Exam 1: Fluid and electrolytes, acid/base

Question 1

intracellular fluid

Answer 1

contained w/in the cell. 2/3 of total body water
higher concentrations:
potassium, magnesium, and phosphorus

Question 2

extracellular fluid

Answer 2

fluid outside of the cells. 1/3 of total body water
higher concentrations:
sodium, calcium, chloride, bicarbonate

Question 3

interstitial fluid

Answer 3

fluid b/t cells, outside of blood vessels

Question 4

intravascular fluid

Answer 4

blood plasma or fluid w/in the blood vessels

Question 5

osmolality

Answer 5

the # of particles of a solute in a unit of solution. Serum osmolality is 280-310 mOsm/kg

Question 6

Starling’s law of capillary forces

Answer 6

the movement of fluid that occurs at every capillary bed using hydrostatic pressure and osmotic pressure (which includes oncotic pressure)

Question 7

filtration

Answer 7

a form of passive transport

movement of both water and smaller molecules through a semi-permeable membrane from an area of high pressure to low pressure

occurs due to hydrostatic pressure being balanced with osmotic

Question 8

reabsorption

Answer 8

fluid shifting back into the capillary from the interstitial space

Question 9

hydrostatic pressure

Answer 9

pressure exerted by fluid within a closed system such as intravascular space. leads to movement of water through the capillary membranes into the interstitial space (greater pressure to lesser pressure)

Question 10

osmotic pressure

Answer 10

Power of a solution to attract or draw water due to concentration. The concentration is through solutes in the solution. In the bloodstream, the concentration is created by electrolytes, nutrients and proteins.

Question 11

oncotic pressure (colloidal)

Answer 11

Also called colloidal oncotic pressure. Refers to the force exerted specifically by albumin in the bloodstream. Good fact to know is that albumin is indicative of the protein nutritional status of the body so low albumin means poor nutritional status

Question 12

edema

Answer 12

Accumulation of fluid within the interstitial space and intercellular fluid causes:

^ hydrostatic pressure

decreased oncotic pressure

increased membrane permeability

lymphatic channel obstruction (lymphedema)

Question 13

generalized vs localized edema

Answer 13

Generalized edema: Palpable swelling produced by expansion of the interstitial fluid volume; when massive and generalized, the excess fluid accumulation is called anasarca

Localized edema: Increased interstitial fluid at a specific sight, generally due to trauma

Question 14

tonicity (hyper-,hypo-,isotonic)

Answer 14

Hypertonic solution: More particles (solutes) than the blood, less water

Hypotonic solution: Fewer particles (solutes) than the blood, more water

Isotonic solution: Same tonicity of the blood. We use 0.9% normal saline or 305 mOsm/kg

Question 15

regular fluid intake and output values

Answer 15

Intake: The amount of fluid a person takes into their body within a day is about 2400-3200ml, generally >1500mL for normal kidneys to function and 500-1000mL from food.

Output: The amount of fluid that leaves the body within a day. Obligatory output should be 300-500mL/day or around 30-40mL/hr. Insensible water loss is about 100mL/day more if you have a fever (through kidneys, lungs, GI, & skin)

Question 16

blood pH

Answer 16

normal is 7.35 - 7.45
reflects acidity or alkalinity in the blood
regulated by lungs and kidneys

Question 17

PaO2

Answer 17

The pressure of oxygen in the arterial blood (90 to 100 mm Hg)

Question 18

PaCO2

Answer 18

The pressure of carbon dioxide in arterial blood (35 to 45 mm Hg)

Question 19

HCO3-

Answer 19

The amount of bicarbonate ion in the blood (22 to 25 mEq/liter)

Question 20

diffusion

Answer 20

passive transport
movement of solute AND solvent through permeable cell membrane from high conc to low conc

Question 21

third spacing

Answer 21

excessive accumulation of fluid w/in body tissue or body cavity (ex. pleural effusion)

