FLUID FLUID AND AND

ELECTROLYTESELECTROLYTESA Practical Bedside ApproachA Practical Bedside Approach

VICENTE V. TANSECO, JR., MD,FPCP, FPSNVICENTE V. TANSECO, JR., MD,FPCP, FPSN

F & E PARAMETERSF & E PARAMETERS

SALINE BALANCESALINE BALANCE

WATER BALANCEWATER BALANCE

POTASSIUM BALANCEPOTASSIUM BALANCE

HYDROGEN ION BALANCEHYDROGEN ION BALANCE

BASIC F&E PRINCIPLESBASIC F&E PRINCIPLES

60 % of BW is H2O60 % of BW is H2O

The major fluid compartments

1. ICF

2. ECF

a. Plasma -

b. Int. FC -

65 % BW55 % BW

70 % BW

80 % BW

20 % BW

5 % BW

15 % BW

- thin- obese

- infants

FLUID COMPARTMENTSFLUID COMPARTMENTS

STOMACH INTESTINES

BLOOD PLASMALUNGS KIDNEYS

INTERSTITIAL FLUID

INTRACELLULAR FLUID

SKIN5 % BODY WT.4 L

15 % BODY WT.

11 L

40 % BODY WT. 30 L

ELECTROLYTE COMPOSITIONELECTROLYTE COMPOSITION

BLOOD PLASMAINTERSTITIAL

FLUID

INTRACELLULARFLUID

EXTRACELLULAR FLUID

Mg++

Ca++

K+

Na+Na+

HCO3

Na+

ClCl

protein

Org. acid

SO4 K+

Ca++

Mg++ AG

K+

Mg ++

HCO3

HPO4=

SO4=

Protein

HCO3

BASIC F&E PRINCIPLESBASIC F&E PRINCIPLESNa+ is the major cation in the ECFNa+ is the major cation in the ECF

K+ is the major cation in the ICF 98-99%K+ is the major cation in the ICF 98-99%

only 1-2 % is extracellularonly 1-2 % is extracellular

All Fluid compartments are separated by a semi-All Fluid compartments are separated by a semi-permeable membranepermeable membrane

Water passes through the semi-permeable Water passes through the semi-permeable membranes but not solutes to maintain equal membranes but not solutes to maintain equal osmolality in all compartmentsosmolality in all compartments

BASIC F & E PRINCIPLESBASIC F & E PRINCIPLESSemi-permeable membrane

ECF ICF

Na+ Na+ K+

Na+ H2O

H2O Na+

K+ H2O

H2O Na+

Na+ K+ H2O

Na+ H2O

Na+ K+ H2O

H2O K+

Na+ K+ H2O

K+ Na+

H2O K+ H2O

K+ H2O

BASIC F&E PRINCIPLES BASIC F&E PRINCIPLES

ICFECF

Volume increase

Addition of Na+

K+ H2O

Na+

H2O Na+

Na+ H2O

K+ Na+

Na+ H2O

H2O K+

Na+ K+

K+ H2O K+

H2O K+

Na+

H2O K+

Na+ Na+

BASIC F&E PRINCIPLES BASIC F&E PRINCIPLES

ICFECF

Volume increase- negligible

Addition of H2O

Osmolality

Na+ H2OH2O Na+

Na+ K+

H2O Na+

K+ Na+

Na+ H2O

H2O K+ Na+

K+ H2O

K+ Na+

K+H2O K+ H2O

WATER BALANCEWATER BALANCEWATER DEFICIT

OSMOLALITY

OSMORECEPTORS

HYPOTHALAMUS PITUITARY

THIRST CENTER

ANTIDIURETIC HORMONE

COLLECTING TUBULE

WATER REABSORPTION

WATER INTAKE

FEEDBACK FEEDBACK

REMEMBER !REMEMBER !

TALK OF SALINETALK OF SALINE

THINK OF VOLUME

•TALK OF WATER

THINK OF OSMOLALITY

SALINE BALANCESALINE BALANCE

SALINE BALANCE ASSESSMENT:SALINE BALANCE ASSESSMENT:

HistoryHistory

PEPE

1. ECF Volume:1. ECF Volume:

-Orthostatic BP-Orthostatic BP

-CVP-CVP

-Urine Output-Urine Output

-Urine Sp. Gr.-Urine Sp. Gr.

