Cairan tubuh Cairan tubuh dan elektrolitdan elektrolit

Dr.H.Hasrul HanDr.H.Hasrul Han

Bag: Patologi klinik FK UnsriBag: Patologi klinik FK Unsri

Learning objectiveLearning objective

Identify the functions of the major serum Identify the functions of the major serum electrolyte.electrolyte.

Understand about acidosis and alkalosisUnderstand about acidosis and alkalosis

Distribusi cairan tubuhDistribusi cairan tubuh

Apakah total cairan tubuh % BB tgt umur Apakah total cairan tubuh % BB tgt umur dan jenis kelamin ?dan jenis kelamin ?

Jumlah cairan diukur dari % BB menurun Jumlah cairan diukur dari % BB menurun dengan meningkatnya umurdengan meningkatnya umur

Persentase BB pria lebih tinggi dari Persentase BB pria lebih tinggi dari wanitawanita

Body Fluids - distributionBody Fluids - distribution Body fluids constitute 55-60% Body fluids constitute 55-60%

of body massof body mass Higher in males due to greater Higher in males due to greater

muscle mass and lower fatmuscle mass and lower fat

Total body water declines Total body water declines throughout life with changes in throughout life with changes in muscle mass and fatmuscle mass and fat

Water occupies 2 main fluid Water occupies 2 main fluid compartments:compartments: Intracellular (~2/3 of total Intracellular (~2/3 of total

water)water)

Extracellular (~1/3 total water)Extracellular (~1/3 total water) plasma (20%)plasma (20%)

interstitial fluid (80%)interstitial fluid (80%)

Water balanceWater balance Normally body fluid volume remains Normally body fluid volume remains

constantconstant water loss = water gainwater loss = water gain

Water Water gaingain:: ~60% ingested liquids~60% ingested liquids ~30% ingested in foods~30% ingested in foods ~10% metabolic water (from ~10% metabolic water (from

oxidation)oxidation)

Water Water lossloss:: ~4% faeces~4% faeces ~28% insensible water loss (skin & ~28% insensible water loss (skin &

lungs)lungs) ~8% perspiration~8% perspiration ~60% urine~60% urine

Additional fluid loss in menstrual Additional fluid loss in menstrual flow in females of reproductive ageflow in females of reproductive age

Regulation of body water Regulation of body water gain and lossgain and loss

Regulation of body water gain depends Regulation of body water gain depends mainly on regulating volume of water mainly on regulating volume of water intake intake Thirst centre in hypothalamus governs Thirst centre in hypothalamus governs

urge to drinkurge to drink Thirst centre stimulated by :Thirst centre stimulated by :

Nerve impulses from osmoreceptors in Nerve impulses from osmoreceptors in hypothalamushypothalamus

in PV or in PV or in plasma osmolality in plasma osmolality Hypothalamic Hypothalamic osmoreceptors lose water to plasmaosmoreceptors lose water to plasma

Increased transmission of nerve impulses Increased transmission of nerve impulses to thirst centreto thirst centre

dry mouth and pharynx - less saliva from dry mouth and pharynx - less saliva from blood plasmablood plasma

in PV = in PV = BPBP increased angiotensin II (via JGA)increased angiotensin II (via JGA)

stimulates thirst centrestimulates thirst centre

Regulation of body water (and solute) Regulation of body water (and solute) loss depends mainly on urinary excretionloss depends mainly on urinary excretion

Water lossWater loss

Ambient air temperatureAmbient air temperature Solar and thermal radiationSolar and thermal radiation Water vapor pressure (humidity)Water vapor pressure (humidity) Solutes and wastes to be excretedSolutes and wastes to be excreted Amount and timing of activityAmount and timing of activity Amount of water intakeAmount of water intake Physiological, behavioral, and anatomical Physiological, behavioral, and anatomical

adaptations to reduce water lossadaptations to reduce water loss

Insensible water lossInsensible water loss (unaware of) (unaware of)

Not precisely regulatedNot precisely regulated

Evaporation (respiration and skin)Evaporation (respiration and skin)

