analisa gas darah

Penilaian Penilaian AnalisaAnalisa Gas Gas Darah Darah dan dan

Keseimbangan Asam Keseimbangan Asam BasaBasa

Az Rifki, SpAn.KICAz Rifki, SpAn.KIC

Intensive Care UnitIntensive Care Unit

RSI Siti Rahmah RSI Siti Rahmah

PadangPadang

Keseimbangan Keseimbangan asam basaasam basa

Saya punya hasil astrup, artinya apa nich..? Who cares Who cares

about acid about acid base base

balance…?balance…?

Indikasi Pemeriksaan Indikasi Pemeriksaan AGDAGD

1.1. Untuk mengetahui kelainan pertukaran gas pada Untuk mengetahui kelainan pertukaran gas pada pasien-pasien sesak nafas akut.pasien-pasien sesak nafas akut.

2.2. Untuk mengetahui ada tidaknya hipoksemia, Untuk mengetahui ada tidaknya hipoksemia, hiperkapnia atau gangguan keseimbangan asam hiperkapnia atau gangguan keseimbangan asam basa pada pasien-pasien dengan perubahan basa pada pasien-pasien dengan perubahan kesadaran.kesadaran.

3.3. Untuk menentukan kelainan pertukaran gas pada Untuk menentukan kelainan pertukaran gas pada pasien-pasien tahipnu.pasien-pasien tahipnu.

4.4. Untuk menilai ada tidaknya dan berat ringannya Untuk menilai ada tidaknya dan berat ringannya gagal nafas pada pasien-pasien yang mengalami gagal nafas pada pasien-pasien yang mengalami kegagalan fungsi paru.kegagalan fungsi paru.

5.5. Untuk memantau pertukaran gas dan ventilasi pada Untuk memantau pertukaran gas dan ventilasi pada pasien-pasien dalam ventilator serta pasien-pasien dalam ventilator serta penatalaksanaan penyapihan dari ventilator.penatalaksanaan penyapihan dari ventilator.

6.6. Untuk penilaian preoperatif pada pasien-pasien Untuk penilaian preoperatif pada pasien-pasien resiko tinggi yang memerlukan tindakan anestesi resiko tinggi yang memerlukan tindakan anestesi umum.umum.

ASAM BASA..ASAM BASA..

pHpH

[H[H++]]

TerminologyTerminology

Acid Base

Notasi pH diciptakan oleh seorang ahli kimia dari Notasi pH diciptakan oleh seorang ahli kimia dari Denmark yaitu Soren Peter Sorensen pada thn 1909, yang Denmark yaitu Soren Peter Sorensen pada thn 1909, yang berarti log negatif dari konsentrasi ion hidrogen. Dalam berarti log negatif dari konsentrasi ion hidrogen. Dalam bahasa Jerman disebutbahasa Jerman disebutWasserstoffionenexponent Wasserstoffionenexponent (eksponen ion hidrogen) dan diberi simbol pH yang (eksponen ion hidrogen) dan diberi simbol pH yang berarti: ‘berarti: ‘ppotenz’ (power) of otenz’ (power) of HHydrogen. ydrogen.

Normal = 7.40 (7.35-7.45)Normal = 7.40 (7.35-7.45)

Viable range = 6.80 - 7.80Viable range = 6.80 - 7.80

Hubungan antara sistem respirasi Hubungan antara sistem respirasi (CO2) dan sistem metabolik (HCO3-)(CO2) dan sistem metabolik (HCO3-)

““c.a” carbonic anhydrase c.a” carbonic anhydrase (mempercepat Rx)(mempercepat Rx)

Persamaan HPersamaan H22COCO33

CO2 + H2O <--> H2CO3 <--> H+ + CO2 + H2O <--> H2CO3 <--> H+ + HCO3-HCO3-

c.a. c.a.

PaOPaO22

Tekanan oksigen arterial Tekanan oksigen arterial (mmHg / Torr)(mmHg / Torr)

Jumlah oksigen yang larut dalam Jumlah oksigen yang larut dalam darahdarah

Normal : Normal : dewasa, anak : 80 – 100 mmHg dewasa, anak : 80 – 100 mmHg newborn : 40 – 70 mmHg newborn : 40 – 70 mmHg 60 – 90 tahun : 60 – 80 mmHg 60 – 90 tahun : 60 – 80 mmHg

PaCOPaCO22

Tekanan carbon dioksida arterial Tekanan carbon dioksida arterial (mmHg / Torr)(mmHg / Torr)

Merupakan carbon dioksida yang Merupakan carbon dioksida yang larut dalam darahlarut dalam darah

Merupakan komponen respirasiMerupakan komponen respirasi Normal : 35 – 45 mmHgNormal : 35 – 45 mmHg

HCOHCO33--

Ion bikarbonat (mEq/l)Ion bikarbonat (mEq/l) Komponen metabolikKomponen metabolik Normal : 22 – 24 mEq/lNormal : 22 – 24 mEq/l

Base excess/defisitBase excess/defisit

Nilai menggambarkan hubungan Nilai menggambarkan hubungan antara PaCOantara PaCO22 dan HCO dan HCO33--

