Clinical Acid Base

Question 1

Respiratory Alkalosis Causes

Answer 1

Overbreathing
Any cause of impaired oxygenation
Central cerebral stimulation- fever, pain, drugs, sepsis
Panic/anxiety

Question 2

Respiratory Acidosis Causes

Answer 2

Reduced ventilation

–> airways disease, neuromuscular or chest wall disease, reduced respiratory drive (opiates or reduced consciousness)

Question 3

Compensated resp acidosis

Answer 3

Normal pH
High pCO2
Compensatory high HCO3-

Question 4

Metabolic acidosis

Answer 4

Low pH
Low HCO3-
Often low CO2
–> Calculate anion gap

Question 5

High anion gap metabolic acidosis

Answer 5

Acids added to blood:

• Ketones
• Lactate
• Titrable acid
• Ingested acid

Question 6

Ketones sources

Answer 6

DKA
Starvation
Alcoholic ketoacidosis

Question 7

Lactate sources

Answer 7

Tissue hypoxia/poor perfusion

Altered cellular respiration

Question 8

Lactic acidosis/ketoacidosis

Answer 8

Impaired oxygenation or glucose entry
–> Low HCO3-
Lactate or ketones

Question 9

Renal failure acidosis

Answer 9

Failure to clear titrable or dietary acid

Question 10

Normal anion gap metabolic acidosis

Answer 10

"Hyperchloraemic metabolic acidosis"
Due to bicarbonate loss
--> kidneys- renal tubular acidosis
--> gut- diarrhoea
Compensatory rise in chloride to maintain electric neutrality

Question 11

Acute consequences of acidosis

Answer 11

Negative ionotropic effects
Confusion
Kussmaul’s breathing
Hyperkalaemia

Question 12

Chronic consequences of acidosis

Answer 12

Bone resorption, calciuria, stones
Insulin resistance
Progressive renal impairment

Question 13

Why does HCO3- rise in metabolic alkalosis

Answer 13

H+ lost- chloride depletion
H+ moves into cells- hypokalaemia
Alkali administered

Question 14

Treatment metabolic alkalosis

Answer 14

H+ replacement
Normal saline if Cl depleted
K+ supplementation
Depends on source