Fluid & Electrolytes Flashcards
Normal Sodium range
135-145 meq/L
Normal Potassium Range
3.5-5 meq/L
Hyponatremia- sodium level
<135 meq/L
Hypernatremia- sodium level
> 145 meq/L
Hypokalemia- K level
< 3.5 meq/L
Hyperkalemia- K level
> 5 meq/L
Normal pH range
7.35-7.45
Normal PCO2 range
35-45 mmHG
Normal HCO3 range
22-26 meq/L
Normal PaO2 range
80-100
Normal SaO2 range
90-93% (elderly/compromised)
>93% (everyone else)
Respiratory Alkalosis Values
H pH
L PCo2
Respiratory Acidosis Values
L pH
H PCo2
Metabolic Alkalosis Values
H pH
H HCO3
Metabolic Acidosis Values
L pH
L HCO3
What does Isotonic IV solutions do? Ex of who would receive it?
Increases vascular volume but does not cause a change in cell volume. The concentration of sodium is nearly equal to that of blood. Ex- Used to increase Blood Pressure.
What does Hypotonic IV solutions do? Ex of who would receive it?
Fluid in blood moves into cells. Hypotonic solutions lower serum osmolarity fluid shifts out of blood vessels and interstitial spaces. It hydrates the cells while depleting circulatory system. Ex- pts who need cellular hydration: diabetic ketoacidosis or pts depleted from diuretic therapy.
What does Hypertonic IV solutions do? Ex of who would receive it?
Fluid in cells moves into blood. Hypertonic solution raises serum osmolarity and pull fluid from interstitial compartments into intravascular compartments. (Pulls excess fluid out of cell) Ex- pts with brain injury swelling or to reduce postop edema
Examples of Isotonic IV Solutions
Ringers Lactate
Normal Saline 0.9%
Examples of Hypotonic IV Solutions
.45 NS
.33 NS
.20 NS
D5W
Examples of Hypertonic IV Solutions
Anything with Dextrose D10W D5W/.9NS D5W/.45NS D5 LR
What is diffusion
Movement of molecules from an area of high concentration to one of low concentration. Must be permeable membrane. No external energy
What is facilitated diffusion
involves the use of a protein carrier in the cell membrane. It combines with a molecule and assists in moving the molecule across the membrane from area of high to low concentration. Req no energy. ex- glucose transport
What is active transport
process where molecules move against the concentration gradient. External energy is required. Ex sodium-Potass pump
What is osmosis and osmotic pressure
Osmosis is the movement of water down a concentration gradient, from region of low solute concentration to high, across a semipermeable membrane. Whenever dissolved substances are contained in a space with a semipermeable membrane, they can pull water into the space by osmosis. The concentration of the solution determines the strength of the osmotic pull or the osmotic pressure.
what is hydrostatic pressure
force within a fluid compartment. In blood vessels its the blood pressure generated by the contraction of the heart. At the capillary level, hydrostatic pressure is the major force that pushes water out of the vascular system and into the interstitial space.
What is oncotic pressure
is the osmotic pressure caused by plasma colloids in solution. Major colloid in vascular system is protein. Plasma protein molecules attract water, pulling fluid from tissue space to vascular space.
The lab values for someone with ECFVD would be all High or all Low?
All High
The lab values for someone with ECFVE would be all High or all Low?
All Low
Causes of Extracellular fluid volume deficit (ECFVD)
Abnormal loss of body fluids, inadequate intake, Severe vomit/diarrhea, NG tube suction, fluid from plasma to interstitial, burns, fever, hemorrhage.
Clinical Manifestations of ECFVD
Thirsty, tired, Decreased BP, Increased Heart Rate, poor skin turgor, wght loss, weakness, dry mucosa, constipated, orthostatic hypertension, decreased Central Venous Pressure, Flat jugular veins, slow capillary refill.GENERALLY NO Neuro changes or confusion.
Expected Labs for ECFVD
All Labs High
- Na > 145
- BUN >25
- hematocrit >55%
- Osmolality > 295
- Urine specific gravity >1.030
Normal Serum Osmlality
275-295 mOsm/kg
Causes of Extracellular fluid volume excess (ECFVE)
Heart failure, renal failure, SIADH, excessive isotonic or hypotonic IV fluids, fluid overload, pulmonary/peripheral overload, increased hydrostatic pressure, cecreased oncotic pressure, ascites.