Lebih digunakan dibandingkan Lebih digunakan dibandingkan HCOHCO33--

Normal : - 2.5 s/d + 2.5Normal : - 2.5 s/d + 2.5

SOSO22

SaOSaO22 : Saturasi oksigen darah arteri : Saturasi oksigen darah arteri SpOSpO2 2 : Saturasi oksigen transkutaneus dg pulse : Saturasi oksigen transkutaneus dg pulse

(pulse oxymetri)(pulse oxymetri) Oksigen yang terikat dengan HbOksigen yang terikat dengan Hb Dipertahankan > 90%Dipertahankan > 90% Tidak akurat pada :Tidak akurat pada :

Dyshemoglobinemia (COHb, MetHb, HbF)Dyshemoglobinemia (COHb, MetHb, HbF) Gangguan perfusi periferGangguan perfusi perifer Anemia Anemia DyesDyes Pigmen (methylene blue, indocyanine green, bilirubin)Pigmen (methylene blue, indocyanine green, bilirubin) Sinar lampuSinar lampu

FiOFiO22

Fraksi inspirasi Fraksi inspirasi OksigenOksigen

Nilai dalam Nilai dalam udara kamar udara kamar Desimal 0.21Desimal 0.21 Persen 21%Persen 21%

Components of room airComponents of room air

OxygenOxygen 20.8% (or 20.8% (or 21%)21%)

NitrogenNitrogen 78.8%78.8%

Argon, Argon, Helium and Helium and a few a few othersothers

0.4%0.4%

TotalTotal 100.0%100.0%

Relationship Between FiO2 and PaO2 Relationship Between FiO2 and PaO2

FiOFiO22 predicted predicted

(theoretical)(theoretical)PaOPaO

22

(without shunt)(without shunt)

0.300.30 150 mmHg150 mmHg

0.400.40 200 mmHg200 mmHg

0.500.50 250 mmHg250 mmHg

0.600.60 300 mmHg300 mmHg

0.700.70 350 mmHg350 mmHg

0.800.80 400 mmHg400 mmHg

0.900.90 450 mmHg450 mmHg

1.01.0 500 mmHg500 mmHg

*Hint: multiply FiO2 by 5

PENILAIAN ANALISA GAS PENILAIAN ANALISA GAS DARAH DAN KESEIMBANGAN DARAH DAN KESEIMBANGAN

ASAM BASAASAM BASA

MENGAPA PENGATURAN MENGAPA PENGATURAN pH SANGAT PENTING ?pH SANGAT PENTING ?

RespirasiRespirasiHiperventilasiHiperventilasiPenurunan kekuatan otot nafas dan Penurunan kekuatan otot nafas dan menyebabkan kelelahan ototmenyebabkan kelelahan ototSesakSesak

MetabolikMetabolikPeningkatan kebutuhan Peningkatan kebutuhan metabolismemetabolismeResistensi insulinResistensi insulinMenghambat glikolisis anaerobMenghambat glikolisis anaerobPenurunan sintesis ATPPenurunan sintesis ATPHiperkalemiaHiperkalemiaPeningkatan degradasi proteinPeningkatan degradasi protein

OtakOtakPenghambatan metabolisme dan Penghambatan metabolisme dan regulasi volume sel otakregulasi volume sel otakKomaKoma

KardiovaskularKardiovaskularGangguan kontraksi otot jantungGangguan kontraksi otot jantung

Dilatasi Arteri,konstriksi vena, dan Dilatasi Arteri,konstriksi vena, dan sentralisasi volume darahsentralisasi volume darah

Peningkatan tahanan vaskular paruPeningkatan tahanan vaskular paru

Penurunan curah jantung, tekanan Penurunan curah jantung, tekanan darah arteri, dan aliran darah hati dan darah arteri, dan aliran darah hati dan ginjalginjal

Sensitif thd Sensitif thd reentrant arrhythmiareentrant arrhythmia dan dan penurunan ambang fibrilasi ventrikelpenurunan ambang fibrilasi ventrikel

Menghambat respon kardiovaskular Menghambat respon kardiovaskular terhadap katekolaminterhadap 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 BERATAKIBAT DARI ASIDOSIS BERAT

KardiovaskularKardiovaskularKonstriksi arteriKonstriksi arteriPenurunan aliran darah koronerPenurunan aliran darah koronerPenurunan ambang anginaPenurunan ambang anginaPredisposisi terjadinya supraventrikel dan ventrikel Predisposisi terjadinya supraventrikel dan ventrikel aritmia yg refrakteraritmia yg refrakter

RespirasiRespirasiHipoventilasi yang akan menjadi hiperkarbi dan Hipoventilasi yang akan menjadi hiperkarbi dan hipoksemiahipoksemia

MetabolicMetabolicStimulasi glikolisis anaerob dan produksi asam organikStimulasi glikolisis anaerob dan produksi asam organikHipokalemiaHipokalemiaPenurunan konsentrasi Ca terionisasi plasmaPenurunan konsentrasi Ca terionisasi plasmaHipomagnesemia and hipophosphatemiaHipomagnesemia and hipophosphatemia

OtakOtakPenurunan aliran darah otakPenurunan aliran darah otakTetani, kejang, lemah delirium dan stuporTetani, kejang, lemah delirium dan stupor

AKIBAT DARI ALKALOSIS BERATAKIBAT 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

The disadvantage of men not The disadvantage of men not knowing the past is that they do not knowing the past is that they do not know the present.know the present.