Question 22

cations

Answer 22

positive
sodium
potassium
magnesium
calcium

Question 23

anion

Answer 23

negative
chloride
bicarbonate
phosphate
sulfate

Question 24

sodium (Na+)

Answer 24

normal serum sodium: 135-145 mEq/L
most plentiful in ECF compartment
function to maintain ECF volume through maintaining osmolarity
stimulates conduction of nerve impulses

Question 25

potassium (K+)

Answer 25

normal serum K: 3.5 - 5 mEq/L
most plentiful in ICF
regulated throguh diet, kidneys, and Na/K pump
functions: electrical impulse transmit (cardiac ex.) and controls H+ ion conc.

Question 26

calcium

Answer 26

8.5 - 10.5 mg/dl

most abundant electrolyte in body

99% in bones and teeth

The other 1% circulates in the blood and affects system function

Necessary for cardiac and muscle contraction
Promotes transmission of nerve impulses

Converts prothrombin to thrombin, necessary for formation of a clot

Question 27

magnesium

Answer 27

Normal Range
1.3 - 2.1 mEq/L

Second major cation in the ICF
Main source of Magnesium is through the diet
Regulates neuromuscular activity
Facilitates transport of Sodium and Potassium across cell membranes
Maintains normal intracellular levels of potassium
Helps with carbohydrate and protein
metabolism
Produces vasodilation peripherally

Question 28

phosphate

Answer 28

Normal serum phosphorus level
2.5-4.5 mEq/L

Most abundant intracellular anion
Phosphate in the ECF is referred to as “Phosphorus”
Most phosphate is bound with calcium in teeth and bones
Inverse relationship to calcium
Requires dietary intake
Functions include
* Major role in bone formation
* Promotes normal neuromuscular action
* Assists in acid base balance
* Important for cell division

Question 29

arterial blood gas (ABG)

Answer 29

shows:
1. amt of O2
2. amt of CO2
3. % of H+ (pH)

normal values:
pH 7.35-7.45
pCO2 35 - 45
HCO3 22 - 26
pO2 90 - 100
base excess -2 - +2

Question 30

aldosterone

Answer 30

causes sodium to be retained by the body which subsequently retains fluid
chief mineralcorticoid secreted by adrenal glands

Question 31

renin-angiotensin system

Answer 31

1. renin (kidneys) released in response to low renal blood flow & low BP
2. Renin stimulates the production of Angiotensin I from Angiotensinogen
3. Angiotensin I is converted to Angiotensin II by the “Angiotensin Converting Enzyme”
4. Angiotensin II acts in two ways: potent vasoconstrictor and stimulates the release of Aldosterone

Ultimately:
low renal blood flow and low BP trigger hormonal cascade that results in release of aldosterone and vasoconstriction

Question 32

Chvostek’s Sign

Answer 32

hypocalcemia facial sign

Question 33

Trousseau’s sign

Answer 33

Carpopedal spasm w/ blood pressure

Question 34

acid base balance

Answer 34

7.35 - 7.45 arterial blood pH

inverse b/t pH and H+ ion conc
(higher H+ the lower the pH and vice versa)

Question 35

pCO2 ABG levels

Answer 35

35 - 45
indicator of respiratory acidosis or alkalosis

Question 36

HCO3 ABG levels

Answer 36

22 - 26
indicator of metabolic acidosis or alkalosis

Question 37

antidiuretic hormone

Answer 37

Secreted from the Posterior Pituitary Gland
Promotes water reabsorption from the kidney tubules
Maintains water balance in the body fluids
– Is also a potent vasoconstrictor
Pressure sensors in the vascular system stimulate or inhibit the release of ADH
– ADH will also be released in response to serum osmolality, fever, pain, stress and some opioids

Question 38

Hyper- & hypokalemic impacts on EKG

Answer 38

Hyperkalemia: Peaked T, loss of P, widened QRS (leads to irregular pulse and V Fib

Hypokalemia: Flattened/Inverted T waves, ST depression, Prolonged QRS; Peaked P Wave; U wave present

