Which factor is responsible for maintaining acid-base balance in the body Quizlet
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acidosis Show a condition of below-normal blood pH due to an excess of acid relative to base Why is it physiologically important to maintain pH within a narrow range? Optimal cellular function occurs within a narrow pH range of 7.35-7.45; pH below or above this will result in some cellular dysfunction that could result to death. Name two major body systems that are involved in maintaining acid-base balance. The pulmonary and renal systems are involved in maintaining acid-base balance. Acid is a substance that dissociates into an H+ and a conjugate base (B-) volatile acid An acid that can dissociate, forming a gas that is eliminated by the lungs carbonic acid A volatile acid produced in the body that dissociates into CO2 and H2O. It is the acid component of the bicarbonate (HCO3-) buffer system Nonvolatile acids (fixed acids) Acids that are not gases and therefore cannot be eliminated by the lungs and are eliminated mainly by the kidneys Base An H+ acceptor Alkalosis A condition of above-normal blood pH due to a deficit of base relative to acid Give examples of a volatile acid and a nonvolatile acid. H2CO3 (carbonic acid) is a volatile acid. Lactic acid is a nonvolatile acid. What is a base? A base is a H+ acceptor. A change in pH by 1 actually means what change in H+ concentration? A change in pH by 1 actually means a change of 10 times the H+ concentration. Is small intestinal pH lower or higher than gastric pH? Small intestinal pH is higher than gastric pH; pancreatic juice is basic and influences small intestinal pH. compensatory mechanisms consist of the following: - Intracellular and extracellular chemical buffers that neutralize excess acids and bases pKa the dissociation constant of the weak acid Compensation is present when various chemical buffers and renal or respiratory function return the pH closer to or actually back within the normal range; however, the underlying disease process responsible for the acid-base imbalance is still present Correction an acid-base imbalance occurs when the condition responsible for the acid-base imbalance is controlled or no longer present and the pH is within the normal range antiport is a transport molecule that moves two different electrolytes in opposite directions across a cell membrane symport is a transport molecule that moves two different electrolytes in the same direction across a cell membrane. How does kidney disease contribute to acid-base imbalance? The kidney regulates acid-base balance by regulating acid (H+) and base (HCO3−) excretion. In renal disease or renal failure, this function becomes impaired, resulting in acid-base imbalance. Salicylate (aspirin) overdose has been associated with respiratory alkalosis. Explain the mechanism that contributes to this. High amounts of salicylates uncouple oxidative phosphorylation, resulting in increased glucose utilization and carbon dioxide production. This stimulates central chemoreceptors, leading to hyperventilation and respiratory alkalosis. four types of simple acid-base imbalances: - Respiratory acidosis simple acid-base imbalance the presence of one type of acid-base imbalance
In respiratory and metabolic acidosis the pH is decreased, and the H+ concentration is increased In respiratory and metabolic alkalosis the pH is increased. and the H+ concentration is decreased Explain how metabolic alkalosis might manifest clinically by numbness and tingling. The numbness and tingling occur because of the decreased oxygen availability resulting from the impact of alkalotic pH on the neurons. The blood work of a patient with metabolic acidosis indicates a rise in potassium level above normal (5.8 mEq/L). As the nurse, how would you explain the change in electrolyte to a student nurse shadowing you? In metabolic acidosis, there is excessive H+ in the ECF. As part of the buffer mechanisms in the body, ICF potassium exchanges with H+, resulting in increased K+ in the ECF. Arterial blood gases (ABGs) are the measure of the pH, PaCO3, PaO2, and bicarbonate in the arterial blood Acidosis the pathophysiologic process resulting in an excess amount of H+ in the body
Acidemia refers to a state of excess H+ and base deficit (low pH) in the blood Alkalosis refers to the pathophysiologic process resulting in a deficit of H+ in the body Alkalemia refers to a state of H+ deficit and base excess (elevated pH) in the blood Total CO2 (TCO2) A measure of carbon dioxide in the form of HCO3- ions, H2CO3, and CO2 attached to proteins such as hemoglobin as well as the CO2 dissolved in plasma Venous blood gases are a measure of the pH, PaCO2, PaO2, and bicarbonate in the venous blood Base Excess (BE) a measure of all bases in the blood, including bicarbonate, phosphate, and proteins such as albumin and hemoglobin; the test detects either a base excess or a base deficit Anion Gap N+-(Cl-+HCO3-) used to detect the presence of an increase level of anions produced from nonvolatile acids Base excess implies what change in acid-base balance?
