Chapter 13: Fluid and Electrolytes: Balance and Disturbance

The nurse is caring for a client diagnosed with bulimia. The client is being treated for a serum potassium concentration of 2.9 mEq/L (2.9 mmol/L). Which statement made by the client indicates the need for further teaching?

"I can use laxatives and enemas but only once a week." The client is experiencing hypokalemia, most likely due to the diagnosis of bulimia. Hypokalemia is defined as a serum potassium concentration <3.5 mEq/L (3.5 mmol/L), and usually indicates a deficit in total potassium stores. Clients diagnosed with bulimia frequently suffer increased 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.

A client is to receive hypotonic IV solution in order to provide free water replacement. Which solution does the nurse anticipate administering?

0.45% NaCl Half-strength saline (0.45%) is hypotonic. Hypotonic solutions are used to replace cellular fluid because it is hypotonic compared with plasma. Another is to provide free water to excrete body wastes. At times, hypotonic sodium solutions are used to treat hypernatremia and other hyperosmolar conditions. Lactated Ringer solution and normal saline (0.9% NaCl) are isotonic. A solution that is 5% NaCl is hypertonic.

The physician has prescribed a hypotonic IV solution for a patient. Which IV solution should the nurse administer?

0.45% sodium chloride Half-strength saline (0.45% sodium chloride) solution is frequently used as an IV hypotonic solution.

Which is considered an isotonic solution?

0.9% normal saline An isotonic solution is 0.9% normal saline (NaCl). Dextran in normal saline is a colloid solution, 0.45% normal saline is a hypotonic solution, and 3% NaCl is a hypertonic solution.

Below which serum sodium concentration might convulsions or coma occur?

135 mEq/L (135 mmol/L) Normal serum concentration level ranges from 135 to 145 mEq/L (135-145 mmol/L). When the level dips below 135 mEq/L (135 mmol/L), hyponatremia occurs. Manifestations of hyponatremia include mental confusion, muscular weakness, anorexia, restlessness, elevated body temperature, tachycardia, nausea, vomiting, and personality changes. Convulsions or coma can occur if the deficit is severe. Values of 140, 142, and 145 mEq/L (mmol/L) are within the normal range.

The nurse is correct to state that a client's body needs to have adequate nutrition to maintain energy. Which type of transport of dissolved substances requires adenosine triphosphate (ATP)?

Active transport Active transport requires the use of the body's energy molecule (ATP) to meet body needs for fluid and particle transport. Osmosis is the movement of body fluids through a semipermeable membrane that allows not all substances to pass through. Passive diffusion allows the movement of substances from an area of higher concentration to lower concentration. Facilitated diffusion has certain dissolved substances that require the assistance from a carrier module to pass through the semipermeable membrane.

To evaluate a client for hypoxia, the physician is most likely to order which laboratory test?

Arterial blood gas (ABG) analysis Red blood cell count, sputum culture, total hemoglobin, and ABG analysis all help evaluate a client with respiratory problems. However, ABG analysis is the only test that evaluates gas exchange in the lungs, providing information about the client's oxygenation status.

Which is an insensible mechanism of fluid loss?

Breathing Loss of fluid from sweat or diaphoresis is referred to as insensible loss because it is unnoticeable and immeasurable. Losses from urination and bowel elimination are measurable. Nausea does not result in fluid loss, however if the client would develop emesis ( vomiting) this would be considered loss of body fluids and would need measured.

The nurse is caring for a client with laboratory values indicating dehydration. Which clinical symptom is consistent with the dehydration?

Dark, concentrated urine Dehydration indicates a fluid volume deficit. Dark, concentrated urine indicates a lack of fluid volume. Adding more fluid would dilute the urine. The other options indicate fluid excess.

A client was admitted to the unit with a diagnosis of hypovolemia. When it is time to complete discharge teaching, which of the following will the nurse teach the client and family? Select all that apply.

Drink at least eight glasses of fluid each day. Drink water as an inexpensive way to meet fluid needs. Respond to thirst In addition, the nurse teaches clients who have a potential for hypovolemia and their families to respond to thirst because it is an early indication of reduced fluid volume; consume at least 8 to 10 (8 ounce) glasses of fluid each day and more during hot, humid weather; drink water as an inexpensive means to meet fluid requirements; and avoid beverages with alcohol and caffeine because they increase urination and contribute to fluid deficits.

What foods can the nurse recommend for the patient with hypokalemia?

Fruits such as bananas and apricots Sources of potassium include fruit juices and bananas, melon, citrus fruits, fresh and frozen vegetables, lean meats, milk, and whole grains (Crawford & Harris, 2011b).

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 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.

An elderly client takes 40 mg of Lasix twice a day. Which electrolyte imbalance is the most serious adverse effect of diuretic use?

Hypokalemia Hypokalemia (potassium level below 3.5 mEq/L) usually indicates a defict in total potassium stores. Potassium-losing diuretics, such as loop diuretics, can induce 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 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. Those with respiratory deficits and allergies may be only able to be outside for a limited period. Those with cardiovascular compromise may need to alternate outdoor activities with indoor rest.

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. 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. Administering a decongestant, offering fluids frequently, and administering supplemental oxygen wouldn't raise the lowered PaCO2 level.

A client hospitalized for treatment of a pulmonary embolism develops respiratory alkalosis. Which clinical findings commonly accompany respiratory alkalosis?