Independent of sweating (anhydrosis)Independent of sweating (anhydrosis)

Minimized by cholesterol-filled cornified Minimized by cholesterol-filled cornified layer of skin (barrier)layer of skin (barrier)

Increase loss in burn patients (10x)Increase loss in burn patients (10x)

SweatingSweating Highly variableHighly variable Dependent on physical activity and Dependent on physical activity and

environment temperatureenvironment temperature ↑ ↑ water intake via thirst mechanismwater intake via thirst mechanism

Loss via fecesLoss via feces Normally small amountNormally small amount Severe during diarrheaSevere during diarrhea

Water loss via kidneyWater loss via kidney The most important regulator of water and electrolyte The most important regulator of water and electrolyte

balancebalance Several mechanisms controlling the rate of excretionSeveral mechanisms controlling the rate of excretion ↓ ↓ water excretion (dehydration), ↑ excretion with ↑ water excretion (dehydration), ↑ excretion with ↑

increased intake (same for electrolyte)increased intake (same for electrolyte) Kidneys adjust the excretion rate to match intake and Kidneys adjust the excretion rate to match intake and

disease statedisease state

Body Fluid CompartmentsBody Fluid Compartments

ExtracellularExtracellular Interstitial fluid and plasma (non-cellular Interstitial fluid and plasma (non-cellular

part of blood)part of blood)

Transcellular Transcellular (specialized type of extracellular (specialized type of extracellular fluid)fluid) Cerebrospinal fluid, intraocular fluid, GI Cerebrospinal fluid, intraocular fluid, GI

tract, potential fluid (peritoneal, joint space)tract, potential fluid (peritoneal, joint space)

IntracellularIntracellular

Fluid BalanceFluid Balance

Fluid and Fluid and electrolytes come electrolytes come into the plasma into the plasma then redistribute then redistribute to the other fluid to the other fluid compartments compartments over time. Note over time. Note also the also the lymphatics as a lymphatics as a recirculator of recirculator of plasma proteinsplasma proteins

Body Fluid CompartmentsBody Fluid Compartments

Total body waterTotal body water - 50-60 % of body weight - 50-60 % of body weight decrease with age, gender and obesitydecrease with age, gender and obesity

Intracellular waterIntracellular water - 40% of body weight - 40% of body weight 75 trillion cells75 trillion cells Similar composition in different speciesSimilar composition in different species

Extracellular waterExtracellular water - 20% of body weight - 20% of body weight % is important in fluid therapy% is important in fluid therapy Transcellular accounts for ~ 1-2 litersTranscellular accounts for ~ 1-2 liters

PlasmaPlasma Plasma is the liquid portion of the blood that is separated from Plasma is the liquid portion of the blood that is separated from

the blood cells by centrifugation.the blood cells by centrifugation. One of the characteristics of plasma is that it clots easily. One of the characteristics of plasma is that it clots easily. Serum plus clotting factors is plasma, and clotted plasma Serum plus clotting factors is plasma, and clotted plasma

yields serum (as an interesting aside, "serum" is Latin for yields serum (as an interesting aside, "serum" is Latin for whey, the liquid portion of clotted milk removed in making whey, the liquid portion of clotted milk removed in making cheese).cheese).

PlasmaPlasma

Exchanges substances with interstitial fluid Exchanges substances with interstitial fluid via pores of the capillary membranevia pores of the capillary membrane

Pores permeable to all solutes in Pores permeable to all solutes in extracellular fluid, except proteinsextracellular fluid, except proteins

Plasma have higher protein concentrationPlasma have higher protein concentration

Hematocrit (PCV)Hematocrit (PCV)

RBC

NormalThrombocytosis

Composition of extracellular Composition of extracellular and intracellular fluidsand intracellular fluids

These represent These represent the the non-non-electrolytes electrolytes in the in the plasmaplasma. . They They also contribute also contribute osmolarity to the osmolarity to the plasma or plasma or extracellular fluid.extracellular fluid.

