Fluid, Electrolyte _ Acid-Base Abnormalities-1.pptx

FLUID, ELECTROLYTE & ACID-BASE ABNORMALITIES-1
(Fluid and Electrolytes)
Dr.Aman Ullah Zubair
[DVM][RVMP]
FLUID AND ELECTROLYTES
FLUID COMPARTMENTS
Electrolytes
DEHYDRATION
Isotonic (loss of Water & Sod. in proportions similar to those in plasma); loss of fluid from GIT.
Hypotonic (Decrease in plasma Sod. Conc); adrenocortical insufficiency – inability of kidneys to conserve sodium.
Hypertonic (Deficit of water in excess of sod); increased plasma sod concentration. Too little water intake, excessive losses from resp tract.
EVALUATION & MANAGEMENT
Consider these aspects
State of Hydration
Electrolyte Balance
Acid-Base Balance
Renal Function
Caloric Balance
History, Physical exam and lab tests (State of Hydration).
FLUID VOLUME REPLACEMENT
Four essential principles of fluid therapy
Existing Deficits; as estimated by history, PE & lab.
Maintenance Needs; 44-66 ml / kg / day
(2ml /kg /hour)
Continuing Losses; to be estimated and accounted for in the replacement therapy.
Response of patient to fluid therapy
Calculation of needed fluid
ELECTROLYTE DISTURBANCES
Mainly Sodium and Potassium
Sodium abnormalities:
Hyponatremia: Usually noticed in adrenocortical insufficiency, chronic renal insufficiency, replacement of isotonic losses with 5% dextrose.
Hypernatremia: may be noticed in
too little water intake, excessive losses from respiratory tract, diabetes mellitus.
SOLUTIONS & ADDITIVES IN ROUTINE USE
Solution Tonicity Usual Use(s)
Normal Saline Isotonic Hypotonic dehydration; acidifying
Dextrose 5% Isotonic Hypertonic
dehydration
Dextrose 20% Hypertonic Osmotic diuresis; Hypoglycemia
Dextrose 50% Hypertonic Parenteral alimentation

1. FLUID, ELECTROLYTE & ACID-BASE ABNORMALITIES-1 (Fluid and Electrolytes) Dr.Aman Ullah Zubair [DVM][RVMP]

2. FLUID AND ELECTROLYTES All living organisms require water & electrolytes Solids = 40 % Fluids = 60 % ICF = 40 % ECF = 20 % Interstitial = 15% Plasma = 5% Aqueous humor, CSF, joints, gut & bile comprise 10% of interstitial compartment Note: Functionally, body fluids are contiguous and each compartment is in dynamic equilibrium with the other.

3. FLUID COMPARTMENTS 30 Kg Dog Solids (40%) = 40/100x30 = 12 Kg Fluids (60%) = 60/100x30 = 18 Kg (L) ICF (40%) = 18/60x40 = 12 L ECF (20%) = 18/60x20 = 06 L Interstitial (extravascular ) { 15%}= 6/20x15 = 4.5 L Intravascular (Plasma) {5%} = 6/20x5 =1.5 L Aqueous humor, CSF, joints, gut & bile comprise 10% of interstitial =4.5/100x10 = 0.45 L

4. FLUID COMPARTMENTS (Two-Third Rules) Total Body Water in a 30 kg dog (60%) 18 L 2/3 rd of total is intracellular (2/3x18) 12 L 1/3 rd of total is extracellular (1/3x18) 06 L 2/3 rd of extracellular is extravascular (interstitial) (2/3x6) 04 L 1/3 rd of extracellular is intravascular (1/3x6) 02 L Aqueous humor, CSF, joints, gut & bile comprise 10% of interstitial ie 0.4 L

5. ELECTROLYTES Electrolyte ( mEq /L) ECF ICF Na + 142 10 K + 5 141 Ca + + 5 < 1 Mg + + 3 58 Cl - 103 4 HCO 3 - 28 10 PO 4 - - 4 75 SO 4 - - 1 2

6. DEHYDRATION Deficit of body water --- ( Dehydration) may be----- Isotonic (loss of Water & Sod. in proportions similar to those in plasma); loss of fluid from GIT. Hypotonic (Decrease in plasma Sod. Conc ); adrenocortical insufficiency – inability of kidneys to conserve sodium. Hypertonic (Deficit of water in excess of sod); increased plasma sod concentration. Too little water intake, excessive losses from resp tract.

