Fluid and Electrolytes Flashcards
Hypernatremia
145 mEq/L=mmol/L or greater
2/3 Fluid
ICF
1/3 Fluid
ECF
1 L of water=
=2.2 lbs of water
Electrolytes in ECF
Na+
Cl-
Ca+
HCO3-
Electrolytes in ICF
K+, PO4-, Mg+
Na:K::Ca:??
PO4 (Phosphorus)
Solutes move
Diffusion
Carrier Molecule
Facilitated Diffusion
Requires protein (ATP) to transport
Active Transport
Normal plasma osmolality
275-295 mOsm/kg
Water excess osmolality
< 275 mOsm/kg
Dilute
Water deficit osmolality
> 295 mOsm/kg
Dehydrated
Measures the weight of a substance compared with an equal part of water
Urine specific gravity
Normal urine specific gravity
1.010-1.020
Urine specific gravity in mOsm/kg
300 mOsm/kg
Solution when no net water movement occurs; ICF and ECF net no movement.
Isotonic solution
Water moves out of the cells causing cells to shrink or possibly die.
Hypertonic
Water moves into the cell, causing the cells to swell or burst due to osmosis
Hypotonic
Examples of Isotonic Fluids
- Normal Saline - 0.9% Sodium Chloride
2. Lactated Ringers (LR)
Examples of Hypotonic Fluids
- 1/2NS - 0.45% Sodium Chloride
2. D5W?
Examples of Hypertonic Fluids
- Dextrose 5% in 1/2NS
- Dextrose 5% in NS
- Dextrose 5% in LR
is the osmotic pressure caused by plasma colloids in solution
oncotic pressure
is the osmotic pressure caused by plasma colloids in solution
oncotic pressure
Describe the abnormal fluid shift: elevation of venous hydrostatic pressure
Increasing the pressure at the venous end of the capillary inhibits fluid movement back into the capillary, which results in edema.
Caused by: fluid overload, heart failure, liver failure, obstruction of venous return to the heart and venous insufficiency.
Describe the abnormal fluid shift: Decrease in Plasma Oncotic Pressure
Fluid remains in the interstitial space if the plasma oncotic pressure is too low to draw fluid back into the capillary. Low plasma protein content decreases oncotic pressure. This can result from excessive protein loss, deficient protein synthesis, and deficient protein intake.
Describe the abnormal fluid shift: Elevation of Interstitial Oncotic Pressure
Trauma, burns, and inflammation can damage capillary walls and allow plasma proteins to accumulate in the interstitial space. This increases interstitial oncotic pressure, draws fluid into the interstitial space, and holds it there.
A term used to describe the distribution of body water.
Fluid spacing
Describes the normal distribution of fluid in ICF and ECF compartments.
First spacing
occurs when fluid accumulates in a portion of the body from which it is not easily exchanged with the rest of the ECF; it’s trapped and unavailable for functional use
EX: Ascites, sequestration, fluid in abdominal cavity, edema associated with burns, trauma, or sepsis.
Third spacing
occurs when fluid accumulates in a portion of the body from which it is not easily exchanged with the rest of the ECF; it’s trapped and unavailable for functional use
EX: Ascites, sequestration, fluid in abdominal cavity, edema associated with burns, trauma, or sepsis.
Third spacing
Hormone for sodium retention and K excretion; from adrenal cortex
Aldosterone
Hormone from Hypothalmus/Pituitary that tells kidneys to reabsorb water
Anti-diuretic hormone
Hormone that acts on/from kidneys that stimulates release of aldosterone
Renin
Hormones made by the heart and suppress secretion of aldosterone, and ADH. Promote excretion of Sodium and water, resulting in decrease in blood volume and blood pressure.
ANP and BNP
Normal water intake and ouput
2000-3000mL
Describe osmotic diuretics
-Mannitol/Resectisol Osmitrol
Used to decrease brain cell swelling and used in acute renal failure (since hanging on to fluids)
Describe Loop Diuretics
Examples: Lasix/Furosemide
Very effective. You’ll lose K (Digoxin Toxicity).
Describe Thiazide Diuretics
- hydrochlorothiazide (HydroDiuril)
- Taken PO, not IV
- Cheap, usually for HTN
- Reduces BP
Describe Potassium Sparing diuretics
Spironolactone/Aldactone
-Used in edema, HTN, Ascites, HF, Instruct to limit foods high in K
Describe Potassium Sparing diuretics
Spironolactone/Aldactone
-Used in edema, HTN, Ascites, HF, Instruct to limit foods high in K
Describe gerontological considerations with fluids.