Intracellular volumeIntracellular volume Can not be measured directlyCan not be measured directly Calculated as Total body water - Calculated as Total body water -

Extracellular volumeExtracellular volume Plasma volumePlasma volume

Indicator can not permeate capillary Indicator can not permeate capillary membranemembrane

Most common Most common 125125I-albumin, also Evans blue I-albumin, also Evans blue dye (T-1824)dye (T-1824)

Interstitial volumeInterstitial volume Can not be measured directlyCan not be measured directly Calculated as Extracellular volume - Plasma Calculated as Extracellular volume - Plasma

volumevolume

Forces impacting fluid Forces impacting fluid distributiondistribution

Plasma vs Interstitial SpacePlasma vs Interstitial Space Balance between Hydrostatic and Colloid Balance between Hydrostatic and Colloid

Osmotic forces across the capillary Osmotic forces across the capillary membranesmembranes

Intracellular vs ExtracellularIntracellular vs Extracellular Osmotic effect (e.g. electrolytes)Osmotic effect (e.g. electrolytes)

OsmosisOsmosis

Osmosis is the net movement of water Osmosis is the net movement of water molecules over a partially permeable molecules over a partially permeable membrane from an area of less osmotic membrane from an area of less osmotic potential to an area of more negative potential to an area of more negative osmotic potential. osmotic potential.

Excessive loss of H2O from ECF

1 2 3ECF osmotic pressure rises

Cells lose H2O to ECF by osmosis; cells shrink

(a) Mechanism of dehydration

OsmosisOsmosis

OsmosisOsmosis

Excessive H2O enters the ECF

1 2 ECF osmotic pressure falls

3 H2O moves into cells by osmosis; cells swell

(b) Mechanism of hypotonic hydration

Osmotic PressureOsmotic Pressure

Determined by number of particles per unit Determined by number of particles per unit volume, not by mass! (Molar Concentration)volume, not by mass! (Molar Concentration)

1 molecule of Albumin (mw 70000) and 1 1 molecule of Albumin (mw 70000) and 1 molecule of Glucose (mw 180) has same osmotic molecule of Glucose (mw 180) has same osmotic effecteffect

What is the osmotic pressure What is the osmotic pressure of a 0.9% NaCl solution?of a 0.9% NaCl solution?

0.9 % NaCl solution= 0.9g in 100 ml of solution or 0.9 % NaCl solution= 0.9g in 100 ml of solution or 9g/1L9g/1L

MW of NaCl =58.5MW of NaCl =58.5 X mM=X mg/mw x 1000ml/ X mlX mM=X mg/mw x 1000ml/ X ml X mM=900mg/58.5 x 1000/100X mM=900mg/58.5 x 1000/100 154 mM = 154 mOsm154 mM = 154 mOsm But wait, NaCl dissociates. So 154 x 2=308 mOsm/LBut wait, NaCl dissociates. So 154 x 2=308 mOsm/L Potential osmotic pressure would be 308 x 19.3 mm Potential osmotic pressure would be 308 x 19.3 mm

Hg/mOsm/L or 5944 mm HgHg/mOsm/L or 5944 mm Hg

What is the osmotic pressure of What is the osmotic pressure of a 5% glucose solution?a 5% glucose solution?

Glucose mw=180Glucose mw=180 5g of glucose in 100mL of solution5g of glucose in 100mL of solution X mM=5000 mg/180 x 1000ml/100mLX mM=5000 mg/180 x 1000ml/100mL 278 mM = 278 mOsm278 mM = 278 mOsm Potential osmotic pressure would be 278 x Potential osmotic pressure would be 278 x

19.3 mm Hg/mOsm/L or 5366 mm Hg19.3 mm Hg/mOsm/L or 5366 mm Hg

Osmolarity of body fluidsOsmolarity of body fluids Interstitial fluid and plasma (80% NaInterstitial fluid and plasma (80% Na++ and Cl and Cl-- ions) ions)

Intracellular fluid (50% KIntracellular fluid (50% K++ ions) ions)

Total osmolarity of each around 300 mOsm/LTotal osmolarity of each around 300 mOsm/L