Base excess is an indication of metabolic alkalosis. What anion is excreted in exchange for bicarbonate (HCO3−)? Chloride is excreted in exchange for bicarbonate. Respiratory acidosis is a state of elevated CO2 (hypercapnia) and H2CO3 and decreased blood pH List three risk factors for respiratory acidosis. Severe hypokalemia, cystic fibrosis, trauma to respiratory muscles such as the diaphragm, and respiratory center depressants (narcotic analgesics) are risk factors for respiratory acidosis. Why is hypokalemia a risk factor for respiratory acidosis? Potassium moves from the intracellular fluid to the extracellular fluid in response to hypokalemia, making the resting membrane potential more negative (hyperpolarized). This decreases excitability and causes muscle weakness and hypoventilation. Respiratory alkalosis a state of decreased CO2 (hypocapnia) and carbonic acid and increased blood pH caused by hyperventilation Hyperventilation is increased alveolar ventilation in excess of carbon dioxide production as a result of an increased rate and/or depth of breathing Severe alkalosis is associated with tetany. This symptom can be explained to be as a result of decreased level of what? Severe alkalosis can be a result of a decreased level of ionized calcium. How can use of antacids contribute to metabolic alkalosis? Antacids are alkaline and would increase the pH of gastric acid. Metabolic acidosis a state of H+ excess, bicarbonate deficit, and decreased blood pH and a decreased ratio of bicarbonate to carbonic acid below 20:1 caused by accumulation of nonvolatile (fixed) acids or excessive loss of the base bicarbonate. two major categories of metabolic acidosis Elevated anion gap metabolic acidosis High anion gap metabolic acidosis MULEPAK - Methanol Hyperchloremic metabolic acidosis acidosis in which increased chloride levels cause metabolic acidosis when the chloride accumulates because it results in increased renal excretion of the base HCO3- Another definition of metabolic acidosis is deficiency of what? Another definition of metabolic acidosis is deficiency in HCO3−. Compensatory mechanisms help to modify acid-base changes but do not correct the cause. Explain. The correction must come from addressing the source of the pH change. Metabolic alkalosis a state of H+ deficit, bicarbonate excess, increased blood pH, and increased ratio of bicarbonate to carbonic acid above 20:1 caused by excessive loss of nonvolatile (fixed) acids or excessive accumulation of the base HCO3- Metabolic alkalosis is caused by three types of conditions: - Excessive loss
of hydrogen ions contraction alkalosis A state of below-normal pH due to loss of extracellular fluid volume without comparable loss of bicarbonate, which increases the concentration of bicarbonate Factors that impair renal excretion of bicarbonate, thereby maintaining metabolic alkalosis - circulating fluid volume deficit two most common causes of metabolic alkalosis - loss of gastric fluid Hypochloremic metabolic alkalosis Chloride deficit contributing to alkalosis List three risk factors for metabolic alkalosis. Three risk factors for metabolic alkalosis are vomiting, excessive intake of base (e.g., antacids), and decreased renal excretion of base/bicarbonate. In hypokalemia, the renal response leads to increased renal acid excretion. Explain this statement In hypokalemia, the kidney resorbs potassium in exchange for H+, thus losing acid in urine. mixed acid-base imbalance two or more types of acid-base imbalances in an individual at the same time. Considering the different case studies presented in this chapter, which of the patients presented with a mixed acid-base imbalance? Sabrina Russell presented with a mixed acid-base imbalance. A patient with type 1 diabetes and COPD is likely to present with what type of mixed acid-base imbalance? A patient with type 1 diabetes and COPD is likely to present with mixed respiratory and metabolic acidosis. ROME can help to determine whether the acid-base imbalance is of respiratory or metabolic
