Stewart and Buffer Base-blok Xiii

8/11/2019 Stewart and Buffer Base-blok Xiii

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INTRODUCTION OF ACIDBASE BALANCE

Warning.!

Most Physician has determined that....This lecture may be harmful to your mental health.


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Keseimbangan asam basaSaya punya hasil

astrup, artinyaapa nich..?

Who cares

about acidbasebalance?


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The disadvantage of men notknowing the past i s that they do notknow the present.

G. K. Chesterton


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ASAM BASA..

pH

[H+

]


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Normal = 7.40 (7.35-7.45)

Viable range = 6.80 - 7.80


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MENGAPA

PENGATURAN pHSANGAT PENTING ?


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RespirasiHiperventilasi

Penurunan kekuatan otot nafas danmenyebabkan kelelahan otot

Sesak

MetabolikPeningkatan kebutuhan

metabolismeResistensi insulin

Menghambat glikolisis anaerobPenurunan sintesis ATP

HiperkalemiaPeningkatan degradasi protein

OtakPenghambatan metabolisme dan

regulasi volume sel otakKoma

KardiovaskularGangguan kontraksi otot jantung

Dilatasi Arteri,konstriksi vena, dansentralisasi volume darah

Peningkatan tahanan vaskular paru

Penurunan curah jantung, tekanandarah arteri, dan aliran darah

hati dan ginjal

Sensitif thd reent rant a r rhythm ia danpenurunan ambang fibrilasi

ventrikel

Menghambat respon kardiovaskularterhadap katekolamin

Management of life-threatening Acid-Base Disorders, Horacio J. Adrogue, And Nicolaos EM:

Review Article;The New England Journal of Medicine;1998

AKIBAT DARI ASIDOSIS BERAT


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KardiovaskularKonstriksi arteri

Penurunan aliran darah koronerPenurunan ambang angina

Predisposisi terjadinya supraventrikel dan ventrikelaritmia yg refrakter

RespirasiHipoventilasi yang akan menjadi hiperkarbi dan

hipoksemia

MetabolicStimulasi glikolisis anaerob dan produksi asam organik

HipokalemiaPenurunan konsentrasi Ca terionisasi plasma

Hipomagnesemia and hipophosphatemia

OtakPenurunan aliran darah otak

Tetani, kejang, lemah delirium dan stupor

AKIBAT DARI ALKALOSIS BERAT

Management of life-threatening Acid-Base Disorders, Horacio J. Adrogue, And Nicolaos EM:Review Article;The New England Journal of Medicine;1998


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TRADITIONAL APPROACHHendersen

HasselbachSorensen

Singer-HastingSiggaard-Andersen

Van- Slyke

Jorgensen

Severinghauss

Astrup


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HCO3 vs BASE EXCESSBOSTON vs COPENHAGEN


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Now for something new


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Boston Style 1. HCO 3

-

Brief historical perspective


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Acid Base

Notasi pH diciptakan oleh seorang ahli kimia dari Denmark yaituSoren Peter Sorensen, yang berarti log negatif dari konsentrasi ionhidrogen. Dalam bahasa Jermandisebut Wasserstoffionenexponent (eksponen ion hidrogen) dandiberi simbol pH yang berarti:

potenz

(power) of Hydrogen.

1909


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pH = -log[H +]

defined by Sorensen

[H +] pH

1 x 10 -6 6.01 x 10 -7 7.08 x 10 -8 7.14 x 10 -8 7.42 x 10 -8 7.71 x 10 -8 8.0


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pH = 6.1 + log [ HCO 3-

] = KIDNEY0.03 x PCO 2 = LUNG

Hasselbalch KA. Die Berechnung der Wasserstoffzahl des Blutes aus der freien undgebundenen Kohlensaure desselben und die Sauerstoffbindung des Blutes als Funktion der

Wasserstoffzahl. Biochemische Zeitschrift 1916; 78: 112 44.

