fluid compartments and fluid shifts

Question 1

kidneys maintain body fluids by

Answer 1

changing volume and composition

Question 2

fluid intake per day

Answer 2

2300 mls per day 200 from synthesized carbs and 2100 from ingested fluids

Question 3

fluid loss output

Answer 3

2300 mls insensible loss (700) sweat (100) feces (100) urine (1400)

Question 4

normal body fluid weight man vs woman

Answer 4

60% vs 50% (more fat)

Question 5

extracellular fluid percent of bodyweight and volume of fluid

Answer 5

20% of body weight 1/3 total volume

Question 6

interstitial fluid percentage of ecf

Answer 6

75%

Question 7

transcellular fluid percent of ecf

Answer 7

25% 1-2 liters

Question 8

transcellular fluids

Answer 8

Synovial  Peritoneal  Pericardial  Intraocular  Cerebrospinal

Question 9

intracellular fluid

Answer 9

40% of body weight 2/3 of total volume

Question 10

know ionic concentrations

Answer 10

know non electrolytes of plasma concentrations

Question 11

ions that have most osmotic effect

Answer 11

Na Cl

Question 12

1 osmole =

Answer 12

1 mole of particles (6.02 x10^23)

Question 13

Each mOsm of solute that cannot cross the membrane will generate

Answer 13

19.3 mmHg

Question 14

Small changes in the concentration of impermeable solute will create

Answer 14

large shifts of water creating large changes in compartment volumes

Question 15

.9% Na Cl solution equals

Answer 15

.9 grams of NaCl per 100 mls solution = 9 grams/L

Question 16

Isosmotic:

Answer 16

Solutions with same osmolarity as intracellular

osmolarity even if some solute is permeable

Question 17

Hypo-osmotic

Answer 17

Solutions with lower osmolarity than intracellular fluid even if some solute is permeable

Question 18

Hyperosmotic

Answer 18

Solutions with higher osmolarity than intracellular fluid even if some solute is permeable

Question 19

causes of fluid imbalance

Answer 19

Water ingestion  Dehydration  Fluid loss from gastrointestinal tract  Abnormal fluid loss by sweating or kidneys

Question 20

adding normal saline to blood

Answer 20

Osmolarity of solution same as ECF
 No change in ECF osmolarity  Expand volume of ECF by volume
of solution
 Add 1 liter – the liter starts in the plasma of the CBV within 15 minutes 75% will move to the Interstitial fluid – 25% will remain in the CBV

Question 21

adding a hypertonic solution

Answer 21

Osmolarity of solution higher than osmolarity of ECF so ECF osmolarity will increase
 Osmolarity of ECF > than osmolarity of ICF so water moves from ICF to ECF
 Overall increase in osmolarity  ECF volume increases (more than
the volume added)  ICF volume decreases
 Most of the sodium and chloride remains in the ECF

Question 22

ecf volume distribution

Answer 22

bodyweight times .2

Question 23

icf volume of distribution

Answer 23

bodyweight times .4

Question 24

starting mosm of ICF and ECF

Answer 24

7840,3920

Question 25

steps in calculating fluid shifts

Answer 25

1) Determine starting volumes, concentrations, & total mOsm
2) Determine initial change to ECF
3) Determine NEW overall osmotic concentration
4) Determine new volumes based on new osmotic concentration

Question 26

adding hypotonic

Answer 26

Osmolarity of solution lower than osmolarity of ECF so ECF osmolarity will decrease
 Osmolarity of ECF < than osmolarity of ICF so water moves from ECF to ICF
 Overall decrease in osmolarity  ECF volume increases  ICF volume increases
 Can use the same process to calculate changes when adding a hypotonic solution

Question 27

nutrient solutions

Answer 27

Glucose most common  All usually adjusted to (or nearly to) isotonic
 If not, given slowly so does not upset balance  As nutrient metabolized patient often left with
surplus of water  Usually removed via kidneys

Question 28

NaCl account for _ amount of solute in ECF

Answer 28

90%

Question 29

hyponatremia Caused by loss of sodium from ECF effect

Answer 29

 Decrease in plasma [Na+]  Decreased ECFV  Increased ICFV

Question 30

hyponatremia Caused by loss of sodium from ECF causes

Answer 30

Diarrhea & vomiting  Diuretic overuse (inhibit ability to conserve sodium)  Renal disease that “wastes” sodium
 Addison’s disease results from decrease secretion of aldosterone

Question 31

Hyponatremia

Caused by addition of excess water to ECF effects

Answer 31

 Decrease in plasma [Na+]  Increased ECFV  Increased ICFV

Question 32

Hyponatremia

Caused by addition of excess water to ECF causes

Answer 32

Excess water retention  Excessive secretion of antidiuretic hormone

Question 33

Consequences of Hyponatremia

Answer 33

 Cell swelling – cerebral edema is major problem  Symptoms: headache; nausea; lethargy;
disorientation
 Significant problems as concentration falls into the 120 to 115 mE/L range
 Significant brain swelling
 Seizures
 Coma
 Permanent brain damage (if brain volume increases by more than 10%)
 Death
 Brain attempts to compensate by moving sodium, chloride, potassium, organic solutes from cells out to ECF
 Have to be careful when treating not to correct too quickly [10 to 12 mmol/L over 24 hours]
 Most common electrolyte disorder (15 to 25% of hospitalized patients)

Question 34

Hypernatremia Caused by water loss from the ECF effect

Answer 34

Increased plasma [Na+]  Decreased ECFV  Decreased ICFV

Question 35

hypernatremia Caused by water loss from the ECF Causes:

Answer 35

Inability to secrete antidiuretic hormone (needed for urine concentration) – produce large amounts of dilute urine (diabetes insipidus)
 Excessive sweating so output greater than intake

Question 36

Hypernatremia
Caused by addition of excess sodium to ECF
 Effect:

Answer 36

Increased plasma [Na+]  Increased ECFV  Decreased ICFV

Question 37

Hypernatremia

Caused by addition of excess sodium to ECF Causes:

Answer 37

Excessive secretion of aldosterone  Reabsorb water and sodium

Question 38

Consequences of Hypernatremia

Answer 38

ssue cells shrink
 Not as common as hyponatremia and requires very high sodium concentration (158 to 160 mEq/L) since high sodium concentrations result in intense thirst
 Patient’s with hypothalamic disease have an impaired thirst reflex
 Slow correction best

Question 39

Intracellular Edema causes

Answer 39

Major causes
 Hyponatremia
 Depression of metabolic systems within cells  Sodium-potassium pump – shift of sodium into the cell
 Lack of adequate nutrition delivery to cells
 Inflammation  Increased cellular permeability – shift of sodium into cell

Question 40

Extracellular Edema Causes

Answer 40

Abnormal leakage of fluid from plasma to interstitial space across capillary
 Most common form created by increased capillary filtration  Failure of lymphatics to return fluid from interstitial
space to vascular system