RNSG 1343 Complex Concepts of Adult Health Ch 12 Evolve

A patient is admitted with chronic anemia. What physiologic imbalance does the nurse suspect the patient is at risk of developing?

Acidosis (Protein buffers, especially hemoglobin buffers, are the primary buffer of hydrogen ions. When patients are anemic, there is less hemoglobin to buffer hydrogen ions and a reduced ability for the body to prevent acidosis. There is no information that suggests the patient is at risk for ineffective ventilation, hypokalemia, or alkalosis.)

The nurse is caring for a group of patients with acidosis. The nurse recognizes that Kussmaul respirations are consistent with which situation?

Aspirin overdose (If acidosis is metabolic in origin, the rate and depth of breathing increase as the hydrogen ion level rises; this is known as Kussmaul respiration. Metabolic acidosis is caused by alcoholic beverages, methyl alcohol, and acetylsalicylic acid (aspirin). Mechanical ventilation is used to correct hypoxemia and hypercapnia (elevated Paco 2). Hydrochlorothiazide causes metabolic alkalosis. Sodium bicarbonate is used in the treatment of metabolic acidosis; administration of this buffer may cause metabolic alkalosis.)

Which conditions place a patient at risk for developing metabolic alkalosis? Select all that apply.

Blood transfusion. Nasogastric suctioning. Total parenteral nutrition. (Conditions placing a patient at risk for metabolic alkalosis result from an overproduction or underelimination of base. Blood transfusion, administration of total parenteral nutrition, and nasogastric suctioning increase a patient's risk for metabolic alkalosis. Hypovolemic shock will result in respiratory alkalosis. Diarrhea and fever will cause metabolic acidosis.)

The nurse is assessing the laboratory reports of a patient with impaired kidney function. What changes most indicate the patient has metabolic acidosis?

Decrease in serum bicarbonate level (In metabolic acidosis, the bicarbonate level is low and arterial blood pH is decreased. The pathology of metabolic acidosis related to impaired kidney function is associated with underelimination of hydrogen ions and underproduction of bicarbonate, not the increase in partial pressure of arterial oxygen or the decrease in partial pressure of arterial carbon dioxide.)

Which conditions can cause metabolic acidosis? Select all that apply.

Diarrhea. Liver failure. Kidney failure. (Diarrhea, liver failure, and kidney failure can result in metabolic acidosis. Airway obstruction and respiratory depression may result in respiratory acidosis.)

A patient is admitted with severe diabetic ketoacidosis. Arterial blood gas results reveal a pH of 7.21. What is this patient's acidosis most likely in response to?

Excessive breakdown of fatty acids (Metabolic acidosis can result from the overproduction of hydrogen ions, underelimination of hydrogen ions, or insufficient bicarbonate ions. Excessive breakdown of fatty acids that occurs with diabetic ketoacidosis or starvation results in overproduction of hydrogen ions and metabolic acidosis. Anaerobic metabolism produces lactic acid as a cause of metabolic acidosis. Excessive intake of alcoholic beverages will also cause metabolic acidosis because of the high concentration of hydrogen ions in alcohol. Excessive intake of insulin will not result in diabetic ketoacidosis.)

How does the body compensate for a low pH?

Increases respiratory rate (When the body has an acid-base imbalance, it finds ways to compensate. Low pH indicates acidosis, which the body can combat with an increased respiratory rate to blow off carbon dioxide. Decreased respirations would result in worsening acidosis. The kidneys may also respond by releasing bicarbonate, not decreasing its release. The body is already retaining carbon dioxide, so continuing to retain it would not affect low pH.)

What is one of the causes of acidosis?

Kidney failure (Causes of acidosis include kidney failure, pancreatitis, liver failure, and dehydration. Excessive body fluids, heart failure, and colitis are causes of alkalosis.)

Deep and rapid breaths consistent with Kussmaul respirations are found in patients with which type of acid-base imbalance?

Metabolic acidosis (In metabolic acidosis, the rate and depth of breathing increase as the hydrogen ion levels rise. The breathing pattern becomes deep and rapid and not under voluntary control. This type of breathing is known as Kussmaul respiration, which is not present in respiratory alkalosis, respiratory acidosis, or metabolic alkalosis.)

When evaluating the laboratory results of a patient with diabetic ketoacidosis, which lab value indicates the body has fully compensated from this acid-base imbalance?

Normal pH on arterial blood gases (Arterial blood gas pH returns to normal when the body's compensatory efforts are fully effective. Glucose, potassium, and bicarbonate are affected by diabetic acidosis, but their return to normal is not an indicator of acid-base balance.)

A diabetic patient shows symptoms of diabetic ketoacidosis. What mechanism causes acidosis in this patient?

