Acid-Base Imbalances
Metabolic Alkalosis
(base carbonic excess) high HCO3 level * high pH( low acid concentration), high bicarb * loss of acid from vomiting or gastric suctioning * diuretic therapy, loss of K+ - monitor volume depletion status, I&O's - monitor K+ and supplementing K+ if needed * so lungs compensate by hypo-ventilating - increases CO2- decreases pH
Role of the Lungs
-Controls blood pH by releasing carbon dioxide from lungs * carbon dioxide is mildly acidic, is a waste product of the processing - Blood carries carbon dioxide to the lungs, where it is exhaled *As carbon dioxide accumulates in the blood, the pH of the blood decreases(acidity increases) -The brain regulates the amount of carbon dioxide that is exhaled by controlling the speed and depth of breathing. (ventilation)
The nurse is caring for a client with severe diarrhea. The nurse recognizes that the client is at risk for developing which acid-base imbalance? A: Metabolic Acidosis B: Respiratory acidosis C: Metabolic alkalosis D: Respiratory alkalosis
A: metabolic acidosis
The nurse is caring for a patient in diabetic renal failure who is in metabolic acidosis. Which laboratory findings are consistent with metabolic acidosis? a: pH 7.3, PaCo2 36, HCO3 19 b: pH 7.5, PaCo2 35, HCO3: 35 c: pH 7.32, PaCo2: 47, HCO3: 23 d: pH 7.35, PaCo2: 40, HCo3: 25
A: pH 7.3, PaCo2: 36, HCO3: 19
Interpretation of ABG
Acid: 7.35-7.45, PaCo2: 35-45, HCO3: 22-26
Respiratory Alkalosis
Arise in blood pH due to hyperventilation (excessive breathing) and a resulting decrease in CO2. * low CO2(<35) and high pH (>7.45) -anxiety, salicylate intoxication, hypoxia, high fever, high altitude can result in a hypoxia-induced hyperventilation. kidneys kick in to get rid of HCO3, decrease pH Treat the underlying cause
A client has a respiratory rate of 38 breaths/min. What effect does breathing faster have on arterial pH level? A: no effect B: Inc. arterial pH C: Dec. arterial pH D: provides long term pH regulation
B: inc. arterial pH
A nurse caring for a patient with metabolic alkalosis knows to assess for the primary, compensatory mechanism of: A: increased serum HCO3 B: increased PaCO2 C: decreased serum HCO3 D: Decreased PaCo2
B: increased PaCo2
Patient states they have been vomiting for the last 4 days. The patient is irritable, weak, and reporting muscle cramping and weakness. The patient has the following ABG results: HCO3: 36, pH: 7.52, PaCo2: 42 Which of the following conditions are present? A: Metabolic acidosis B: Metabolic alkalosis C: Respiratory acidosis D: Respiratory alkalosis
B: metabolic alkalosis
Which blood gas result will the nurse expect to observe in a patient with respiratory alkalosis? a: pH 7.60, PaCO2 40 mm Hg, HCO3- 30 mEq/L b.pH 7.53, PaCO2 30 mm Hg, HCO3- 24 mEq/L c.pH 7.35, PaCO2 35 mm Hg, HCO3- 26 mEq/L d.pH 7.25, PaCO2 48 mm Hg, HCO3- 23 mEq/L
B: pH 7.53, PaCO2: 30 mm Hg, HCO3-24 mEq/L
A 2-year-old child is brought into the emergency department after ingesting a medication that causes respiratory depression. For which acid-base imbalance will the nurse most closely monitor this child? A: respiratory alkalosis B: respiratory acidosis C: Metabolic acidosis D: Metabolic alkalosis
B: respiratory acidosis
Bicarbonate HCO3
Bicarbonate ion acts as a H ion acceptor and is responsible for buffering the hydrogen ions in the blood. Kidney excrete or retain bases to control pH * If I am acidotic(low pH), I need to reserve bicarb to increase pH * if I am alkalonic (high pH) I need to excrete bicarb to decrease pH.
Respiratory Acidosis compensation
Bicarbonate is retained
A nurse is planning care for a nephrology with a new nursing graduate. The nurse states, " A client with kidney disease partially loses the ability to regulate changes in pH." What is the cause of this partial inability? A: The kidneys regulate and reabsorb carbonic acid to change and maintain pH B: The kidneys buffer acids through electrolyte changes C: The kidneys regenerate and reabsorb bicarbonate to maintain a stable pH. D: The kidneys combine carbonic acid and bicarbonate to maintain a stable pH.
C: The kidneys regenerate and reabsorb bicarbonate to maintain a stable pH.
