Fluid, Electrolyte, and Acid-Base Balance Flashcards
Fluid:
water that contains dissolved or suspended substances such as glucose, mineral salts, and proteins
ECF:
Extracellular fluid: outside the cells
ICF:
Intacellular fluid: inside the cells
ECF has 2 major divisions, and 1 minor division:
Major:
1. Intravascular fluid: liquid portion of blood
2. Interstitial fluid: between cells and outside blood vessels
Minor:
1. Transcellular fluids: secreted by epithelial cells-cerebrospinal, pleural, peritoneal, and synovial fluids
ECF Contains
Sodium, chloride, and bicarbonate
Albumin (intravas)
Gastric and intestinal secretions (trans)
ICF Cations and Anions:
C: Potassium and magnesium
A: phosphate
Osmolality of a fluid is a
measure of particles per kilogram of water
Normal value range for Osmolality:
280-300 mOsm/kg H2O
Normal range for Sodium:
136-145 mEq/L
Normal range for Potassium:
3.5-5.0 mEq/L
Normal range for Chloride:
98-106 mEq/L
Normal range for Bicarbonate (HCO3):
22-26 mEq/L
Normal range for calcium:
8.5-10 mg/dL
Normal range for magnesium:
1.5-2.5 mEq/L
Normal range for Anion gap:
5-11 mEq/L
Normal range for pH:
7.35-7.45
Normal range for PaCO2 (Arterial blood gases):
35-45 mm Hg
Normal range for Arterial blood gases PaO2:
80-100 mm Hg
Normal range for Arterial blood gases O2 Sat:
95-100%
Brain Natriuretic peptide:
determine presence of heart failure with fluid excess
Evaluation for patients who have congestive heart failure 0-100
Isotonic:
Use 5% dextrose in water
fluid with the same concentration of nonpermeant particles as normal blood
Hypotonic:
45% normal solution
more dilute than the blood
Hypertonic:
5% dextrose in normal saline, 10% dextrose in water, lactated ringers
more concentrated than normal blood
Active transport:
cells maintain their high intracellular electrolyte concentration
ATP moves electrolytes across cell membranes against the concentration gradient
Ex. Sodium potassium pump: Na out and K in
Osmosis:
Water moves through membrane that separates fluid with different particle concentrations –> meet equilibrium
osmotic pressure: inward pulling force caused by particles in the fluid
Filtration:
fluid moves into and out of capillaries
Hydrostatic pressure: the force of the fluid pressing outward against a surface
Colloids: containing albumin and other proteins
Colloid osmotic pressure or oncotic pressure: inward pulling force caused by blood proteins that help move fluid from interstitial area back into capillaries
Diffusion:
passive movement of electrolytes or other particles down the concentration gradient (high areas to low)
Normal range for Fluid Intake:
Women: 2700 ml/day
Men: 3500 ml/day
Normal range for Output:
Urine 1500 ml/day
Defecation 100-200 ml/day
Fluid output normally occurs through 4 organs:
Skin
Lungs
GI tract
Kidneys
Abnormal fluid includes:
Vomiting
Wound drainage
Hemorrhage
ADH:
Vasopressin
water retainer, increasing water retention
regulates the osmolality of the body fluids by influencing how much water is excreted in urine
Renal failure will not be able to absorb or secrete this hormone
More ADH is released if body fluids become more concentrated
RAAS:
Converts Angiotensis 1 to 2, stimulates production of aldosterone = increases BP
High BP = ACE inhibitor
Angiotensin
Converting
Enzyme
Aldosterone:
Passive, water absorbed and blood volume expands
Maintains BP and fluid balance
Thyroid:
cardiac output increased glomerular excretion rate, filter faster more urine
Extracellular fluid volume imbalances:
- ECV deficit: present when there is insufficient isotonic fluid in the extracellular compartment
- Hypovolemia: decreased vascular volume, often used when discussing ECV deficit
- ECV excess: there is too much isotonic fluid in the extracellular compartment, intake of sodium containing isotonic fluid has exceeded fluid output
Osmolality imbalances:
Hypernatremia: water deficit, hypertonic condition,
2 causes: loss of relatively more water than salt
gain of relatively more salt than water
Hyponatremia: water excess or water intoxication, hypotonic condition, arises from gain of relatively more water than salt or loss of relatively more salt than water
Clinical dehydration:
the combination of ECV deficit and hypernatrmia occur at same time
Where can you find Potassium?
Fruits Potatoes Instant coffee Molasses Brazil nuts Absorbs easily
Where can you find calcium?
dairy products canned fish with bones broccoli oranges requires vitamin D for best absorption undigested fat prevents absorption
Where can you find Magnesium?
dark green leafy vegetables
whole grains
Mg containing laxatives and antacids
Undigested fat prevents absorption
Where can you find phosphate?
