quantitative acid base analysis fencl stewart approach
TRANSCRIPT
Fencl–Stewart approach: Quantitative Acid-Base Analysis(Strong Ion Difference Changes)
Kiki MK Samsi, dr.,Sp.A, M.Kes
Pediatric Critical Care UnitSumber Waras Hospital
There are three general mechanisms by which SID changes:
changing the water content of plasma (contraction alkalosis and dilutional acidosis)
changing the Cl- (hyperchloremic acidosis and hypochloremic alkalosis),
increasing the concentration of unidentified anions (organic acidosis).
30
Dilutional Acidosis
2 liter
15
WATER
Changing The Water Content Of Plasma
Changing The Water Content Of Plasma
3015
Hyperchloremic acidosis resulting from NS
Changing The Water Content Of Plasma
Changing The Water Content Of Plasma
Normal acid-base following LR
Changing The Water Content Of Plasma
30
Contraction Alkalosis
Changing The Water Content Of Plasma
DIURETIKx
Changing the Cl-
Seorang anak 2 thn, BB 10 kg: Ileus obstruktif Muntah-muntah Dehidrasi berat pH 7.6, Kalium 2 meq/L, Cl 82 meq/L
Tatalaksana Pasang NGT untuk DEKOMPRESI Resusitasi cairan dengan RL Beri KCl untuk hipokalemia
Changing the Cl-
58
Na+ = 140 mEq/LCl- = 82 mEq/L
SID = 58 mEq/LOH- = 58 mEq/L
Hypocloremic Alkalosis
The adverse effects of a severe alkalosis
Decreased myocardial contractility Arrhythmias Decreased cerebral blood flow Confusion Mental obtundation Neuromuscular excitability Impaired peripheral oxygen
unloading (due shift of oxygen dissociation curve to left).
The adverse effects of a severe alkalosis
Hypoventilation (due respiratory response to metabolic alkalosis)
Pulmonary microatelectasis (consequent on hypoventilation)
Increased ventilation-perfusion mismatch (as alkalosis inhibits hypoxic pulmonary vasoconstriction).
Na+ = 140 mEq/LCl- = 82 mEq/L
SID = 58 mEq/LOH- = 58 mEq/L
+
Hypocloremic Acidosis
Na+ = 137 mEq/LCl- = 109 mEq/LLactat = 28 mEq/L
SID = 0 mEq/LOH- = 0 mEq/L
Ringer Lactat
Na+ = (140 + 137 mEq/L) : 2 = 138,5 mEq/L Cl- = ( 82 + 109 mEq/L) : 2 = 95,5 mEq/L
SID = 43 mEq/LOH- = 43 mEq/L
5843
Na+ = 140 mEq/LCl- = 95 mEq/L
SID = 45 mEq/LOH- = 45 mEq/L
+
Hypocloremic Acidosis
Na+ = 154 mEq/LCl- = 154 mEq/L
SID = 0 mEq/LOH- = 0 mEq/L
NaCl 0,9%
Na+ = (140 + 154 mEq/L) : 2 = 147 mEq/L Cl- = ( 82 + 154 mEq/L) : 2 = 118 mEq/L
SID = 29 mEq/LOH- = 29 mEq/L
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Treatment of the elevated Cl- and decreased SID would be done by increasing the SID. This could be accomplished through sodium bicarbonate administration. Other ways of administering Na+ with a metabolizable anion are through the use of the sodium salts of lactate, gluconate, acetate or citrate.