1916

Hasselbach:Used Sorensen's terminology for Henderson's equationin logarithmic form:

Hendersen-Hasselbach equation (H-H)


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Regulasi asam basa diatur melalui proses di:

1. Ginjal dengan cara mempertahankan [HCO 3-] sebesar24 mM dan

2. Mekanisme respirasi dengan cara mempertahankantekanan parsial CO 2 arteri (PaCO 2) sebesar 40mmHg.

Hendersen-Hasselbalch


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pH = 6.1 + log [ HCO 3-]0.03 x

1. Change inMetabolic disturbance

2. Change afterRenal compensation forRespiratory disturbance

1. Change inRespiratory disturbance

2. Change afterRespiratory compensation for

Renal disturbance

pCO2


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Diagram Davenport

[ H C O

3 - ]

PCO 2 = 80 40

20

pH 7.0 7.2 7.4 7.6 7.8

10

20

30

40

50

pH = 6.1 + GinjalParu

B

A

C

7.4 / 40 / 24

7.2 / 80 / 30

7.6 / 20 / 18Normal


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pH

Alkalosis Metabolik

pH

Alkalosis Respiratori

pH

Asidosis Respiratori

pH

Asidosis Metabolik

Gangguan asam-basa primer


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Diagnosis menggunakan nilai asam basa serum:Davenport Diagram

[ H C O

3 - ]

P CO 2 = 80 40

20

pH 7.0 7.2 7.4 7.6 7.8

10

20

30

40

50

Henderson- Hasselbalch:

pH = pK + log [HCO 3-] s PCO 2 Asidosis

Respiratori Alkalosis

Metabolik

AlkalosisRespiratori

AsidosisMetabolik

pH = 6.1 + GinjalParu

atau,

Normal


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Alkalosis Respiratori

[ H C O

3 - ]

P CO 2 = 80 40

20

pH 7.0 7.2 7.4 7.6 7.8

10

20

30

40

50


terkompensasi

Penyebab:1) Nyeri2) Histerik 3) Hipoksia


Normal

kompensasi = [HCO 3-]


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Asidosis Respiratori

[ H C O

3 - ]

P CO 2 = 80 40

20

pH 7.0 7.2 7.4 7.6 7.8

10

20

30

40

50

AsidosisRespiratori

kompensasi = [HCO 3-] Penyebab:1) PPOK, Gagal jantung

kronik, bbrp pnyktparu

2) Obat anestesi

AsidosisRespiratori

terkompensasi


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Metabolic Alkalosis

[ H C O

3 - ]

P CO 2 = 80 40

20

pH 7.0 7.2 7.4 7.6 7.8

10

20

30

40

50

Alkalosis

Metabolik

kompensasi = PCO 2Penyebab:1) Intake basa >>2) Kehilangan asam

(Muntah,penyedotan lambung)

AlkalosisMetabolik

terkompensasi


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Metabolic Asidosis

[ H C O

3 - ]

P CO 2 = 80 40

20

pH 7.0 7.2 7.4 7.6 7.8

10

20

30

40

50

AsidosisMetabolik

kompensasi = PCO 2

Penyebab:1) Kehilangan basa

(eg. diare)2) Akumulasi asam

(diabetes, gagal ginjal)

3) Asidosis Tubular Ginjal

AsidosisMetabolik

terkompensasi


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Kompensasi ginjal terhadap asidosis resp. kronik

Kompensasi ginjal & paru terhadap asidosis non ginjal

PPOK

Keto/Laktat asidosis


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DISORDER pH PRIMER RESPONKOMPENSASI

ASIDOSISMETABOLIK

HCO3- pCO2

ALKALOSISMETABOLIK

HCO3- pCO2

ASIDOSISRESPIRATORI

pCO2 HCO3-

ALKALOSISRESPIRATORI

pCO2 HCO3-

RANGKUMAN GANGGUANKESEIMBANGAN ASAM BASA

TRADISIONAL


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2. BDE (Base Deficit Excess)&

SBE (Standard Base Excess)

Copenhagen style


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Singer and Hastings, 1948,

Whole blood buffer base (BB), defined as the sum ofbicarbonate [HCO 3 -] & nonvolatile buffer anions (A -)

The change in BB from "normal" was called delta BB(BB). This change in BB was an expression of themetabolic component of an acid-base disturbance

BE (Base Excess)

Singer RB, Hastings AB: An improved clinical method for the estimation of disturbances of theacid-base balance of human blood. Medicine (Baltimore) 1948; 27:223-242

Introduced the concept of buffer base [BB][BB] = [HCO 3 -] + [A -]


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Modified Base Excess

ECF includes plasma, red cells, and thesurrounding interstitial fluid. It

s where the actiontakes place in the body regarding acid-base

movement.

