THE POINT CH 13: ELECTROLYTES
You are caring for a 72-year-old client who has been admitted to your unit for a fluid volume imbalance. You know which of the following is the most common fluid imbalance in older adults?
Dehydration Explanation: The most common fluid imbalance in older adults is dehydration. Because of reduced thirst sensation that often accompanies aging, older adults tend to drink less water. Use of diuretic medications, laxatives, or enemas may also deplete fluid volume in older adults. Chronic fluid volume deficit can lead to other problems such as electrolyte imbalances.
Hypokalemia can cause which symptom to occur?
Excessive thirst Explanation: If prolonged, hypokalemia can lead to an inability of the kidneys to concentrate urine, causing dilute urine and excessive thirst.
A nurse is caring for a client with metastatic breast cancer who is extremely lethargic and very slow to respond to stimuli. The laboratory report indicates a serum calcium level of 12.0 mg/dl, a serum potassium level of 3.9 mEq/L, a serum chloride level of 101 mEq/L, and a serum sodium level of 140 mEq/L. Based on this information, the nurse determines that the client's symptoms are most likely associated with which electrolyte imbalance?
Hypercalcemia Explanation: The normal reference range for serum calcium is 9 to 11 mg/dl. A serum calcium level of 12 mg/dl clearly indicates hypercalcemia. The client's other laboratory findings are within their normal ranges, so the client doesn't have hypernatremia, hypochloremia, or hypokalemia.
The nurse is assessing residents at a summer picnic at the nursing facility. The nurse expresses concern due to the high heat and humidity of the day. Although the facility is offering the residents plenty of fluids for fluid maintenance, the nurse is most concerned about which?
Insensible fluid loss Explanation: Due to the high heat and humidity, geriatric clients are at a high risk for insensible fluid loss through perspiration and vapor in the exhaled air. These losses are noted as unnoticeable and unmeasurable.
Which intervention is most appropriate for a client with an arterial blood gas (ABG) of pH 7.5, a partial pressure of arterial carbon dioxide (PaCO2) of 26 mm Hg, oxygen (O2) saturation of 96%, bicarbonate (HCO3-) of 24 mEq/L, and a PaO2 of 94 mm Hg?
Instruct the client to breathe into a paper bag. Explanation: The ABG results reveal respiratory alkalosis. The best intervention to raise the PaCO2 level would be to have the client breathe into a paper bag.
A client has the following arterial blood gas (ABG) values: pH, 7.12; partial pressure of arterial carbon dioxide (PaCO2), 40 mm Hg; and bicarbonate (HCO3-), 15 mEq/L. These ABG values suggest which disorder?
Metabolic acidosis Explanation: This client's pH value is below normal, indicating acidosis. The HCO3- value also is below normal, reflecting an overwhelming accumulation of acids or excessive loss of base, which suggests metabolic acidosis. The PaCO2 value is normal, indicating absence of respiratory compensation. These ABG values eliminate respiratory alkalosis, respiratory acidosis, and metabolic alkalosis.
A nurse reviews the arterial blood gas (ABG) values of a client admitted with pneumonia: pH, 7.51; PaCO2, 28 mm Hg; PaO2, 70 mm Hg; and HCO3--, 24 mEq/L. What do these values indicate?
Respiratory alkalosis Explanation: A client with pneumonia may hyperventilate in an effort to increase oxygen intake. Hyperventilation leads to excess carbon dioxide (CO2) loss, which causes alkalosis — indicated by this client's elevated pH value. With respiratory alkalosis, the kidneys' bicarbonate (HCO3-) response is delayed, so the client's HCO3- level remains normal. The below-normal value for the partial pressure of arterial carbon dioxide (PaCO2) indicates CO2 loss and signals a respiratory component. Because the HCO3- level is normal, this imbalance has no metabolic component. Therefore, the client is experiencing respiratory alkalosis.
A client comes to the emergency department with status asthmaticus. His respiratory rate is 48 breaths/minute, and he is wheezing. An arterial blood gas analysis reveals a pH of 7.52, a partial pressure of arterial carbon dioxide (PaCO2) of 30 mm Hg, PaO2 of 70 mm Hg, and bicarbonate (HCO3??') of 26 mEq/L. What disorder is indicated by these findings?
Respiratory alkalosis Explanation: Respiratory alkalosis results from alveolar hyperventilation. It's marked by a decrease in PaCO2 to less than 35 mm Hg and an increase in blood pH over 7.45.