G. K. Chesterton G. K. Chesterton

Hendersen-Hendersen-Hasselbalch Hasselbalch

Regulasi asam basa diatur melalui proses di:Regulasi asam basa diatur melalui proses di:

1.1. Ginjal dengan cara mempertahankan [HCOGinjal dengan cara mempertahankan [HCO33--] ]

sebesar 22-24 mEq/L dan sebesar 22-24 mEq/L dan

2.2. Mekanisme respirasi dengan cara Mekanisme respirasi dengan cara mempertahankan tekanan parsial COmempertahankan tekanan parsial CO2 2 arteri arteri

(PaCO(PaCO22) sebesar 40 mmHg.) sebesar 40 mmHg.

Hendersen-Hasselbalch Hendersen-Hasselbalch

pH pH = 6.1 + log= 6.1 + log[HCO[HCO33

--]]

pCOpCO22

GINJALGINJAL

PARUPARU

BASA BASA

ASAMASAM CO2

HCO3HCO3

CO2

KompensasiKompensasi

NormalNormal

NormalNormal

pH = 6.1 + logpH = 6.1 + log[ HCO[ HCO33

--]]

0.03 0.03 xx

1. Change in1. Change inMetabolic disturbanceMetabolic disturbance

2. Change after2. Change afterRenal compensation forRenal compensation forRespiratory disturbanceRespiratory disturbance

1. Change in1. Change inRespiratory disturbanceRespiratory disturbance

2. Change after2. Change afterRespiratory compensation forRespiratory compensation for

Renal disturbanceRenal disturbance

pCO2pCO2

Each Each primaryprimary (metabolic or respiratory) (metabolic or respiratory) disturbance is accompanied by a disturbance is accompanied by a secondarysecondary (opposing) response in the (opposing) response in the other system (respiratory or metabolic)other system (respiratory or metabolic)

pH is returned nearly but not pH is returned nearly but not completely to normalcompletely to normal

Overcompensation does not occurOvercompensation does not occur

Acid Base Disorders: Acid Base Disorders: Principles of Principles of

interpretationinterpretation

Compensation for acid base Compensation for acid base disturbancesdisturbances

Respiratory compensation for Respiratory compensation for metabolic disorders should be metabolic disorders should be complete in 24 hourscomplete in 24 hours ““Acute” is < 24-48 hrsAcute” is < 24-48 hrs ““Chronic” is > 24-48 hrsChronic” is > 24-48 hrs

Metabolic (renal) compensation for Metabolic (renal) compensation for respiratory disorders is slower and respiratory disorders is slower and requires 2 to 6 daysrequires 2 to 6 days

Nilai DasarNilai Dasar

FactorFactor MeanMean RangeRange

pHpH 7.407.40 7.35 – 7.457.35 – 7.45

PaO2 (mmHg)PaO2 (mmHg) 8080 60 – 10060 – 100

PaCO2 (mmHg)PaCO2 (mmHg) 4040 35 – 4535 – 45

HCO3- (mEq/l)HCO3- (mEq/l) 2424 22 - 2422 - 24

Normal Ranges of Laboratory Values

NomenclatureNomenclature

Physiologic conditionPhysiologic condition ValuesValues

AcidosisAcidosis pH <7.35pH <7.35

AlkalosisAlkalosis pH >7.45pH >7.45

HypoxemiaHypoxemia PaOPaO22 <80 <80

HyperoxiaHyperoxia PaOPaO22>100>100

Alveolar HyperventilationAlveolar Hyperventilation(hipokarbia)(hipokarbia)

PaCOPaCO22 <35 <35

Ventilatory FailureVentilatory Failure(Hiperkarbia)(Hiperkarbia)

PaCOPaCO22 >50 >50

Diagnosis menggunakan nilai asam basa serum:

Davenport Diagram

[ H

CO

3- ]

PCO2 = 80 40

20

pH7.0 7.2 7.4 7.6 7.8

10

20

30

40

50

Henderson- Hasselbalch:

pH = pK + log [HCO3-]

s PCO2AsidosisAsidosis RespiratoriRespiratori AlkalosisAlkalosis

MetabolikMetabolik

AlkalosisAlkalosis RespiratoriRespiratori

Asidosis Asidosis MetabolikMetabolik

pH = 6.1 + Ginjal Paru

atau,

Normal

Alkalosis Respiratori[

HC

O3

- ]

PCO2 = 80 40

20

pH7.0 7.2 7.4 7.6 7.8

10

20

30

40

50

AlkalosisAlkalosis Respiratori Respiratori

terkompensasiterkompensasi

Penyebab:Penyebab:Acute alveolar Acute alveolar

hyperventilationhyperventilation

a.a. AnxietyAnxiety

b.b. HypoxiaHypoxia

c.c. drugs (aspirin, drugs (aspirin,

catecholamines, catecholamines,

progesterone)progesterone)

d.d. SepsisSepsis

e.e. hepatic hepatic

encephalopathy encephalopathy

AlkalosisAlkalosis RespiratoriRespiratori

Normal

kompensasi = [HCO3-]

Asidosis Respiratori[H

CO

3- ]

PCO2 = 80 40

20

pH7.0 7.2 7.4 7.6 7.8

10

20

30

40

50

AsidosisAsidosis RespiratoriRespiratori

kompensasi = [HCO3-]