origin What does "ME" in the mnemonic ROME mean in analyzing ABG data? "ME" stands for "metabolic equal," implying that any pH change that reflects the same direction as bicarbonate level must be due to a metabolic change or disorder. By applying ROME, indicate how you would analyze these ABG data: pH 7.55, pCO2 32, and HCO3− 22. The patient has respiratory alkalosis because the pH is high and pCO2 level is low (opposite each other) but the bicarbonate level is normal. A female patient is admitted with a diagnosis of COPD. What arterial blood gas (ABG) result should the nurse expect? pH 7.33, PaCO2 49, HCO3 23 Rationale: The patient has uncompensated respiratory acidosis due to retention of CO2. A client presents in the hospital with pneumonia. His ABG results are pH 7.48, PaCO2 31 mmHg, HCO3 28 mEq/L, PaO2 88 mmHg. How would the nurse interpret this result? Mixed respiratory and metabolic alkalosis Rationale: pH is elevated, PaCO2 is low (alkalosis), and HCO3 is high (alkalosis). This confirms mixed respiratory and metabolic alkalosis A 70-year-old female presents to her primary care provider and reports dizziness, confusion, and tingling in the extremities. Blood tests reveal pH 7.47, PCO2 32, and HCO3 16. Which of the following is the most likely diagnosis? Respiratory alkalosis with renal compensation Rationale: The pH is high and the pCO2 is low (respiratory alkalosis), but the HCO3 is slightly low. A 49-year-old male with a long history of smoking complains of excessive tiredness, shortness of breath, and overall ill feelings. Lab results reveal decreased pH 7.31, PaCO2 47 mmHg, and HCO3 24. These findings help to confirm the diagnosis of: respiratory acidosis Rationale: The pH is low (acidotic), the PaCO2 is high (acidotic), and HCO3 is normal, confirming uncompensated respiratory acidosis. A patient is admitted, and the blood lab results indicate metabolic acidosis and hyperkalemia. Which of the following diseases would be associated with these changes? Renal failure Rationale: Renal failure is associated with decreased potassium excretion and acidosis. The nurse is teaching a student nurse about body buffer systems involved in acid-base balance. Which of the following buffer pairs is considered the major plasma buffering system? Carbonic acid-bicarbonate Rationale: Although potassium/hydrogen pair is one of the buffers, the carbonic acid/bicarbonate pair is the most important and effective. A 36-year-old woman has presented to the emergency department following a panic attack. Her blood pressure, respiratory rate, and heart rate are all highly elevated, while her temperature and oxygen saturation are within normal ranges. How will her body try to deal with the resulting change in pH? Decreased resorption of HCO3 by the kidneys Rationale: The renal system compensates for respiratory alkalosis by decreasing bicarbonate resorption in order to lower the pH. Regulation of acid-base balance achieved through the removal or retention of volatile acids is accomplished by which of the following systems? Pulmonary Rationale: The lungs can compensate or induce acid-base balance through hyperventilation or hypoventilation. The nurse is teaching a coworker about how the kidneys compensate for respiratory acidosis. Which explanation by the nurse is accurate? "The kidneys add base bicarbonate to compensate for respiratory acidosis." If the issue causing the pH imbalance is the lungs, then the kidneys will compensate to help restore the pH to the normal range. The kidneys will add base bicarbonate to help decrease the acid effect and restore homeostasis. Adding hydrogen will not compensate for acidosis and the kidneys do not have an effect on volatile acids like CO2. Which compensatory mechanism is responsible for the regulation of acidic pH? The lungs regulate the amount of carbonic acid by eliminating more CO2 in exhaled air by breathing at a faster rate. The lungs regulate the amount of carbonic acid by eliminating more CO2 in exhaled air by breathing at a faster, not slower, rate. The renal system does not produce more hydrogen or excrete more bicarbonate from the body to help acidosis. Which compensatory mechanism for acid-base regulation is performed by the lungs to prevent acid from building up in the body? The lungs hyperventilate to exhale carbon dioxide to keep acid from building up in the body. The lung's compensatory mechanism is to hyperventilate—breathe faster—to exhale carbon dioxide to keep acid from building up in the body. Hypoventilation would cause carbon dioxide to build up, leading to acidosis. The lungs exhale neither hydrogen nor carbon monoxide.
