Fluid & Electrolyte Balance

hypotonic solution example

0.45% normal saline, 0.33% sodium chloride, 2.5% dextrose in water, and 0.2% sodium chloride

hypertonic solution example

3% NaCl

Hypomagnesemia is a common yet often overlooked imbalance in acutely and critically ill patients. Which of the following patients is most likely at the highest risk of experiencing low serum magnesium levels?

A female patient who has liver cirrhosis and who is experiencing withdrawal from heavy alcohol use Explanation: Alcoholism is currently the most common cause of symptomatic hypomagnesemia in the United States. Hypomagnesemia is particularly troublesome during treatment of alcohol withdrawal. Therefore, the serum magnesium level should be routinely measured in patients undergoing withdrawal from alcohol. TPN, heart disease, and lymphoma are not identified as central risk factors for the development of hypomagnesemia.

Why is it important for the nurse to thoroughly assess maternal bladder and bowel status during labor?

A full bladder or rectum can impede fetal descent. Explanation: Throughout labor the nurse needs to assess the woman's fluid balance status as well as check skin turgor and mucous membranes. In addition she needs to monitor the bladder and bowel status. A full bladder or rectum can impede fetal descent.

What is the lab test commonly used in the assessment and treatment of acid-base balance?

Arterial blood gas

Which assessment should be prioritized in the care of a client who is being treated for a serum potassium level of 2.7 mEq/L (2.7 mmol/L)?

Cardiac monitoring looking for prolonged PR interval and flattening of the T wave. explanation: The most serious effects of hypokalemia are on the heart, a fact that necessitates frequent electrocardiography or cardiac telemetry. Hypokalemia produces a decrease in the resting membrane potential, causing prolongation of the PR interval. It also prolongs the rate of ventricular repolarization, causing depression of the ST segment, flattening of the T wave, and appearance of a prominent U wave. This supersedes the importance of fluid balance monitoring, arterial blood gases, oxygen saturation, or hemoglobin levels.

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

Dark, concentrated urine explanation: Dehydration indicates a fluid volume deficit. Dark, concentrated urine indicates a lack of fluid volume. Adding more fluid would dilute the urine.

An older adult male prescribed anabolic steroids for a deficiency condition has presented with blood pressure above the normal baseline. What might be the cause for an increase in blood pressure associated with anabolic steroid therapy?

Fluid and sodium retention explanation: Sodium and water retention are associated with androgen and anabolic steroid use, which aggravates hypertension.

Immediately after a burn injury, electrolytes need to be evaluated for a major indicator of massive cell destruction, which is:

Hyperkalemia. Explanation: Circulating blood volume decreases dramatically during burn shock due to severe capillary leak with variation of serum sodium levels in response to fluid resuscitation. Usually, hyponatremia (sodium depletion) is present. Immediately after burn injury, hyperkalemia (excessive potassium) results from massive cell destruction. Hypokalemia (potassium depletion) may occur later with fluid shifts and inadequate potassium replacement.

The nurse identifies which of the following as a potential cause of premature ventricular complexes (PVCs)?

Hypokalemia explanation: PVCs can be caused by cardiac ischemia or infarction, increased workload on the heart (e.g., exercise, fever, hypervolemia, heart failure, tachycardia), digitalis toxicity, acidosis, or electrolyte imbalances, especially hypokalemia.

A preschooler has vomiting, diarrhea, and a potassium level of 3 mEq/L (3 mmol/L). Which prescribed order will the nurse implement first?

I.V. infusion of 500 ml of dextrose 5% in water and half-normal saline solution with 20 mEq (20 mmol/L) of potassium chloride at 100 ml/hr

The nurse notes that the post cardiac surgery client demonstrates low urine output (< 25 mL/hr) with high specific gravity (> 1.025). What will the nurse anticipate the health care provider will order?

Increase intravenous fluids explanation: Urine output of less than 25 mL/hr may indicate a decrease in cardiac output. A high specific gravity indicates increased concentration of solutes in the urine, which occurs with inadequate fluid volume. The health care provider may increase intravenous fluids. Irrigating the urinary catheter will be done if there is a suspected blockage. Dialysis is not indicated by urinary volumes.

A client had an open cholecystectomy (gallbladder removal) 36 hours earlier, and the nurse's assessment this morning confirms that the client has not yet had a bowel movement since prior to surgery. How should the nurse best respond to this assessment finding?

Monitor the client closely and promote fluid intake. explanation: Bowel function does not typically return immediately after surgery, but it can be promoted by encouraging fluid and fiber intake as appropriate to the client and his or her surgery. A medical assessment is likely unnecessary at this early postoperative stage, and an enema would likely be premature. The nurse may not independently increase the client's IV infusion, and doing so would not necessarily promote a bowel movement.

Hypocalcemia is associated with which of the following manifestations?

Muscle twitching explanation: Clinical manifestations of hypocalcemia include paresthesias and fasciculations (muscle twitching).

A nurse is caring for a client who had a thyroidectomy and is at risk for hypocalcemia. What should the nurse do?

Observe for muscle twitching and numbness or tingling of the lips, fingers, and toes.

