Acid/Base Disorders Flashcards
What is normal blood pH?
7.35 - 7.45
Describe pulmonary compensation
Exhalation of CO2 by the lungs allows a shift of H+ to decr acidity
How is the amount of CO2 exhaled by the lungs regulated?
regulated by central & arterial chemoreceptors in response to acidity of blood
Is pulmonary compensation fast or slow and takes how long?
- fast
- minutes to hours
Describe renal compensation
Excretion of H+ by the kidneys in urine will work to decr acidity of blood
How is the amount of H+ excreted by kidneys regulated ?
regulated by many mechanisms
Is renal compensation fast or slow & takes how long?
- slower
- days
Describe the movement of HCO3 in the renal system (nephron)
Almost all bicarb is excreted in the glomerulus but then almost completely reabsorbed in the PCT
If either of these compensatory mechanisms fails or becomes overwhelmed, what happens to the pH?
the pH in the body becomes abnormal
What causes acidosis?
caused by either a fall in HCO3 or elevation in pCO2
What causes alkalosis?
caused by either an elevation in serum HCO3 or fall in pCO2
What happens during metabolic acid base disturbance?
alteration of serum HCO3 levels
What happens during respiratory acid base disturbance?
alteration of CO2 tension (pCO2)
Which acid/base disturbance can be acute or chronic?
Respiratory acidosis
Describe Metabolic Acidosis
acid accumulates in the blood
Metabolic Acidosis is a result of…
- Excess production of acid
- Decr excretion of acid
- Loss of base in urine or stool
Metabolic Acidosis causes can be divided into what two groups?
- HAGMA
- NAGMA
What is a normal anion gap?
8 - 12
Examples of HAGMA
(mudpiles)
- Methanol
- Uremia
- Diabetic ketoacidosis
- Paraldehyde/Propylene glycol
- Iron/Isoniazid
- Lactic acidosis
- Ethanol/Ethylene glycol
- Salicylates
Examples of NAGMA
- Carbonic anhydrase inhibitors (acetazolamide)
- Adrenal insufficiency
- RTA
- Fistula (small bowel or pancreatic)
- Excess chloride (hyperalimentation or excessive saline administration)
- Urinary diversion/Ureteroenterostomy
- Diarrhea
- Spironolactone
Causes of Metabolic Alkalosis
“clever PD”
- Contraction
- Licorice
- Endocrine disorder (Conn’s, Bartter’s, Cushing’s)
- Vomiting
- Excess alkali
- Refeeding
- Post-hypercapnea
- Diuretics
If urine Cl- is high, correcting the underlying dz & supplementing K+ will usually correct…
- Cushing’s
- Bartter’s
- Conn’s
Respiratory Acidosis is caused by…
increase in CO2 tension in blood
Respiratory acidosis is a result of…
- Incr CO2 production
- Decr alveolar ventilation