Penyebab:Penyebab:Acute ventilatory Acute ventilatory

failurefailure

1.1. acute airway acute airway

obstructionobstruction

2.2. severe pneumonia severe pneumonia

/ pulmonary edema/ pulmonary edema

3.3. neuromuscular neuromuscular

disordersdisorders

4.4. CNS depression CNS depression

(drugs, CNS event)(drugs, CNS event)

5.5. ventilator ventilator

dysfunction dysfunction

Chronic ventilatory Chronic ventilatory

failurefailure

1.1. chronic lung chronic lung

diseases diseases

AsidosisAsidosis Respiratori Respiratori


Metabolic Alkalosis[

HC

O3-

]

PCO2 = 80 40

20

pH7.0 7.2 7.4 7.6 7.8

10

20

30

40

50

AlkalosisAlkalosis MetabolikMetabolik

kompensasi = PCO2

Penyebab:

Metabolic alkalosis

a. vomiting/ NG

suctioning

b. diuretic therapy

c. mineralocorticoid

activity

(Cushing's

syndrome,

exogenous

steroids)

AlkalosisAlkalosis Metabolik Metabolik


Metabolic Asidosis[

HC

O3-

]

PCO2 = 80 40

20

pH7.0 7.2 7.4 7.6 7.8

10

20

30

40

50

AsidosisAsidosis MetabolikMetabolik

kompensasi = PCO2

Penyebab:Penyebab:Metabolic acidosisMetabolic acidosis

a.a. ketoacidoses ketoacidoses

(diabetic/alcoholic(diabetic/alcoholic

))

b.b. renal failurerenal failure

c.c. lactic acidosislactic acidosis

d.d. RhabdomyolysisRhabdomyolysis

e.e. toxins (methanol, toxins (methanol,

ethylene glycol, ethylene glycol,

salicylates, salicylates,

paraldehyde)paraldehyde)

f.f. DiarrheaDiarrhea

g.g. HCl administrationHCl administration

AsidosisAsidosis Metabolik Metabolik


[HC

O3- ]

PCO2 = 80 40

20

pH7.0 7.2 7.4 7.6 7.8

10

20

30

40

50

AsidosisAsidosis MetabolikMetabolik

Base Defisit

AlkalosisAlkalosis MetabolikMetabolik

Base Excess

Base Base Excess/ Excess/

Base DeficitBase Deficit

BE = (1 - 0.014Hgb) (HCOBE = (1 - 0.014Hgb) (HCO33 – 24 + (1.43Hgb + 7.7) (pH - – 24 + (1.43Hgb + 7.7) (pH - 7.4)`7.4)`

Normal

Oxyhemoglobin Dissociation CurveOxyhemoglobin Dissociation Curve

Hub. antara SatO2 Hub. antara SatO2 dl Hb dan PO2dl Hb dan PO2

Tergantung afinitas Tergantung afinitas Hb thd O2Hb thd O2 Meningkat : sukar Meningkat : sukar

melepaskan O2 ke melepaskan O2 ke jaringan (bergeser ke jaringan (bergeser ke kiri)kiri)

Menurun : mudah Menurun : mudah melepaskan O2 ke melepaskan O2 ke jaringan (bergeser ke jaringan (bergeser ke kanan)kanan)

the basic OHDC

Oxyhemoglobin Dissociation CurveOxyhemoglobin Dissociation Curve

what happens when the curve is shifted

Interpretation Guidelines Interpretation Guidelines

Step 1Step 1:: Look at pH - this is the starting point.Look at pH - this is the starting point. 1.1. If within normal range, a normal or compensated If within normal range, a normal or compensated

state exists. state exists. 2.2. If outside normal limits, assess whether acidosis If outside normal limits, assess whether acidosis

or alkalosis is present. or alkalosis is present. 3.3. The body never overcompensates. Whichever The body never overcompensates. Whichever

state exists on the pH scale is the primary state exists on the pH scale is the primary abnormality. abnormality.

Step 2:Step 2: Assess hypoxemic state.Assess hypoxemic state. 1.1. If PaOIf PaO22 is <60 mmHg, hypoxic state exists. is <60 mmHg, hypoxic state exists.

2.2. If PaOIf PaO22 is between 80 -100 mmHg, a normal is between 80 -100 mmHg, a normal

condition exists. condition exists.

3.3. If PaOIf PaO22 is >100 mmHg, a hyperoxic state is >100 mmHg, a hyperoxic state

exists. exists.


Step 3:Step 3: Assess ventilatory status.Assess ventilatory status. 1.1. If PaCOIf PaCO22 is <35 mmHg, it is termed "alkalosis" is <35 mmHg, it is termed "alkalosis"

(alveolar hyperventilation or hypocarbia). (alveolar hyperventilation or hypocarbia).

2.2. If PaCOIf PaCO22 is between 35-45 mmHg, it is within is between 35-45 mmHg, it is within

normal limits. normal limits.

3.3. If PaCOIf PaCO22 is >45 mmHg, it is termed "acidosis" is >45 mmHg, it is termed "acidosis"

(ventilatory failure or hypercarbia). (ventilatory failure or hypercarbia).

4.4. If possible, determine whether this is an acute or If possible, determine whether this is an acute or chronic state (see the compensation explanation). chronic state (see the compensation explanation).