Overproduction of hydrogen ions (In diabetic ketoacidosis, there is an excessive breakdown of fatty acids. This produces strong acids (ketoacids) with the release of large amounts of hydrogen ions. Underelimination of hydrogen ions occurs when hydrogen ions are produced at normal rates, but their elimination is reduced. This is seen in patients with lung and kidney problems. Bicarbonate ion is made in the kidney or in the pancreas. In patients with impaired kidney or pancreatic function, there is underproduction of bicarbonate ions leading to acidosis. Overelimination of bicarbonate ions occurs when there is an excessive loss of bicarbonate ions. This occurs in diarrhea.)

When caring for a patient with kidney failure who has metabolic acidosis, which symptom does the nurse expect as evidence of the body's compensatory effort?

Rapid and deep respirations (Kussmaul respirations (rapid, deep respirations) represent the body's attempt to compensate for metabolic acidosis. The skin is warm, dry, and flushed in metabolic acidosis. Cardiovascular symptoms may occur, but they are manifestations of acidosis, not evidence of compensation.)

Which acid-base imbalance does the nurse anticipate the patient with morbid obesity may develop?

Respiratory acidosis (Respiratory acidosis is related to CO 2 retention secondary to respiratory depression, inadequate chest expansion, airway obstruction, or reduced alveolar-capillary diffusion. Respiratory acidosis is common in morbidly obese patients who experience inadequate chest expansion owing to their size and work of breathing. Metabolic acidosis is related to overproduction of hydrogen ions, underelimination of hydrogen ions, underproduction of bicarbonate ions, and overelimination of bicarbonate ions. Metabolic alkalosis is related to loss of bicarbonate or buffers (i.e., vomiting or nasogastric suction). Respiratory alkalosis usually is caused by excessive loss of CO 2 through hyperventilation secondary to fever, central nervous system lesions, and salicylates.)

Lab results for a 62-year-old patient show the following results: pH 7.48; bicarbonate 26; PaO 2 90; PaCO 2 32. These findings are consistent with which acid-base imbalance?

Respiratory alkalosis

A patient with diabetes mellitus is brought to the emergency department after vomiting for several days. The patient has rapid, deep respirations and a urine dipstick reveals ketonuria. Which process does the nurse suspect is occurring with this patient?

Respiratory compensation for metabolic acidosis (Patients with diabetes mellitus can develop metabolic acidosis. Respiratory compensation occurs through the lungs as the rate and depth of respirations increase in order to reduce hydrogen ion levels. Kidney compensation is not occurring.)

What is taking place in the body when hyperventilation occurs?

The central nervous system is responding to a rise in carbon dioxide. (When the amount of carbon dioxide in the brain, blood, and tissues rise, the central nervous system responds by increasing the rate and depth of breathing (hyperventilation). Hyperventilation is not a response to lactate rising in the body. It is most related to a decreased (not increased) pH and a decreased (not increased) level of bicarbonate.)

To decrease the risk of acid-base imbalance, what goal must the patient with diabetes mellitus strive for?

Maintaining blood glucose level within normal limits. (Maintaining blood glucose levels within normal limits is the best way to decrease the risk of acid-base imbalance. Blood glucose levels must be checked not once but several times a day. Drinking 3 L of fluid per day is not necessary to maintain acid-base balance. Eating regularly is a way to achieve acid-base balance but is not the goal itself.)

Which electrolyte abnormality does the nurse anticipate when reviewing laboratory data for a patient admitted with metabolic acidosis?

Hyperkalemia (Serum potassium (hyperkalemia) occurs during metabolic acidosis as the body attempts to maintain pH by moving potassium ions from the cell in exchange with hydrogen ions moving into the cell. Hypokalemia may occur as the cause of the metabolic acidosis is corrected. Sodium concentrations (hypernatremia and hyponatremia) are not affected in the buffering process of acid-base balance.)

A patient admitted with diabetic ketoacidosis was treated for metabolic acidosis with intravenous (IV) fluids and insulin. Which electrolyte imbalance does the nurse monitor for as the acid-base imbalance resolves?

Hypokalemia (In acidosis, extracellular hydrogen ions move into the cell and potassium moves out, causing hyperkalemia. In diabetic ketoacidosis, by treating the elevated serum glucose with insulin and IV fluids, the acid-base imbalance resolves. As the acidosis resolves, the hydrogen ions move out of the cell, and potassium moves back into the cell, causing hypokalemia in the plasma. Sodium levels are not affected by diabetic ketoacidosis.)

Which arterial blood gas laboratory values would be seen in metabolic alkalosis?

pH 7.49, HCO 3 - 32 (In metabolic alkalosis, pH is greater than 7.45 and HCO 3- is greater than 28. pH 7.28 and CO 2 54 = respiratory acidosis (pH < 7.35, CO 2 >45). pH 7.53 and CO 2 28 = respiratory alkalosis (pH > 7.45, CO 2 < 35). pH 7.31 and HCO 3- 18 = metabolic acidosis (pH < 7.35, HCO 3- < 21).)