1. For anything worth having one must pay the price; and the price is always work, patience, love, self-sacrifice – no paper currency, no promises to pay, but the gold of real service.
John Burroughs

2. Fluid distribution Intracellular fluid = 2/3rd of body fluid
Extracellular is the other 1/3rd
Interstitial
Blood vessels = intravascular
Fluid composition is very different:
Extracellular: (serum/interstitial)
lots of sodium/chloride
Intracellular:
lots of potassium!!!
Think about the sodium
potassium pump

3. Na+ K+ Cl- Ca+ Ca+ Ca+ Mg+ Proteins (neg charge)
Serum levels are accurate indicators for most electrolytes – BUT NOT potassium
Potassium is much higher intracellular (98%) than extracellular

4. Remember ions?
Cations carry which type of charge?
Anions carry which type of charge?
They can be exchanged for same type of charge:
H+ for a K+ (this happens to buffer acidosis)
Cl- for a HCO3-

5. Osmotic pressure is how much pressure this movement creates
Water moves from low solute to high
Sodium and glucose determine serum osmolality – the ability to pull water into a space.

6. Isotonic – same osmolality as ICF
Hypotonic – lower osmolality – fewer solutes
Hypertonic – higher osmolality – more solutes

7. Solutions that have a greater osmolality than the ICF are called:
Hypertonic
Hypotonic
Hyperactive
Isotonic
What would each cause cells to do?
Question

8. Another pressure Hydrostatic – Pressure of fluid within a space
When your heart beats – systolic – the pressure inside the vascular space increases – forcing fluid out in the capillary beds – hydrostatic -
Venous side of capillary bed – low hydrostatic pressure allows fluid to lazily, maybe …… flow back……
ONCOTIC pressure PULLS fluid back due to plasma proteins! (ALBUMIN is major player!)

10. Edema Increase in Hydrostatic or capillary pressures
Increase in arterial hydrostatic pressure
Increase in venous hydrostatic pressure – fluid can’t come back
Increase in vascular volume= hydrostatic pressure
Decrease in osmotic/oncotic forces
Not enough Plasma Proteins to pull fluid back
Increase in permeability – think inflammation
Obstruction of lymph vessels

12. Edema Local Think inflammation General Increase in vascular volume
CHF, venous obstruction, fluid overload
Dependent edema from sitting too long
Decrease in colloidal osmotic pressure (Oncotic)
Liver disease – it makes albumin
Kidney disease – proteinuria
Sepsis – capillaries leak from inflammation

13. Water balance 60% of body weight is water
Water and caloric intake should equal
Water loss – output:
Kidneys – main
GI tract – fecal matter has water content
Insensible – cannot measure with I&Os
Skin –
Lungs -

14. Antidiuretic Hormone Acts on the collecting duct
Stored in Posterior Pituitary – released with even slight change in ECF osmolality.
Change in blood volume trigger release
Causes water to be reabsorbed at higher rate – urine is concentrated – high osmolality.

15. SIADH ADH won’t shut off! Results in dilutional Hyponatremia!
Too much water – so serum sodium levels are low
Urine has high specific gravity (concentrated)
Treat with diuretics and fluid restrictions

16. DI The opposite of SIADH – Deficiency of ADH
Urine excretion can be from 3-20 L/day
okay unless they can’t drink enough to equal
Results in hypernatremia – high serum osmolality

17. ADH helps maintain appropriate fluid levels in the body
ADH helps maintain appropriate fluid levels in the body. AHD is released when there is a(n):
Decreased blood osmolality
Increased blood osmolality
Ion gap
Osmoreceptor decrease
Question

18. Sodium Most plentiful electrolyte in ECF – 135-145 mEq/L
Main function is regulation of ECF volume
Also participates in Acid/base balances
Carries an electrical charge so involved in nerves
Changes in sodium usually have equal changes in water
Kidneys control output – very efficient – can reabsorb 100% of filtered sodium if needed.