Question 39

calcium - phosphorus relationship

Answer 39

Calcium and phosphorus have an inverse relationship
One has high serum osmolality then the other will be low

Question 40

renin

Answer 40

A hormone released from the kidneys when low renal blood flow and low BP
Stimulates the production of Angiotensin I from Angiotensinogen

Question 41

Angiotensin I

Answer 41

A hormone in the middle of the renin-angiotensin system
transforms into angiotensin II with the help of “angiotensin converting enzyme”

Question 42

Angiotensin II

Answer 42

Byproduct of angiotensin I after “angiotensin converting enzyme” acts on it
the final step in the renin-angiotensin system
potent vasoconstrictor
stimulates the release of aldosterone

Question 43

Sodium-potassium pump

Answer 43

a form of active transport
located on the cell membrane and acts to balance Na and K in ICF and ECF (sodium diffuses into ICF and pump brings back out to ECF)
** relies on ATP that needs adequate oxygen to be produced - so someone hypoxic will have electrolyte imbalance

Question 44

Naturietic peptides (NPs)

Answer 44

• Hormones secreted by special cells that line the atria and the ventricles of the heart
• Secreted in response to increased blood volume and blood pressure (this will stretch the heart tissue)
• NP’s bind to receptor sites in the kidneys, and oppose the renin- angiotensin system

Question 45

Chemical buffer systems

Answer 45

Bicarbonate Buffer System

Transcellular Hydrogen-Potassium Exchange System

Protein Buffer System

Question 46

Transcellular Hydrogen-Potassium Exchange System

Answer 46

Both H+ and K+ are positively charged

Both H+ and K+ move freely between the ICF and ECF compartments

When excess H+ is present in the intravascular space, it moves into the ICF in exchange for K+

When excess K+ is present in the intravascular space, it moves into the ICF in exchange for H+

Thus, potassium levels will influence acid-base balance…
And acid-base balance will influence potassium levels

Question 47

How do kidneys regulate acid-base balance?

Answer 47

Bicarbonate reabsorption and formation
along with excreting H+ ions

Question 48

Hyponatremia

Answer 48

Low Na+ ( <135 mEq/L)

Causes: sweating, vomiting diarrhea, decrease aldosterone levels, syndrome of inappropriate antidiuretic hormone (SIADH), Heart failure, liver disease, renal disease

Clinical manifestations:
Neurological symptoms (HA, Irritability, Confusion, Seizures to coma), lethargy, nausea, vomiting, diarrhea, muscle cramps & spasms (most often occur with severe hyponatremia - fewer than 125 mEq/L)

Question 49

Hypotonic dilutional hyponatremia

Answer 49

water and Na both lost

Causes: sweating, vomiting diarrhea, decrease aldosterone levels

Question 50

Euvolemic or normovolemic hypotonic hyponatremia

Answer 50

retention of water with dilution of Na

Causes: syndrome of inappropriate antidiuretic hormone (SIADH)

Question 51

Hypervolemic hypotonic hyponatremia

Answer 51

low Na with edema disorders

Causes: Heart failure, liver disease, renal disease

Question 52

Hypernatremia

Answer 52

High Na+ ( >145 mEq/L)

Causes:
- excess intake of sodium (PO or IV or hypertonic tube feedings)
- “Relative” Hypernatremia - water deprivation/ water loss (sodium is concentrated in low H2O)

Clinical manifestations:
Due to decrease ECF volume:
*Restlessness, agitation, lethargy, seizures, coma, intense thirst, dry swollen, tongue, dry mucous membranes, orthostatic hypotension, weight loss, oliguria, tachycardia

Specific to increase in sodium w/normal ECF volume:
*Twitching, weight gain, peripheral and pulmonary edema, increased BP

Question 53

Hyperkalemia

Answer 53

High K+ ( >5.0 mEq/L)

Etiology:
* Renal failure, high K+ intake, certain meds, acidosis, hypoaldosteronism (decreased aldosterone causing K+ and H+ exchange places)

