Fluids and Electrolytes for nursing student.ppt

Nursing College

1. Fluid & Electrolyte balance
1

2. Body Composition
Fluid 60%
Solid 40 %
Fat
Protein
Carbohydrate
Minerals
2

3. Distribution of body fluids (by wt)
Fluid 60% of BW
Intracellular
Extracellular
Intrstitial
Intra vascular(plasma)
Intracellular 40%25 L
(cytoplasm, nucleoplasm)
Intrastitial 15%12 L
(lymph, CSF, synovial fluid, aqueous humor
and vitreous body of eyes, between serous
and visceral membranes, glomerular filtrate of
kidneys. )
Plasma 5%3 L
There is continuous ongoing equilibrium between the intracellular and
extracellular spaces.
3
TBW 40 L

4. Fluid content according to age
Total body water (TBW) vary with age:
Preterm = 80-85%
Term = 75%
Infant= 65%
Older children & adult male= 60%
Adult female=50%
•TBW ↓to60% by 1st yr of life
•Female has less fluid content because of more fat cells
4

5. Effective circulating volume (ECV)
Def: Portion of the ECF that take part in tissue
perfusion.
Only 5% of TBW (intra vascular fluid) are ECV
Adequate ECF must be maintained all the times
5

6. Composition of body fluid
Water
Electrolytes: Inorganic salts, Sodium(Na), Potassi
um(K), Calcium (Ca), Chloride(Cl), Phosphate(
Po4), Bicarbonate(HCO3, Sulphate(SO4)
Nonelectrolytes: Minerals -iron and zinc, Gluc
ose, Lipids, Creatinine, Urea
6

7. Electrolytes of body fluid
Electrolytes are measured in mEq or mmol
Circulating electrolytes electrically charged
When positively charge called cation: Na
+
, K
+
, Ca
++
When negatively charge called anions: Cl
-
,HCO3
-
, SO4
-
7

8. Electrolytes composition of body fluids
Normal Values(serum)
Cation:
Sodium (Na
+)
135 –145 mEq/L
Potassium (K
+
) 3.5 –5.50 mEq/L
Calcium (Ca
++
) 8.5 –10.5 mg/dL
Ionized Calcium 4.5 –5.5 mg/dL
Magnesium (Mg++) 1.5 –2.5 mEq/L
Anion:
Bicarbonate (HCO
-
3) 24 –30 mEq/L
Chloride (Cl
--
) 95 –105 mEq/L
Phosphate (PO
4
---
) 2.8 –4.5 mg/dL
8

9. Distribution of Cation and Anion in ECF & ICF (mEq/l)
INTRA CELLULAR FLUID
CATION
Mg 1.1
Ca
+
2.5
K+ 4
HCO3
–
24
Prot
–
14
Others 6PO4 -2
Na+ 13
Mg+ 17
Prot
-
40
HCO3-10
Cl-3
ANION ANIONCATION
EXTRA CELLULAR FLUID
Na
+
140
9
K
+
140Cl
-
140 Phos
-
107

10. Fluid & Electrolyte balance?
10
INTAKE
=
OUT PUT

11. Daily physiological fluid balance
INTAKE
Ingested liquid: 1500 ml
Ingested food:800 ml
Metabolism: 200 ml
Total 2500 ml/day
OUTPUT
Kidney: 1500 ml
Skin loss: 600 ml
GI: 100 ml
Lung 300 ml
Total 2500 ml
Daily fluid balance of an adult
11

12. Movement of fluid & electrolytes
12
A. Passive transport (no energy required):
Osmosis:Fluidmove from higher concentration to lower
concentration
Diffusion= Moleculesmove from higher concentration t
o lower (Concentration gradient)
Filtration= Fluid and diffusible substances move toge
ther across a membrane; moving from ↑pressure to ↓p
ressure
Hydrostatic pressure : Fluids moves from an area of hig
her pressure to area of lower pressure
B. Active transport( energy required):
Sodium-Potassium Pump

13. Concentration of Body fluid
Units of solute concentration are osmolarity and osmo
lality
Osmolarity: Number of osmoles of solute per liter
(L) of solution. It is expressed as osmol/L
e.g 1 mol/L NaCl solution has an osmolarity of 2
osmol/L
Osmolality: Number of osmoles of solute per kilo
gram(kg) of solvent. It is expressed as osmol/kg
Normal serum osmolality=280-298 mosmol/kg
13

