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Fluids&Electrolytes
GWCC Block 2 nursing
Question | Answer |
---|---|
Hypotonic solutions do | move water from vascular system into cells |
Isotonic solutions do | nothing- water stays in the appropriate compartments |
Hypertonic solutions do | move water from cells into vascular system |
Hypertonic is ___ mEq/kg | less than body osmolality at less than 250 |
Isotonic is ___ mEq/kg | 285- 295, equal to body osmolality |
Hypertonic is ___ mEq/kg | more than body osmolality, 375+ |
ADH | a hormone secreted from the pituitary mechanism that causes the kidney to conserve water |
ANP | atrial natiuretic peptide, a cardiac hormone found in the atria of the heart that is released when atria are stretched by high blood volume |
Parathyroid hormone | regulates calcium and phosphate balance. |
Aldosterone | responsible for renal absorption of sodium, which results in retention of chloride and water. |
Epinephrine | increases blood pressure, dilates blood vessels needed for emergencies and constricts others. |
Cortisol | produces sodium and fluid retention, and K deficit |
A ___ mg/Hg fall in systolic BP when shifting from lying to standing position indicates fluid volume deficit | 20 |
What respiratory signs indicate fluid volume excess? | tachypnea and dyspnea |
HCT and BUN in hypovolemia | normal or high HCT and BUN |
HCT and BUN in hypervolemia | low |
Conditions that cause isotonic overhydration | excess administration of IV fluids, excessive irrigation of body cavities/organs, use of hypotonic fluids to replace isotonic fluid loss. Also corticosteriods, renal and heart failure, high aldosterone levels. |
Conditions that cause hypotonic over-hydration | aka water intoxication- SAIDH (syndrome of inappropriate antidiuretic hormone hypersecretion), excess water intake, CHF |
A dehydrated pt should have __mL fluid intake per day | 2000 |
candy and gum can ___ mucous membranes | dry |
normal BUN | 10-20; BUN is normal or high in FVD |
normal specific gravity of urine | 1.005- 1.030; high in FVD |
suppression of PTH results in | FVD |
Potassium | 3.5 -5 |
Sodium | 135-145 |
Magnesium | 1.5 - 2.5 |
Phosphate (HPO4) | 3.0- 4.5 |
Chloride | 95-108 |
Concentrations of K greater than ___ should never be given in a peripheral vein | 60 |
Concentrations of K greater than ___ can cause pain and irritation in peripheral veins, leading to phlebitis | 8mEq/100mL |
Do not add K to a ____ | hanging container |
Administer K at a rate not more than ___ through a peripheral vein | 10mEq/hr |
Calcium and __ have a reciprocal relationship- when one in higher the other is lower. | phosphate |
The most dangerous sign of hypocalcemia is | laryngospasm |
Patients with calcium imbalances may need | seizure precautions |
SAIDH is the most common cause of __ in hospitals | hyponatremia |
serum osmolality | 285-295; less than 280 is hypovolemia, more than 300 is hypervolemia |
When K moves out of cells | H moves in and vice versa |
Roles of K | regulates fluid volume within a cell; promotes nerve impulses, cx of mucles, acid base balance, enzyme function |
If ECF K becomes depleted | K moves out of cells and into the ECF |
an increase in aldosterone levels stimulates and increases excretion of | K |
On an EKG, hypokalemia results in | flattened T wave and appearance of U wave |
On an ECG, hyperkalemia results in | tall tented T wave, S-T segment depression, wide QRS wave ("shark teeth") |
Insuline facilitates movement of | K back into cells from ECF. Giving insulin is one treatment of hyperkalemia |
Calcium | 8.5- 10.5 |
Most common cause of hypocalcemia | inadequate secretion of PTH |
Symptoms of hypocalcemia | numbness of fingers, cramps, Trousseu's sign, Chvostek's sign, hyperactive deep tenden reflexes |
A deficiency in chloride reflects a deficiency in | K |