- Decreased Rennin and aldosterone
- Increased ADH and ANP
- Increased loss of moisture through the skin
- Thirst center is less effective
Children and Elderly susceptible to fluid and electrolyte imbalances… why?
- Inability to obtain fluid without help
- Inability to express feelings of thirst
- Inaccurate assessment of output (diapers)
- loss of fluid through perspiration (fever)
- Loss of fluid through diarrhea and vomiting
Define dehydration
- Serum osmolality and sodium concentration increasees
- refers to loss of pure water alone without loss of Na
Causes of Dehydration
- Decreased intake of H2O
- Osmotic diuresis ( uncontrolled DM)
- Diabetes Insipidus (lowers ADH)
- Over-use of diuretics
dehydration - what to look for?
- Tachycardia
- Hypotension
- Changes in mental status (ALOC)
- Seizures
- Coma
- Dizziness
- Weakness
- Wt loss
- Extreme thirst
- Fever
- Dry skin and mucous membranes
- Poor turgor (tenting)
- Urine output decreased
- Concentrated urine
Dehydration Lab Values
- Elevated Hematocrit (HCT)
- Elevated serum osmolality (above 300 mOsm/kg)
- Elevated serum sodium level (above 145 mEq/L)
- Urine specific gravity above 1.030
Dehydration Lab Values
- Elevated Hematocrit (HCT)
- Elevated serum osmolality (above 300 mOsm/kg)
- Elevated serum sodium level (above 145 mEq/L)
- Urine specific gravity above 1.030
How to treat dehydration?
REPLACE FLUIDS
Causes of hypovolemia
- GI Losses (NV, diarrhea, suction, fistula drainage)
- Hemorrhage
- Third Spacing
Hypovolemia: What to look for when blood loss is minimal? (25%)
- Increasing confusion, restlessness and anxiety to unconsciousness
- Weak to absent peripheral pulses
- Flat jugular veins
- Dizziness
- Nausea
- Extreme thirst
- Urine output <10ml
Hypovolemia: What to look for when blood loss is minimal? (25%)
- Increasing confusion, restlessness and anxiety to unconsciousness
- Weak to absent peripheral pulses
- Flat jugular veins
- Dizziness
- Nausea
- Extreme thirst
- Urine output <10ml
Hypovolemia: What to look for when blood loss is minimal? (40% or more)
Hypovolemic SHOCK occurs
- Hypotension
- Tachycardia
- Weak or absent peripheral
- Cool, mottled skin
- Cyanosis
Hypovolemia: Lab Values
- Normal or high sodium values (>145)
- Decreased Hgb and HCT levels (due to blood loss)
- Elevated BUN and Creatinine
- Increased urine specific gravity
- Increased serum osmolality
How to treat Hypovolemia?
Replace w/Isotonic Fluids
Define hypervolemia
Excess of isotonic fluid in the EC compartment
Causes of Hypervolemia
- Heart Failure
- Renal failure
- Increased oral Na intake
- Increased cortisol secretion (cushing’s syndrome)
- Long term use of corticosteroids
Causes of Hypervolemia
- Heart Failure
- Renal failure
- Increased oral Na intake
- Increased cortisol secretion (cushing’s syndrome)
- Long term use of corticosteroids
Hypervolemia what to look for?
SOB
- Tachypnic
- Pink frothy sputum
- Cough
- Crackles
- Tachycardia
- Increased BP (HTN)
- Rapid and bounding pulse
- Edema
- Weight gain
- S3 gallop
- JVD
Hypervolemia Lab Values
- Low HCT
- Normal serum sodium
- Low serum potassium and BUN
- Decreased serum osmolality
- -Low oxygen level PaO2
Causes of water intoxication
- Increased ADH secretion
- Excessive H2O intake
- Continuous hypo-osmolar IV fluids (1/2 NS, D5W)
- Altered thirst mechanism
Causes of water intoxication
- Increased ADH secretion
- Excessive H2O intake
- Continuous hypo-osmolar IV fluids (1/2 NS, D5W)
- Altered thirst mechanism
Water Intoxication: What to Look for?
Dyspnea Pupillary changes Bradycardia Increased intracranial pressure (ICP) Headache Personality changes ALOC Confusion Low sodium levels Irritability Lethargy Nausea Cramping Muscle weakness Twitching Thirst
Water Intoxication: Lab Values
-Low sodium (,<280 mOsm/kg)
How to manage volume imbalances?
I & O Monitor VS Monitor Neurological function Daily Weights Fluid restriction Assess skin and manage edema
How to manage volume imbalances?