Step 4:Step 4: Assess metabolic component.Assess metabolic component. 1. If bicarbonate (HCO1. If bicarbonate (HCO33-) is <22 mEq/l, it is termed -) is <22 mEq/l, it is termed

"acidosis". "acidosis". 2. If bicarbonate is between 22-28 mEq/l, it is within 2. If bicarbonate is between 22-28 mEq/l, it is within

normal limits. normal limits. 3. If bicarbonate is >28 mEq/l, it is termed 3. If bicarbonate is >28 mEq/l, it is termed

"alkalosis". "alkalosis". 4. If possible, determine whether this is an acute or 4. If possible, determine whether this is an acute or

chronic state (see the compensation chronic state (see the compensation explanation).explanation).


Eight Primary Blood Gas Eight Primary Blood Gas Classifications Classifications

ClassificationClassification pHpH PaCO2PaCO2 HCO3-HCO3-

Acute ventilatory failure Acute ventilatory failure (acute respiratory (acute respiratory acidosis)acidosis)

vv ^̂ N N

Chronic ventilatory Chronic ventilatory failure (compensated failure (compensated respiratory acidosis)respiratory acidosis)

vv N N ^̂ ^̂

Acute alveolar Acute alveolar hyperventilationhyperventilation(acute respiratory (acute respiratory alkalosis)alkalosis)

^̂ vv N N

Chronic alveolar Chronic alveolar hyperventilation hyperventilation (compensated (compensated respiratory alkalosis)respiratory alkalosis)

^ ^ N N vv vv

Acute metabolic acidosisAcute metabolic acidosis vv N N vv

Chronic metabolic Chronic metabolic acidosisacidosis vv N N vv vv

Acute metabolic Acute metabolic alkalosisalkalosis ^̂ N N ^̂

Chronic metabolic Chronic metabolic alkalosisalkalosis ^̂ N N ^̂ ^̂

Hint: in compensated states, the PaCO2 and HCO3- have matching arrows (directions).

Some Basic Interpretations Some Basic Interpretations

alkalosis

alkalosis

alkalosis

1. pH - normal, acidosis or alkalosis?

alkalosis

7.307.30

7.497.49

7.197.19

7.617.61

7.377.37

Condition (choose)Condition (choose)pHpH

alkalosis

Interpretation Answers Interpretation Answers

XX 7.307.30

XX 7.497.49

XX 7.197.19

XX 7.617.61

XX 7.377.37

Alkalosis Alkalosis Acidosis Acidosis Normal Normal pH pH

normal

respiratory acidosis

normal

respiratory alkalosis

normal


normal


normal


7.387.38 4141

7.467.46 3030

7.357.35 5050

7.547.54 2727

7.207.20 7575

Condition (choose)Condition (choose)pHpH PaCO2 PaCO2

2. In this exercise, identify whether the respiratory situation is normal, 2. In this exercise, identify whether the respiratory situation is normal, acute, chronic, acidotic or alkalotic. Choose the appropriate categories, acute, chronic, acidotic or alkalotic. Choose the appropriate categories, then check your answers. then check your answers.

X X 4141 7.387.38

XX X X 3030 7.467.46

XX X X 5050 7.357.35

XX X X 2727 7.547.54

X X X X 7575 7.207.20

RespRespalkalosis alkalosis

RespRespacidosis acidosis

ChroniChronic c Acute Acute NormaNorma

l l PaCOPaCO22 pH pH


3. Identify whether the metabolic situation is normal, acute, 3. Identify whether the metabolic situation is normal, acute, chronic, acidotic or alkalotic. Choose the appropriate chronic, acidotic or alkalotic. Choose the appropriate categories, then check your answers. categories, then check your answers.

metabolic alkalosis

normal

metabolic alkalosis

normal

metabolic alkalosis

normal

metabolic alkalosis

normal

metabolic acidosis

normal

metabolic alkalosis

normal

7.44 26

7.35 18

7.38 42

7.60 36

7.25 19

7.25 19

Condition (choose)pH HCO3-

X X 2626 7.447.44

X X X X 1818 7.357.35

X X X X 4242 7.387.38

XX X X 3636 7.607.60

X X X X 1919 7.257.25

Met Met alkalosialkalosi

s s

Met Met acidosiacidosi

s s

ChroniChronic c

AcutAcute e

NormaNormal l

HCOHCO33- - pH pH


4. Identify the primary disturbance (acidosis/alkalosis). This might be 4. Identify the primary disturbance (acidosis/alkalosis). This might be just slightly off normal. Note whether the situation is of respiratory or just slightly off normal. Note whether the situation is of respiratory or metabolic in origin. Then note if compensation exists (partial or metabolic in origin. Then note if compensation exists (partial or complete). complete).

acidosis

metabolic

partial compensation

acidosis

metabolic

partial compensation

acidosis

metabolic

complete compensation

alkalosis

respiratory


acidosis

respiratory


33 42 7.50

18 30 7.41

32 60 7.24

19 32 7.38

26 32 7.50

Condition (choose)HCO3- PaCO2 pH


acuteacute metabolicmetabolic alkalosisalkalosis 3333 4242 7.507.50

chronicchronic respiratorrespirator

yy alkalosisalkalosis 1818 3030 7.417.41

chronicchronic respiratorrespirator

yy acidosisacidosis 3232 6060 7.247.24

chronicchronic metabolicmetabolic acidosisacidosis 1919 3232 7.387.38

acuteacute respiratorrespirator

yy alkalosisalkalosis 2626 3232 7.507.50

Acute/Acute/chronic chronic Cause Cause DisturbancDisturbanc

e e HCOHCO33- - PaCOPaCO22 pH pH

Case Studies Case Studies Evaluate the ABG results. Select the disturbance, whether the situation is Evaluate the ABG results. Select the disturbance, whether the situation is respiratory or metabolic and whether an acute or chronic state exists, respiratory or metabolic and whether an acute or chronic state exists, then check your answers)then check your answers)

