Ch 39 Fluid, Electrolyte, and Acid-Base Balance

While reviewing the diagnostic reports of a patient, the nurse finds that the sodium level is 148 mEq/L, the potassium level is 4.8 mEq/L, the calcium level is 6.5 mg/dL, and the magnesium level is 1.1 mEq/L. What does the nurse infer from these findings? A The patient has low calcium levels. B The patient has low sodium levels. C The patient has high potassium levels. D The patient has high magnesium levels.

A A calcium level of 6.5 mg/dL indicates that the patient has hypocalcemia; normal calcium levels range from 8.5 to 10.5 mg/dL. Normal sodium levels range from 135 to 145 mEq/L; a sodium level of 148 mEq/L indicates a high sodium level, or hypernatremia. Normal potassium levels range from 3.5 to 5.0 mEq/L; a potassium level of 4.8 mEq/L is normal. Normal magnesium levels range from 1.3 to 2.1 mEq/L; a magnesium level of 1.1 mEq/L indicates that the patient has low magnesium levels, or hypomagnesemia. STUDY TIP: Consider creative ways to memorize that normal calcium levels range from 8.5 to 10.5 mg/dL. For instance, draw 8.5 cows on one side of a page with a line down the middle, and 10.5 cows on the other side of the page. Write "8.5 to 10.5 mg/dL of calcium" on the line. Glance at it throughout the days you study this chapter, and continue to add detail to the cows that will help you laugh at the drawings-anything to encourage you to look at the range (get it? cows on the range!) again and again.

A patient who is comatose is admitted to the hospital with an unknown history. Respirations are deep and rapid. Arterial blood gas levels on admission are pH, 7.20; PaCO2, 21 mm Hg; PaO2, 92 mm Hg; and HCO3-, 8. The nurse interprets these laboratory values to indicate: A Metabolic acidosis B Metabolic alkalosis C Respiratory acidosis D Respiratory alkalosis

A The low pH indicates acidosis. The low PaCO2 is caused by the hyperventilation, either from primary respiratory alkalosis (not compatible with the measured pH) or as a compensation for metabolic acidosis. The low HCO3- indicates metabolic acidosis or compensation for respiratory alkalosis (again, not compatible with the measured pH). Thus metabolic acidosis is the correct interpretation.

A patient develops acute hemolytic transfusion reaction following transfusion with incompatible blood. What treatment strategies should be included in the patient's management? Select all that apply. A Stop the transfusion immediately. B Remove tubing and replace with new IV tubing and normal saline solution. C Avoid keeping the IV line connected. D Send blood and urine to the lab. E Document the reaction, subsequent treatment, and patient response.

AB DE Stop the transfusion immediately. Remove tubing and replace with new IV tubing and normal saline solution. IV at keep-vein-open rate (KVO). Notify prescribing healthcare provider immediately. Notify blood bank. Monitor vital signs. Have emergency equipment available. Send remaining blood, blood tubing and filter, and a sample of patient's blood and urine to the lab. Document the reaction, subsequent treatment, and patient response.

A nurse is teaching a group of patients about the importance of fluid and electrolyte balance in a health awareness program. Which common causes of hypokalemia would the nurse educate the patients about? Select all that apply. A Diarrhea B Acute oliguria C Repeated vomiting D Calcium-deficient diet E Hyperaldosteronism

ACE Hypokalemia is a low potassium concentration in the blood that results from the loss of potassium. This can occur in patients with diarrhea or repeated vomiting. Hyperaldosteronism can also cause hypokalemia. Acute oliguria decreases the loss of potassium from the body and results in increased concentration of potassium or hyperkalemia. A calcium-deficient diet can cause decreased intake and absorption of calcium, thus resulting in hypocalcemia. STUDY TIP: Become familiar with reading questions on a computer screen. Familiarity reduces anxiety and decreases errors.

