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Prof. Mehdi Hasan Mumtaz. Water, Electrolyte &. Acid-Base Balance. BALANCE. Water Balance Electrolyte Balance. Acid Base Balance. Nutritional Balance. IVS. ISS. ICS. 5L. 14L. 23L. TOTAL BODY WATER 42L. FLUID THERAPY. INTRACELLULARINTERSTITIAL VASCULAR. CAPILLARY. EG. - PowerPoint PPT Presentation

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  • Water, Electrolyte &Prof. Mehdi Hasan MumtazAcid-Base Balance

  • BALANCEWater BalanceElectrolyte Balance.Acid Base Balance.Nutritional Balance.

  • TOTAL BODY WATER 42L

  • FLUID THERAPYCELLCAPILLARYEGOSMOLALITYNa+COPINTRACELLULARINTERSTITIAL VASCULAR

  • FLUIDS

  • ACID-BASE BALANCETerminology.Physiologic Compensation By Body.Pathophysiologic Disturbances.Practical Approach To Assessment.Biochemical Reports & Case Histories.

  • DEFINITION OF TERMINOLOGYACID- STANDARD BICARBONATE.BASE- BUFFER BASE & BASE DEFICIT.ALKALIBUFFERING & BUFFER.PH.24 x PCO2 (mmHg)H+(nmol/L)=- -----------------------------HCO3 (meq/L)(40nmol/L)

  • PRODUCT OF METABOLISMH++- Anaerobic Metabolism.

    CO2- Aerobic Metabolism.

  • PHYSIOLOGIC COMPENSATIONHYDROGEN IONS.Incoporation in water. H++HCO3 H2C3O CO2 + H2O.Loss from body.Kidney regeneration of HCO3.Intestine.CO2.Chemoreceptors in hypothalamus.HCO3.HCO3 generation by erythrocytes.HCO3 re-absorption in renal tubules.HCO3 generation in renal tubules.

  • BICARBONATE GENERATION BY ERYTHROCYTESCl

    HCO-3

    CO2Cl

    -HCO3 +H+

    CO2+H2OHHB

    Hb

  • BICARBONATE REABSORPTION BY KIDNEYRENAL T. LUMENSTIMULATED BY HCO3- M. ACIDOSIS

  • BICARBONATE GENERATION IN KIDNEYSTIMULATED PCO2(BY RESP ACIDOSIS)& -HCO3(M. ACIDOSIS)B-Na+Na+CELLH2OHCO3-H+H2OCO3B-HBHCO3-

  • PATHOPHYSIOLOGIC DISTURBANCESLungs Disturbances of CO2=R. Centre

    Disturbance of H++HCO3 = Metabolic

  • Henderson - HosselbalchEQUATION Proton Acceptor (Base)PH=PK+Log = -------------------------------- Proton Donor (Acid)

    -HCO3 (Metabolic)PH=PK+Log = ---------------------------------- H2CO3 or PCO2 x 0.03(Respiratory)

  • ACID-BASE DISTURBANCE-HCO3PCO2 x 0.03MEATBOLICRESPIRATORYACIDOSISALKALOSISACIDOSISALKALOSISHCO3----------------PCO2x0.03HCO3----------------PCO2x0.03RATIOHCO3----------------PCO2x0.03HCO3----------------PCO2x0.03

  • Metabolic acidosis =

    Respiratory acidosis =

    Metabolic alkalosis =

    Respiratory alkalosis =Defect

    HCO3----------PCO2

    HCO3----------PCO2

    HCO3 ----------PCO2

    HCO3 ----------PCO2 Correction

    HCO3----------PCO2

    HCO3 ----------PCO2

    HCO3 ----------PCO2

    HCO3 ----------PCO2

  • CAUSES OF M. ACIDOSISGlomeralar failure.Keto-acidosis.Lactic acidosis.Intestinal loss.R. Tubular failure.Actazolamide therapy.R. Tubular acidosis.Ureteric transplantation.NH4Cl el therapy.Hyperkalamic M. AcidosisVariable Hyppkalamic AcidosisHyperchloraemic Acidosis

  • SCREENING TESTS METABOLIC ACIDOSISBLOOD GLUCOSE.

    URINE/ BLOOD KETONES.

    SERUM CHLORIDE.

    SERUM POTASSIUM

  • RESPIRATORY ACIDOSISAcute Respiratory Failure.Erythrocyte Chronic Respiratory Failure.Renal Generation.

  • METABOLIC ALKALOSIS

    Administration of HCO3.

    K+ depletion Generation by kidney.

    Pyloric Stenosis.