-Hct. -Hct. (3 x Hb = Hct.)(3 x Hb = Hct.)

Blood Volume Blood Volume

2. Interstitial volume2. Interstitial volume

-skin turgor-skin turgor

-edema-edema

-crackles in the -crackles in the lungslungs

-mucosal dryness-mucosal dryness

SALINE

VOLUME

ESTIMATION OF SALINE DEFICITESTIMATION OF SALINE DEFICIT

WT LOSS SALINE CLINICALREPLACEMENT PRESENTATION

5 % 50 CC/Kg BW weak, ambulatory, good mental status

10 % 100 CC/Kg BW weaker, non-ambulatory,

slow mental status15 % 150 CC/Kg BW Obtunded, stuporous,

Coma, seizures

20 % 200 CC/Kg BW Not compatible with life

A SIMPLE ONE !A SIMPLE ONE !

1 Kg change in 1 Kg change in Body weightBody weight

•1 L change in isotonic saline or sodium balance

CORRECTION OF SALINE CORRECTION OF SALINE IMBALANCEIMBALANCE

MAKE THE MAKE THE DIAGNOSISDIAGNOSIS

COMPUTE FOR COMPUTE FOR DEFICIT OR DEFICIT OR EXCESSEXCESS

CORRECT 50 % CORRECT 50 % OF EXCESS OR OF EXCESS OR DEFICITDEFICIT

WATER BALANCEWATER BALANCE

ESTIMATION OF WATER ESTIMATION OF WATER IMBALANCEIMBALANCE

H20 Deficit (L):H20 Deficit (L):=0.5(BW) (Na+/140)-1=0.5(BW) (Na+/140)-1

•100 mg% increase in Blood sugar, add 3 mEq to the serum Na+

•3 mEq change in Na+=1L change in H2O

•1 mEq dec in Na+ for every 4.6 g/l Inc in Lipids

CORRECTION OF WATER CORRECTION OF WATER IMBALANCEIMBALANCE

MAKE THE MAKE THE DIAGNOSISDIAGNOSIS

COMPUTE FOR COMPUTE FOR WATER EXCESS WATER EXCESS OR DEFICITOR DEFICIT

CORRECT 50 % CORRECT 50 % OF COMPUTED OF COMPUTED EXCESS OR EXCESS OR DEFICITDEFICIT

POTASSIUM BALANCEPOTASSIUM BALANCE

RENAL HANDLING OF K+RENAL HANDLING OF K+

K+ IS FREELY FILTEREDK+ IS FREELY FILTERED

90 % IS REABSORBED FROM 90 % IS REABSORBED FROM PROXIMAL TUBULEPROXIMAL TUBULE

SECRETION FROM THE DCT AND SECRETION FROM THE DCT AND CT IS THE PRIMARY MODULATOR CT IS THE PRIMARY MODULATOR OF K+ EXCRETIONOF K+ EXCRETION

FACTORS AFFECTING K+ FACTORS AFFECTING K+ EXCRETIONEXCRETION

ALDOSTERONEALDOSTERONE

Na + DELIVERY TO DISTAL TUBULESNa + DELIVERY TO DISTAL TUBULES

H + EXCRETION:H + EXCRETION:

- ALKALOSIS ---- K + - ALKALOSIS ---- K + EXCRETIONEXCRETION

- ACIDOSIS ----- K + - ACIDOSIS ----- K + EXCRETIONEXCRETION

URINE FLOWURINE FLOW

DIURETICSDIURETICS

MORE ABOUT K+MORE ABOUT K+

98 % OF K+ IS 98 % OF K+ IS INTRACELLULARINTRACELLULAR

SERUM K + SERUM K + CONCENTRATION CONCENTRATION GENERALLY GENERALLY REFLECTS TOTAL REFLECTS TOTAL BODY K+BODY K+

SERUM K + IS SERUM K + IS AFFECTED BY AFFECTED BY THE SERUM pHTHE SERUM pH

POTASSIUM BALANCEPOTASSIUM BALANCE

Acidosis Acidosis K+ is highK+ is high

Alkalosis Alkalosis K + is lowK + is low

H+

ECF ICF

H+

K+ H+

K+ H+

H+

K+ K+

K+ H+

H+ K+

K+

K+ H+

H+

K+ K+

H+ K+

K+ H+

H+

EFFECT OF pH CHANGEEFFECT OF pH CHANGE

FOR EVERY 0.1 FOR EVERY 0.1 pH CHANGEpH CHANGE

15 % CHANGE IN 15 % CHANGE IN SERUM K + SERUM K + LEVELLEVEL

POTASSIUM ASSESSMENT:POTASSIUM ASSESSMENT:

