Unit 2 (fluid and electrolytes)

Which of the following solutions is hypotonic? a) Lactated Ringer's solution b) 0.9% NaCl c) 5% NaCl d) 0.45% NaCl

0.45% NaCl Correct Explanation: Half-strength saline is hypotonic. Lactated Ringer's solution is isotonic. Normal saline (0.9% NaCl) is isotonic. A solution that is 5% NaCl is hypertonic.

Below which serum sodium level may convulsions or coma can occur? a) 140 mEq/L b) 142 mEq/L c) 145 mEq/L d) 135 mEq/L

135 mEq/L Correct Explanation: Normal serum concentration level ranges from 135 to 145 mEq/L. When the level dips below 135 mEq/L, there is hyponatremia. 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 are within the normal range

The nurse is caring for a patient with hypernatremia. What complication of hypernatremia should the nurse continuously monitor for? a) Cerebral edema b) Red blood cell hydrolysis c) Red blood cell crenation d) Renal failure

Cerebral edema Explanation: Treatment of hypernatremia consists of a gradual lowering of the serum sodium level by the infusion of a hypotonic electrolyte solution (e.g., 0.3% sodium chloride) or an isotonic nonsaline solution (e.g., dextrose 5% in water [D5W]). D5W is indicated when water needs to be replaced without sodium. Clinicians consider a hypotonic sodium solution to be safer than D5W because it allows a gradual reduction in the serum sodium level, thereby decreasing the risk of cerebral edema. It is the solution of choice in severe hyperglycemia with hypernatremia. A rapid reduction in the serum sodium level temporarily decreases the plasma osmolality below that of the fluid in the brain tissue, causing dangerous cerebral edema.

A confused client exhibits a systolic blood pressure of 108, heart rate of 112 beats per minute, and respirations of 28 breaths per minute. The client's skin is cold and clammy. The nurse assesses this shock as a) Progressive b) Circulatory c) Cardiogenic d) Compensatory

Compensatory

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? a) Hypovolemia b) Dehydration c) Hypervolemia d) Fluid volume excess

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. Therefore, options A, C, and D are incorrec

A priority nursing intervention for a client with hypervolemia involves which of the following? a) Drawing a blood sample for typing and crossmatching. b) Establishing I.V. access with a large-bore catheter. c) Encouraging the client to consume sodium-free fluids. d) Monitoring respiratory status for signs and symptoms of pulmonary complications.

Explanation: Hypervolemia, or fluid volume excess (FVE), refers to an isotonic expansion of the extracellular fluid. Nursing interventions for FVE include measuring intake and output, monitoring weight, assessing breath sounds, monitoring edema, and promoting rest. The most important intervention in the list involves monitoring the respiratory status for any signs of pulmonary congestion. Breath sounds are assessed at regular intervals

The loss of ECF volume exceeds intake of fluids Caused by abnormal fluid loss(sweating, GI suctioning,diarrhea,vomiting), decreased intake, third space fluid shifts, diabetes insipidus, hemorrhage,adrenal insufficiency

FVD hypovolemia

You are caring for a client who has been admitted with a possible clotting disorder. The client is complaining of excessive bleeding and bruising without cause. You know that you should take extra care to check for signs of bruising or bleeding in what condition? a) Hypomagnesemia b) Dehydration c) Hypocalcemia d) Hypokalemia

Hypocalcemia Explanation: Hypocalcemia or low serum calcium levels can affect clotting. Therefore, in this condition, the nurse should take extra care to check for bruising or bleeding.

