D. This is a with a urinary diuretic screen. mixed disturbance of metabolic acidosis and chronic respiratory alkalosis. There are no 9. You are called to see a 19-year old male specific clues to an acid-base disturbance in the found to be stuporous at home. According to history. Headaches might suggest the use of his father whoArchive found him this morning, he had ofsalicylates SID or a CNS lesion both of which apparently been complaining of continuous might be associated with respiratory alkalosis. tension type headaches for the past several The physical examination suggests that months. He was otherwise asymptomatic in hyperventilation is present which could good health with only a history of mild indicate severe acidosis or primary alkalosis. hypertension for which he had been treated Ecchymoses are consistent with the use of with a beta-blocker. On examination he salicylates. Laboratory studies reveal a low appeared well-developed, stupourous. Temp HCO3 and an increased AG consistent with the was 37ºC; BP 141/88 mmHg; Pulse 88 presence of AG metabolic acidosis. However, beats/min; respitatory rate 34/min, weight 59 the fall in the HCO3 concentration (-11) is kg, height160 cm. The heart rate is regular, greater than the increase in the AG (+7)

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suggesting the presence of another process 12. An arterial blood gas was obtained and which lowers the HCO3; either chronic res- revealed the following: pH 7.45; pCO2 60; piratory alkalosis or hyperchloremic acidosis. HCO3 40, pO2 55. Blood gas values reveal a low HCO , low 3 What is the acid-base diagnosis? (Select all pCO and a normal pH indicative of a mixed 2 that apply) disturbance with metabolic acidosis and A. Metabolic alkalosis primary respiratory alkalosis. The combination B. Respiratory acidosis of AG metabolic acidosis and primary C. Respiratory alkalosis respiratory alkalosis occurs in several D. Metabolic acidosis situations including sepsis, salicylate intox- ication, and lactic acidosis in a patient with The correct answers are A and B. This is a hepatic failure. Salicylate intoxication is the mixed disturbance with chronic respiratory likely diagnosis in this patient in view of the acidosis and metabolic alkalosis. The history history of severe headaches, stupor and the and physical exam indicate that the patient has presence of ecchymoses. chronic bronchitis and COPD which can produce chronic respiratory acidosis. He was placed on loop diuretics for apparent right 11. A 16-year old boy with a recent history of sided congestive heart failure. These may tuberculosis, diagnosed 2 months ago, returns produce metabolic alkalosis. Laboratory data for follow-up examination. He has been com- show an elevated HCO3 and a normal AG plaining of shortness of breath on exertion as which could represent either chronic well as chronic cough with sputum production respiratory acidosis or metabolic alkalosis or in the morning. He was placed on furosemide both. There is also mild hypokalemia several weeks ago. On examination: Temp consistent with the use of diuretics and 37ºC, BP 148/82 mmHg; Pulse 84 beat/min; metabolic alkalosis. respiratory rate 22/min; weight 63 kg; height The pH is only minimally elevated above 157 cm. The heart rate is regular, there are no the normal range with a markedly elevated extra sounds or murmurs. Respiratory excur- pCO2 and HCO3. These data are not sions are shallow and there is occasional compatible with either metabolic alkalosis wheezing. The abdomen is soft without alone or chronic respiratory acidosis with palpable masses. Bowel sounds are present. normal compensation alone. Therefore both There is 2+ edema on lower extremities. Lab metabolic alkalosis and chronic respiratory data revealed: Hemoglobin 12.0g/dL; WBC acidosis are present. 6600 cells/uL; sodium 140 mEq/L; potassium - 3.4 mEq/L; HCO3 42 mEq/L; calcium 10.0 mg/dL; phosphate 3.5 mg/dL, magnesium 1.8 13. A 16-year old female decided to attempt a mg/dL; albumin 3.4 g/dL, blood ketones 0; starvation diet. To speed up initial weight loss, glucose 94 mg/dL and plasma osmolality 284 she also took furosemide. After one week she mosmol/kg. had lost 10 pounds but felt terrible and decided Archive ofto see herSID physician. As she approached the Would you like to order a blood gas? office, she became acutely anxious and felt A. Yes weak. Physical examination in the office B. No revealed a BP of 90/60 mmHg and respiratory The correct answer is A. The history suggests rate 20/min. There was a positive Trousseau’s the possibility of more than one disturbance sign. The remainder of the examination was and thus the pH cannot be predicted with normal. Laboratory data showed: Hemoglobin certainly. 13.5 g dL; BUN 40 mg/dL; creatinine 1.5 mg/dL; sodium 140 mEq/L; chloride 98 mEq/L; potassium 3.0 mEq/L; HCO - 18 3 mEq/L; calcium 10.0 mg/dL; phosphate 3.5