I & O Monitor VS Monitor Neurological function Daily Weights Fluid restriction Assess skin and manage edema
Normal Na levels
135-145 mEq/L
Normal K levels (Potassium)
3.5-5 mEq/L
Normal Cl- levels
95-108 Meq/L
Normal Ca levels
9-11 mg/dL
Normal Mg levels
1.8-2.3 mg/dL
Normal PO4 levels
2.5-4.5 mg/dL
Normal HCO3 levels
22-26 mEq/L
Sodium is greaterouts ___ the cell and tends to move passively ___ the cell
Potassium is greater ___ the cell and tends to move passively ___ of the cell.
In order to keep normal levels: the pump works to keep potassium IN and sodium OUT of the cell by means of active transport.
outside; into; inside; out
Causes of Hyponatremia
<135 mEq/L
Sodium loss: renal (salt wasting nephropathy) or non-renal (hypo-osmolar IV therapy)
Water gain
Inadequate sodium intake
SIADH
Hyponatremia Lab Values
20mEq/L in patients with SIADH (Holding on to H2O due to SIADH)
-Decreased HCT and plasma proteins (if caused by H2O excess or SIADH)
Medications that cause Hyponatremia
<135 mEq/L Anticoagulants: heparin Anticonvulsants: dilantin, acetazolum Antidiabetics: chlorpropamide Antipsychotics: Thorazine Diuretics: thiazide, loop Sedatives: barbituates, morphine
Hyponatremia: What to look for?
<135 mEq/L Shortened attention span Lethargy Confusion Disorientation Muscle weakness Irritability Headache Weakness (lowered excitability of nerves) Vomiting/Diarrhea - may be cause
Hyponatremia: How is it treated?
<135 mEq/L
Correct the cause
Fluid restriction
Sodium supplements
Isotonic fluids (if caused by Hypovolemia)
Diuretics (if caused by SIADH)
Underlying cause of SIADH must be treated
Hyponatremia Nursing Considerations
<135 mEq/L 24-hour I&O √ Urine specific gravity √ Bounding pulses √ BP and respiratory changes √ Changes in sensorium signs of cerebral edema √ Check and compare daily weights √ Pitting edema with fluid excess
Causes of Hypernatremia
> 145 mEq/L
Water deprivation, hypertonic tube feedings, greatly increases insensible fluid loss, watery diarrhea, excessive parenterial administration of 3% NS, Bicarbonate, diabetes insipidus, drowning in salt water
Hypernatremia Lab Values?
Serum sodium levels: >145 mEq/L
>145 mEq/L
Urine specific gravity: >1.030
- If hypernatremia with normal or increased ECF volume
-Ingestion of Na, or hypertonic IV or tube feedings
Urine specific gravity 300 mOsm/kg
Hypernatremia - what to look for?
>145 mEq/L ALOC Restlessness Agitation Coma Lethargy Confusion Stupor Increased thirst Dry mucous membranes Twitching Flushed Skin
Hypernatremia - how is it treated?
>145 mEq/L Underlying disorder is corrected Restrict dietary sodium IV of D5W or ½ NS Hypotonic fluid replacement should be carefully done so it does not cause cerebral edema
Hypernatremia Nursing Consderations
>145 mEq/L 24-hour I&O √ Urine specific gravity √ Thready pulses & flat neck veins √ Tachycardia & tachypnea √ Changes in sensorium √ Check and compare daily weights √ Skin turgor & mucous membranes
Hypokalemia
<3.5 mEq/L Increased losses: -GI: vomiting, NGT suctioning -Diarrhea, fistula, ileostomy Excessive urinary loss: -Hyperaldosterone states, -Thiazide and Loop diuretics, Inadequate intake -Anorexia, IV (K free) Intracellular shift Alkalosis: 0.1 ↑ pH = ↓ K 0.4mEq/L -Insulin
Hypokalemia
<3.5 mEq/L
Hypokalemia - what to look for?
<3.5 mEq/L Cardiac arrhythmias Cardiac arrest Digoxin toxicity Paralytic ileus Respiratory arrest Paralysis (rare) Weakness Parathesia Leg cramps Reflexes decreased Hyperglycemia Polyuria Low BP
Hypokalemia - How is it treated?
<3.5 mEq/L Correct the cause Restore normal K levels IV with 20-40 mEq/L per liter Increase dietary intake
Hypokalemia - how is it treated?