7. EVALUATION & MANAGEMENT Consider these aspects State of Hydration Electrolyte Balance Acid-Base Balance Renal Function Caloric Balance History, Physical exam and lab tests (State of Hydration).

8. STATE OF HYDRATION History: Physical Exam: <5% ----- No abnormalities 5% ------ Slightly “doughy” inelasticity of skin. 7% ------- Definite inelasticity of skin, CRT (2-3 sec); slight depression of eye into orbit

9. STATE OF HYDRATION 10-12% -- Severe skin inelasticity, CRT(>3sec); markedly sunken eyeballs; shock in debilitated animals, involuntary muscle twitching. 12-15 % ---- Marked shock, imminent death Lab Tests: PCV, TS, Urine specific gravity and blood urea ( in absence of renal dysfunction)

10. FLUID VOLUME REPLACEMENT Four essential principles of fluid therapy Existing Deficits; as estimated by history, PE & lab. Maintenance Needs; 44-66 ml / kg / day (2ml /kg /hour) Continuing Losses; to be estimated and accounted for in the replacement therapy. Response of patient to fluid therapy

11. FLUID VOLUME REPLACEMENT (2) Example: Weight of animal = 25kg Estimated dehydration = 7 % PCV = 54% Plasma TS = 8.5 gm /100ml Urine Sp. Gr = 1.058 Daily Vol of vomitus = 6 00ml How much fluid is needed? What type of fluid is needed? What will be the rate of administration?

12. Calculation of needed fluid (1) Existing deficit = 7/100 x 25 = 1.75kg = 1750 ml Maintenance needs ( 2ml/kg/hour ) (2x25x24) = 1200 ml Continuing losses (estimated) = 600ml Total fluid volume needed = 3550ml (Round figure) =3600 ml Replace half of it in the first 4-6 hrs and the remainder in the next 12 to 18 hrs.

13. Calculation of needed fluid (2) Suppose you want to replace 1800 ml in 5 hours So; 1800 / 5 = 360 ml / hour Drip set give you 10 drops / ml Therefore, 3600 drops / hour or 3600 drops / 60 = 60 drops per minute 60 drops / 60 = 1 drop per second

14. ELECTROLYTE DISTURBANCES Mainly Sodium and Potassium Sodium abnormalities: Hyponatremia : Usually noticed in adrenocortical insufficiency, chronic renal insufficiency, replacement of isotonic losses with 5% dextrose. Hypernatremia : may be noticed in too little water intake, excessive losses from respiratory tract, diabetes mellitus.

15. ELECTROLYTE DISTURBANCES (cont) Potassium abnormalities: Hypokalemia : Usually seen in Prolonged anorexia, vomiting, chronic diarrhea, diabetes mellitus. Hyperkalemia : Seen in Adrenocortical insufficiency, Urethral Obstruction, acute renal insufficiency.

16. SOLUTIONS & ADDITIVES IN ROUTINE USE Solution Tonicity Usual Use(s) Normal Saline Isotonic Hypotonic dehydration; acidifying Dextrose 5% Isotonic Hypertonic dehydration Dextrose 20% Hypertonic Osmotic diuresis ; Hypoglycemia Dextrose 50% Hypertonic Parenteral alimentation

17. SOLUTIONS & ADDITIVES IN ROUTINE USE Solution Tonicity Usual Use(s) Ringers Isotonic Polyionic replacement; acidifying Lactated Ringers Isotonic Polyionic replacement; alkalinizing Amino acid hydrolysate 10% Hypertonic Parenteral alimentation

18. SOLUTIONS & ADDITIVES IN ROUTINE USE Solution Tonicity Usual Use(s) NaHco 3 7.5 % ( 1mEq/L) Hypertonic Alkalinizing Kcl 3 14.85 % 20 or 40 mEq /ampule Hypertonic Potassium deficiency