serum osmolality | 285-295 |
urine specific gravity | 1.003 - 1.030, OR 3-30 |
Hypocalcemia- Check for__ | rapid labored respirations, stridor= tetany/spasms in the airways, Chvosteks's sign- face twitch, test for deep tendon reflexes with hammer, numbness of extremities. |
How does hypocalcemia affect the body? (2 things) | Impairs clotting; Hypocalcemia causes lowered threshold of muscle excitement --> spasms, tetany |
Hyperkalemia, check for s/s | Weakness, fatigue, HR (will be lower than normal),Check ability to move muscle groups against resistance and gravity |
How does hyperkalemia work in the body? | Prolongs re-polarization period, slows HR, reduces BP; Na builds up, K does not leave cells, depolarization is difficult. |
How is hyperkalemia treated (esp. in renal patients)? | In renal failure K is not excreted effectively, increases blood K level. Treated with drug therapy |
Continuous cardiac monitoring | |
What is SIADH? | Syndrome of inappropriate antidiuretic hormone hypersecretion, excessive release of antidiuretic hormone (ADH). The result is hyponatremia, and sometimes fluid overload. |
How is SIADH treated? | loop diuretic, hypertonic IV solution, restrict fluid intake, I&O, weigh daily, hyperactive bowel and filud build up in abdomen, monitor LOC frequently, monitor for signs of GI involvement |
3 ways the body tries to maintain pH levels | 1.blood buffer pH 7.35-7.45 2.lungs: pco2 35-45 (short term but limited). Breathe faster, blow off acid co2. 3.kidneys: hco3 22-26 (long-term) |
Respiratory acidosis | not enough breathing, retaining acid. Body accomodates by breathing more. anxiety, hyperventilation, exercise, high altitude, pregnancy, diarrhea,hypoventillation, airway obs, COPD, chest trauma, neuro-muscular disease, drug overdose (pass out). |
Respiratory alkalosis | breathing too much, try to slow down to not blow off too much acid. |
anxiety, hyperventilation, | |
Metabolic acidosis | not enough bicarbonate being produced. renal failure, aspirin overdose, (diarrhea, lose it through their "acid"dosis). |
Metabolic alkalosis | losing acid, vomiting, suction, Alcoholic throws up, alkalosis, diuretics--> urine is acidic. |
Isotonic IV salines (2) | 0.9% NaCl (normal saline); LR (Lactated Ringers), like Gatorade. For someone who's healthy but dehydrated, or to go to surgery with. |
Hypotonic IV fluids | pulls fluid from blood vessels into intracellular spaces, rehydrates cells. 0.45% (1/2 normal saline); D5W (5% dextrose in water) |
Hypertonic IV fluids | Has more salt. 3% saline; TPN (has so much glucose, NA, lipids, etc). Can only do through central line because of caustic veins. Never D/C TPN because will cause PT to crash, must wean down to saline and then D/C. |
Osmolality | stuff in blood |
Osmolarity | stuff in IV bags |
aldosterone - what does it do? | Holds onto sodium! Aldosterone is a hormone that increases the reabsorption of sodium and water and the release (secretion) of potassium in the kidneys. This increases blood volume and, therefore, increases blood pressure. |
What to give IV for hyper-K? | Glucose IV with insuline. It will take the K with it and lower K levels in the body. |
Production of aldosterone is triggered by | low blood volume, low Na, high K, low CO, stress |
When aldosterone is secreted, what happens to Na, K and H? | Na is held onto. K and H are excreted by kidneys. |
Loss of skin turger means | dehydration |
regulation of K excretion depends on (3) | amt of Na available for exchange; number of H ions being excreted, aldosterone levels. |
Low serum K levels associated with (acidosis or alkalosis) | alkalosis |
Hig serum levels of K associated with (acidosis or alkalosis) | acidosis |
Ca and __ are antagonistic | Mg |
Biggest risk of hypocalcemia | tetany |
Signs of hypercalcemia | muscle weakness, bradycardia |