1. 64 year old male with advanced Chronic Obstructive Pulmonary Disease (COPD).

chronic

metabolic

uncompensated

alkalosis

acute metabolic acidosis

0.21FiO2

10.6COHb

49.7SaO2

32.5HCO3-

28.3PaO2

78.0PaCO2

7.238pH

2. 60 year old male with metastatic lung cancer

acute

respiratory

compensated

alkalosis

hypoxemia

32.0FiO2 (nasal cannula 3 liters)

0.6COHb

94.2SaO2

34.8HCO3-

64.8PaO2

46.4PaCO2

7.492pH


3. 80 year old female with COPD

acute

respiratory

partially compensated

alkalosis

hypoxemia

0.40FiO2(6 liter mask)

0.1COHb

59.9SaO2

36.4HCO3-

64.8PaO2

129.4PaCO2

7.058pH


4. This is a series of two ABG's run about 2 hours apart. 30 year old male who ran a gas powered paint compressor in his home.

acute

respiratory

compensated

alkalosis

normal

1.00.21FiO2 (100% by mask)

6.730.3COHb

98.497.7SaO2

24.724.9HCO3-

89.273.1PaO2

38.638.8PaCO2

7.4237.423pH


5. 79 year old female with arthritis and a cardiac history.

acute

respiratory

compensated

alkalosis

hypoxemia

21.0FiO2

0.3COHb

98.3SaO2

10.1HCO3-

114.7PaO2

15.5PaCO2

7.387pH


6. 21 year old male with an altered level of consciousness. (This memorable patient went home the next day.)

acute

respiratory

compensated

alkalosis

hypoxemia

0.21FiO2

0.4COHb

95.9SaO2

1.6HCO3-

148.3PaO2

6.9PaCO2

6.979pH



7. 69 year old female with long standing COPD. She endearingly called herself the "old tattooed biker chick".

acute

respiratory

compensated

acidosis

hypoxemia

0.21FiO2

4.8COHb

87.4SaO2

23.7HCO3-

52.5PaO2

39.3PaCO2

7.388pH


8. 69 year old male with COPD. This was just prior to intubation.

acute

respiratory

compensated

alkalosis

hypoxemia

~0.90FiO2 (via bag/ valve/mask ventilation)

2.4COHb

95.9SaO2

26.2HCO3-

278.8PaO2

83.3PaCO2

7.143pH


9. 68 year old male brought in by medics for an altered level of consciousness.

acute

respiratory

compensated

acidosis

corrected hypoxemia

~0.95FiO2 (by non-rebreather mask)

0.8COHb

89.9SaO2

17.7HCO3-

59.8PaO2

36.1PaCO2

7.295pH

Acid Base DisordersAcid Base Disorders

SimpleSimple Primary disturbance and Primary disturbance and expected adaptive (secondary) expected adaptive (secondary) responseresponse

MixedMixed Two separate primary Two separate primary disturbances present simultaneously in disturbances present simultaneously in the same individualthe same individual

Must know expected adaptive Must know expected adaptive (compensatory) response to recognize (compensatory) response to recognize mixed disturbancesmixed disturbances

Acid Base DisordersAcid Base Disorders

Primary disorderPrimary disorder Compensatory responseCompensatory response

Metabolic acidosisMetabolic acidosis 0.7-1.2 mmHg 0.7-1.2 mmHg pCO pCO22 per 1.0 mEq/L per 1.0 mEq/L HCOHCO33

--

Metabolic alkalosisMetabolic alkalosis 0.7 mmHg 0.7 mmHg pCO pCO22 per 1.0 mEq/L per 1.0 mEq/L HCO HCO33--

Acute respiratory acidosisAcute respiratory acidosis 0.15 0.15 mEq/L HCO mEq/L HCO33-- per 1.0 mmHg per 1.0 mmHg pCO pCO22

Chronic respiratory Chronic respiratory acidosisacidosis

0.35 0.35 mEq/L HCO mEq/L HCO33-- per 1.0 mmHg per 1.0 mmHg pCO pCO22

Acute respiratory Acute respiratory alkalosisalkalosis

0.25 mEq/L 0.25 mEq/L HCO HCO33-- per 1.0 mmHg per 1.0 mmHg pCO pCO22

Chronic respiratory Chronic respiratory alkalosisalkalosis

0.55 mEq/L 0.55 mEq/L HCO HCO33-- per 1.0 mmHg per 1.0 mmHg pCO pCO22

Acid Base Disorders: Acid Base Disorders: InterpretationInterpretation

Is an acid base disturbance Is an acid base disturbance present?present?

What is theWhat is the primaryprimary disturbance?disturbance? Is theIs the secondarysecondary (adaptive) (adaptive)

response as expected?response as expected? What underlying disease process is What underlying disease process is

responsible for the acid base responsible for the acid base disturbance?disturbance?