19. THINK Diffusion/osmosis – movement of water
Sodium why do we care?
Hyponatremia=BURST Hypernatremia=SHRINK
THINK Diffusion/osmosis – movement of water

20. Sodium why do we care?
Electrical activity of cells is impacted by sodium levels

21. Too much sodium – make cells hyper!!!
Too little makes them lethargic…….
Sodium influx in cardiac cells

22. The table lists causes and S/S of each – nice condensed comparison
See Table 17-4
Hypernatremia = serum sodium >145 mEq/L
Hyponatremia=serum sodium <135 mEq/L
The table lists causes and S/S of each – nice condensed comparison

23. Potassium WHAT HAPPENS TO CARDIAC CELLS?
Major cation of ICF – 98% of body K+ is inside cells
Serum potassium levels mEq/L
Very NARROW range and ANYTHING outside this range results in cardiac arrhythmias.
Potassium moves from ECF to ICF with Insulin and stress
BUT
Moves from ICF to ECF with acidosis as the H+ trades places with K+ in attempt to decrease acidosis.
WHAT HAPPENS TO CARDIAC CELLS?

24. Figure 17-14
Notice the impact of potassium on cardiac electrical activity
Both depolarization and repolarization are impacted!
See Table 17-5 for causes and S/S

25. A patient with an acid-base imbalance has an altered potassium level
A patient with an acid-base imbalance has an altered potassium level. The nurse recognizes that the potassium level is altered because
A. potassium is returned to extracellular fluid when metabolic acidosis is corrected.
B. hyperkalemia causes an alkalosis that results in potassium being shifted into the cells.
C. acidosis causes hydrogen ions in the blood to be exchanged for potassium from the cells.
D. in alkalosis, potassium is shifted into extracellular fluid to bind excessive bicarbonate.
Answer: 3
Rationale: Changes in pH (hydrogen ion concentration) will affect potassium balance. In acidosis, hydrogen ions accumulate in the intracellular fluid (ICF) and potassium shifts out of the cell to the extracellular fluid to maintain a balance of cations across the cell membrane. In alkalosis, ICF levels of hydrogen diminish and potassium shifts into the cell. If there is a deficit of H+ in the extracellular fluid, potassium will shift into the cell. Acidosis is associated with hyperkalemia, and alkalosis is associated with hypokalemia.

26. Calcium Normal serum levels = 8-10 mg/dL
Plays a key role in muscle contraction
Serum levels controlled by Parathyroid Hormone (PTH), calcitonin, and vit D.
Chvostek’s Sign:
Trousseau’s Sign:

27. Na+
Ca+ K+
Cl-
Mg+
Ca+
Proteins (neg charge)
Ca+

28. Acid/Base balances NORMAL metabolic functions produce ACIDS
These are neutralized by bases or
Excreted by the kidneys (they resorb/make bicarb and filter acids – hydrogen ions)
pH scale – measurement of Hydrogen ions
Negative logarithm scale: higher the H+ = lower #

29. Acid/Base balances Normal blood leves = 7.35 – 7.45
acidosis = anything below 7.35
alkalosis = anything above 7.45
pH < 6.8 or >7.8 usually fatal

30. Occurs in the serum/blood #1
Buffers:
Three ways to buffer or neutralize acids:
- Serum – Respiratory - Renal
Buffers: immediate response – works well unless respiratory system cannot get rid of CO2
Occurs in the serum/blood #1
1- CHEMICAL REACTIONS: acids recombine w/bases – this produces a salt and a weak acid that breaks into water and CO2.
HCL + NaH2CO3 NaCl +H2CO3 then
H2CO3 breaks into H2O + CO2

31. Buffers: Buffering occurs in the blood - Other SERUM buffers:
Proteins can combine w/H+
Cells exchange K+ for H+ - this removes the acid from serum and puts it into a cell
Buffering occurs in the blood -

32. Respiratory: #2 Starts within minutes but lasts only a few hours
CO2 is an acid
In serum = carbonic acid H2CO3
In Lungs = H2O and CO2
IF CO2 levels increase – brain increases rate and depth of breathing to blow excess off….
The opposite happens if serum CO2 levels drop