A patient admitted with electrolyte imbalance has carpopedal spasm, ECG changes, and a positive Chvostek sign. What deficit does the nurse suspect the patient has?

This is not necessary, unless it has been prescribed by your health care provider explanation: The body usually has sufficient amounts of calcium for these reactions. Most of the coagulation factors are proteins synthesized in the liver. Vitamin K is necessary for the synthesis of factors VII, IX, and X; prothrombin (factor II); and proteins C and S. Calcium (factor IV) is required in all but the first two steps of the clotting process. Unless prescribed, excessive calcium can contribute to electrolyte imbalance and complications.

The nurse is caring for a client after cardiac surgery. What laboratory result will lead the nurse to suspect possible renal failure?

a serum BUN of 70 mg/dL Explanation: These four laboratory results should always be assessed after cardiac surgery. Serum osmolality (N = >800 mOsm/kg) should also be included. A BUN reading of greater than 21 mg/dL is abnormal; a reading of greater than 60 mg/dL is indicative of renal failure. Urine output needs to be greater than 30 mL/hr. Normal urine specific gravity is 1.005-1.030. Normal serum creatinine values are between 0.5-1.2 mg/dL.

A patient admitted with electrolyte imbalance has carpopedal spasm, ECG changes, and a positive Chvostek sign. What deficit does the nurse suspect the patient has?

calcium explanation: Calcium deficit is associated with abdominal and muscle cramps, stridor, carpopedal spasm, hyperactive reflexes, tetany, positive Chvostek's or Trousseau's sign, tingling of fingers and around mouth, and ECG changes.

An osmotic diuretic such as mannitol is given to the client with increased intracranial pressure (ICP) to:

dehydrate the brain and reduce cerebral edema. explanation: Osmotic diuretics draw water across intact membranes, thereby reducing the volume of brain and extracellular fluid. Antipyretics and a cooling blanket are used to control fever in the client with increased ICP. Chlorpromazine may be prescribed to control shivering in the client with increased ICP. Medications such as barbiturates are given to the client with increased ICP to reduce cellular metabolic demands.

A client who has just completed running a marathon reports muscle weakness, cramping, and general fatigue despite drinking adequate amounts of water. The nurse suspects which type of hypotonic hyponatremia?

hypovolemic Explanation: Hypovolemic hypotonic hyponatremia develops when both water and sodium have been lost (as in sweating) but only water, rather than electrolyte-containing liquids, is used to replace fluids lost. This may also be caused by gastrointestinal sodium loss caused by frequent irrigation with distilled water as well as by adrenal insufficiency. Hypervolemic hyponatremia is caused when excess water is retained compared to sodium, resulting in a dilutional hyponatremia. Because the intravascular sodium is low, there is less osmotic pressure, and the water often ends up moving into the interstitial spaces due to osmosis resulting in edema or ascites. This is why it is termed hypervolemic even if the intravascular volume is low. The terms "euvolemic" and "normovolemic" are synonymous and occur when hyponatremia is present in a client with a normal total body water balance.

The nurse is caring for a child in the early stages of burn recovery. Which nursing diagnosis does the nurse prioritize?

impaired skin integrity

Isotonic solution examples

normal saline (0.9% sodium chloride), lactated Ringer's solution, 5% dextrose in water (D5W), and Ringer's solution.

Which is a correct route of administration for potassium?

oral

Fluid and electrolyte balance is maintained through the process of translocation. What specific process allows water to pass through a membrane from a dilute to a more concentrated area?

osmosis

While reviewing the basic information related to hemodialysis, the nurse explains that water molecules move through adjacent phospholipid molecules in the cell membrane by:

osmosis explanation: Water molecules move through adjacent phospholipid molecules in the cell membrane by osmosis without actually dissolving in the region occupied by the fatty acid side of the chains. Osmosis is regulated by the concentration of nondiffusible particles on either side of the membrane, with water moving from the side with the lower concentration of particles to the side with the higher concentration.

After being sick for three days, a client with a history of diabetes mellitus is admitted to the hospital with diabetic ketoacidosis (DKA). Which diagnostic test will the nurse prioritize in monitoring?

serum potassium level explanation: The nurse would prioritize the monitoring of the client's potassium level because potassium leaves the cell during periods of acidosis, causing hyperkalemia, which may cause cardiac arrhythmias. As blood glucose levels normalize with treatment, potassium reenters the cell, causing hypokalemia if levels aren't monitored closely. Hypokalemia places the client at risk for cardiac arrhythmias such as ventricular tachycardia. DKA has a lesser effect on serum calcium, sodium, and chloride levels. Changes in these levels don't typically cause cardiac arrhythmias, which the nurse would consider a priority.

A client has been experiencing lower GI difficulties that have increased in severity, and the gastroenterologist is concerned that the client's bowel is not functioning properly. What function of the lower GI tract is most likely to be affected by the client's disorder?

water and electrolyte absorption Explanation: Disorders of the lower GI tract usually affect movement of feces toward the anus, absorption of water and electrolytes, and elimination of dietary wastes.