Clinical manifestations:
*Weakness, fatigue, confusion, cardiac dysrhythmias (irregular or Vfib)
– ECG Changes - peaked T waves, loss of P wave, widened QRS
*Neuromuscular (Restlessness, irritability, weakness, paresthesia, muscle (leg) cramps, respiratory muscle weakness)
*GI (N/V/D)
*Metabolic acidosis

Question 54

Hypokalemia

Answer 54

Low K+ ( <3.5 mEq/L)

Etiology:
* Certain meds (diuretics, corticosteroids), GI fluid losses (V/D), hyperaldosteronism, anorexia nervosa

Clinical manifestations:
* Cardiac ECG Changes and Dysrhythmias (Flattened/Inverted T waves, ST depression, Prolonged QRS; Peaked P Wave; U wave present)
* Neuromuscular: Weakness, muscle cramping, hypoactive reflexes
* GI: Decreased motility, hypoactive bowel sounds, constipation, ileus, N/V, anorexia
* Metabolic Alkalosis, Weakness of respiratory muscles, Hyperglycemia (impairs insulin secretion)

Question 55

Hypercalcemia

Answer 55

Etiology: Hyperparathyroidism, malignant bone disease, prolonged immobilization, excess calcium supplements, certain meds (thiazide diuretics, lithium)

Clinical manifestations:
GROANS (constipation or Anorexia, N/V)
MOANS (psychic moans = fatigue, lethargy, depression)
BONES (bone pain)
STONES (kidney stones - nephrolithias)
Psychiatric OVERTONES (including depression, memory issues and confusion)
Can’t pick up the PHONE! (muscle weakness, lack of coordination)

Question 56

Hypocalcemia

Answer 56

Etiology: Hypoparathyroidism, malabsorption, vitamin D deficiency, liver or kidney disease

Clinical manifestations:
CATS go numb
C = Convulsions
A = Arrhythmias
T = Tetany (+Trousseau and +Chvostek’s)
S = Spasms, Seizures, & Stridor
Numbness in the fingers

Question 57

Hypermagnesemia

Answer 57

Etiology: renal failure, excessive replacement (typically IV)

Clinical manifestations: Lethargy or drowsiness, N/V, depressed reflexes, muscle weakness/ paralysis, bradycardia, hypotension, respiratory depression, cardiac arrest

Question 58

Hypomagnesemia

Answer 58

Etiology: chronic alcoholism, malabsorption, prolonged gastric suction

Neuromuscular (increased nerve impulse transmission, hyperactive deep tendon reflexes, muscle cramps, tremors, seizures) and cardiac dysrhythmias

Question 59

Respiratory acidosis

Answer 59

PH <7.35
PCO2 >45mmHG
Bicarbonate: 22-26 mEq/L NORMAL

Etiology: hypoventilation which leads to CO2 retention
Patho: Retention of CO2 lowers the arterial pH

Question 60

Respiratory alkalosis

Answer 60

PH > 7.45
PCO2 < 35 mmHG
Bicarbonate: 22-26 mEq/L NORMAL

Etiology: hyperventilation which leads to CO2 elimination
Patho: Elimination of CO2 raises the arterial pH

Question 61

Metabolic acidosis

Answer 61

PH < 7.35
PCO2 35 -45 mmHG NORMAL
Bicarbonate: < 22 mEq/L

Etiology: accumulation of lactic acids or ketoacids, excess ingestion of acids, excessive loss of bicarbonate by the kidneys or GI tract (diarrhea), hyperkalemia (due to potassium / H+ relationship)

Question 62

Metabolic alkalosis

Answer 62

PH > 7.45
PCO2 35 -45 mmHG NORMAL
Bicarbonate: > 26 mEq/L

Etiology: sodium retention (bicarb often accompanies sodium), excess intake of antacids, loss of stomach acids, hypokalemia (H+ is excreted instead of K+)