Clinical manifestations of ECFVE
(No Edema) Increased BP, Bounding Pulse, Crackles, distended jugular veins, headache, lethargy, wgt gain, polyuria
Interventions for ECFVD
- TREAT CAUSE
- I/O
- Daily Wgts
- Ortho bp every 4 hrs
- Fall precautions
- Assess skin (Increased skin breakdown)
- BUN/creatinine
- Fluids
- oral care frequently
Interventions for ECFVE
- TREAT CAUSE
- I/O
- Restrict sodium and fluids
- Assess labs, Neuro, skin
- Elevate legs
- Support extremities
- Mobilize fluids
- Promote urinary elimination
- Aspiration precautions
Expected labs for ECFVE
ALL LABS LOW
- Osmolality < 275
- Na < 135
- Hematocrit < 1.010
Intracellular fluid volume deficit (ICFVD) cause, symptoms, interventions
Very rare. Cells shrink. Causes: wrong IV fluid given, or ECFVD is so bad that it pulls fluid from cells. Symp: thirst, oliguria, confusion, coma. Very critical. Intervent: restore fluids, address underlying cause.
Intracellular fluid volume excess (ICFVE) cause, sympt, interventions
Water intoxication (excess), sodium deficit, intracellular shift of water toward sodium. Sympt: increased intracranial pressure, altered LOC, critical care. Intervent: Assess LOC and pupils, I/O, decrease intracranial pressure (keep calm, stool soft, treat any incr. in BP), fluid restriction, hypertonic IV, steroids + diuretics, Admin NA.
Causes of Extracellular fluid volume shift: third spacing
Increased capillary permeability, poor nutritional status, decreased serum protein/ albumin levels, obstructed lymphatic drainage, tissue injury, protein malnutrition, increased capillary hydrostatic pressure. Tissue injury or protein malnutrition leading to fluid shift. Fluid in useless spacing.
Clinical manifestations of Third spacing
EDEMA, Weak pulse, hypotension, pallor, decreased urine, decreased LOC
Interventions for Third spacing
- TREAT CAUSE
- I/O
prevent skin breakdown
promote vascular repletion
Albumin: what it is, what it does, normal serum albumin range?
Albumin is a protein made by the liver. A serum albumin test measures the amount of this protein in the clear liquid portion of the blood. Albumin helps keep fluid in blood from leaking into tissues. NORMAL RANGE: 3.4-5.4 g/dL
Hyponatremia: pathophys?
Na < 135 Too much water or losing too much Na - decreased NM excitability - delayed membrane potential - fluid shift into ICF- cells swell - Increased intracranial pressure
Hyponatremia: sympt?
- Headache, fatigue, thready pulse
- apprehension, confusion, altered LOC
- weakness, nausea, cramping
- seizures
- Hypovolemia: poor skin turgor, dry, thready pulse, wt loss
- Hypervolemia: bounding pulse, wt gain, edema.
Hyponatremia: mgmt?
- TREAT CAUSE
- Monitor CNS, GI, CV, resp, renal
- Monitor I/O, wt, vitals
FVD: 3% saline infusions
FVE: diuretics and fluid restrictions
Hypernatremia: pathophys?
Na>145 Water loss or Na gain - Increased NM excitability - fluid shift to ECF- cells shrink - Increased serum osmolality - ICF dehydration - Decreased myocardial contractility - decreased total body water (TBW) - hyperosmolar
Hypernatremia: sympt?
Restlessness, agitation, muscle twitches, anorexia, wt loss, tachycardia, poor turgor, dry skin, fever, neuro issues.
Hypervolemia: HTN, bounding pulse, dyspnea
Hypovolemia: dry membranes, oliguria
Hypernatremia: mgmt?
- TREAT CAUSE
- Monitor CNS, GI, CV, resp, renal
- Monitor I/O, wt, vitals
- Seizure precautions
- Hypotonic IV to restore cell volume
- Diuretics + D5W (turns hypotonic)
Hypokalemia: Etiology/patho?
K <3.5 meq/l
Decreased K intake or increased K loss (vomit, diarrhea, NG suction, fistula, ileostomy, DKA, diuresis, diuretics(LOOP = K wasting), stress of surgery)
Patho: increased NM excitability
Hypokalemia: Sympt?
- may not show signs
- thready pulse, weakness, lethargy
- shallow resp
- U wave on EKG
- muscle cramps
- slow GI
- decrease in deep tendon responses
- cardiac event will result
Hypokalemia: Mgmt?
- TREAT CAUSE
- If Mg low, replenish Mg. K will not come up if Mg is not right
- IV replacement always diluted and on pump. NO IV PUSH.
- NEVER > 10 meq/hr*
- monitor vitals
- Put on remote tele
Hyperkalemia: Etiology/patho?
K > 5 meq/l Retention of K (renal failure) Excess K release from injured cells (traumatic accident) Adrenal insufficiency Altered NM excitability
Hyperkalemia: sympt?
- Early: muscle twitches cramps, tingling
- Late: weakness, paralysis
- diarrhea, hyperactive bowel sounds
- dysrhythmia
- PEAKED T WAVE on EKG
Hyperkalemia: mgmt?
- TREAT CAUSE
- decrease K intake
- Cation exchange resin (Kayexalate “code brown”) oral or enema causes K to be pulled out of body and into stool.
- dialysis
- Low K diet
- Insulin will shift K back into ICF
- Ca to reverse membrane excitability