Body fluids IVBody fluids IV

Content areas Content areas

• Fluid disturbances & compensatory Fluid disturbances & compensatory mechanismsmechanisms

• Changes in volume and electrolytes inChanges in volume and electrolytes in– DiarrhoeaDiarrhoea– VomitingVomiting

• Importance of rehydrationImportance of rehydration

• Fluids used for rehydrationFluids used for rehydration– Limitations/ risks involved with their useLimitations/ risks involved with their use

• Usefulness of fluids in replacing lost Usefulness of fluids in replacing lost fluid fluid

WATER BALANCEWATER BALANCE Ingested fluid 1,300mlIngested fluid 1,300ml

Solids 800mlSolids 800ml

Metabolic water Metabolic water 400ml 400ml

2,500ml2,500ml

Skin 500mlSkin 500ml

Lungs 400mlLungs 400ml

Urine 1,500mlUrine 1,500ml

Faeces Faeces 100ml 100ml

2,500ml2,500ml

ICF 28 L

ECF14 L

Causes of fluid lossCauses of fluid loss

• Skin Skin - - burns, large woundsburns, large wounds

• GIT GIT -- Diarrhoea, vomiting Diarrhoea, vomiting ……

• Kidney Kidney -- Polyuria, diureticsPolyuria, diuretics

• Haemorrhage, oedema …… Haemorrhage, oedema ……

Transpiration / Insensible Transpiration / Insensible lossloss- Inevitable loss - Inevitable loss - Depends on environment- Depends on environment integrity of skinintegrity of skin- The evaporation of water from skin- The evaporation of water from skin- 500-750 ml/day- 500-750 ml/day- Loss of electrolytes is negligible- Loss of electrolytes is negligible (Perspiration – visible excretion)(Perspiration – visible excretion) Breathing Inevitable lossBreathing Inevitable loss

24 hr transcellular fluid secretion into 24 hr transcellular fluid secretion into the the

gut by an adultgut by an adult Saliva 1,500 mlSaliva 1,500 ml Gastric juice 2,500 mlGastric juice 2,500 ml Bile 500 mlBile 500 ml Pancreatic juice 700 mlPancreatic juice 700 ml Succus entericus Succus entericus 3,000 ml3,000 ml 8,200 ml8,200 ml Faeces 100 mlFaeces 100 ml Diarrhoea & vomiting can alter water Diarrhoea & vomiting can alter water balancebalance

KidneysKidneys

- 180 L of fluid passes into the 180 L of fluid passes into the Bowman’s space dailyBowman’s space daily

- Average daily urine output is 1000 mLAverage daily urine output is 1000 mL

(500 mL of urine – obligatory loss)(500 mL of urine – obligatory loss)

The balance depends on intakeThe balance depends on intake

Kidney disease can effect water Kidney disease can effect water balancebalance

Dehydration & Dehydration & overhydrationoverhydration

Key wordsKey words

SymptomsSymptoms - What the patient tells us - What the patient tells us

SignsSigns - What we find out by examining - What we find out by examining the the

patientpatient

DehydrationDehydration - Loss of body water- Loss of body water

Over hydrationOver hydration - Excess of body water- Excess of body water

DehydrationDehydration↓ ↓ in ECF volume due to loss of Hin ECF volume due to loss of H22O & NaO & Na++

SymptomsSymptoms

- Dry throat & mouthDry throat & mouth - Difficulty in speech- Difficulty in speech

- LethargyLethargy - - ↓ urine output↓ urine output

- Weight lossWeight loss

SignsSigns

- - ↓↓ Skin turgor Skin turgor - Sunken eye balls - Sunken eye balls

-- Dry lips and tongue Dry lips and tongue - Sunken fontanelle(in - Sunken fontanelle(in infants) infants)

-- Flat neck veinsFlat neck veins - - ↑ ↑ Heart rate and pulse Heart rate and pulse rate rate

-- ↓ ↓ Blood pressureBlood pressure

Over hydrationOver hydration

• Puffy eyelids Puffy eyelids

• Bulging fontanelle (in infants)Bulging fontanelle (in infants)

• Oedema Oedema

• Weight gain Weight gain

………………....