Which assessment findings indicate fluid volume excess in a patient with the syndrome of inappropriate antidiuretic hormone secretion (SIADH)? Select all that apply. A Total body weight gain of 8% B Total body weight loss of 5% C Urine specific gravity of 1.001 D Blood urea nitrogen level of 22 mg/dL E Serum sodium level of 130 mg/mL

ACE SIADH causes fluid volume excess. This disorder increases a patient's body weight due to the accumulation of fluids. An 8% gain of total body weight indicates that the patient has severe fluid volume excess. A urine specific gravity less than 1.005 and serum sodium concentration less than 135 mg/mL also indicate fluid volume excess from SIADH. A 5% loss of total body weight may indicate hypotonic fluid volume deficit. A blood urea nitrogen level of 22 mg/dL indicates dehydration; a blood urea nitrogen below 7 would indicate hypotonic fluid volume excess from SIADH. STUDY TIP: Be sure you understand the term antidiuretic. Diuresis is increased urination. The prefix anti- means against. Thus the antidiuretic hormone works AGAINST increased urination. SIADH leads to fluid volume excess, because less fluid is being excreted.

Aldosterone

Acts on the distal convoluted tubule of the kidney or increase the amount of water and sodium rea sorbet back into the bloodstream

Electrolytes

Are charged atoms or molecules that conduct electrical impulses across cells

Solutes

Are chemical substances that dissolve in a liquid

Bases

Are substances that can accept hydrogen ions. Most bases are chemicals that break down into hydroxide ions

Which clinical manifestation does the nurse expect to find in a patient with hypercalcemia? A Paresthesia B Renal calculi C Hyperreflexia D Increased bruising

B Hypercalcemia is an excess concentration of calcium. Excess calcium may form crystals resulting in renal caliculi, also called kidney stones. Paresthesia is caused by hyperkalemia. Hyperreflexia is caused by hyperphosphatemia. Increased bruising and bleeding occurs in hypophosphatemia.

Which sign is an indicator of fluid volume imbalance in a patient? A Moist tongue B Reduced skin turgor C Pink mucous membranes D Absence of edema in the legs

B Skin turgor acts as an indicator of fluid volume imbalance. If fluid volume deficit is present, the skin remains pinched, or tented, after pinching, which indicates decreased skin turgor. The tongue and mucous membranes can also indicate the patient's hydration status; a moist tongue and pink mucous membranes indicate a normal condition. Absence of edema in the legs is normal; edema in the legs can indicate a fluid excess imbalance.

The nurse is caring for a patient who has an intravenous line for fluid therapy. Which potential complications should the nurse be vigilant about while assessing the patient? Select all that apply. A Pallor B Bleeding C Phlebitis D Infection E Jaundice

BCD Bleeding at the venipuncture site is a potential complication of intravenous therapy, which can be noted as oozing or slow seepage of blood at the site. Phlebitis, which is characterized by tenderness, pain, or burning is an inflammation of the inner layer of a vein. Infection is a potential complication of intravenous therapy if aseptic measures were not taken during the procedure. Pallor is not a potential complication of intravenous therapy and can occur in other conditions like reduced hemoglobin. Jaundice, characterized by yellowish discoloration of skin, is not a potential complication of intravenous therapy and can occur in other conditions like hepatitis

A nurse is learning about fluid, electrolyte, and acid-base balance. Which clinical findings would the nurse evaluate in a patient with hypomagnesemia? Select all that apply. A Lethargy B Seizures C Irritable nerves and muscles D Hypoactive deep tendon reflexes E Hyperactive deep tendon reflexes

BCE As hypomagnesemia occurs due to low serum magnesium level, it increases neuromuscular excitability. The patient may experience seizures. Muscle cramps, twitching, and hyperactive deep tendon reflexes are also observed because low serum magnesium levels increase neuromuscular excitability. Lethargy is observed in hypermagnesemia, which causes decreased neuromuscular excitability. Hypoactive deep tendon reflexes are also found in hypermagnesemia. STUDY TIP: Anxiety leading to an exam is normal. Reduce your stress by studying often, not long. Spend at least 15 minutes every day reviewing the "old" material. This action alone will greatly reduce anxiety. The more time you devote to reviewing past material, the more confident you will feel about your knowledge of the topics. Start this review process on the first day of the semester. Don't wait until the middle to end of the semester to try to cram information.

Which nursing interventions are included in a patient's care plan to prevent an air embolism during intravenous (IV) therapy? Select all that apply. A Position the patient in a high Fowler's position. B Clamp the IV catheter when changing the tubing. C Monitor all gravity flow sets during the infusion. D Prime all IV tubing with solution first. E Apply ice and elevate the extremity for 24 to 48 hours.