HistoryHistory

Physical examinationPhysical examination

Laboratory:Laboratory:– Serum Potassium level Serum Potassium level

(n.v.= 3.5-4.5)(n.v.= 3.5-4.5)– EKG:EKG:– H+; pHH+; pH

POTASSIUM DEPLETIONPOTASSIUM DEPLETION

Muscle weakness, fatigue due to Muscle weakness, fatigue due to hyperpolarization of cell hyperpolarization of cell membranes potential of cells & membranes potential of cells & nervesnerves

Low serum K+ (< 3.8 mEq/L)Low serum K+ (< 3.8 mEq/L)

EKG changes: flat inverted T EKG changes: flat inverted T waves, prolonged QT interval, waves, prolonged QT interval, prominent U wavesprominent U waves

ESTIMATION OF K + DEFICITESTIMATION OF K + DEFICIT

A drop of K+ from 4 to 3 A drop of K+ from 4 to 3

100-200 mEq deficit100-200 mEq deficit

Below 3 mEq/L 1 mEq/L drop in K Below 3 mEq/L 1 mEq/L drop in K ++

200-400 mEq deficit200-400 mEq deficit

At 1.5 mEq/L serum K +At 1.5 mEq/L serum K +

400-800 mEq deficit400-800 mEq deficit

A SIMPLE METHODA SIMPLE METHOD

For every 1 For every 1 mEq/L change in mEq/L change in serum K+serum K+

Equivalent 100-Equivalent 100-150 mEq/L 150 mEq/L change in total change in total body K+body K+

GUIDE TO K + DEFICIT GUIDE TO K + DEFICIT CORRECTIONCORRECTION

Oral therapy is desirableOral therapy is desirable

For intravenous correction:For intravenous correction:

- If K+ > 2.5 mEq/L and no EKG changes- If K+ > 2.5 mEq/L and no EKG changes

rate < 10 mEq/HR & conc. Not > rate < 10 mEq/HR & conc. Not > than 30 mEq/L of IVFthan 30 mEq/L of IVF

- If K+ < 2 mEq/L w/ EKG changes- If K+ < 2 mEq/L w/ EKG changes

40 mEq/HR & conc. Up to 60 40 mEq/HR & conc. Up to 60 mEq/LmEq/L

TREATMENT OF HYPER K+TREATMENT OF HYPER K+Calcium Gluconate - 5-10 ml of 10% solnCalcium Gluconate - 5-10 ml of 10% solnNaHCO3 - 45 mEq iv push (5 min)NaHCO3 - 45 mEq iv push (5 min)

- 1 L D10W + 90 mEq NaHCO3, 1st - 1 L D10W + 90 mEq NaHCO3, 1st 300 cc in 30 min, the rest 300 cc in 30 min, the rest

in 2-3 HRs.in 2-3 HRs.Glucose-Insulin (4 gm:1 Unit)Glucose-Insulin (4 gm:1 Unit)

- 300 cc D20W + 15 U RI- 300 cc D20W + 15 U RI - 50 cc D50W + 6 U RI- 50 cc D50W + 6 U RI

Cation Exchange Resin: 1 mEq/gm of resinCation Exchange Resin: 1 mEq/gm of resinDialysisDialysis