• Osmolality Number of osmoles/Kg of solventOsmolality Number of osmoles/Kg of solvent• Osmolarity –Number of osmoles/Liter of solventOsmolarity –Number of osmoles/Liter of solvent• Tonicity of fluidsTonicity of fluids• Osmotically active particalls ab=nd volume homeostasis Homeostasis –maintenance of the interior of the body in a stable stateOsmotically active particalls ab=nd volume homeostasis Homeostasis –maintenance of the interior of the body in a stable state• Fluid volume is mainly determined by the total amount of osmotically active particals on the compartmentFluid volume is mainly determined by the total amount of osmotically active particals on the compartment• Osoticallly active particals fluid volumeOsoticallly active particals fluid volume

Dehydration StatesDehydration States

• Isosmotic dehydrationIsosmotic dehydration

• Hyperosmotic dehydrationHyperosmotic dehydration

• Hypo-osmotic dehydrationHypo-osmotic dehydration

↓ Plasma volume – Blood loss (hemorrhage) Diarrhoea and vomiting Burns

MechanismMechanismLoss of fluid from plasma loss from Loss of fluid from plasma loss from

interstitiuminterstitium

ECF volume no change in ECF volume no change in osmolality osmolality

- No shift of fluid into/out of ICF- No shift of fluid into/out of ICF

Treatment – isotonic salineTreatment – isotonic saline

Isosmotic DehydrationIsosmotic Dehydration

ICFICF

ISFISF

PlasmaPlasmaIntestines Intestines

Hyperosmotic DehydrationHyperosmotic Dehydration

Loss of water in excess of saltLoss of water in excess of salt

CausesCausesa)a) ↓↓ Water intakeWater intakeb)b) Diabetes insipidus - Diabetes insipidus - loss of water from kidney loss of water from kidneyc)c) Diabetes mellitusDiabetes mellitusd)d) AlcoholismAlcoholisme)e) FeverFeverf)f) Excessive sweating Excessive sweating

MechanismMechanism

i.i. Loss of fluid from plasma (water > solutes)Loss of fluid from plasma (water > solutes)

Hyperosmotic plasmaHyperosmotic plasma

Fluid moves from interstitium Fluid moves from interstitium PlasmaPlasma

ii.ii. Osmolality of interstitial fluidOsmolality of interstitial fluid

Fluid moves from ICF ECFFluid moves from ICF ECF

in ECF & ICF volumesin ECF & ICF volumes in osmolality of ECF & ICFin osmolality of ECF & ICF

Hyposmotic DehydrationHyposmotic Dehydration

• Solute loss in excess of waterSolute loss in excess of water

• CausesCauses

Renal loss of NaCl due to Renal loss of NaCl due to

Adrenal insufficiency Adrenal insufficiency (Addison’s (Addison’s diseasedisease))

MechanismsMechanisms

i.i. Loss of NaCl from plasma Loss of NaCl from plasma

Plasma osmolalityPlasma osmolality

Fluid moves from plasma Fluid moves from plasma interstitiuminterstitium

ii.ii. Interstitial osmolalityInterstitial osmolality

Fluid moves from ECF ICFFluid moves from ECF ICF

ECF volume , ICF volume ECF volume , ICF volume

Osmolality in ECF & ICF Osmolality in ECF & ICF

OverhydrationIsosmotic overhydrationIsosmotic overhydration

CausesCauses

a) Oral/IV administration of large volume of a) Oral/IV administration of large volume of isotonic normal saline (0.9 % NaCl)isotonic normal saline (0.9 % NaCl)

MechanismMechanism

I.I. ECF volume ECF volume ↑↑

II.II. No change in osmolality of ECF/ ICFNo change in osmolality of ECF/ ICF

TreatmentTreatment

DiureticsDiuretics

Hyperosmotic overhydrationHyperosmotic overhydration

CausesCausesa)a) Oral/IV administration of large volume of hypertonic Oral/IV administration of large volume of hypertonic

salinesaline

MechanismMechanismI.I. Plasma osmolalityPlasma osmolality

Fluid moves from interstitium PlasmaFluid moves from interstitium Plasma

II.II. Interstitial osmolality Interstitial osmolality

Fluid flow from ICF ECFFluid flow from ICF ECF

II.II. ICF & ECF volumeICF & ECF volume

ICF & ECF osmolalityICF & ECF osmolality

Hypo-osmotic overhydrationHypo-osmotic overhydration

Intake of water exceeds the excretory Intake of water exceeds the excretory capacity of kidneycapacity of kidney

CausesCauses

a) Ingestion of large volume of watera) Ingestion of large volume of water

b) Retention of Hb) Retention of H22O by kidney (SIADH)O by kidney (SIADH)

Syndrome of inappropriate secretion of Syndrome of inappropriate secretion of ADHADH

(ADH – anti diuretic (ADH – anti diuretic hormone)hormone)

MechanismMechanism

I.I. Plasma osmolality Plasma osmolality

Fluid flows from plasma Fluid flows from plasma InterstitiumInterstitium

Osmolality of InterstitiumOsmolality of Interstitium

II.II. Fluid flows from plasma ECF ICFFluid flows from plasma ECF ICF

III.III. ICF & ECF volumeICF & ECF volume

ICF & ECF osmolalityICF & ECF osmolality

Volume & Osmolality in ECF & ECFVolume & Osmolality in ECF & ECF

NMS_ DIAGRAMNMS_ DIAGRAM

Volume & Osmolality in ECF & ECFVolume & Osmolality in ECF & ECF

NMS_ DIAGRAMNMS_ DIAGRAM

Volume & Osmolality in ECF & ECFVolume & Osmolality in ECF & ECF

Metabolic consequences of VOMITINGMetabolic consequences of VOMITING Gastric juice Isotonic with plasmaGastric juice Isotonic with plasma