BD Air emboli occur due to the accidental entry of air into the bloodstream due to improper preparation of IV tubing or loose connections. To prevent this, the nurse clamps the IV catheter before changing the tubing. Priming all tubing with IV solution before attaching it to the catheter removes all air from the tubing and prevents its entry into the bloodstream. Placing the patient in a high Fowler's position helps during fluid overload. Monitoring the gravity flow sets during infusion is done to prevent speed shock in the patient. Applying ice to the extremity for 24 to 48 hours and elevating the extremity is helpful if extravasation occurs during the IV infusion.

A nurse is examining a patient who is suspected of having fluid, electrolyte, and acid-base imbalances. What inquiries would help the nurse obtain a relevant history? Select all that apply. A Obtain details of the patient's sleep patterns. B Inquire about the patient's sexual behavior. C Obtain a history of medication or herbal remedies used. D Inquire whether the patient is on any weight-loss diet plan. E Inquire about the type of fluids the patient drinks daily.

CDE Asking the patient about a history of any medications or herbal remedies is very important. This is because medications such as antacids, diuretics, and laxatives can have an effect on fluid, electrolyte, and acid-base balance. Weight-loss diet plans can cause deficiencies in certain electrolytes and also lead to ketoacidosis. Drinking certain types of fluids including colas and fruit juices can have an effect on fluid, electrolyte, and acid-base balance. Details about the patient's sleep patterns and sexual behavior are not relevant to fluid, electrolyte, and acid-base imbalance. STUDY TIP: Identify your problem areas that need attention. Do not waste time on restudying information you know.

Oncotic pressure

Colloid osmotic pressure

Which patient being cared for by the nurse is at the highest risk of developing respiratory acidosis? A patient with hypokalemia B A patient with pulmonary fibrosis C A patient with salicylate overdose D A patient with chronic obstructive pulmonary disease (COPD)

D Chronic respiratory acidosis is most commonly caused by COPD. Hypokalemia, pulmonary fibrosis, and salicylate overdose do not predispose a patient to respiratory acidosis. Hypokalemia can lead to cardiac dysrhythmias. Pulmonary fibrosis can result in respiratory arrest, and salicylate overdose results in central nervous system changes. Test-Taking Tip: When using this program, be sure to note if you guess at an answer. This will permit you to identify areas that need further review. Also it will help you to see how correct your guessing can be.

Hypovolemia

Decrease in fluid volume

Orthostatic hypotension

Decrease of more than 20 mmHg in systolic pressure or 10 mmHg in diastolic pressure when moving from one position to another, such as sitting to standing

Hypoxemia

Decreased oxygen concentration in arterial blood

Metabolic acidosis

Defined as high acid content in the blood, with a pH less than 7.35 and a bicarbonate level less than 22 mEq/L

Hypermagnesemia

Defined by serum levels greater than 2.1 mEq/L, does not commonly occur

Milliequivalent

Denotes the ability of cations to bond with anions to firm molecules

Extracellular fluid

Fluid outside the cell

Isotonic solution

Has the same osmols ritzy as blood plasma

Dehydraion

Hypertonic fluid volume deficit

Transcellular fluid

Includes cerebrospinal, synovial, peritoneal, pleural, and pericardial fluids.

Hyperglycemia

Increased blood glucose levels

Phlebitis

Inflammation of the vein

Acid

Is a chemical that can release hydrogen ions in solution

Total parenteral nutrition (TNP)

Is a hypertonic IV solution designed to meet a patient's total nutritional needs

Respiratory alkalosis

Is a result of hyperventilation and excess exhalation of carbon dioxide

Intermittent infusion device

Is a saline lock or PRN adapter that allows periodic or emergency venous acess

Hypomagnesemia

Is a serum level than 1.3 mEq/L

Ascities

Is an abnormal collection of fluid in the peritoneal cavity

Peripherally inserted central catheter (PICC)

Is becoming more common in long term IV therapy

Interstitial fluid

Is fluid between the cells of an organ or tissue; it account for approximately 25% of total body fluid

Central venous catheter

Is inserted into a major vein in the arm or chest, and the lies in the superior vena cava, outside the right atrium

Edema

Is the abnormal accumulation of fluid in the interstitial spaces, typically in the face, fingers, abdomen, ankles, and feet.