Arterial blood gas from a dog: pH 7.27, HCOArterial blood gas from a dog: pH 7.27, HCO33--

12 mEq/L, pCO12 mEq/L, pCO22 27 mmHg (normal: pH 7.39, 27 mmHg (normal: pH 7.39,

HCOHCO33-- 22 mEq/L, pCO 22 mEq/L, pCO22 37 mmHg) 37 mmHg)

Is an acid base disturbance present?Is an acid base disturbance present? YES (look at the pH)YES (look at the pH)

Of what general type?Of what general type? ACIDOSIS (pH 7.27 < 7.39)ACIDOSIS (pH 7.27 < 7.39)

Metabolic or respiratory?Metabolic or respiratory? pCOpCO22 is LOW (can’t be respiratory acidosis) is LOW (can’t be respiratory acidosis)

HCOHCO33-- is LOW (must be METABOLIC ACIDOSIS) is LOW (must be METABOLIC ACIDOSIS)



12 mEq/L, pCO12 mEq/L, pCO22 27 mmHg (normal: pH 7.39, 27 mmHg (normal: pH 7.39, HCOHCO33

-- 22 mEq/L, pCO 22 mEq/L, pCO22 37 mmHg) 37 mmHg)

Is secondary (adaptive) response as expected?Is secondary (adaptive) response as expected? Observed HCOObserved HCO33

-- is 10 mEq/L is 10 mEq/L lowerlower than “normal” than “normal” (22-12)(22-12)

““Normal” dog can lower pCONormal” dog can lower pCO22 1 mmHg for every 1 mmHg for every 0.7-1.2 mEq/L decrement in HCO0.7-1.2 mEq/L decrement in HCO33

-- (use 1.0 mEq/L (use 1.0 mEq/L as “average”)as “average”)

Expected pCOExpected pCO22 = 37-10 = 27 mmHg = 37-10 = 27 mmHg Observed pCOObserved pCO22 = 27 mmHg = 27 mmHg Conclusion: YES, adaptive response is as expected. Conclusion: YES, adaptive response is as expected.

This is a simple metabolic acidosis with respiratory This is a simple metabolic acidosis with respiratory compensationcompensation


Arterial blood gas from a dog sick for 1 week: Arterial blood gas from a dog sick for 1 week:

pH 7.33, HCOpH 7.33, HCO33-- 29 mEq/L, pCO 29 mEq/L, pCO22 57 mmHg 57 mmHg

(normal: pH 7.39, HCO(normal: pH 7.39, HCO33-- 22 mEq/L, pCO 22 mEq/L, pCO22 37 37

mmHg)mmHg)

Is an acid base disturbance present?Is an acid base disturbance present? YES (look at the pH)YES (look at the pH)

Of what general type?Of what general type? ACIDOSIS (pH 7.33 < 7.39)ACIDOSIS (pH 7.33 < 7.39)

Metabolic or respiratory?Metabolic or respiratory? HCOHCO33

-- is HIGH (can’t be metabolic acidosis) is HIGH (can’t be metabolic acidosis)

pCOpCO22 is HIGH (must be RESPIRATORY ACIDOSIS) is HIGH (must be RESPIRATORY ACIDOSIS)


Arterial blood gas from a dog sick for 1 week: pH Arterial blood gas from a dog sick for 1 week: pH 7.33, HCO7.33, HCO33

-- 29 mEq/L, pCO 29 mEq/L, pCO22 57 mmHg (normal: pH 57 mmHg (normal: pH 7.39, HCO7.39, HCO33


Is secondary (adaptive) response as expected?Is secondary (adaptive) response as expected? Observed pCOObserved pCO22 is 20 mmHg is 20 mmHg higherhigher than “normal” (57- than “normal” (57-

37)37) ““Normal” dog can increase HCONormal” dog can increase HCO33

-- 3.5 mEq/L for every 3.5 mEq/L for every 10 mmHg increment in pCO10 mmHg increment in pCO22 (in “chronic” disturbance) (in “chronic” disturbance)

Expected HCOExpected HCO33-- = 22+7 = 29 mEq/L = 22+7 = 29 mEq/L

Observed HCOObserved HCO33-- = 29 mEq/L = 29 mEq/L

Conclusion: YES, adaptive response is as expected. Conclusion: YES, adaptive response is as expected. This is a simple respiratory acidosis with metabolic This is a simple respiratory acidosis with metabolic compensationcompensation


Even inEven in simplesimple disturbances, disturbances, calculated compensatory calculated compensatory pCOpCO22 and and HCOHCO33

-- values usually won’t match values usually won’t match observed values because calculations observed values because calculations are based on “average” valuesare based on “average” values

Do not diagnose aDo not diagnose a mixedmixed disturbance disturbance unless calculated value is > 2 to 3 unless calculated value is > 2 to 3 mmHg (pCOmmHg (pCO22) or mEq/L (HCO) or mEq/L (HCO33

--) ) different from observed valuedifferent from observed value



12 mEq/L, pCO12 mEq/L, pCO22 44 mmHg (normal: pH 7.39, 44 mmHg (normal: pH 7.39,

HCOHCO33-- 22 mEq/L, pCO 22 mEq/L, pCO22 37 mmHg) 37 mmHg)