  • RESPIRATORY ALKALOSISHysterical Over-breathing.ICP.Brain Stem Injury.Hypoxia.Pulmonary Oedema.Lobar Pneumonia.Pulmonary Collapse.Excessive Artificial Ventilation.

  • BALANCE OF ACID-BASENORMAL VALUESPCO230-50mmHg or 4-6.6kPa.>50mmHgrespiratory or 6.6kPaacidosis 7.50 alkalaemia.
  • BALANCE OF ACID-BASERELATIONSHIPPCO2 and PH.PCO2 & ventilation.PO2 and normal range.PO2 and FIO2.PCO2, and temperature.

  • TERMINOLOGYACIDAEMIA- PH7.50.

    ACIDOSIS- Base Deficit Present.

    ALKALOSIS - Base Excess Present.

  • HOW TO ASSESS BLOOD GASES?STEP-1 Assessment of Acid-Base Balance.

    STEP-2 Assessment of Hypoxaemic State.

    STEP-3 Assessment of Tissue Oxygenation State.

  • STEP-1Assessment of Acid-Base BalanceCLASSIFICATIONACIDOSIS ALKALOSIS METABOLICRESPIRATORY METABOLICRESPIRATORY ACUTE CHRONICACUTE CHRONICACUTE CHRONICACUTE CHRONIC

  • STEP-1Assessment of Acid-Base Balance

    Acute- Uncompensated.Chronic- Compensated.-Fully.- Partially.

    COMPENSATED PH 7.30-7.50

    DIAGNOSIS.

  • DIAGNOSISSEQUENCE.PH.PCO2.HCO3.PH Normal 7.4Compensated 7.3-7.5PCO3 Normal 40mmHg (5.3kPa)Compensated 30-50mmHg (4-6.6 kPa)

  • DIAGNOSISIF PH LOW acidosis. Look at PCO2.If PCO3 high - respiratory acidosisIf PH low - acidosis Look at PCO2 If it is normal or low.Look at HCO3. It is low metabolic acidosis.IF PH HIGH - alkalosisLook at PCO2.If it is low - respiratory alkalosis If PH high - PCO2 normal or high.Look at HCO3. High - metabolic alkalosis.

    NOW LOOK FOR COMPENSATION

  • ACIDOSISALKALOSIS Primary changePrimary change

  • STEP-2Hypoxaemic StateBelow 60 years of age:Normal PO2 = 97mmHg.Acceptable range= >80mHg.Mild hypoxiaemia=
  • STEP-2Hypoxaemic StateAbove 60 years of age:Subtract 1mmHg from minimal 80mmHg for every year over 60; this means acceptable range:60 years = >80 mmHg.70 years = >70 mmHg.80 years = >70 mmHg.90 years = >50 mmHg.New Born:Acceptable = 40-70 mmHg.

  • STEP-2Hypoxaemic StateOxygen TherapyFIO2 x 5 = Expected PO2.

    Uncorrected Hypoxaemia = PO2 Room Air Acceptable Limit. 100mmHg < minimal predicted.

  • STEP-3Assessment of Tissue OxygenationCardiac Status.Peripheral Perfusion Status.Blood Oxygen Transport Mechanism.Depends on:Vital SignsPhysical Examination.

  • STEP-3Assessment of Tissue OxygenationBP.Pulse Pressure.Heart RateECG.Skin Color & Condition.Capillary Fill.Senosrium.Electrolyte Balance.Urine Out Put.If Above 1,2 Good Only 3 Interfering.Arterial Oxygen Tension Po2.Blood Oxygen Content.Hb Oxygen Affinity.

  • SUMMARYASSESS ACID/BASE STATUS.ASSESS HYPOXAEMIC STATEASSESS TISSUE OXYGENATION.TRY TO FIND OUT THE CAUSE.SEE FOR THE NEED OF HCO3.

  • SUMMARY6. If Cl- K+ Think of actazolamide therapy and R. Tubul Acidosis.

    7. If Cl-N K+ Proximal Tubul Failure.

    OTHERWISE THINK ABOUT GIT INVOLVEMENTAcidosis MetabolicLook at1. Blood urea If and K+ G.F.2. Blood Glucose ket If and K+ ketoacidosis.3. PO2 If K+ Lactic acidosis4. Serum HCO3. If only H/o Therapy5. If K+ think of NH4Cl therapy + G. Transplantation

  • SUMMARYLung Functions will HelpRespiratory METABOLICLook at K+ & Cl-K+ Cl- H/o vomiting Pyloric stenosisIf K+ find cause.H/o bicarb therap. Alkalosis RESPIRATORY - H/o H. Injury- L. Infection- IPPV

  • BASE EXCESS/ DEFICITmEq of HCO3 that is excess/ deficit per litre of E. C. Water

    PREDICTED RESPIRATORY PH?

