Acid Base Disorder,Hemodialysis , Renal Transplant Flashcards
Most efficient buffer
Bicarbonate buffer system
Extracellular buffer are
Bicarbonate buffer system
Phosphate buffer system
If pka levels are close to blood pH it means
pka means ph at which molecules can exist as both associated and dissociated form. So if pka is close to 7.4 pH blood it means it will exist in ionic form also to act as buffer
Intracellular buffer most important
Protein -Hb
Phosphate
How does lungs act as buffer
Lungs exhale or retain CO2 in response to extracellular pH
In metabolic acidosis more CO2 is exhaled from lungs
Non volatile Acids produced in kidney per day?
80meq of non volatile Acids
Total H+ excreted per day
4320 + 80 = 4400meq
4320 HCO3 filtered per day at glomerulus for which 4320 H+ excreted
80 meq non volatile acid
Net acid excretion is?
80mEQ ie Ammonium and titrable acid (phosphate/creatinine)
Urinary buffer are
Ammonia buffer
Phosphate buffer
Site of injury in RTA TYPE 1
Damage to Na-H exchanger in proximal tubule
Leading to inability to excrete H into lumen and excess conc in blood.
Acidifying machinery of kidney
Cortical collecting duct alpha intercalated cells
RTA type II
Damage to distal CD H+ATPase pump
Leading to inability to excrete H+ and increased levels in blood
Metabolic acidosis
Importance of ammonia in acid base regulation
Ammonia synthesis and excretion is most important way kidney eliminates non volatile acids
Where is ammonia formed
In proximal tubule by catabolism of glutamime to glutamate to alpha ketoglutarate
2 ammonium ion are generated
In response to increased acid load ammonia excretion increases
How does ammonium ion reach urine
NH3- at ThA L through NaK2Cl-it passes into interstitium and collecting duct and by combining with H+ excreted in form of NH4+
What are volatile and non volatile acids in body
Volatile excreted as CO2 from lungs
Formed by metabolism of carb fat protein
Non volatile formed by metabolism of phospholipid nucleic acid
Sulfuric acid phosphoric acid
Excreted by kidney
Henderson hasselbach equation
Important determinant of H+
pH=pka +log [H+] /[HCO3-]
Bicarbonate
pCO2
First line defense in acid base regulation
Chemical buffer
Then respiratory buffer 2nd
Then renal 3rd
Anion Gap is
Unmeasured cations and anions = 8-12meq/L
Measured anion and cation in body are
Na+
Cl and HCO3
Corrected anion gap is
Anion gap +2.5(4.5 - S.albumin)
Effect of Met acidosis on heart cns
Heart - decrease myocardial contractility
Sympathetic overactivity
CNS
Lethargy disorientation stupor coma
Hyperventilation
Hyper kalemia
HAGMA
Causes
Ketoacidosis DM ALCOHOL STARVATION Uremic acidosis Salicylate Methanol /ethylene glycol Lactic acidosis
NAGMA normal anion gap Metabolic acidosis is also k a
Hyperchloremic metabolic acidosis because loss of HCO3 - leads to increase levels of chloride