Diffusion

Is the movement of so lutes across a selectively permeable membrane from areas of higher concentration to areas of lower concentration until equilibrium is reached

Osmolarity

Is the number of osmols per liter of solvent

Filtration

Is the process by which fluid and solute so move together from an area of higher pressure to one of lower pressure

Active transport

Is the transport of a solute from areas of lower to higher concentrations; it is the opposite of diffusion

Electronic infusion device

Is used for even more precise delivery

Solvent

Liquid

Peripheral IV therapy site

Located in the hands and arms and include the cephalic, basilic, accessory and upper cephalic, median basilic, median cubical, and the metacarpal veins of the hand. Foot veins are not used in adult because of the risk of thrombophlebitis. In the older adult causing inconsistent administration of fluids and medication. Veins of the foot - infants and children Scalp vein - newborn nod infant

Osmoreceptors

Located in the hypothalamus Monitor the osmolality of blood plasma

Vasoconstriction

Narrowing of blood vessels

Fluid volume excess (FVE)

Occurs when fluid intake exceeds output.

Respiratory acidosis

Occurs when gas exchange is decreased due to abnormal ventilation, perfusion, or diffusion

Hypercalcemia

Occurs when serum calcium levels exceed 10.5mg/dL

Hypocalcemia

Occurs when serum calcium levels fall below 8.5mg/dL Causes: hypoparathyroidism, Pancreatitis, Vit. D deficiency, inadequate intake of calcium rich food, Hyperphosphatemia, Chronic alcoholism

Hypophosphatemia

Occurs when serum phosphorus levels fall below 1.7 mEq/L.

Hypokalemia

Occurs when the serum potassium level falls below 3.5 mEq/L

Hypernatremia

Occurs when the serum sodium level is greater than 145 mEq/L

Hyponatremia

Occurs when the sodium level is decreased in relationship to body water. It is defined as a serum level less than 135 mEq/L.

Fluid volume deficit (FVD)

Occurs with excessive loss or inadequate intake of fluid

Hyperphosphatemia

Or serum phosphorus levels greater than 2.6 mEq/L, most often occurs as a result of impaired renal function

Albumin

Plasma proteins

Arterial blood gases

Provides essential information on a patient 's acid base balance and oxygenation status

Hypertonic solution

Pulls water from the cells to the extra cellular fluid compartment, causing cellular shrinkage

Tonicity

Refers to the level of osmotic pressure of a solution

Osmolality

Refers to the number of osmol (unit of osmotic pressed) per kg of solvent, which in this case is water

Rein-angiotensin system

Regulates blood pressure and fluid balance through vasoconstriction and excretion or reabsorption of sodium

Anti diuretic hormone ( ADH)

Secreted by the pituitary gland Maintain serum osmolality by controlling the amount of water excreted in the urine

Hyperkalemia

Serum potassium>5.0 mEq/L

Crystalloids

So lutes that dissolve easily

Hypotonic solutions

Solution with a lower osmolarity than body fluids

Colloids

Substance such as proteins that do not dissolve easily

Selectively permeable membrane

The cell membrane allows to move across but not the solutes

Osmotic pressure

The force created when two solutions of different concentration are separated by selectively permeable membrane

Hydrostatic pressure

The force of the fluid pressing against the blood vessel; it is controlled by force of myocardial contraction, rate of contraction, and blood flow.

Homeostasis

The maintenance of fluid balance

Osmosis

The movement of water across cell membrane

Metabolic alkalosis

There is an excess of bicarbonate ions, which raises the pH above 7.45 and produces bicarbonate level greater than 26 mEq/L

Hemolytic reactions

When an Rh- person is exposed to Rh+ blood for first time, Rh antibodies develop This can occur when a pregnant woman who is Rh- is carrying a fetus who is Rh+ or Rh - person receivesRh+ blood. After the person has been exposed, subsequent contact with Rh+ blood can lead to life-treating destruction of red blood cells, known as hemolytic reaction

Intravascular fluid

Which is blood plasma, accounts for approximately 8% of body fluid

Intracellular fluid

Within the cell

Atrial natriuretic peptide (ANP)

created by cells in the atrium of the heart in response to an increase in blood pressure