Milk
processed foods
Aluminum antacids prevents absorption
What are used to monitor a patient’s acid base balance?
lab tests of blood called ABGs Arterial blood gases
-Also reveals adequacy of ventilation and oxygention
Acid production: 2 types
Cellular metabolism creates
- Carbonic acid: H2CO3
- Metabolic acids: any acids are not carbonic acid which include citric acid, lactic acid
Acid Excretion: 2 systems
- Lungs: Excretion of Carbonic Acid - exhale = form of CO2 and water
people who have lung disease have difficulty with normal excretion of carbonic acid = more acidic - Kidneys: Excretion of metabolic acids - too many H+ ions in the blood, renal cells move more H+ ions into renal tubules to be expelled, retaining more HCO3, too few = renal cells secrete fewer H+ ions
Phosphate buffers keep urine from being too acidic
Anion gap:
relfection of unmeasured anions in plasma
What removes carbonic acid from the body?
Compensatory hyperventilation
Values for Normal anion gap:
5-11 mEq/L, varies depending on lab
Daily weights and fluid intake and output measurement: Each kilogram of weight gained or lost overnight is equal to ___ retained or lost.
1 L of fluid
Assessment body weight changes from previous day:
loss of 2.2 ilbs in 24 hr in adults = ECV deficit
gain of 2.2 ilbs in 24 hr in adults = ECV excess
Infiltration:
occurs when an IV catheter becomes dislodged or a vein ruptures and IV fluids inadvertently enter subcutaneous tissue around venipuncture site
Extravasation:
when the IV fluid contains additives that damage tissue
Phlebitis:
inflammation that results from chemical, mechanical, or bacterial causes
After ABG puncture, apply pressure to site for at least how many minutes and why?
5 minutes to reduce the risk of hematoma formation
Edema forms with changes in
hydrostatic pressure differences between the capillary blood and the interstitial fluid, such as patients with right sided heart failure
-definition: tissue swelling from excess fluid
Minimum amount of urine per day is called
Obligatory urine output
400-600 mL
Insensible water loss vs sensible:
Insensible: skin, lungs
Sensible: urine, defecation, wounds
The patient with fluid overload and edema is at risk for
skin breakdown
Paralytic ileus:
severe hypokalemia can cause the absence of peristalsis
Palmar reflex indicates
positive Trousseau’s sign in hypocalcemia
Kussmaul respiration:
pattern of breaths that are deep and rapid and not under voluntary control
Causes of Hypovolemia:
- fluid loss (bleeding) or 2. third-space fluid shift
1. Fluid loss – Abdominal surgery Diabetes mellitus Diuretic therapy, excessive sweat Fever Hemorrhage Nasogastric drainage Renal failure with increased urination, Vomiting & diarrhea – raises Ph level causing alkalosis
3rd space fluid shift – Acute intestinal obstruction Acute peritonitis, burns, Crush injuries Heart failure Hypoalbuminemia Liver failure Pleural effusion
: Thirst, dizziness, nausea
Increased heart rate
Orthostatic hypotension
flat jugular veins
Deterioration in mental status (Restlessness, Anxiety, confusion) because of hypoxia
Initially Urine output > 30 mL/ hr then 10-30 ml/hr
weight loss
Delayed capillary refill, Cool ,pale skin, weak peripheral pulses
Normal blanching is 2-3 seconds- anything over that is delayed capillary refill
What to look for in Hypovolemia
Fluid replacement- isotonic (normal saline/ lactated ringers)
Oxygen therapy
Control bleeding
Lower HOB bring blood flow to brain
IV access
Monitor mental status & VS
I & O
Lung sounds: do not want fluid to go through lungs –proper adm of fluids
Weight
Mental status
Skin temperature & pulses – vital signs ia
Tests & treatment for Hypovolemia
Causes of dehydration:
prolonged fever, watery diarrhea –give meds like diphenoxylate, renal failure & hyperglycemia
Changes in mental status Dizziness, weakness, extreme thirst Fever Dry skin & mucous membranes; poor skin turgor –tenting of skin Tachycardia, hypotension Decrease urine output, concentrated
What to look for n dehydration
Tests/ Treatment Elevated hematocrit (over 42) Elevate serum osmolality above 300 Elevated serum sodium (NA) above 145 Hypotonic solution
Dehydration
Nursing Interventions Symptoms & vital signs I & O Monitor labs Safety due to fall risks Daily weights Skin assessment
Dehydration
Edema – pitting edema rate
1-4
Dependent areas
Anasarca: edema everywhere, cannot give diuretic for to get rid of
ASSOCIATED WITH HYERVOLEMIA
Tests Low hematocrit (hemodilution) Normal sodium Low potassium Low BUN Decreased serum osmolality Low oxygen level: due to too much fluid Chest x-ray = pulmonary congestion – dots of white
hypervolemia
Treatment:
Restrict sodium & fluid intake