Blood-gas machines calculate SBE as:

Standard Base Excess

SBE = (1 - 0.014Hgb) (HCO 3 24 + (1.43Hgb + 7.7) (pH - 7.4)`


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[ H C O

3 -

]

pCO 2 = 80 40

20

pH7.0 7.2 7.4 7.6 7.8

10

20

30

40

50

AsidosisMetabolik

Base deficit;Kekurangan Basa;

Jumlah Basa (HCO 3 ) yg

harus ditambahkan agarpH normal

AlkalosisMetabolik

Base excess;Kelebihan Basa; JumlahBasa (HCO 3 ) yang harus

dikurangi agar pHnormal

Base Excess/Base Deficit

NormalBase Defisit

Base Excess


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Unmeassured anion

Limitasi dari H-H tidak dapat

mengukur metabolic acidosis yangdisebabkan unmeassured anionseperti laktat dan keton

Emmet dan Narins Anion Gap AG= Na + - (Cl - + HCO 3 -) Normal Gap 10-15


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How to determine the

cause of Metabolicacidosis?

Anion Gap Improve Anion Gap

Strong Ion Gap


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Anion Gap

Anion gap (AG) was introduced by Emmet andNarins and is derived from the electroneutralityprinciple.

It determines the gap between measured andunmeasured ions, in this instance, in plasma. It iscomputed as:

Narins RG, Emmett M: Simple and mixed acid-base disorders: Apractical approach. Medicine 59:161-187, 1980

[AG] = [Na+

] + [K+

] - [Cl-

] - [HCO 3-

]

Normal


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Increased anion gap acidosisNormal anion gap acidosis

Na

K Cl

AG

HCO -3

AG = 10-15

25

105145

Normal

Na

K Cl

HCO -3

AG

15

115

145

= 15 (normal)

Na

K

Cl

HCO -3

AG/Otheranion

= 25

15

105(normal)

145

HCO3- decreases and replaced by Cl - sothere is a Cl - shift :Eg. Diarrhea orsimple gain of H+

HCO3- decreases and replaced by anionsother than Cl - so no Cl - shift: Eg.renalfailure and diabetic keto-acidosis

Metabolic acidosis

HCO3-


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Perbedaan dgn AG pd SIG, nilai albumin ikut dalam kalkulasi

Na +

K + 4

Ca ++Mg ++

Cl -

HCO 3-

KATION ANION

SID a

STRONG ION GAP

= [Na +] + [K+] + [Mg ++] + [Ca ++] - [Cl-] [Lactate -]

LactateA-

= 12.2 pCO 2/ 10-pH )+10 [alb] 0.123pH 0.631) + [PO 4 ] 0.309pH 0.469)

SID e

SIG = SID a SID e Normal value = zero

Jika SIG > terdapat

SIG

UA

Kellum JA, Kramer DJ, Pinsky MR: Strong ion gap: A methodology forexploring unexplained anions. J Crit Care 1995,10:51--55.


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elaksplease


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3. STEWART ANDTRADITIONAL APPROACH

(Stew art-Fen cl app ro ach )


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SID = Buffer Base

0

20

40

60

80

100

120

140

160

Cations Anions

Na + Cl -

K+, Mg ++ , Ca ++

m E q

/ L

Lactate,Otheranions

Cl -

A-

HCO 3-SID BB


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SID = Buffer Base

0

20

40

60

80

100

120

140

160

Cations Anions

Na + Cl -

K+, Mg ++ , Ca ++

m E q

/ L

Cl -

A-HCO 3-SID BB

BaseDeficit


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SID = Buffer Base

The standard baseexcess corresponds tothe change in SIDrequired to restore theplasma (in vivo) to pH7.40 with pCO 2 of 40mm Hg

R2=0.9527

-10

-8

-6

-4

-2

0

2

4

6

-8 -6 -4 -2 0 2 4

A/V SIDe

A / V S B E

Kellum et al. J Crit Care 1997; 12: 7-12


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SBE = SIDex

[SIDex] mEq/L

[ S

B E ] m

E q

/ L

-30

-20 -10

0

10

20

-30 -20 -10 0 10 20

Schlichtig R. Adv Exper Med Bio. 1997;411:91-95


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The Fencl-Stewart

Formula


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BE from the Blood Gas Machine SID effect , mEq/l = A + B

A. Free Water effect on Na +

= 0.3 x ([Na+

]

140) B. Corrected Cl - effect

= 102 ([Cl -] x 140/[Na + ]) Total weak acids effect , mEq/l

= 0.123 x pH - 0.6310 x (42 - [Albumin])UA effect = BE ef SID ef ATot ef

BASE EXCESS DAN STEWART

Stewart-Fencl, 2000


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BDE adjustment for serum albumin