14. Clinical relevance of osmolality
Calculation
Serum osmolality (mosmol/kg) =
Effective osmolality: Osmotic force that is mediating the shi
ft of water between the ECF and the ICF =
The osmotic gap(osmolal gap): is the difference between the actua
l osmolality (measured by the laboratory) and the calculated osmolali
ty
A normal osmolal gap is < 10 mOsm/kg
14
2(Na
+
+K
+
) mmol/l + Urea (mmol/l)+ Glucose (mmol/l)
2 x Na
+
(mmol/l )+ Glucose (mmol/l)

15. Regulation of Body Fluids
Body fluid Homeostasis is maintained through
A.Fluid intake
B.Hormonal regulation
1.Antidiuretic hormone(ADH)
2.Renin-Angeotensin-Aldosterone Mechanism
3.Natriuretic Peptides
C.Fluid output
15

16. A. Fluid intake
Intake is control by hypothalamic thirst center
•↑plasma osmolality
of 1–2%
•↓plasma volume
10%–15%
•Baroreceptor input,
angiotensin II, and
other stimuli
•Moistening of the mucosa of
the mouth and throat
•Activation of stomach and
intestinal stretch receptors
−ve
16

17. 1. Antidiuretic hormone(ADH)
ADH: Secreted by the hypothalamus, and stored in the posterior
pituitary gland
ADH is released by, thrust, ↓fluid volume, High serum osmolali
ty
Acton
reabsorb water from collecting duct of kidney
inhibit sweat glandsto ↓perspiration to conserve water
acts on arterioles, causes constriction thus ↑ BP
ADH is Inhibited by
Excessive of fluid volume
Low osmolality of serum
17
B. Hormonal regulation

18. 2. Renin-Angiotensin-Aldosterone Mechanism
•Low blood
volume
•↓Renal perfusion
Angiotesinogen
Angiotesin I
Angiotensin II
Aldosterone
ACE
↑ Proximal
renal tubule
Systemic
vasoconstriction
↑ Na & Water
reabsorption
↑ Na & Water retention
•↑ BP
Renin
•↑ ADH
•↑H2O absorption
•Water and salt retention
•↑ effective circulating volume
•↑Renal perfusion
Net effect
Jaxtaglomerular apparatus

19. 3. Natriuretic Peptides
Natriuretic Peptides
Atrial Natriuretic Peptide(ANP ) from atria
Brain Natriuretic Peptide(BNP) from ventricle
Action
Acts like a diuretic that causes sodium loss and inh
ibits the thirst mechanism
Inhibit rennin release
Inhibit the secretion of ADH and aldosterone
Vasodilatation
19

20. C. Regulation by fluid output
20
Daily fluid losses: 2500 ml for an adult
Kidney(Urine): 55%
Skin: 30%
Lung: 10%
GI (Stool): 2-5%

21. Renal handling of Fluid & Electrolytes
SubstanceFiltered Excreted Net
reabsorption
Water 180 L 1.5 L 98-99%
Na+ 26,000 mmol100-250 mmol>99%
Cl- 21,000 mmol100-250 >99%
K+ 800 mmol 40-120 mmol>85-95%
HCO3_ 4,800 mmol0 mmol 100%
Urea 54 gm 27-32 g 40-50%
21

22. Regulation of Electrolytes
22

23. Regulation of Sodium & Water
Major cation in the ECF (N=135 -145 mEq/L)
Combines with chloride and bicarbonate to help regulate
acid-base balance
Recommended daily in take 2.5gm/day
Kidney regulates sodium balance and is the principal site
of sodium excretion
Aldosteronehelps in sodium and water conservation
23

24. Potassium regulation
Major electrolyte and principle cation in the ICF
Regulates metabolic activities
Required for glycogen deposits in the liver and skeletal
muscle
Required for transmission of nerve impulses, normal car
diac conduction and normal smooth and skeletal muscle
contraction
Daily intake 1-2 mEq/kg
Regulated by dietary intake and renal excretion
Intestine absorbs about 90% of ingested potassium
Regulate by renin-angiotensin-aldosterone mechanism
24