<3.5 mEq/L Correct the cause -Restore normal K levels --IV with 20-40 mEq/L per liter -K+ supplements Increase dietary intake -chocolate, dried fruit, nuts and seeds -oranges bananas, apricots -potatoes, mushrooms, celery, tomatoes
Causes Hyperkalemia?
>5.0 mEq/L Renal impairment IV K+ infusions Meds: K+ sparing diuretics & ACE inhibitors excessive K+ oral intake Burns Hypoaldosterone states, Acidosis Crushing Injuries
Hyperkalemia Lab Values?
> 5.0 mEq/L
- Serum potassium >5 mEq/L
- Decreased arterial pH
- EKG abnormalities
Hyperkalemia What to look for?
>5.0 mEq/L Irregular pulse Decreased HR Decreased CO Hypotension Cardiac arrest -VT -VF Tall tented t wave Flattened p wave Prolonged pr interval Parathesia Abdominal cramping Diarrhea
How to treat severe hyperkalemia?
> 6 mEq/L Insulin and glucose Renal failure = hemodialysis -Kayexelate (cation exchange) --As the med sits in the intestine Na moves across the bowel into the blood acausing K to move out of the blood into the intestine = loose stools remove K from the body -Calcium gluconate --Counteracts myocardial effects -Bicarbonate
How to treat severe hyperkalemia?
> 6 mEq/L Insulin and glucose Renal failure = hemodialysis -Kayexelate (cation exchange) --As the med sits in the intestine Na moves across the bowel into the blood acausing K to move out of the blood into the intestine = loose stools remove K from the body -Calcium gluconate --Counteracts myocardial effects -Bicarbonate
Nursing Considerations Hyperkalemia?
- Assess dietary potassium intake
- Monitor renal function
- Teach patient use of ACE inhibitors & K-sparing diuretics cause ↑ in K level
- Teach pt to limit K containing foods
- Continuous cardiac monitoring during EKG changes
Functions Magneium?
- Neuromuscular transmission
- Cardiac contraction
- Activation of enzymes for cellular metabolism
Hypomagnesemia
Mg <1.8 mg/dL
Hypomagnesemia Causes
Mg <1.8 mg/dL increased excretion NG suctioning, diarrhea, fistula Prolonged Diuretic therapy -Mg loss through kidneys osmotic dieresis (DM) -Same as above Increased calcium intake -Promotes mg loss in feces Decreased intake ETOH-mg loss through gi tract malnutrition
Hypomagnesia Lab Values
<1.8 mg/dl
Other e- abnormalities: low Ca, K
-low mg – less PTh secreted
- up renin – up Na, down K
Hypomagnesia - what to look for?
<1.8 mg/dL Irregular heart rate Tremors Twitching Tetany Hyperactive DTR Flat or inverted T waves
mild Hypomagnesia - How is it treated?
<1.8 mg/dL
dietary changes may be enough:
–Nuts, seafood, chocolate, dry beans, green leafy veggies, meats, seafood, whole grains
Severe hypomagnesia - how is it treated?
<1.8 mg/dL
May need IV bolus Mg
Magnesium sulfate
Assess renal function first!
Hypermagnesia
> 2.3 mEq/L
Hypermagnesia Lab Values
> 2.3 mEq/L serum
EKG changes: prolonged PR interal, widened QRS complexes, tall T waves
Hypermagnesiia What to look for?
>2.3 mEq/L serum Too much can have sedative effect on the neuromuscular system, causing: *Lethargy/ drowsiness *Slow, shallow, depressed respirations flushed N/V Weak pulse Bradycardia Decreased BP Cardiac arrest Decreased muscle and nerve activity Hypoactive DTR’s Generalized weakness
Hypermagnesia Nursing Considerations
>2.3 mEq/L Assess neurologic status & reflexes Assess & report absence of DTR’s Assess skin for flushing & diaphoresis Provide continuous cardiac monitoring
Calcium levels
9-11 mg/dL
Calcium Functions
9-11mg/dL
Major cation for the structure of bone & teeth
1% contained in ECF
Co-enzyme factor in clotting & hormone secretion
Maintains plasma membrane stability & permeability, especially of the cardiac cell nerve receptors
Aids in transmission of nerve impulses & muscle contraction
How does body regulate calcium?
9-11 mg/dL
PTH
Calcitonin
PTH and Ca
9-11mg/dL
PTH is released which pulls Ca from bone into serum.
PTH signals kidneys to reabsorb Ca.