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WORKSHOP ACIDBASESTEWART PERDICI 2006

THE SIX SIMULTANEOUSEQUATIONS USED BY STEWART

Water Dissociation Equlibrium

[H+] x [OH -] = Kw

Electrical Neutrality Equation

[SID] + [H +] = [HCO 3-] + [A -] + [CO3 2] + [OH -]

Weak acid Dissociation Equilibrium

[H+] x [A -] = KA x [HA] Conservation of Mass for A

[ATot ] = [HA] + [A -]

Bicarbonate Ion Formation Equilibrium

[H+

] x [HCO 3] = Kc x pCO 2 Carbonat Ion Formation Equilibrium

[H+] x [CO 3 2] = K3 x [HCO 3-]


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SID

PCO 2

Weak acid

pH

Renal Failure

Lactic acidosisKeto-acidosisVomiting

Diare

Heart Failure

Lung diseaseHyperventilationHypoventilation

Nephrotic SyndromeDehydrationMalnutrition

Charge BalanceDissociation of:WaterProteinCarbonic acid

CONCLUSION


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Henderson-Hasselbalch Stewart

s Approach


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VARIABEL INDEPENDEN

CO 2 STRONG IONDIFFERENCE

WEAK ACID

pCO 2 SID A totControlled by

the respiratorysystem The electrolyte

composition of theblood (controlled

by the kidney)

The proteinconcentration

(controlled by theliver and metabolic

state)


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DEPENDENT VARIABLES

H +

OH -

CO 3 = A -

AH

HCO 3 -


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The difference;

The Stewart approach emphasizes mathematically

independent and dependent variables.

Actually, HCO 3 - and H + ions represent the effects

rather than the causes of acid-base derangements.


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KLASIFIKASI GANGGUAN KESEIMBANGAN ASAMBASA BERDASARKAN PRINSIP STEWART

Fencl V, Jabor A, Kazda A, Figge J. Diagnosis of metabolic acid-base disturbances in critically ill

patients. Am J Respir Crit Care Med 2000 Dec;162(6):2246-51


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RESPIRATORY M E T A B O L I C

in pCO 2 in SID in Weak acid

Alb PO 4-

Alkalosis

Acidosis

Decrease

Increase

Decrease

Excess

Deficit

Positive Increase

Fencl V, Am J Respir Crit Care Med 2000 Dec;162(6):2246-51

WATER STRONGANION

Cl UA

Hypo

Hyper

Large infusion saline cause


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Large infusion saline causeacidosis


Pasien BB 50 kg = TB water 60% =0.6 x 50 kg = 30 liter

Konc Na 140 = 30 x 140 = 4200

Konc Cl 100 = 30 x 100 = 3000

Di infus larutan NaCl 0.9% 10 liter,Na = 154 x 10 = 1540Cl = 154 x 10 = 1540

Setelah di infus,Na 4200 + 1540 = 5740Cl 3000 + 1540 = 4540.

Karena jumlah total cairan tubuh + larutanNaCl = 30 + 10 L = 40 L

Maka SID dilusi =

Na = 5740/40 = 143.5Cl = 4540/40 = 113.5SID = 30.0 (asidosis)

Namun jika SID tanpa air (jadi hanya 30 L)Na = 5740/30 = 191.5Cl = 4540/30 = 151.3SID = 40.0

Jadi sebenarnya yg membuat asidosis adalah dilusinya. Pemberian larutan NaCl jumlah sedikit tidak menyebabkan asidosis yg nyata, kecuali dibarengi pemberian

cairannya jumlah banyak.


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Na + = 140 mEq/LCl - = 130 mEq/LSID =10 mEq/L

Na + = 165 mEq/LCl - = 130 mEq/LSID = 35 mEq/L1 liter 1.025

liter

25 mEqNaHCO3

SID : 10 35 : Alkalosis, pH kembali normal namun mekanismenya bukankarena pemberian HCO 3- melainkan karena pemberian Na + tanpa anion kuat yg

tidak dimetabolisme seperti Cl - sehingga SID alkalosis

Plasma;asidosis

hiperkloremik

MEKANISME PEMBERIAN NA-BIKARBONAT PADA ASIDOSIS

Plasma + NaHCO 3

HCO3 cepatdimetabolisme


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TERIMA KASIH

Stewart and Buffer Base-blok Xiii

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