Light-headedness or paresthesia The client with respiratory alkalosis may complain of light-headedness or paresthesia (numbness and tingling in the arms and legs). Nausea, vomiting, abdominal pain, and diarrhea may accompany respiratory acidosis. Hallucinations and tinnitus rarely are associated with respiratory alkalosis or any other acid-base imbalance.

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?

Metabolic acidosis The client is at risk for developing metabolic acidosis. Metabolic acidosis is caused by diarrhea, lower intestinal fistulas, ureterostomies, and use of diuretics; early renal insufficiency; excessive administration of chloride; and the administration of parenteral nutrition without bicarbonate or bicarbonate-producing solutes (e.g., lactate).

The calcium concentration in the blood is regulated by which mechanism?

Parathyroid hormone (PTH) The serum calcium concentration is controlled by PTH and calcitonin. The thyroid hormone, adrenal gland, or androgens do not regulate the calcium concentration in the blood.

Which electrolyte is a major cation in body fluid?

Potassium Potassium is a major cation that affects cardiac muscle functioning. Chloride, bicarbonate, and phosphate are anions.

A client is being treated in the ICU 24 hours after having a radical neck dissection completed. The client's serum calcium concentration is 7.6 mg/dL (1.9 mmol/L). Which physical examination finding is consistent with this electrolyte imbalance?

Presence of Trousseau sign After radical neck resection, a client is prone to developing hypocalcemia. Hypocalcemia is defined as a serum value <8.6 mg/dL (<2.15 mmol/L). Signs and symptoms of hypocalcemia include Chvostek sign, which consists of muscle twitching enervated by the facial nerve when the region that is about 2 cm anterior to the earlobe, just below the zygomatic arch, is tapped; and a positive Trousseau sign can be elicited by inflating a blood pressure cuff on the upper arm to about 20 mm Hg above systolic pressure; within 2 to 5 minutes, carpal spasm (an adducted thumb, flexed wrist and metacarpophalangeal joints, and extended interphalangeal joints with fingers together) will occur as ischemia of the ulnar nerve develops. Slurred speech and muscle weakness are signs of hypercalcemia.

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 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.

Which of the following electrolytes is the primary determinant of extracellular fluid (ECF) osmolality?

Sodium Sodium is the primary determinant of ECF osmolality. Sodium plays a major role in controlling water distribution throughout the body because it does not easily cross the intracellular wall membrane and because of its abundance and high concentration in the body. Potassium, calcium, and magnesium are not primary determinants of ECF osmolality.

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 All the choices are signs and symptoms of hypocalcemia, but tetany is the most characteristic manifestation that occurs when the calcium level is less than 4.4 mg/dL.

A 54-year-old male patient is admitted to the hospital with a case of severe dehydration. The nurse reviews the patient's laboratory results. Which of the following results are consistent with the diagnosis? Select all that apply.

Urine specific gravity of 1.03 Serum sodium of 148 mEq/L Serum osmolality of 310 mOsm/kg Blood urea nitrogen (BUN) of 23 mg/dL Severe dehydration is associated with an increased BUN (N = 10 to 20 mg/dL), serum osmolality (N = 275 to 300 mOsm/kg), serum sodium (N = 135 to 145 mEq/L) and urine specific gravity (N = 1.01 to 1.025). Glucose and hematocrit levels would also be elevated but are within normal range for this question.

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. Although changes in all these findings 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.

Clients diagnosed with hypervolemia should avoid sweet or dry food because it

increases the client's desire to consume fluid. 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. Sweet or dry food does not obstruct water elimination or cause dehydration. Weight regulation is not part of hypervolemia management except to the extent it is achieved on account of fluid reduction.

Following a unilateral adrenalectomy, a nurse should assess for hyperkalemia as indicated by:

muscle weakness. Muscle weakness, bradycardia, nausea, diarrhea, and paresthesia of the hands, feet, tongue, and face are findings associated with hyperkalemia, which is transient and results from transient hypoaldosteronism when the adenoma is removed. Tremors, diaphoresis, and constipation aren't seen in hyperkalemia.

When evaluating arterial blood gases (ABGs), which value is consistent with metabolic alkalosis?

pH 7.48 Metabolic alkalosis is a clinical disturbance characterized by a high pH and high plasma bicarbonate concentration. The HCO value is below normal. The PaCO value and the oxygen saturation level are within a normal range.

Which set of arterial blood gas (ABG) results requires further investigation?

pH 7.49, PaCO2 30 mm Hg, PaO2 89 mm Hg, and HCO3- 18 mEq/L The ABG results pH 7.49, PaCO2 30 mm Hg, PaO2 89 mm Hg, and HCO3- 18 mEq/L indicate respiratory alkalosis. The pH level is increased, and the HCO3- and PaCO2 levels are decreased. Normal values are pH 7.35 to 7.45; PaCO2 35 to 45 mm Hg; HCO3- 22 to 26 mEq/L.

A client has been admitted to the hospital unit with signs and symptoms of hypovolemia; however, the client has not lost weight. The client exhibits a localized enlargement of her abdomen. What condition could the client be presenting?

third-spacing 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. Pitting edema occurs when indentations remain in the skin after compression. Anascara is another term for generalized edema, or brawny edema, in which the interstitial spaces fill with fluid. Hypovolemia (fluid volume deficit) refers to a low volume of extracellular fluid.