Parathyroid
Calcitonin and Ca
9-11mg/dL
From thyroid
Acts as antagonist to PTH to inhibit bone reabsorption
Hypocalcemia Causes
<9 mg/dL Causes Renal failure ↓ dietary intake of Ca and vit D Hypoparathyroidism (↓PTH) Neck surgeries ↑ serum Phosphate Blood transfusions – citrate used to anticoagulant blood binds to ca alkalosis mg deficiency – inhibits PTH
Hypocalcemia Lab Values
Serum Ca < 9 mg/dl
low mg+ levels
Characteristic EKG changes: Prolonged QT - Ventricular Tachycardia
Hypocalcemia Cardiac
prolonged ST segment and QT interval,
decreased myocaridal contractility-> ↓ CO and BP
Hypocalcemia Neuromuscular
<9 mg/dL
Anxiety confusion, irritability progressing to seizures
Paresthesia, - extremities and around the mouth
twitching, cramps,
tetany, tremors
laryngeal stridor or dysphasia
+ Chvostek and/or Trousseau signs
Hypocalcemia Nursing Considerations
<9 mg/dL Monitor serum Ca levels q4-6 h \+ Chvostek and/or Trousseau signs Assess for IV infiltration – can cause tissue necrosis --central line administration preferred Monitor cardiac rhythm & EKG changes Assess for low BP Avoid rapid IV push = rapid drop in BP, + arrhythmias, and cardiac arrest
Hypercalcemia
> 11 mg/dL
Hypercalcemia Causes
> 11 mg/dL
Hyperparathyroidism
–Increased PTH excretion, kidney & intestinal reabsorption
Cancer
Bone destruction (malignant cells) cause hormone release similar to PTH
Hypercalcemia associated with malignancy: 1 year survival rate is 10-30%
Thiazide diuretics
Steroids
Prolonged immobilization
Decreased serum phosphorus
Hypercalcemia What to Look for?
> 11 mg/dL Shortened QT segments Depressed T waves Bradycardia->Heart block Dig Toxicity Vent arrhythmias Fatigue Weakness Lethargy Anorexia Nausea kidney stones bone pain / fractures (disuse osteoporosis or PTH increase)
Hypercalcemia: How is it treated?
>11 mEq/dL Promote renal excretion Loop diuretics along with IV NS Calcitonin Pamidronate (Aredia) if caused by malignancy
Nursing Considerations Hypercalcemia
Increase oral intake to 3L
Assess for altered gait & weakness
Monitor for arrhythmias
Teach patient to avoid Ca rich foods
Phosphate levels
2.5-4.5 mg/dL
Phosphate Functions
2.5-4.5 mg/dL Metabolism of protein, carbs, & fats Acid-base buffering Helps with production of ATP Needed for bone and teeth formation Proper function of red blood cells
Hypophosphatemia
<2.5 mg/dL
Hypophosphatemia Causes
<2.5 mg/dL Malnutrition/ malabsorption syndromes ETOH ism TPN Hyperparathyoidism DKA Vomiting/ diarrhea Aluminum containing antacids
Hypophosphatemia Lab values
- -Serum phos < 2.5g mg/dl
- -Abnormal electrolytes (decreased Mg & increased Ca)
Hypophosphatemia What to Look for?
<2.5 mg/dL Confusion coma respiratory weakness muscle weakness cardiac dysrhythmias tissue hypoxia
Hypophosphatemia - How is it treated?
<2.5 mg/dL Dietary changes Eggs, nuts, whole grains, organ meats, fish, poultry, & milk products oral supplements-Neutra phos IV supplement- Na or K phos
Hypophosphatemia Nursing considerations
<2.5 mg/dL
Monitor Phos, & Ca levels
↑Urine output
Watch for neurological changes and muscle weakness
Discourage client in taking antacids with Aluminum
Instruct client to eat foods high in phos
Hyperphosphatemia
> 4.5 mg/dL
Hyperphosphatemia Causes
>4.5 mg/dL Renal failure Chemo Enemas containing phos Excessive ingestion of milk phosphate containing laxatives hypoparathyroidism
Hyperphosphatemia Lab values
> 4.5 mg/dL
- Serum phos > 4.5 mg/dl
- Abnormal electrolytes (decreased Ca)
Hyperphosphatemia What to look for?
> 4.5 mg/dL
Due to the inverse relationship of Calcium & phosphorus s/s would mimic hypocalcaemia -Paresthesia -s/s of hypocalcaemia o Chvostek o Trousseau
Hyperphosphatemia How is it treated?
> 4.5 mg/dL
Reduce dietary phosphorus Eliminate use of phosphorous based laxatives Phosphorus binding medications Calcium gluconate IV saline to induce renal excretion
