ACID BASE DISORDERS

                                                                  Importance of Ph

1.To keep the enzymatic activity

2.To maintain the active structural and functional conformation of biomolecules

3.To maintain the cellular viability

  Na-K+ pump failure

  sickle cell syndrome

  acidaemia

  digitalis toxicity

                                                                Source of acid

                             Both exo & endogenous

Acid     amount             source            disposal  amount           reserve

Volatile   15mole/day                           lung        15mole/day    30-40

      CO2

Non volatile  70mmol/day                                    kidney           70mmol/day         500

    

      H2SO4                               protein

      H3PO4                               PL/P.prot

      HCL

      LA

      KA

Respiratory acidosis Ventilatory failure                  pneumonia                  bronchitis                  Asthma                  emphysema Depressed nervous Morphine poisoning

Respiratory alkalosis Hyperventilation                   voluntary                   hysteric CNS disease affecting respiratory center Salicylate poisoning Hepatic coma

Metabolic acidosis Normal anion gap (HYPERCHLOREMIC)                 (git     HCO3 loss)                         diarrhoea                         fistulae                         uretero sigmoidostomy                   renal HCO3 loss                           RTA                           acetazolamide                   ↑HCL production                           NH4cl ingestion Increased anion gap (NORMOCHLOREMIC)                     DKA                     LA                     RF( acute + chronic)                     salicylate poisoning

METABOLIC ALKALOSIS        Loss of acid             vomiting             aspiration        Excess alkali  adminstration   (citrate,acetate,lactate,gluconate,HCO3-)        Diuretic        ECF vol  depletion(renal Na+ reab in exchange of H+)        Aldosteronism(primary/2nd ary) Cushing’s syndrome        Post hypercapnic alkalosis

       Total buffer base    =  48meq/L

            HCO3-           25-28meq/L

            Hb -                    15meq/L

            prot-

             HPO4- -

Standard serum HCO3- conc

      body temp 37°c

      Pco2          40mmHg

      Hb              normal concentration

                         saturated with O2