25. Calcium regulation
99% of calcium is in the bones and teeth
1% is in ECF
50% of calcium in the ECF is bound to protein (albumin)
40% is free & in ionized form-Ionized calcium
Ca++ is needed for
Bone and teeth formation
Blood clotting
Hormone secretion
Cell membrane integrity
Cardiac conduction
Transmission of nerve impulses
Muscle contraction
25

26. Anions
Chloride (Cl
-
)
Major anion in ECF
Follows sodium
Bicarbonate (HCO
3
-
)
Is the major chemical base buffer required for
acid base balance
Is found in ECF and ICF
Regulated by kidneys
26

27. ELECTROLYTE IMBALANCES
●SODIUM IMBALANCE
–HYPONATREMIA[< 135mEq/L serum Na]
•GI LOSSES [vomiting/diarrhea]
•KIDNEY DISEASE
•SKIN LOSS –PERSPIRATION
•PSYCHOGENIC POLYDYPSIA
•SIADH (SYNDROME OF INAPPROPRIATE ADH)
27

28. ELECTROLYTE IMBALANCES
●SODIUM IMBALANCES
–HYPERNATREMIA[>145mEq/L]
•EXCESS SALT INTAKE
•INFUSION OF HYPERTONIC SALINE ( 3%, 5%)
•EXCESS ALDOSTERONE
•DIABETES INSIPIDUS [low ADH/thirst/dilute urine excreted –
Na+ not excreted]
•DEHYDRATION [H2O follows Na+, but Na+ does not follow H2
O]
28

29. ELECTROLYTE IMBALANCES
●POTASSIUM K+
–HYPOKALEMIA[<3.5mEq/L]
•Common, affects cardiac conductivity/ function
•POTASSIUM WASTING DIURETICS
•DIARRHEA, VOMITING
•ALKALOSIS [shifts into cells in exchange for H+]
•EXCESSIVE ALDOSTERONE SECRETION
•POLYURIA
•EXCESSIVE PERSPIRATION
•TREATMENT OF DKA WITH INSULIN[decreases serum potas
sium by redistributing it intocells]
29

30. ELECTROLYTE IMBALANCES
●POTASSIUM K+
–HYPERKALEMIA[>5mEq/L]
•Cardiac conduction, altered ECG, arrest
•RENAL FAILURE
•FLUID VOLUME DEFICIT
•CELL DAMAGE FROM BURNS, TRAUMA
•ADRENAL INSUFFICIENCY
•RAPID INFUSION OF STORED BLOOD
•POTASSIUM SPARING DIURETICS
•SALT SUBSTITUTES
30

31. ELECTROLYTE IMBALANCES
●Hypocalcemia[ionized Ca < 4.5 mEq/L OR total
serum Ca < 8.5mEq/L]
•Illnesses affecting thyroid, parathyroid
•Renal failure [not excreting Phosphate] alcoholics, pancreat
itis
•Neuromuscular and Cardiac sx
•↑↑reflexes, cramps, numbness/tingling
31

32. ELECTROLYTE IMBALANCES
●Hypercalcemia[serum Ionized Ca+ > 5.5 or total
serum Ca > 10.5 mEq/L]
•Immobility, osteoporosis, neoplasm → bone loss of Ca into bl
ood.
•Kidney stones, ↓ reflexes, N&V.
32

33. ELECTROLYTE IMBALANCES
●Magnesium[1.5-2.5 mEq/L]
•Malnutrition, malabsorption → ↓Mg [looks like ↓Ca] ↓ ↓ -
Mg hyperactive reflexes
•Excess intake + renal problems → ↑Mg, ↓HR, RR, B/P, DTR
↓ [e.g. Sulfate in L&D]
●Chloride
•Follows Na+, Acid/base imbalance
33

34. Fluid Imbalance
Fluid deficit -Dehydration
Fluid excess-Hypervolemia
34

35. Dehydration
Abnormal fluid loss causes fluid deficit called dehydration
Conditions can leads to dehydration:
Skin: Fever, under heater, heat exhaustion, burn
GI: Gastroenteritis, fistula, intestinal obstruction
Lung: Tachypnea
Kidney: Polyuria e.g. diabetes
Miscellaneous: Surgical drain, third spacing
35