The nurse reviews the signs of compensated respiratory acidosis with a new nurse. Which observation by the nurse identifies a manifestation of this compensation? Increased acidity of the urine As a sign of compensation, the urine becomes more acidic, owing to increased excretion of hydrogen ions and increased resorption of bicarbonate back into the blood. Since it is a respiratory issue, the lungs are the problem and do not compensate with changes in respiration. The kidneys compensate. The nurse reviews acid-base balance with a colleague. Which explanation by the nurse describes the renal regulatory mechanism of hydrogen to help prevent acidosis from developing? NH3 is able to diffuse out of the renal tubule cells into the tubule lumen fluid, where it can combine with H+ ions to form NH4+. As the NH3 produced in the renal tubule cells accumulates, a concentration gradient develops, causing NH3 to diffuse out of the tubule cells into the tubule lumen fluid, where it can combine with H+ ions to form NH4+. Retaining hydrogen would increase acidosis. NH3 does not migrate into the blood plasma to bind with hydrogen. Hydrogen does not combine with bicarbonate. The nurse is teaching a coworker about the renal system and how it affects intracellular pH. "The renal system helps by controlling the excretion and reabsorption of bicarbonate to help regulate the pH in the cells." The renal system helps by controlling the excretion and reabsorption of bicarbonate to help regulate the pH in the cells. The renal system does not produce hydrogen, CO2 or lactic acid. While reviewing the laboratory data of a patient with respiratory acidosis,
the nurse notes an elevated potassium level. "The ion exchange of hydrogen and potassium is necessary to maintain the normal negative electrical charge in cells." In order to maintain the correct electrical charge in the cell, when hydrogen builds up in acidosis, potassium must move out of the cells into the blood, resulting in hyperkalemia. Lactic acid, sodium, and HCO3- do not contribute to this shift. The nurse reviews respiratory acidosis with a colleague. "Respiratory acidosis produces tissue hypoxia due to CO2 retention." Respiratory acidosis produces tissue hypoxia due to CO2 retention. Respiratory acidosis does not increase O2 levels or retain hydrogen. CO2 retention is the issue, not excretion. The nurse is reviewing arterial blood gas results for a patient. pH 7.48 Normally, the respiratory system maintains a partial pressure of CO2 in the arterial blood (PaCO2) of 35-45 mmHg. The renal system maintains a HCO3- level between 22 and 26 mEq/L. Normally, the ratio of the base bicarbonate (HCO3) to carbonic acid (H2CO3) is 20:1. As long as that ratio is maintained at 20:1, the pH stays within the normal range. Since CO2 is an acid, a rise will create acidosis and a fall will create alkalosis. HCO3- is a base. A rise will create alkalosis and a fall will create acidosis. The nurse is caring for a patient with respiratory alkalosis caused by hypoxemia. Which action should the nurse take to best treat the cause of the patient's acid-base imbalance? Applying oxygen The preferred treatment for respiratory alkalosis is the identification and treatment of the underlying cause. For example, if respiratory alkalosis is caused by hyperventilation as a reflex response to hypoxemia, therapy with supplemental oxygen, as well as treatment of the cause of the hypoxemia is indicated. Rebreathing exhaled air is not the treatment of choice for patients with lung disease and hypoxemia; that could lower their blood oxygen levels more than it currently is as a result of the lung disease. Bicarbonate would worsen the alkalosis, not help compensate for it. Breathing needs to be slower only if hyperventilation is the cause of the imbalance. The nurse is assessing a patient with metabolic acidosis for signs of compensation. Increased rate of respiration Signs of compensation include increased rate and depth of breathing as the lungs eliminate more than the normal amount of carbon dioxide. CO2 levels would fall to compensate; the level would be below 35 mmHg. Shallow respirations would not help compensate. The nurse is assessing a patient with metabolic alkalosis. Slow, shallow respirations Signs of compensation include decreased rate and depth of breathing as the lungs retain more than the normal amount of carbon dioxide. As the lungs compensate for metabolic alkalosis by decreased elimination of CO2, the serum carbonic acid level increases, and the pH decreases back down toward normal. Fast, rapid, or Kussmaul respirations are not expected. The nurse is teaching a colleague about treating respiratory