    PCO2 -- PH RELATIONSHIP

    PCO2 20mmHg = 0.1PH. PCO2 10mmHg = 0.1PH

  • BASE EXCESS/ DEFICITCalculate difference between measured PCO2 and 40mmHg. Move decimal 2 places to left.If PCO2 > 40 subtract difference from 7.4.If PCO2 < 40 add the difference to 7.40.

    PH 7.21 PCO2 9090-40 = 50 = 0.50 = 0.50x = 0.257.40-0.25 =7.15PH 7.47 PCO2 1840-18 = 22= 0.227.40 + 0.22 =7.62 Predicted Resp PH.

  • DETERMINATION OF METABOLIC COMPONENT10mEq/L variance from buffer basePH change of c-15 units.

    Move decimal 2 places to right i.e. 15 ratio 15:, 2:3=2/3Measured PH - Predicted PH (resp)- metabolic PH change.

  • DETERMINATION OF METABOLIC COMPONENTDetermine PCO2 variance. I.e. PCO2 -40mmHg PCO2.Move decimal 2 point to left.Determine Predicted Resp. PH.Measured PH Predicted PH difference move decimal 2 places to rt. X 2/3=base excess/deficit.

    Base Excess = measured PH> predicted PH.Base Deficit = measured PH> predicted PH.

  • APPROXIMATE Na+ & K+ CONCENTRATION IN BODY FLUID

  • DOES TRADITIONAL BLOOD GAS ANALYSIS SERVES THE PURPOSE?PH

    PCO2

    PO2

    HCO3

  • WHAT INFORMATION DOES IT GIVE?OXYGEN UPTAK

    CO2 PRODUCTION

    ACIDITY/ ALKALINITY

  • WHAT INFORMATION IS REQUIRED FOR THERAPY?UPTAKE- O2 uptake in lungs.TRANSPORT- from lungs to capillaries.RELEASE- from capillaries to tissues.

    HOW TO WE GET?DEEP PICTURE OF BLOOD GASES

  • O2 UPTAKEMOUTH TO ALVEOLIGrahams Lawof diffusion

  • O2 UPTAKEAlveoli to HbHenrys Lawof diffusion

  • COMBINE BOTH LAWSMouth to AlveoliGrahams Law of diffusionAlveoli to HbHenrys Law of diffusion.

  • TRANSPORT TO CAPILLARIESDO2

    520 - 720ml/min/m2

  • O2 RELEASE TO TISSUEVO2

    110 - 160ml/min/m2

  • WIHAT IS DEEP PICTURE?PCO2.tHb.oS2.O2Hb.ctO.p50.VO2.

  • O2 TRANSPORTAMOUNT OF HB.

    FRACTION OF OXYGENATED HB.

    O2 TENSION.

  • MAJOR CHALLENGESBalancing O2 SupplyandO2 Demand

  • O2 CARRYING CAPACITY98% Bound to Hb.2% in plasma.Forms of hemoglobins.Oxygenated O2 Hb.Deoxygenated RHb.Dyshaemoglobins.Carboxyhaemoglobin (CoHb).Methaemoglobin (MetHb).

    tHb = cO2Hb + cRHb + cCoHb + cMetHb

  • DEGREE TO WHICH Hb CARRIES O2Expressed in two Different Ways.

    1. Fraction of Oxygenated Hb.cO2HbO2Hb = -----------------------------------------------cO2Hb + cRHb + cCoHb + cMetHb

    FRACTIONAL SATURATION2. O2 Saturation. cO2HbsO2 = --------------------------- X 100 cO2Hb + cRHb

  • DEGREE TO WHICH Hb CARRIES O2FUNCTIONAL SATURATION

    Relationship between Oxygenated Hb (O2Hb)and Oxygen Saturation sO2)

    O2Hb = sO2 x (1-CoHb cMetHb)

  • Example:Patient exposed to carbon monoxidetHb =10.0 mmol/LcO2Hb =07.7 mmol/LcRHb = 0.3 mmol/L cCoHb =2.0 mmol/L

    7.7 mmol/L 0.77cO2Hb = ---------------------------= ---------- (7.7+0.3+2.0) mmol/L (or 77%)

    7.7 mmol/L sO2 = -------------------------- X 100 = 96.25%(7.7+0.3) mmol/L

  • OXYGEN CONTENTctO2 = tHb x O2Hb + pO2 x DYSHAEMOGLOBINSBLOOD TRANSFUSIONFIO2

  • OXY

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