Plasma 1 mOsm/L greater because of osmotic Plasma 1 mOsm/L greater because of osmotic affect of plasma proteins (20 mmHg greater affect of plasma proteins (20 mmHg greater pressure in the capillaries)pressure in the capillaries)

Factors that impact Factors that impact intracellular and extracellular intracellular and extracellular volumevolume

Ingestion of waterIngestion of water DehydrationDehydration IV infusion of different solutionsIV infusion of different solutions Loss of fluid via GI tractLoss of fluid via GI tract Loss via sweatLoss via sweat Loss via kidneysLoss via kidneys

Important principles for fluid Important principles for fluid therapytherapy

Water moves rapidly across cell membranesWater moves rapidly across cell membranes Osmolarity between compartments will be Osmolarity between compartments will be

almost exactly except for a few minutes almost exactly except for a few minutes after one changesafter one changes

Cell membranes are almost completely Cell membranes are almost completely impermeable to many solutesimpermeable to many solutes Osmoles remains constant, unless solutes Osmoles remains constant, unless solutes

are added or lost from the extracellular are added or lost from the extracellular compartmentcompartment

Edema FormationEdema Formation“Excess fluid in body tissue”“Excess fluid in body tissue”

Most cases in the extracellular fluid Most cases in the extracellular fluid compartmentcompartment

Can also occur in the intracellular fluid Can also occur in the intracellular fluid compartment as wellcompartment as well

Decreased kidney excretion of salt and waterDecreased kidney excretion of salt and water Disease state (acute glomerulonephritis) Disease state (acute glomerulonephritis)

with failure to filtrate adequate amounts of with failure to filtrate adequate amounts of fluidfluid

Decreased plasma proteinsDecreased plasma proteins Failure of body to produce normal amounts Failure of body to produce normal amounts

of proteinsof proteins Leakage of proteins from plasmaLeakage of proteins from plasma

Extracellular - pitting edemaExtracellular - pitting edema

Decreased plasma proteins (con’t)Decreased plasma proteins (con’t)

Nephrotic syndrome (damage to the Nephrotic syndrome (damage to the membranes of the renal glomeruli). membranes of the renal glomeruli). Serious edema when plasma protein falls Serious edema when plasma protein falls below 2.5g/100ml.below 2.5g/100ml.

Cirrhosis of the liver (hepatic tissue Cirrhosis of the liver (hepatic tissue fibrosis). ↓ protein synthesis leading to ↓ fibrosis). ↓ protein synthesis leading to ↓ colloid osmotic pressure.colloid osmotic pressure.

ElektrolitElektrolit ion in the body ion in the body fluidfluid

KationKation (Na,K,Ca,Mg) (Na,K,Ca,Mg)

AnionAnion (Cl) (Cl)

Penting pada perawatan penyakit akutPenting pada perawatan penyakit akut

Tujuan:Tujuan: D/ dan Th/ gangguan elektrolit D/ dan Th/ gangguan elektrolit Monitor hasil Th/ Monitor hasil Th/ Mencegah komplikasi Mencegah komplikasi

C a r a :C a r a :

Flame emission spectrophotometryFlame emission spectrophotometry Ion selective electrode (ISE)Ion selective electrode (ISE) Spectrofotometer kinetikSpectrofotometer kinetik

Fungsi KationFungsi Kation

Na :tek. Osmotik CES, aktifitas neuro Na :tek. Osmotik CES, aktifitas neuro muskuler,mempengaruhi asam basa, Cl dan K muskuler,mempengaruhi asam basa, Cl dan K serta membantu pengeluar-an air.serta membantu pengeluar-an air.

K: tek.Osmotik CIS, aktifitas enzym dan K: tek.Osmotik CIS, aktifitas enzym dan neuromuskuler, mempengaruhi asam basa dan neuromuskuler, mempengaruhi asam basa dan fungsi ginjalfungsi ginjal

Ca: aktifitas neuromuskuler,perkem-bangan Ca: aktifitas neuromuskuler,perkem-bangan rangka, pembekuan darah,rangka, pembekuan darah,

Mg: aktifitas intraseluler dan mempengaruhi Mg: aktifitas intraseluler dan mempengaruhi level Na,K,Ca dan fosforlevel Na,K,Ca dan fosfor

Fungsi AnionFungsi Anion

Cl: mempengaruhi asam basa, menjaga tek. Cl: mempengaruhi asam basa, menjaga tek. Osmotik darah.Osmotik darah.