What foods can the nurse recommend for the patient with hypokalemia?
Sources of potassium include fruit juices and bananas, melon, citrus fruits, fresh and frozen vegetables, lean meats, milk, and whole grains
To compensate for decreased fluid volume (hypovolemia), the nurse can anticipate which response by the body?
Tachycardia Explanation: Fluid volume deficit, or hypovolemia, occurs when the loss of extracellular fluid exceeds the intake of fluid. Clinical signs include oliguria, rapid heart rate, vasoconstriction, cool and clammy skin, and muscle weakness. The nurse monitors for rapid, weak pulse and orthostatic hypotension.
A nurse is conducting an initial assessment on a client with possible tuberculosis. Which assessment finding indicates a risk factor for tuberculosis?
The client had a liver transplant 2 years ago. Explanation: A history of immunocompromised status, such as that which occurs with liver transplantation, places the client at a higher risk for contracting tuberculosis. Other risk factors include inadequate health care, traveling to countries with high rates of tuberculosis (such as southeastern Asia, Africa, and Latin America), being a health care worker who performs procedures in which exposure to respiratory secretions is likely, and being institutionalized.
Metabolic acidosis is marked by
a decrease in HCO3? to less than 22 mEq/L, and a decrease in blood pH to less than 7.35.
Metabolic alkalosis is a clinical disturbance characterized by
a high pH and high plasma bicarbonate concentration.
What arterial blood gas results would be consistent with metabolic alkalosis?
a pH greater than 7.45 and a serum bicarbonate concentration greater than 26 mEq/L.
Decreased renal function in older adults can cause
an inability to concentrate urine and is usually associated with fluid and electrolyte imbalance
A client with emphysema is at a greater risk for developing which acid-base imbalance?
chronic respiratory acidosis Explanation: Respiratory acidosis, which may be either acute or chronic, is caused by excess carbonic acid, which causes the blood pH to drop below 7.35.
Hypercalcemia causes
deep bone pain, constipation, anorexia, nausea, vomiting, polyuria, thirst, pathologic fractures, and mental changes.
A client is taking spironolactone (Aldactone) to control her hypertension. Her serum potassium level is 6 mEq/L. For this client, the nurse's priority should be to assess her:
electrocardiogram (ECG) results. Explanation: Although many changes are seen in hyperkalemia, ECG results should take priority because changes can indicate potentially lethal arrhythmias such as ventricular fibrillation. It wouldn't be appropriate to assess the client's neuromuscular function, bowel sounds, or respiratory rate for effects of hyperkalemia.
ABG analysis is the only test that evaluates
gas exchange in the lungs, providing information about the client's oxygenation status.
Anascara is another term for
generalized edema, or brawny edema, in which the interstitial spaces fill with fluid.
In metabolic alkalosis, the HCO3? is
greater than 26 mEq/L and the pH is greater than 7.45.
A client reports muscle cramps in the calves and feeling "tired a lot." The client is taking ethacrynic acid (Edecrin) for hypotension. Based on these symptoms, the client will be evaluated for which electrolyte imbalance?
hypokalemia Explanation: Hypokalemia causes fatigue, weakness, anorexia, nausea, vomiting, cardiac dysrhythmias, leg cramps, muscle weakness, and paresthesias. Many diuretics, such as ethacrynic acid (Edecrin), also waste potassium.
Oral intake is controlled by the thirst center, located in which cerebral area?
hypothalamus
A poor appetite, erratic meal patterns, inability to prepare nutritious meals, or financial circumstances may influence nutritional status, resulting in
imbalances of electrolytes
Clients diagnosed with hypervolemia should avoid sweet or dry food because it
increases the client's desire to consume fluid. Explanation: The management goal in hypervolemia is to reduce fluid volume. For this reason, fluid is rationed and the client is advised to take a limited amount of fluid when thirsty. Sweet or dry food can increase the client's desire to consume fluid.
Pitting edema occurs when
indentations remain in the skin after compression.
Calcium deficit is associated with the following symptoms:
numbness and tingling of the fingers, toes, and circumoral region; positive Trousseau's sign and Chvostek's sign; seizures, carpopedal spasms, hyperactive deep tendon reflexes, irritability, bronchospasm, anxiety, impaired clotting time, decreased prothrombin, diarrhea, and hypotension.