36. According to serum Sodium (Na) concentration:
Isonatremic (Isotonic)=S. Na 135-150 mmol/l
Hyponatremic (Hypotonic)= S. Na <135 mmol/l
Hypernatremic (Hypertonic)= S. Na>150 mmol/l
Types of dehydration
36

37. What types of IV fluid ?
Types of IVF used:
Normal saline (0.9% NaCl/L)= 154 mEq Na
+
/L
One-half NS (0.45% NaCl/L) = 77 mEq Na
+
/L
One-third NS (0.33% NaCl/L)= 57 mEq Na
+
/L
One-quarter NS (0.25% NaCl/L)= 38 mEq Na
+
/L
One fifth NS(0.18% Nacl) = 30 mmol/l
Ringer’s lactate= Na
+
130 mmol/l, K
+
4 mmol/l, Cl
-
109
mmol/l, bicarb 28 mmol/l , and Ca
++
3 mg/dl )
37

38. REGULATION OF ACID-BASEBALANCE
38
—BUFFER
A SUBSTANCE THAT CAN EITHER ABSORB OR
RELEASE A HYDROGEN ION (H+)
—ARTERIAL pH
REFLECTS TH CONCENTRATION OF HYDROGEN
IONS IN THE BLOOD
—THE pH SCALE
MEASURES THE ACIDITY OR ALKALINITY OF A
FLUID
NORMAL RANGE FOR ARTERIAL BLOOD

39. REGULATION OF ACID-BASEBALANCE
•BIOLOGICAL REGULATION OF Ph
•●BUFFERING SYSTEMS
•★HYDROGEN IONS ARE ABSORBED OR
• RELEASED BY THE CELLS.
•—SWITCH PLACES WITH POTASSIUM.
•★HEMOGLOBIN-OXYHEMOGLOBIN SYSTEM.
•★CHLORIDE SHIFT WITHIN RBC.
39

40. REGULATION OF ACID-BASEBALANCE
•PHYSIOLOGICAL: Lungs, Kidneys
•LUNGS Early response
••↑ HYDROGEN & CARBON DIOXIDE [acidosis]
•Stimulates ↑ Respiratory rate, depth → exhaled CO2
••↓ Co2 & H+ [alkalosis] → retain CO2 by ↓RR
•♡EXAMPLES
•–DIABETIC KETOACIDOSIS
•–CO2 RETAINING PATIENTS WITH COPD
40

41. REGULATION OF ACID-BASEBALANCE
•♡Takes longer/lasts longer
•–Hours to days
•♡Increased or decreased production of Bicarb,
•excretion of H+ by ammonia formation, phosphoric
•acid.
•♡Acid excess [acidosis] → reabsorption of bicarb,
•♡Phosphate + H+ = H3PO4 and NH3-+ H+ = NH4 →
•excretion of H+, lowers acid
41

42. TYPES OF ACID-BASE IMBALANCE
RESPIRATORYACIDOSIS
RESPIRATORY ALKALOSIS
METABOLICACIDOSIS
METABOLIC ALKALOSIS
Name reflects underlying cause, compensation
42

43. Blood Gases & Acid/Base Balance
Normal arterial blood pH: 7.35-7.45
Acidosis: pH < 7.35
Alkalosis: pH > 7.45
Respiratory Acidosis/Alkalosis
–Reflected in PaCO2: [35-45 mg Hg]
▪︎resp rate from any cause blows off CO2
▪︎Resp rate from any cause conserves CO2
–Compensation is via kidneys
43

44. Blood Gases & Acid/Base Balance
Metabolic Acidosis/Alkalosis
–Base Excess: amount of buffer [Hgb & bicarb]
–Normal : -2mEq/L -+2mEq/L [HCO3-22-26]
–Alkalosis: BE > +2mEq/L or Bicarb>26
▪︎[from acid loss/ vomiting, gastric suction]
–Acidosis: BE< -2 mEq/L or Bicarb < 22
▪︎[e.g. from diarrhea, renal disease]
–Compensation is via Respiratory system
44