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mg/dL; magnesium 1.8 mg/dL; albumin 4.0 is also present. Blood gas studies show a g/dL; blood ketones 0; glucose 99 mg/dL; and significantly increased pH with a low pCO2 plasma osmolality 283 mosmol/kg. confirming the presence of respiratory Would you like to obtain an arterial blood alkalosis. gas? Thus, the data from the history and physical A. Yes examination, laboratory studies, and blood gas B. No studies together indicate the presence of a The correct answer is A. The history suggests triple acid-base disturbance. the possibility of more than one disturbance and thus the pH cannot be predicted with certainty. References 1. Assadi F. Acid-base disturbances: Clinical 14. An arterial blood gas was obtained and quiz. Pediatr Nephrol. 1993; 7(3): 321-5. revealed the following: pH 7.53; pCO2 20; 2. Bushinsky DA, Coe FL, Katzenberg C et al. HCO3 16; pO2 105. Arterial pCO2 in chronic metabolic acidosis. What is the acid-base diagnosis? (Select all Kidney Int. 1982; 22(3): 311-4. that apply) A. Metabolic alkalosis 3. Emmett M, Seldin DW. Clinical syndromes of metabolic acidosis and metabolic B. Respiratory alkalosis alkalosis. In: Seldin, Giebisch. The Kidney: C. Metabolic acidosis Physiology and . New D. Respiratory acidosis York, Raven Press. 1985; pp1567-639. The correct answers are A, B, and C. This is 4. Javaheri S, Shore NS, Rose BD, et al. a triple disturbance with metabolic alkalosis, Compensatory hyperventilation in meta- metabolic acidosis, and acute respiratory bolic alkalosis. Chest. 1982; 81(3): 296- alkalosis. The history and physical exam- 301. ination suggest that three acid-base processes 5. Kappy M, Morrow G. A diagnostic may be present. approach to metabolic acidosis in children. 1. Starvation is associated with Pediatr. 1980; 65(2): 351-6. ketoacidosis 6. Krapf R, Beeler I, Hertner D, etal. Chronic 2. Loop diuretics with metabolic alkalosis respiratory alkalosis: The effect of sustained 3. Acute anxiety with hyperventilation and hyperventilation on renal regulation of acid- acute respiratory alkalosis base equilibrium. N Engl J Med. 1991; Hypotension suggests volume contraction 324(20): 1394-401. which can maintain the metabolic alkalosis. 7. Oster JR. Metabolic acidosis. Seminar Trousseau’s sign is indicative of a reduction in Nephrol. 1981; 1:250. ionized calcium concentration which can be 8. Sabatini S, Arruda JAL, Kurtzman NA. caused by the sudden increase in pH due to Disorders of acid-base balance. Med Clin respiratory alkalosis. The change in pH leads North Am. 1978; 62(6): 1223-55. to increased bindingArchive of ionized calcium to of SID protein, principally albumin. Laboratory 9. Seldin DW, Rector FC. Symposium on acid-base homeostasis degeneration and studies reveal an increased BUN to creatinine maintenance of metabolic alkalosis. Kidney ration consistent with volume contraction. The Int. 1972; 1(5): 306-21. HCO3 is reduced and the AG is increased consistent with AG metabolic acidosis. 10. Nascimentol WFC. Respiratory acidosis However, the increase in the AG (+12) is and alkalosis. Seminar Nephrol. 1981; significantly greater than the decrease in the 1:220. HCO3 (-7) suggesting that metabolic alkalosis

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