Normally, urine contains NO:
protein, glucose, ketones, bilirubin, bacteria, casts, or crystals.
Nausea, vomiting, abdominal pain, and diarrhea may accompany
respiratory acidosis
A client admitted with acute anxiety has the following arterial blood gas (ABG) values: pH, 7.55; partial pressure of arterial oxygen (PaO2), 90 mm Hg; partial pressure of arterial carbon dioxide (PaCO2), 27 mm Hg; and bicarbonate (HCO3-), 24 mEq/L. Based on these values, the nurse suspects:
respiratory alkalosis. Explanation: This client's above-normal pH value indicates alkalosis. The below-normal PaCO2 value indicates acid loss via hyperventilation; this type of acid loss occurs only in respiratory alkalosis. These ABG values wouldn't occur in metabolic acidosis, respiratory acidosis, or metabolic alkalosis.
Red blood cell count, sputum culture, total hemoglobin, and ABG analysis all help evaluate a client with
respiratory problems
Third-spacing describes the translocation of fluid from
the intravascular or intercellular space to tissue compartments, where it becomes trapped and useless. The client manifests signs and symptoms of hypovolemia with the exception of weight loss. There may be signs of localized enlargement of organ cavities (such as the abdomen) if they fill with fluid, a condition referred to as ascites.
Signs of hypocalcemia include
tingling in the extremities and the area around the mouth and muscle and abdominal cramps
Dextran in normal saline is a
colloid
Symptoms of hyperkalemia include
diarrhea, nausea, muscle weakness, paresthesias, and cardiac dysrhythmias.
A patient is diagnosed with hypocalcemia. The nurse advises the patient and his family to immediately report the most characteristic manifestation. What is the most characteristic manifestation?
Tingling or twitching sensation in the fingers
Chloride, bicarbonate, and phosphate are
anions
Which electrolyte is a major cation in body fluid?
K+
Chronic respiratory acidosis is associated with disorders such as
emphysema, bronchiectasis, bronchial asthma, and cystic fibrosis.
0.45% normal saline is a
hypotonic solution
Clients diagnosed with bulimia frequently suffer
potassium loss through self-induced vomiting and misuse of laxatives, diuretics, and enemas; thus, the client should avoid laxatives and enemas. Prevention measures may involve encouraging the client at risk to eat foods rich in potassium (when the diet allows), including fruit juices and bananas, melon, citrus fruits, fresh and frozen vegetables, lean meats, milk, and whole grains. If the hypokalemia is caused by abuse of laxatives or diuretics, client education may help alleviate the problem.
Electrocardiogram findings associated with hypocalcemia include
prolonged QT interval and lengthened ST.
Which is the most common cause of symptomatic hypomagnesemia?
Alcoholism Explanation: Alcoholism is currently the most common cause of symptomatic hypomagnesemia. Intravenous drug use, sedentary lifestyle, and burns are not the most common causes of hypomagnesemia.
Potassium is never administered by
IV push, IM, or SQ
A client hospitalized for treatment of a pulmonary embolism develops respiratory alkalosis. Which clinical findings commonly accompany respiratory alkalosis?
Light-headedness or paresthesia Explanation: The client with respiratory alkalosis may complain of light-headedness or paresthesia (numbness and tingling in the arms and legs).
A client with a suspected overdose of an unknown drug is admitted to the emergency department. Arterial blood gas values indicate respiratory acidosis. What should the nurse do first?
Prepare to assist with ventilation. Explanation: Respiratory acidosis is associated with hypoventilation; in this client, hypoventilation suggests intake of a drug that has suppressed the brain's respiratory center. Therefore, the nurse should assume the client has respiratory depression and should prepare to assist with ventilation. After the client's respiratory function has been stabilized, the nurse can safely monitor the heart rhythm, prepare for gastric lavage, and obtain a urine specimen for drug screening.
Which condition leads to chronic respiratory acidosis in older adults?
Thoracic skeletal change Explanation: Poor respiratory exchange as the result of chronic lung disease, inactivity, or thoracic skeletal changes may lead to chronic respiratory acidosis
Potassium depletion depresses the release of
insulin and results in glucose intolerance.
In respiratory acidosis, the pH is
less than 7.35 and the PaCO2 is greater than 45 mm Hg.
Overuse of sodium bicarbonate may lead to
metabolic alkalosis
