Exam 2 Hydration

What is hydration?

Water and electrolytes; approximately 60% of body weight in adult

What does water serve as in the body?

Medium for metabolic reactions; transporter of nutrients waste products and substances; lubricant; insulator and shock absorber; regulates and maintains body temperature

What is intracellular fluid?

2/3 to 3/4 of body's total fluid; primarily in skeletal muscles; 40% of body weight in average adult

Principle electrolytes in intracellular fluid

K+ (potassium) and phosphates/sulfates

What is extracellular fluid?

Interstitial fluid and intravascular fluid (plasma)

What is interstitial fluid?

Fills spaces between cells; 15% of body weight in adult

What is intravascular fluid?

Plasma in blood and lymph; 5% of body weight

Principle electrolytes in extracellular fluid (plasma)

Na+ (sodium) and Cl- (chloride)

Ways body gains fluid

Oral; enteral; parenteral (by vein)

Ways body loses fluid

Kidneys; lungs; skin (sensible and insensible perspiration); GI tract

What is sensible perspiration?

Sweat (visible water loss)

What is insensible perspiration?

Invisible form of water loss through skin and lungs

What is aldosterone?

Major influence on fluid regulation; from adrenal cortex; regulates Na and K balance

How does aldosterone work?

Causes kidney tubules to excrete K and reabsorb Na; water is also reabsorbed

What do kidneys regulate?

ECF volume and osmolality

What do lungs regulate in fluid balance?

H+ concentration by controlling level of CO2

Nursing history for fluid and electrolyte assessment

Food and fluid intake; fluid output; signs of fluid imbalances; disease processes; medications

Physical examination for fluid assessment

Skin turgor; moisture in oral cavity; facial appearance; edema; hand and neck veins; neuromuscular irritability; mental status; crackles in lungs

Where to assess skin turgor in infants?

Check tongue turgor (skin turgor unreliable in infants)

Best measurement for fluid status

Daily weights

Daily weight to fluid conversion

Each 1 liter of fluid = 1 kg of weight = 2.2 lbs

Vital sign changes with deficient fluid

Increased pulse; decreased BP; increased respirations

Vital sign changes with excess fluid

Increased BP; bounding pulse; crackles in lungs

What to measure for intake?

Oral fluids; ice chips; foods that are liquid at room temperature; IV fluids; NG tube feedings

What to measure for output?

Urinary output; emesis and liquid feces; tube drainage

Fluid measurement conversions

1 cup = 8 ounces; 1 ounce = 30 ml

Normal potassium (K+)

3.5-5 mEq/L

Normal sodium (Na+)

135-145 mEq/L

Normal chloride (Cl-)

95-105 mEq/L

Normal bicarbonate (HCO3-)

22-26 mEq/L

Normal total proteins

6-8 g/dL

Normal albumin

3.5-5.5 g/dL

Normal arterial pH

7.35-7.45

Normal PaCO2

35-45 mm Hg

Normal PaO2

80-100 mm Hg

Nursing diagnosis: Hypovolemia

Decreased intravascular interstitial and/or intracellular fluid; dehydration; water loss alone without change in sodium

Can patient be NPO with hypovolemia nursing diagnosis?

No (must NOT be NPO)

Nursing diagnosis: Hypervolemia

Increased isotonic fluid retention

What happens in hypervolemia?

Fluid and Na retained in isotonic proportions

Nursing diagnosis: Impaired oral mucous membranes

Disruptions of lips and/or soft tissue of oral cavity

NOC for fluid balance

24 hour intake and output stable; adventitious breath sounds not present; body weight stable; neck vein distention not present

Hydration interventions

Monitor I&O; daily weights; managing oral fluids (force or restrict); diet modification; patient teaching; IV fluids

Foods high in potassium (K+)

Bananas; oranges; leafy green vegetables; salt substitutes

Foods high in sodium (Na+)

Bacon; ham; processed cheese; table salt

Isotonic IV fluids purpose

Expand vascular volume

Examples of isotonic IV fluids

Normal saline (NS); D5W; Lactated Ringer's (LR)