acidosis. Using suction to remove mucus from the airway For improving ventilation in order to increase the elimination of carbon dioxide, decreasing the level of carbonic acid is the best action for respiratory acidosis. Ventilation may need to be improved, for example, by suctioning mucus out of the airway. Oxygen administration to reverse hypoxemia-accompanying hypercapnia will not increase elimination of carbon dioxide. Breathing into a paper bag and slowing respiration would increase CO2. The nurse is assessing a patient with an acidic pH. Muscle weakness The excess free calcium caused by acidosis blocks sodium channels in nerve and muscle cells, impairing sodium entry, which normally occurs during the action potential. The result is decreased neuromuscular excitability. The decreased neuromuscular activity causes muscle weakness and weak, not strong, reflexes. Decreased sodium entry into vascular smooth muscle leads to vasodilation with subsequent increased cerebral blood flow, which can increase intracranial pressure. Which statement best explains the anion gap? "The anion gap is useful in determining whether the sum of anion and cations are equal." The anion gap is based on the principle of electroneutrality of extracellular fluid. That is, the sum of the concentration of cations in the extracellular fluid equals the sum of the concentration of the anions. They should be equal in fluid, and both anion and cation need to be counted for the gap to be measured. A patient has shallow respiration and asks the nurse why it is important to take deeper breaths. Which response should the nurse make that best explains why deeper breaths can help? "Acculmulation of carbon dioxide increases the level of carbonic acid, which can lead to acidosis in the body." Accumulation of carbon dioxide increases the level of carbonic acid, a volatile acid, which can lead to acidosis in the body. Hydrogen does not produce bicarbonate, increase carbonic acid, or lead to alkalosis. Bicarbonate does not increase carbonic acid levels. The nurse is caring for a patient with sepsis and respiratory alkalosis. Hypoxemia It is important to recognize the presence of respiratory alkalosis, not only in order to quickly intervene to normalize pH, but because respiratory alkalosis could be the result of hypoxemia caused by a potentially life-threatening condition, such as a pulmonary embolus or sepsis. Increased hydrogen and increased bicarbonate levels are not associated with respiratory alkalosis. Hypocapnia, not hypercapnia, is associated with respiratory alkalosis. Which mechanism does the renal system use to increase bicarbonate in the body? Retains HCO3- by the resorption of bicarbonate from the renal tubule lumen back into the blood. The renal system keeps HCO3- by the resorption of bicarbonate from the renal tubule lumen back into the blood, not by excreting from the body or the urine. The renal system does not increase hydrogen to influence bicarbonate. The nurse is assessing a patient who has a rapid respiratory rate. Respiratory alkalosis The patient is at risk for respiratory alkalosis due to hyperventilation by increased alveolar ventilation in excess of carbon dioxide production as a result of an increased rate and/or depth of breathing. Since it is the lungs, it is not a metabolic issue. Getting rid of too much CO2 is loss of an acid; therefore, acidosis is not the result. A patient is hyperventilating due to a panic attack. Have the patient breathe into a paper bag. A patient who is hyperventilating due to anxiety or emotional reasons needs to rebreathe exhaled air to help retain CO2. It is not an oxygenation issue; neither oxygen nor intubation are required. Breathing deeper and faster would worsen the imbalance by further decreasing CO2. Which compensatory mechanism of the renal system helps decrease acidosis in the body? Conservation of HCO3- by the resorption of bicarbonate The kidneys regulate the elimination of both H+ and the base bicarbonate. To decrease acidosis, the kidneys conserve HCO3- by the resorption of bicarbonate from the renal tubule lumen, and put it back into the blood. This conservation of bicarbonate—a base—would help decrease acidosis. Retaining hydrogen, decreasing ammonia, or excreting the bicarbonate out of the body would increase acidosis. The nurse