HCOHCO33: sistem bufer yg mengatur pH: sistem bufer yg mengatur pH

HPOHPO44: mengatur level Ca, metabolisme energi dan : mengatur level Ca, metabolisme energi dan asam basaasam basa

Nilai RujukanNilai Rujukan

Na: 135 – 145 mEq/LNa: 135 – 145 mEq/L K: 3,8 – 5,5 mEq/LK: 3,8 – 5,5 mEq/L Ca: 8,9 – 10,1 mg/dL anak sp 10,6Ca: 8,9 – 10,1 mg/dL anak sp 10,6 Mg: 1,7 – 2,1 mg/dLMg: 1,7 – 2,1 mg/dL Cl: 100 – 108 mEq/LCl: 100 – 108 mEq/L POPO44: 2,5 – 4,5 mg/dL anak 7mg/dL: 2,5 – 4,5 mg/dL anak 7mg/dL

HOMEOSTASISHOMEOSTASIS

Tubuh selalu mempertahankan pH darah Tubuh selalu mempertahankan pH darah 7,47,4

Ggan asam basa tidak berat karena di Ggan asam basa tidak berat karena di toleransi oleh tubuh walaupun dlm toleransi oleh tubuh walaupun dlm kondisi tertentu dapat berakibat fatal bila kondisi tertentu dapat berakibat fatal bila pH<7,0 atau pH>7,7 juga bila pH<7,0 atau pH>7,7 juga bila perubahannya berlansung cepat.perubahannya berlansung cepat.

GinjalGinjal

Fungsinya mengeluarkan ion HFungsinya mengeluarkan ion H

Agar asam basa seimbang.Agar asam basa seimbang.

Untuk mengetahui perubahan asam Untuk mengetahui perubahan asam basa dilakukan tes analisa gas darahbasa dilakukan tes analisa gas darah

Untuk tes ini diperlukan pengambilan Untuk tes ini diperlukan pengambilan darah arteri radialis,brachialis atau darah arteri radialis,brachialis atau femoralis yg sebelumnya dilakukan tes femoralis yg sebelumnya dilakukan tes Allen.Allen.

Dengan alat “blood gas analyzer” di Dengan alat “blood gas analyzer” di dapat nilai rujukan (pH, Podapat nilai rujukan (pH, Po2,2,PcoPco2, B.E, 2, B.E,

HCOHCO3 3 )) Penilaian dng “Henderson Haselbalch Penilaian dng “Henderson Haselbalch

equation”equation”

Misalnya, peningkatan ion klorida Misalnya, peningkatan ion klorida yang bermuatan negatif akan yang bermuatan negatif akan menyebabkan peningkatan [Hmenyebabkan peningkatan [H++] ] untuk mempertahankan kenetralan untuk mempertahankan kenetralan muatan listrik.muatan listrik.Peningkatan [HPeningkatan [H++] ini disebut ] ini disebut asidosis.asidosis.

Karena hubungan terbalik antara [HKarena hubungan terbalik antara [H++] ] dengan [OHdengan [OH--] maka dapat juga ] maka dapat juga (lebih mudah) menilai perubahan pH (lebih mudah) menilai perubahan pH tersebut melalui perubahan pada [OHtersebut melalui perubahan pada [OH--].].Peningkatan [OHPeningkatan [OH--] menyebabkan ] menyebabkan alkalosis, penurunan [OHalkalosis, penurunan [OH--] menyebabkan ] menyebabkan asidosis.asidosis.Sebagai contoh, pada keadaan Sebagai contoh, pada keadaan hiperkloremia, setiap peningkatan klorida hiperkloremia, setiap peningkatan klorida akan menurunkan SID.akan menurunkan SID.

Semoga bermanfaatSemoga bermanfaat

Terima KasihTerima Kasih