A physician orders an isotonic I.V. solution for a client. Which solution should the nurse plan to administer? a) Lactated Ringer's solution b) 5% dextrose and normal saline solution c) 10% dextrose in water d) Half-normal saline solution

Lactated Ringer's solution Correct Explanation: Lactated Ringer's solution, with an osmolality of approximately 273 mOsm/L, is isotonic. The nurse shouldn't give half-normal saline solution because it's hypotonic, with an osmolality of 154 mOsm/L. Giving 5% dextrose and normal saline solution (with an osmolality of 559 mOsm/L) or 10% dextrose in water (with an osmolality of 505 mOsm/L) also would be incorrect because these solutions are hypertonic

The nurse is caring for a patient with severe diarrhea. The nurse recognizes that the patient is at-risk for developing which of the following acid-base imbalances? a) Metabolic acidosis b) Respiratory alkalosis c) Respiratory acidosis d) Metabolic alkalosis

Metabolic acidosis Correct Explanation: The patient 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).

Translocation is a term used to describe the general movement of fluid and chemicals within body fluids. In every client's body, 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? a) Osmosis b) Filtration c) Active transport d) Evaporation

Osmosis Explanation: Osmosis is the movement of water through a semi permeable membrane—one that allows some but not all substances in a solution to pass through from a diluted area to a more concentrated area. Filtration promotes the movement of fluid and some dissolved substances through a semi permeable membrane according to pressure differences. This is the process of converting water into a vapor. Active transport requires the energy source ATP to drive dissolved chemicals from an area of low concentration to an area of higher concentration—the opposite of passive diffusion

Which of the following electrolytes is a major cation in body fluid? a) Potassium b) Chloride c) Bicarbonate d) Phosphate

Potassium Correct Explanation: Potassium is a major cation that affects cardiac muscle functioning. Chloride is an anion. Bicarbonate is an anion. Phosphate is an anion.

A patient is being treated in the ICU 24 hours after having a radical neck dissection completed. The patient's serum calcium level is 7.6 mg/dL. Which of the following physical examination findings is consistent with this electrolyte imbalance? a) Presence of Trousseau's sign b) Slurred speech c) Muscle weakness d) Negative Chvostek's sign

Presence of Trousseau's sign Correct Explanation: A patient status post radical neck resection is prone to developing hypocalcemia. Hypocalcemia is defined as a serum values lower than 8.6 mg/dL [2.15 mmol/L]. Signs and symptoms of hypocalcemia include: Chvostek's 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's 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 57-year-old homeless female with a history of alcohol abuse has been admitted to your hospital unitwith signs and symptoms of hypovolemia—minus the weight loss. She exhibits a localized enlargement of her abdomen. What condition could she be presenting? a) Third-spacing b) Pitting edema c) Hypovolemia d) Anasarca

Third-spacing Correct Explanation: 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. This occurs when indentations remain in the skin after compression. This 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.

hypertonic solution

a solution with an osmolality higher than that of serum

hypotonic solution

a solution with an osmolality lower than that of serum

isotonic solution

a solution with the same osmolality as serum and other body fluids

alkalosis

an acid-base imbalance characterized by a reduction in H+ concentration (increased blood pH) (A high arterial pH with increased bicarbonate concentration is called metabolic alkalosis; a high arterial pH due to reduced PCO2 is called respiratory alkalosis.)

acidosis

an acid-base imbalance characterized by an increase in H+ concentration (decreased blood pH) (A low arterial pH due to reduced bicarbonate concentration is called metabolic acidosis; a low arterial pH due to increased PCO2 is called respiratory acidosis.)

osmolarity

the number of milliosmoles (the standard unit of osmotic pressure) per liter of solution; expressed as milliosmoles per liter (mOsm/L); describes the concentration of solutes or dissolved particles

hydrostatic pressure

the pressure created by the weight of fluid against the wall that contains it. In the body, hydrostatic pressure in blood vessels results from the weight of fluid itself and the force resulting from cardiac contraction.

osmosis

the process by which fluid moves across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration; the process continues until the solute concentrations are equal on both sides of the membrane

diffusion

the process by which solutes move from an area of higher concentration to one of lower concentration; does not require expenditure of energy

tonicity

fluid tension or the effect that osmotic pressure of a solution with impermeable solutes exerts on cell size because of water movement across the cell membrane