Is an acid base disturbance present?Is an acid base disturbance present? ABSOLUTELY! (look at the pH)ABSOLUTELY! (look at the pH)

Of what general type?Of what general type? ACIDOSIS (pH 7.05 << 7.39)ACIDOSIS (pH 7.05 << 7.39)

Metabolic or respiratory?Metabolic or respiratory? pCOpCO22 is HIGH (could be respiratory acidosis) is HIGH (could be respiratory acidosis)

HCOHCO33-- is LOW (could be metabolic acidosis) is LOW (could be metabolic acidosis)


Is secondary (adaptive) response as expected?Is secondary (adaptive) response as expected? NONO

If simple metabolic acidosis, pCOIf simple metabolic acidosis, pCO22 should should

be low in responsebe low in response

If simple respiratory acidosis, HCOIf simple respiratory acidosis, HCO33--

should be high in responseshould be high in response Conclusion: This is a Conclusion: This is a mixedmixed metabolic and metabolic and

respiratory acidosis. The extremely low pH respiratory acidosis. The extremely low pH

alerts you to the possibility of a mixed alerts you to the possibility of a mixed

disturbancedisturbance


Arterial blood gas from a dog with sudden onset of Arterial blood gas from a dog with sudden onset of

gastric dilatation/volvulus: pH 7.38, HCOgastric dilatation/volvulus: pH 7.38, HCO33-- 12 mEq/L, 12 mEq/L,

pCOpCO22 21 mmHg (normal: pH 7.39, HCO 21 mmHg (normal: pH 7.39, HCO33-- 22 mEq/L, pCO 22 mEq/L, pCO22

37 mmHg)37 mmHg)

Is an acid base disturbance present?Is an acid base disturbance present?

If so, it’s not obvious from pHIf so, it’s not obvious from pH

Of what general type?Of what general type?

From pCOFrom pCO22 could be respiratory alkalosis or from HCO could be respiratory alkalosis or from HCO33--

could be metabolic acidosiscould be metabolic acidosis

Metabolic or respiratory?Metabolic or respiratory?

pCOpCO22 is LOW (could be respiratory alkalosis) is LOW (could be respiratory alkalosis)

HCOHCO33-- is LOW (could be metabolic acidosis) is LOW (could be metabolic acidosis)


Arterial blood gas from a dog with sudden onset of Arterial blood gas from a dog with sudden onset of gastric dilatation/volvulus: pH 7.38, HCOgastric dilatation/volvulus: pH 7.38, HCO33

-- 12 mEq/L, 12 mEq/L, pCOpCO22 21 mmHg (normal: pH 7.39, HCO 21 mmHg (normal: pH 7.39, HCO33

-- 22 mEq/L, 22 mEq/L, pCOpCO22 37 mmHg) 37 mmHg)

Is secondary (adaptive) response as expected?Is secondary (adaptive) response as expected? If primary metabolic acidosisIf primary metabolic acidosis

10 mEq/L decrement in HCO10 mEq/L decrement in HCO33-- (22-12) (22-12)

Expected pCOExpected pCO22 = 27 mmHg (37-10) = 27 mmHg (37-10) Observed pCOObserved pCO22 = 21 mmHg = 21 mmHg

If primaryIf primary acuteacute respiratory alkalosisrespiratory alkalosis 16 mmHg decrement in pCO16 mmHg decrement in pCO22 (37-21) (37-21) Expected HCOExpected HCO33

-- = 18 mEq/L (22-4) = 18 mEq/L (22-4) Observed HCOObserved HCO33

-- = 12 mEq/L = 12 mEq/L Conclusion: Conclusion: MixedMixed metabolic acidosis and respiratory metabolic acidosis and respiratory

alkalosisalkalosis


IsIs mixedmixed metabolic acidosis and metabolic acidosis and respiratory alkalosis compatible respiratory alkalosis compatible with acute gastric with acute gastric dilatation/volvulus?dilatation/volvulus? YESYES

Metabolic acidosis due to shock and Metabolic acidosis due to shock and decreased tissue perfusiondecreased tissue perfusion

Respiratory alkalosis due to Respiratory alkalosis due to hyperventilation induced by pain or hyperventilation induced by pain or septicemiasepticemia


Arterial blood gas from a dog with sudden Arterial blood gas from a dog with sudden onset of gastric dilatation/volvulus: pH 7.38, onset of gastric dilatation/volvulus: pH 7.38, HCOHCO33

-- 12 mEq/L, pCO 12 mEq/L, pCO22 21 mmHg (normal: pH 21 mmHg (normal: pH 7.39, HCO7.39, HCO33


What if dog had been sick with some What if dog had been sick with some other disorder for 1 week?other disorder for 1 week? If primaryIf primary chronicchronic respiratory alkalosisrespiratory alkalosis

16 mmHg decrement in pCO16 mmHg decrement in pCO22 (37-21) (37-21) Expected HCOExpected HCO33

-- = 13.2 mEq/L (22-8.8) = 13.2 mEq/L (22-8.8) Observed HCOObserved HCO33

-- = 12 mEq/L = 12 mEq/L Difference is < 2 mEq/LDifference is < 2 mEq/L

Conclusion ofConclusion of simplesimple chronic respiratory chronic respiratory alkalosis would be justifiedalkalosis would be justified

analisa gas darah

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