Fluid/electrolyte/acid/base

Question 1

ANP

Answer 1

Atrial Natriuretic Peptides (ANP)
REMEMBER atrial=heart

Produced by heart response to changes in ECF ( extra cellular fluid)

When BP increases, ANP is released. When BP is low, ANP is inhibited.

ANP acts on kidneys to increase Na+ excretion (remember, where sodium goes, so does water!!!)

Leads to decreased ECF volume

Question 2

Metabolic acidosis

Answer 2

When pH is low= acidosis (under 7.35) 
Low bicarbonate (under 22 mEq/L)

Hyperkalemia may occur as potassium shifts out of the cell. But when acidosis is corrected, potassium shifts back into the cell and potassium levels decrease.

Increased levels of keto acids, lactic acidosis, etc.

Decreased bicarbonate levels

This is caused by renal failure, DKA (diabetic keto acidosis), and shock.

Symptoms: headache, decreased BP, hyperkalemia, muscle twitching, warm flushed skin, nausea/vomiting, diarrhea, confusion, drowziness, kussmal respirations (compensatory hyperventilation)

Question 3

Active Transport

Answer 3

Pump that moves fluid from an area of lower concentration to an area of higher concentration

Moves along the concentration gradient

Sodium-potassium pump maintains higher concentration of extra cellular sodium and intracellular potassium.

Requires ATP

Question 4

Magnesium

Answer 4

1.8-2.7 mg/dL

Cofactor for enzymatic reactions (ATP, DNA replication, mRNA production)

Metabolism of carbohydrates & proteins

Question 5

Fluid volume deficit

Answer 5

A loss in extra cellular fluid exceeds intake ratio of water. Electrolytes are lost in the same proportaion as they exist in normal body fluids.

Dehydration is JUST H2O loss, with increases serious sodium levels. You are not losing electrolytes.

Causes: vomiting, diarrhea, GI suctioning, sweating, decreases intake/inability gain access fluids

Risk factors: diabetes insipid is, adrenal insufficiency, osmotic diuretics, hemorrhage, coma

Question 6

Hypertonic solution

Answer 6

High osmolalities (high solute concentration)

Increases extra cellular fluid volume (pulls fluid from the cells into ECF). Is used as a volume expander.

Prescribed for severe hyponatremia (low sodium).

Can cause fluid volume overload and PE, and should only be administered when pt is under constant supervision.

Examples:
3% sodium chloride (NaCl)
5% sodium chloride

If you add dextrose 5%, it will turn hypertonic.

Question 7

Fluid volume excess

Answer 7

Due to fluid overload or diminished homeostatic Mechanisms.

Risk factors: heart failure, renal failure, cirrhosis of liver.

Contributing factors: excessive dietary sodium of sodium containing IV solutions.

Question 8

Sodium

Answer 8

135-145 mEq/L

Regulates extra cellular fluid volume and osmolarity.

Hyponatremia (remember hypoNAtremia, Na is sodium): Hypertonic. Low sodium, your body has too much water. Restrict fluids!

Hypernatremia: You’d body doesn’t have enough water (deficit), drink water or IV fluids.

If sodium goes up, chloride goes up. If sodium goes down, chloride goes down.

Question 9

Respiratory Alkalosis

Answer 9

When pH is high= alkalosis (over 7.45)
Decreased PCO2 (under 35 mmHg)
Decreased carbonic acid
Decreased H+
Decreased bicarbonate 

Respiratory rate or depth increases, causing lungs to eliminate CO2.

Symptoms: lightheadedness, inability to concentrate, numbness and tingling, sometimes loss of consciousness, seizures, deep rapid breathing, hyperventilation, tachycardia, low or normal BP, hypokalemia, lethargy and confusion, light headed, nausea, vomiting

Nursing interventions: need to rebreathe CO2, so breath slowly, and into a bag or mask.

This condition is always due to hyperventilation.

Question 10

Hydrostatic pressure

Osmotic pressure

Answer 10

Hydrostatic pressure is the “pushing pressure”. Pressure pushes fluid out of the tissue resulting in more fluid in the capillary.

Osmotic pressure is the “pulling pressure.” Pressure is the capillary is pulled/keeping fluid in the capillary.

Question 11

Potassium

Answer 11

3.5-5.0 mEq/L

Maintain as intracellular osmolarity.

Controls cells resting potential.

Needed for Na+/K+ pump. REMEMBER, this pump moves sodium to ECF and potassium to ICF with the help of ATP.

Exchanges for H+ to buffer changes in blood.

Need potassium for muscles (including the heart)

Question 12

Maintaining acid-base balance

Answer 12

Normal plasma pH. 7.35-7.45

Kidneys regulate bicarbonate in ECF (aka bicarbonate-carbonic acid buffer system)

Lungs under control from medulla regulate CO2 m/carbonic acid in ECF

Acidosis= high concentration of H+

Alkalosis= low concentration of H+

CO2= acid

HCO3= base

Question 13

Filtration

Answer 13

Movement of water and solutes from an area of higher hydrostatic pressure to an area of lower hydrostatic pressure.