Hypotonic IV fluids purpose

Shift fluid from ECF into cells

Examples of hypotonic IV fluids

0.45% saline; 2.5% dextrose

Hypertonic IV fluids purpose

Expand intravascular compartment; draw fluid from cells

Examples of hypertonic IV fluids

D5/0.45% NS; D5/NS; D5/LR

Caution with hypertonic IV fluids

Use caution with patients with heart or kidney disease or dehydrated patients

Blood product for fluid volume

Albumin

Typical adult IV fluid rate

75-125 ml/hour

KVO (Keep Vein Open) rate

Slow rate around 30 ml/hour (defined by institutional policy)

Bolus IV rate

Large amount infused over 15-30 minutes; often 250 ml in adult patient

IV infusion maintenance requirements

Sterile procedure; changing tubing per policy; fluid rate ordered by MD

NIC for hydration

Fluid management; fluid monitoring; hypovolemia management

When to weigh patient for fluid volume assessment

Same scale each day; same time; same clothes

Correctly stated fluid volume nursing diagnosis

Excess fluid volume r/t heart failure; Deficient fluid volume r/t difficulty swallowing

Incorrectly stated fluid volume nursing diagnosis

Deficient fluid volume r/t NPO status (can't use NPO as etiology)

Signs of hypovolemia (dehydration)

Weak rapid pulse; decreased BP; dry mucous membranes; poor skin turgor; decreased urine output

Signs of hypervolemia (fluid overload)

Increased BP; bounding pulse; jugular vein distention; crackles in lungs; edema; weight gain

First action for vomiting and diarrhea patient

Obtain blood for serum electrolytes (assess before treating)

Infant fluid percentage

70-80% of total body weight (greater than adults; more vulnerable to loss)

Adult gender difference in fluid

Women have less fluid volume than men due to differences in muscle mass

Pregnancy fluid changes

48% plasma volume increase; even greater with multiples

Older adult fluid changes

Approximately 6% reduction in total body water; loss of muscle mass; decreased ratio of ICF to ECF; decreased renal function and inability to concentrate urine; decreased aldosterone; decreased sensation of thirst; decreased saliva volume

Climate effect on hydration

High heat and low humidity increase loss through perspiration

Diet effect on hydration

Adequate intake of fluid salt K+ Ca++ Mg++ carbohydrates fats and proteins maintains balance; protein depletion leads to hypoalbuminemia and edema

Stress effect on hydration

Increases aldosterone and glucocorticoid production leading to water retention

Exercise effect on hydration

Increases sensible water loss and electrolyte loss

Surgery effect on hydration

Stress response increases fluid retention

Burns effect on hydration

Loss of skin leads to increased fluid loss

CV disorders effect on hydration

Decreased cardiac output leads to decreased kidney perfusion leading to circulatory overload

Respiratory disorders effect on hydration

Increased risk of respiratory acidosis

Cancer effect on hydration

Increased risk of calcium disturbances with bone destruction

Head injury effect on hydration

Alteration in ADH secretion

GI disturbances effect on hydration

Loss of fluid K+ H+ and Cl-

Diabetes effect on hydration

Poorly controlled leads to increased fluid loss to clear glucose through kidney

Fever effect on hydration

Leads to insensible water loss

Diuretics effect on hydration

Loss of water and changes in K+

Laxatives effect on hydration

Fluid loss

Corticosteroids effect on hydration

Na+ and fluid retention

GI suctioning effect on hydration

Increases H+ and K+ losses

Sample I&O calculation

Half cup jello (4 oz = 120 ml) + bowl soup (6 oz = 180 ml) + can soda (12 oz = 360 ml) + 1 cup water (8 oz = 240 ml) + 800 ml IV = 1700 ml total intake

Why is daily weight best measurement?

Most accurate indicator of fluid status changes; 1 kg = 1 liter of fluid

What causes edema?

Fluid accumulation in interstitial spaces; can be caused by decreased albumin heart failure or kidney disease

Why does protein depletion cause edema?

Low albumin decreases oncotic pressure allowing fluid to shift from vascular space to interstitial space (third spacing)