is reviewing acid-base balance with colleagues. "When acidosis is detected in the brain, the respiratory center increases the rate and depth of breathing, which increases the elimination of CO2, thus decreasing carbonic acid." When acidosis is detected by the brain, the respiratory center increases the rate and depth of breathing, which increases the elimination of CO2, triggering a decrease in carbonic acid, which brings the pH back up toward normal. Alkalosis would cause the respiratory rate to slow. The nurse is assessing a patient with severe ketoacidosis. Kussmaul respirations Signs of compensation for metabolic acidosis such as ketoacidosis include increased rate and depth of breathing as the lungs eliminate more than the normal amount of carbon dioxide. Kussmaul respirations, which are very deep and rapid respirations, are present in severe cases of metabolic acidosis. Shallow or slowing respirations would not be expected. The nurse is teaching a coworker about the best management of metabolic acidosis. "The best way to approach treatment of metabolic acidosis is controlling the underlying cause of the disorder." The best way to approach treatment of metabolic acidosis is controlling the underlying cause of the disorder. Oxygen, slowing breathing, and administering bicarbonate are not the best approaches to treatment. A patient receiving high-dose pain medication is diagnosed with respiratory
acidosis. Improving ventilation Improving ventilation in order to increase the elimination of carbon dioxide, thereby decreasing the level of carbonic acid, is the best action for respiratory acidosis. Oxygen administration to reverse hypoxemia accompanying hypercapnia will not increase elimination of carbon dioxide. Breathing into cupped hands and slowing respirations would increase CO2. The nurse is assessing a patient with respiratory acidosis. Evidence of tissue hypoxia Tissue hypoxia would be expected on assessment. CO2 levels would be above 45 mmHg. Breathing would generally be slow or shallow, allowing for CO2 levels to rise. Blood oxygen levels would decrease. The
nurse is explaining to a patient how acidosis can affect the heart. "Acidosis in the body can lead to a decreased contractility of heart muscle." Acidosis in the body can lead to a decrease in the contractility of the heart. Acidosis may not cause the heart to be slow and it does not cause increased blood pressure. The nurse is teaching a colleague about the effect of acidosis on heart function. Which statement should the nurse make that summarizes the effects of acidosis on heart functions? "Acidosis decreases cardiac contractility." Acidosis has a negative inotropic effect on the heart; that is, it decreases cardiac contractility. It does not increase contractility or have a positive effect. To say that acidosis has no effect on the heart muscle is incorrect. The
nurse is reviewing laboratory data collected on a patient. pH 7.25 The lab values that reflect acidosis are pH 7.25, CO2 50 mmHg, HCO3- 24 mEq/L. A normal pH is between 7.35 and 7.45. A pH of 7.25 is acidosis. A pH above 7.45 is alkalotic. The nurse is reviewing arterial blood gas results in a patient with
respiratory acidosis. pH 7.28 Normally, the respiratory system maintains a partial pressure of CO2 in the arterial blood (PaCO2 ) of 35-45 mmHg. The renal system maintains a HCO3- level between 22 and 26 mEq/L. Normally, the ratio of the base bicarbonate (HCO3) to carbonic acid (H2CO3) is 20:1. As long as that ratio is maintained at 20:1, the pH stays within the normal range. Since CO2 is an acid, a rise will create acidosis and a fall will create alkalosis. HCO3- is a base. A rise will create alkalosis and a fall will create acidosis. What factor is responsible for maintaining acidYour kidneys and lungs work to maintain the acid-base balance. Even slight variations from the normal range can have significant effects on your vital organs.
Which of the following systems maintains the acidThe two body systems that help regulate acid-base balance in the body are the kidney and the lungs that work continuously to help with regulation of acid base balance by excreting the excess acidic and basic ions.
Which system regulates the acidThe renal system affects pH by reabsorbing bicarbonate and excreting fixed acids. Whether due to pathology or necessary compensation, the kidney excretes or reabsorbs these substances which affect pH. The nephron is the functional unit of the kidney.
What is acidAcid base balance is defined as the process of regulating the pH, bicarbonate concentration and. partial pressure of carbon dioxide of body fluids.
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