Metabolic Acidosis Causes
Keto-acid accumulation DKA, lactic acid shock, severe diarrhea results in low HCO3, renal failure impairs HCO3 absorption * so lungs are going to compensate by hyperventilating- low CO2-increase pH
Metabolic alkalosis compensation
Respiratory compensation by decreasing ventilation- hypoventilation to conserve Co2
Metabolic Alkalosis values
inc pH(>7.45), normal CO2(35-45) inc. HCO3(>26)
Respiratory Alkalosis values
inc. pH(>7.45), decreased CO2(<35), normal HCO3 (22-26)
Respiratory Acidosis
occurs with hypoventilation and build up of CO2 * high CO2 (more than 45) in the body and low pH (<7.35) *occurs in situations like aspiration of a foreign object, atelectstasis, diaphragmatic paralysis, OD on sedative, sleep apnea syndrome, severe PNA * disease that impair respiratory muscle like MG, GBS, muscular dystrophy * renal compensatory mechanism kicks in to conserve HCO3 to increase pH. * treat underlying cause * adequate hydration 2/3L day
Metabolic acidosis compensation
respiratory system kicks in by inc. ventilation rate - because lungs respond to acid-base disorders within minutes, compensation for metabolic imbalances occurs faster than compensation for respiratory imbalances.
Acid-Base Imbalances
-For optimal cell function, body maintains a balance between acids and bases -Normal balance maintained with acid excretion equal to acid production -Degree of acidity reported as pH -pH of 7.0 is neutral, normal arterial blood gas: 7.35 to 7.45(acidic vs. alkalosis) -Maintaining pH within this normal range is very important for optimal cell function * if pH goes out of normal range, enzymes within cells do not function properly, hemoglobin does not manage O2 properly, serious physiological problems occur, including death.
A client who is found unresponsive has arterial blood gases drawn and the results indicate the following: pH is 7.12, Pco2 is 90, and HCO3- is 22. the nurse interprets the results as indicating which condition? 1) Metabolic Acidosis with compensation 2) Respiratory Acidosis with compensation 3) Metabolic Acidosis without compensation 4) Respiratory Acidosis without compensation
2- respiratory acidosis with compensation
You are caring for a 65-year-old male patient admitted to your unit 72 hours ago with pyloric stenosis. a nasogastric tube was placed upon admission and has been on low intermittent suction ever since. You notice that the patients K+ is very low. What would you be concerned that the client is at risk for? A: hypercalcemia B: Metabolic acidosis C: Metabolic alkalosis D: respiratory acidosis
C: metabolic alkalosis
Which condition leads to chronic respiratory acidosis in older adults? A: dec. renal function B: erratic meal patterns C: thoracic skeletal change D: overuse sodium bicarbonate
C: thoracic skeletal change
The emergency-room nurse is caring for a trauma client who has the following ABG results: pH: 7.26, PaCo2: 28, HCO3: 11. How should the nurse interpret these results? A: respiratory acidosis with no compensation B: metabolic alkalosis with a compensatory alkalosis C: Metabolic acidosis with no compensation D: Metabolic acidosis with a compensatory respiratory alkalosis
D: metabolic acidosis with a compensatory respiratory alkalosis
Hyperventilation
Decrease CO2 in the body, increase pH- more alkalonic
Respiratory Alkalosis Compensation
Renal excretion of bicarbonate
Respiratory Acidosis values
dec pH(<7.35), increased CO2(>45), normal HCO3(22-26)
Metabolic Acidosis values
dec. pH(<7.35), normal CO2(35-45), dec. HCO3(<22)
Role of the Kidneys (Buffer system)
-Kidneys able to affect blood pH by excreting excess acids and bases. -have some ability to alter the amount of acid/base that is excreted, but they make these adjustments more slowly than the lungs, usually takes several days. *intestines, pancreas, diet.
Mixed Acid-Base Disorders
A normal pH in the presence of changes in the PaCo2 and plasma HCO3 concentration immediately suggests a mixed disorder. * acidosis compensation: (pH 7.35-7.40) * alkalosis compensation: ( pH 7.40-7.45) -generally the pulmonary and renal systems compensate for eachother to bring pH back to normal. -lungs compensate for metabolic disturbances for metabolic disturbances by changes in CO2 exertion - kidneys compensate for respiratory disturbances by altering bicarbonate retention
A client presents with severe diarrhea and a history of chronic renal failure to the emergency department.ABG results are as follows: pH: 7.30, Co2: 37, HCO3: 18 The nurse would expect which of the following sets of assessment findings? A: Headache, BP 90/54, dry skin B: BP 188/20, n/v C: confusion, RR 8, dry skin D: clammy skin, BP 86/46, headache
D: clammy skin, BP 86/46, headache
Hypoventilation
Increases CO2 in the body, decrease pH- more acidotic
Metabolic Acidosis
Low HCO3( base bicarbonate deficit) * low pH( high acid) and low bicarb