CARBONIC ACID CARBONIC ACID DISSOCIATION EQUATIONDISSOCIATION EQUATION

CO2 + H2O H2CO3 H+ + HCO3-

HYDROGEN ION BALANCEHYDROGEN ION BALANCEANION GAPANION GAP

PROTEINS

SODIUM

POTASSIUM

HCO3

CHLORIDE

ANION GAP

(Sodium + Potassium)-(Bicarbonate+Chloride)=+10

ANION GAPANION GAP

NORMAL

EXTRACELLULAR FLUID

Mg++

Ca++

K+

Na+Cl

protein

Org. acid

SO4

HCO3

UREMIA

Mg++

Ca++

K+

Na+Cl

protein

Org. acid

SO4

HCO3

DIABETIC K-A

Mg++

Ca++

K+

Na+Cl

protein

Org. acid

SO4

HCO3

PO4

AG

PO4

AG KETONESAG

PO4

HYDROGEN ION BALANCEHYDROGEN ION BALANCE

NORMAL NORMAL VALUESVALUES

-pH : 7.35-7.45-pH : 7.35-7.45

-pCO2: 40 torr-pCO2: 40 torr

-HCO3: 24 mEq/L-HCO3: 24 mEq/L

SIMPLE A/B PROBLEMSSIMPLE A/B PROBLEMS

– Check for pH:Check for pH:

High - High - ALKALOSISALKALOSIS

Low - Low - ACIDOSISACIDOSIS– Check for pCO2:Check for pCO2:

(OR) (OR) Opposite-Opposite-RESPIRATORYRESPIRATORY

(SM) Same- (SM) Same- METABOLICMETABOLIC

HYDROGEN ION BALANCEHYDROGEN ION BALANCE

MIXED ACID-BASE PROBLEMS:MIXED ACID-BASE PROBLEMS:– If pH is NORMAL:If pH is NORMAL:

No Acid-Base problemNo Acid-Base problem

Chronic Respiratory AlkalosisChronic Respiratory Alkalosis

Mixed Acid-Base ProblemMixed Acid-Base Problem– If Anion Gap is High - If Anion Gap is High - METABOLIC ACIDOSISMETABOLIC ACIDOSIS

RULESRULES

HCO3 w/ in pCO2 = 1 mEq/l of HCO3 w/ in pCO2 = 1 mEq/l of HCO3 for each 10 Torr in pCO2> HCO3 for each 10 Torr in pCO2> 4040

HCO3 w/ an acute in pCO2 = 2 HCO3 w/ an acute in pCO2 = 2 mEq/ of HCO3 for each 10 Torr in mEq/ of HCO3 for each 10 Torr in pCO2 below 40pCO2 below 40

HCO3 w/ chronic in pCO2 = 4 HCO3 w/ chronic in pCO2 = 4 mEq/L of HCO3 for each 10 Torr mEq/L of HCO3 for each 10 Torr in pCO2 above 40in pCO2 above 40

HYDROGEN ION BALANCEHYDROGEN ION BALANCE

HistoryHistory

PEPE

LaboratoryLaboratory–pCO2; pH; HCO3-;pCO2; pH; HCO3-;

CORRECTION OF H + CORRECTION OF H + IMBALANCEIMBALANCE

Base deficit or excess =Base deficit or excess =

change in actual HCO3 X BW X change in actual HCO3 X BW X 0.20.2

22

F&E THERAPEUTIC PLANF&E THERAPEUTIC PLANBASIC ALLOWANCE: LOSS H20 Na+ Cl- K+ urine 1500 50 90 40 S&I 1000 0 0 0

TOTAL 2500 50 90 40

CORRECTIONAL ALLOWANCE:

Water Sodium K+ H+

TOTAL

NA K H CL HCO3SWEAT 50 5 55GASTRICSECRETIONS

40 10 90 140PANCREATICFLUID

135 5 50 90BILE 135 5 105 35SMALL INT.FLUID

130 10 115 25DIARRHEALFLUID

50 35 40 45

ELECTROLYTE CONCENTRATIONS IN DIFFERENTBODY FLUIDS IN Meq/L

PRACTICAL PEARLSPRACTICAL PEARLS

SALINE BALANCE = VOLUMESALINE BALANCE = VOLUME

H2O BALANCE = SERUM SODIUMH2O BALANCE = SERUM SODIUM

NEVER USE D5W TO CHALLENGE NEVER USE D5W TO CHALLENGE VOLUMEVOLUME

NEVER GIVE K+ TO OLIGURIC PTS.NEVER GIVE K+ TO OLIGURIC PTS.VOMITING - D5NSSVOMITING - D5NSSDIARRHEA - D5LRSDIARRHEA - D5LRSCORRECT ONLY 50 % OF DEFICIT/EXCESSCORRECT ONLY 50 % OF DEFICIT/EXCESS

THANK YOUTHANK YOU