Medications – diuretic furosemide (Lasix) –changes in bp, tenitis (ringing in ears)
Hyervolemia
Nursing interventions: Vital signs- look for tachypnea, elevated B/P Jugular vein distention I &o Lung sounds- crackles; sputum pink frothy Monitor labs Elevate HOB to help with breathing Monitor edema Weights –morning daily Skin care See it in sacrum
hypervolemia
Causes: vomiting, diarrhea, excessive sweating, burns, wound drainage, diuretics
S&S: headache, irritable, disoriented, poor skin turgor, weak, rapid pulse, low B/p, dry mucous membranes
Hyponatremia – common with dehydration
Treatment: hypertonic solution= infused slowly
Hyponatremia – common with dehydration
Causes: thirst, salt tablets, high-sodium foods, medication, gastric/ enteral tube feeding
S&S: restlessness, anorexia, N&V, weakness, lethargy, confusion, lower-grade fever, flushed skin, thirst, elevated b/p, bounding pulse, dyspnea
Hypernatremia
Treatment: underlying disorder, oral fluids, salt-free solution, diuretics
Hypernatremia
Causes: prolonged intestinal suction, dietary intake, prolonged vomiting, diarrhea, laxative misuse, severe diaphoresis, medications: diuretics (furosemide & thiazide), corticosteroids and insulin
Hypokalemia
S&S: muscle weakness, leg cramps, decreased deep tendon reflexes, decreased bowel sounds, dilute urine, pulse weak & irregular, orthostatic hypotension, palpitations
Hypokalemia
Treatment: high-potassium low-sodium diet, oral supplement, IV replacement
Hypokalemia
Causes: increased dietary intake, excessive salt substitute, potassium supplements, medications: beta-adrenergic, potassium-sparing diuretic, chemotherapy, kidney damage, burn, severe infection, trauma, crush injury, renal failure
Hyperkalemia
S&S: skeletal muscle weakness, decreases reflexes, smooth muscle hyperactivity, decreased heart rate, irregular pulse, hypotension, cardiac arrest
Hyperkalemia
Treatment: loop diuretic, potassium restricted diet, Kayexalate
Hyperkalemia
Causes: dietary, poor absorption GI tract, enteral feedings, excretion (loop/ thiazide diuretic), renal absorption
Hypomagnesemia
STARVED S&S for hypo magnesium:
Siezures Tetany Anorexia and arrtheymia Rapid heart rate Vomiting Emotional liability Deep tendon reflexes increases
Tests: low magnesium, low potassium & calcium, ECG changes
Treatment: underlying cause, diet, oral supplement, intravenous magnesium
hypomagniusm
Causes: renal dysfunction, TPN, continuous intravenous infusions
Hypermagnesemia
S&S: sleepy, weakens respiratory muscles, weak pulse , bradycardia, vasodilatation, hypotension, flushed, hypoactive reflexes
Hypermagnesemia
increase fluids= increase urine output, loop diuretic
Hypermagnesemia
Causes: inadequate intake, malabsorption GI tract (esp. high phosphorus), acute pancreatitis (loss thru feces); medication: calcitonin, loop diuretic
Hypocalcemia
S&S: confusion, irritability, seizures, paresthesia: numbness, twitching, muscle cramps, fractures
Hypocalcemia
Treatment: intravenous calcium, vitamin D supplements, oral calcium supplements, diet
Hypocalcemia
Causes: hyperparathyroidism & cancer; GI tract, kidneys, fractures
Hypercalcemia
S&S: fatigue, confusion, memory loss, personality change, depression, muscle weakness, hyporeflexia, hypertension, GI effects
Hypercalcemia
Treatment: reduce dietary intake & medications; hydrate
Hypercalcemia
-causes: due to refeeding regular food again, alcohol withdrawal
Hypophosphatemia
S&s: seizures, joint stiffness, paresthesia
Hypophosphatemia
-iv- tpn
Hypophosphatemia
Causes- due to renal failure, hypothyroidism, chemo therapy, laxities that contain phosphate
Hyperphosphatemia
S&s: tetany, cramps
Hyperphosphatemia
Treatments -increase calcium, med adm binder to phosphorus (fas-low)
Hyperphosphatemia
Most abundant ECF
Associated with sodium (potassium & calcium)
Chloride
ICF & ECF; kidneys regulate
Buffer
Bicarbonate
compound that contains hydrogen (H+) ions
Acid
compound that accepts hydrogen ions
Base
3 complex mechanisms maintain acid-base balance
Buffers
Respiratory control carbon dioxide
Renal regulation of bicarbonate
Prevent wide swings in ph
contains weak acid and base
Keep strong acids and bases either by absorbing or releasing
Buffer systems
Lungs second line of defense
Control carbonic acid
Too basic: rapid deep breathing
Too acid: shallow respiration
- Respiratory mechanisms
Kidneys last line
Regulate plasma bicarbonate
Can neutralize more acid or base
It is slow, 3 days
Renal mechanisms
Respiratory Acidosis cause:
retention of CO2
Metabolic Acidosis cause:
loss of bicarbonate
Respiratory Alkalosis cause:
blowing off CO2
Metabolic Alkalosis cause:
increase in bicarbonate