[Cl[Cl--], [K], [K++]]

Very high [HVery high [H++]]

Therefore net result of vomiting,Therefore net result of vomiting,

a) Isotonic dehydrationa) Isotonic dehydration

b) Acid loosing Alkalosisb) Acid loosing Alkalosis

c) Hypochloraemiac) Hypochloraemia

d) Hypokalaemiad) Hypokalaemia

e) Hypovolaemiae) Hypovolaemia

Metabolic consequences of Metabolic consequences of DIARRHOEADIARRHOEA

Intestinal, pancreatic, biliary & colonicIntestinal, pancreatic, biliary & colonic secretions secretions Isotonic with Isotonic with plasmaplasma

[Na[Na++], [K], [K++], [HCO], [HCO33--]]

Therefore net result of diarrhoea,Therefore net result of diarrhoea,

a) Isotonic dehydrationa) Isotonic dehydration

b) Base loosing Acidosisb) Base loosing Acidosis

d) Hypokalaemiad) Hypokalaemia

e) Hypovolaemiae) Hypovolaemia

Diarrhoea & vomiting in infants & Diarrhoea & vomiting in infants &

childrenchildren

- Serious problem- Serious problem

- Total deprivation of food & H- Total deprivation of food & H22OO

Adults Survive > 10 daysAdults Survive > 10 days

Children Survive < 3 daysChildren Survive < 3 days

ReasonsReasons

1.1. Absolute volume of water in ECF - child < Absolute volume of water in ECF - child < adultadult

2. Water distribution2. Water distribution

1/7 exchanged 1/7 exchanged

1/2 exchanged1/2 exchanged

Fluid is lost more rapidlyFluid is lost more rapidly

TBWTBW ICFICF ECFECF

AdultAdult 55-60%55-60% 2/32/3 1/3 1/3

Children Children

65-70%65-70% 1/21/2 1/21/2

3. Infants kidney is less efficient3. Infants kidney is less efficient

- Response to ADH & Aldosterone is - Response to ADH & Aldosterone is less therefore reabsorption of less therefore reabsorption of fluids is fluids is

- Treatment must be prompt & - Treatment must be prompt & efficientefficient

a) Assess the level of dehydrationa) Assess the level of dehydration

b) Rehydrate accordinglyb) Rehydrate accordingly

Rehydration SolutionsRehydration Solutions

1. Oral Rehydration solution (ORS)1. Oral Rehydration solution (ORS)

‘ ‘Jeewani’Jeewani’

-NaCl - 3.5g-NaCl - 3.5g

-Na Citrate – 2.9g-Na Citrate – 2.9g

-KCl – 1.5g-KCl – 1.5g

-Glucose 20g-Glucose 20g

1L of H2O

2.2. Blood Blood

Whole blood Whole blood Plasma Plasma Packed cells Packed cells

DisadvantagesDisadvantagesDiseases (hepatitis B, HIV)Diseases (hepatitis B, HIV)Allergies Allergies

a. Colloids a. Colloids

Dextran, Gelafundin Dextran, Gelafundin

Maintains /increases plasma oncotic pressure Maintains /increases plasma oncotic pressure

helps draw fluid into the intravascular helps draw fluid into the intravascular compartmentcompartment

3. Intravenous solutions3. Intravenous solutions

DisadvantagesDisadvantages• Coagulation problemsCoagulation problems

• Adverse reactionsAdverse reactions

• ExpensiveExpensive

b. Crystalloidsb. Crystalloids

Normal saline (0.9% NaCl)Normal saline (0.9% NaCl) Hartmann’s solution (Ringer Hartmann’s solution (Ringer

lactate)lactate)

Isotonic solutionIsotonic solution Glucose (Dextrose) - 5% , 10%Glucose (Dextrose) - 5% , 10%

↑ ↑ ECF space ECF space

Proportional distribution of fluid Proportional distribution of fluid into different compartmentsinto different compartments

• Infusion of 1L of normal Infusion of 1L of normal salinesaline

1L will remain in the ECF1L will remain in the ECF

1/4 in plasma 1/4 in plasma

¾ in interstitial fluid ¾ in interstitial fluid

• Infusion of 1L of colloidInfusion of 1L of colloid

1L remain in plasma1L remain in plasma

• Infusion of 1L of 5% dextroseInfusion of 1L of 5% dextrose 1/3 rd in ECF 1/3 rd in ECF

2/3 rd in ICF2/3 rd in ICF