Question 14

Hypotonic solutions

Answer 14

Low osmolalities (low concentration of solutes).

This solution hydrates the cells and is used for fluid loss.

Used to treat patients with conditions causing intracellular dehydration, such as DKA, hyperglycemic state. These are when fluid needs to be shifted into the cell.

Don’t give to someone with increased risk of intracranial pressure. It can cause fluid to shift into brain cells and swell. Dont give to pt with liver disease, trauma, or burns because they need their intravascular fluid. Monitor patients for sign and symptoms of FVD as fluid is pulled back into the cell and out of the vascular bed.

Examples:

0. 45% sodium chloride (NaCl)
1. 33% sodium chloride
2. 2% sodium chloride
3. 5% dextrose in water

Question 15

ABG

Answer 15

Arterial blood gas: measures levels of gases in arterial blood.

Blood gases (oxygen and carbon dioxide) are measured in partial pressures (Pa).

ABGs evaluate the ability of the lungs to move oxygen into the blood and remove carbon dioxide form blood.

Oxygen moves into blood from alveoli.

Carbon dioxide moves out of blood into alveolar sacs.

Question 16

Diffusion

Answer 16

Movement of molecules and ions from an area of higher concentration to an area of lower concentration.

Question 17

Osmosis

Answer 17

Movement of fluid from and area of lower solute concentration to an area of higher solute concentration

Question 18

Isotonic solution

Answer 18

Concentration of dissolved particles is equivalent to plasma. No shifting of fluid present.

Used to treat low extracellular fluid from hemorrhage, severe vomiting, diarrhea, heavy drainage, fistulas, wounds, shock, hyponatremia, metabolic acidosis like DKA, and hypocalcemia.

Examples:
0.9% sodium chloride aka Normal Saline Solution

Question 19

Concentration of extra cellular and

intracellular electrolytes

Answer 19

Sodium 135-145 mEq

Potassium 3.5-5.0 mEq

Chloride 98-106 mEq

Bicarbonate 24-31 mEq

Calcium 8.5-10.5 mg/dL

Phosphate/phosphorous 2.5-4.5 mg/dL

Magnesium 1.8-3.0 mg/dL

Question 20

Metabolic alkalosis

Answer 20

When pH is high= alkalosis (over 7.45)
High bicarbonate (over 26 mEq/L)

HCO3 increases, hydrogen ions lost

Decreased H+ levels
Increased bicarbonate levels

Caused by vomiting or gastric suction, medications, and long term diuretic use.

Question 21

Calcium

Answer 21

8.5-10.5 mg/dL

Extra cellular: nerve impulses, blood clotting. Also controls nerve firing.
Hypercalcemia blocks more Na+ gates, making nerves less able to fire.
Hypocalcemia blocks fewer Na+ gates, making nerves fire more easily. Conditions include Trousseaus sign, tetany/spasm, Chvosteks Sign. Tap someone’s cheek, does it elicit a twitch or spasm?

Intracellular: needed for all muscle contraction

Question 22

Arterial blood gases

Answer 22

pH 7.35-7.45

PaCO2 35-45 mmHg (Respiratory)

HCO3 22-26 mEq/L (Metabolic)

SaO2 >95%

Question 23

Respiratory Acidosis

Answer 23

When pH is low= acidosis (under 7.35)
Increased PaCO2 (over 42 mmHg)
Increased carbonic acid 
Increased H+
Increased bicarbonate 

Unable to eliminate enough CO2 to maintain a normal pH. The excess CO2 increases in bloodstream and pH drops.

Nursing interventions: cough, take deep breaths

Cause: by respiratory problem with inadequate excretion of CO2. Drug overdose, anesthesia, COPD, pneumonia, atelectasis.

Symptoms: Hypoxia, shallow or rapid breathing, dyspnea, headache, hyperkalemia, dysrhythmias, drowziness/dizziness/disorientation, muscle weakness, hyperreflexia,

Question 24

Fluid volume Imbalances

Answer 24

Fluid volume deficit (FVD):
hypovolemia

Fluid volume excess (FVE):
hypervolemia

Question 25

Blood Osmolarity

Answer 25

Hypothalamus monitors osmolarity (concentration of solutes in fluid), and regulates posterior pituitary gland (secretes ADH)

When osmolarity increases, ADH is released and less H2O is excreted (more concentrated urine). If you have concentrated urine, you don’t have enough water… therefore you don’t have enough to excrete.

When osmolarity decreases, ADH is not released and more water is excreted (less concentrated urine). You have extra water to excrete.