33. RENAL: #3 Takes 2-3 days to get started BUT it lasts forever!!!!
Kidneys can reabsorb bicarbs and can make new bicarbs (HCO3-)
They filter/excrete excess H+
Combine H+ w/ammonia to make ammonium – excreted
Also excrete weak acids
Urine pH can range from 4-8 – normal is 6

34. Anne is experiencing a disruption in her pH balance
Anne is experiencing a disruption in her pH balance. Which buffer system is the first to respond?
Renal
Plasma
Respiratory
Alkaline
Question

35. Acid/base imbalance The long list is in table 17-10-
Basically you have two sources of problems:
Respiratory
Any lung issues: asthma, COPD, drug overdose, pneumonia, hyperventilation……
Metabolic
Uncontrolled diabetes, starvation, kidney disease, Shock, severe vomiting, excessive gastric suctioning, excess bicarb intake

36. ABGs Know These!!! Arterial Blood Gasses Normal Values: pH 7.35-7.45
PaCO mm Hg
HCO mEq/L
PaO mm Hg
SaO2 > 90%
some include Base excess ±2.0mEq/L
Know These!!!
From here you can determine all sorts of information including the source of the problem and if the body is compensating or at least trying to…….

37. ABGs Arterial Blood Gasses Which ABG would your lungs impact?
What does the PaCO2 tell us?
What does the PaO2 tell us?
What does the SaO2 tell us?
What changes would you see with:
COPD/emphysema
Pneumonia
Hyperventilation
What might respond in an attempt to neutralize?

38. Six questions: 1- what is the pH? 2- what is the PaCO2? Answers:
3- what is the HCO3?
4- are they all normal?
5- if no to 4:
-match the ‘guilty’ parties
6- attempt at compensation?
Remember: PaCO2 indicates respiratory
HCO3 indicates metabolic
Answers:
Acid
Base/alkaline
Normal

39. Let’s try a few: pH 7.30 PaCO2 50 mm Hg HCO3- 24 mEq/L PaO2 70 mm Hg
SaO %
1- pH tells us what?
2- PaCO2 is which?
3- HCO3- is which?
4- match the pH to the guilty party
5- Is there compensation?

40. Let’s try a few: pH 7.33 PaCO2 50 mm Hg HCO3- 30 mEq/L PaO2 70 mm Hg
SaO %
1- pH tells us what?
2- PaCO2 is which?
3- HCO3- is which?
4- match the pH to the guilty party
5- Is there compensation?

41. Let’s try a few: Common labs For COPD pH 7.35 PaCO2 55 mm Hg
HCO mEq/L
PaO mm Hg
SaO %
Common labs
For COPD
1- pH tells us what?
2- PaCO2 is which?
3- HCO3- is which?
4- match the pH to the guilty party
5- Is there compensation?

42. Let’s try a few: pH 7.48 PaCO2 28 mm Hg HCO3- 24 mEq/L PaO2 100 mm Hg
SaO %
Why is the CO2 so low???
What is this patient doing?
1- pH tells us what?
2- PaCO2 is which?
3- HCO3- is which?
4- match the pH to the guilty party
5- Is there compensation?

43. Let’s try a few: pH 7.30 PaCO2 35 mm Hg HCO3- 18 mEq/L PaO2 90 mm Hg
SaO %
1- pH tells us what?
2- PaCO2 is which?
3- HCO3- is which?
4- match the pH to the guilty party
5- Is there compensation?

44. Renal-Fluid/electrolytes
This WeeK:
Exam one
Renal-Fluid/electrolytes
& Acid/bases
Unit one homework due
Study: outlines AND
worksheets

45. Serum levels are accurate indicators for most electrolytes – BUT NOT potassium
Potassium is much higher intracellular (98%) than extracellular

46. Osmotic pressure is how much pressure this movement creates
Fluid Balance
Osmotic pressure is how much pressure this movement creates