Acid Base Balance

Question 1

How are hydrogen ions buffered in the blood?

Answer 1

Hydrogen is buffered with bicarbonate to form carbonic acid

Question 2

Wht is the henderson hassleback equation to remember?

Answer 2

pH=Hco3/pCO2

Question 3

How long does compensation of metabolic changes usually take?

Answer 3

12-24 hours

Question 4

What is the compensation for metabolic acidosis?

Answer 4

Increases respiratory drive to decrease CO2 and hence cause the blood to become more alkaline

Question 5

What is the compensation for metabolic alkalosis?

Answer 5

Depresses respiratory drive to increase CO2 and hence cause blood to become more acidic

Question 6

What is the compensation for respiratory acidosis?

Answer 6

Kidney increases bicarb to cause blood to become more alkaline

Question 7

How long does compensation for a respiratory change usually take?

Answer 7

2-4 days

Question 8

What are the 5 steps when approaching an acid base disorder?

Answer 8

Does the patient have an acidosis or an alkilosis?
Is it a metabolic or a respiratory cause?
Is compensation appropiate?
If acidosis, is there an anion gap?
Is there more than one disorder present?

Question 9

What are the normal ranges for pH, PCO2, HCO3 and PO2?

Answer 9

pH - 7.35-7.45
PCO2 - 4.7-6.0
HCO3 - 24-30
PO2 - 10.6-13.3

Question 10

What are some of the causes for a metabolic acidosis?

Answer 10

Ketoacidosis
Lactic acidosis
Drugs
Methanol
Ethanol
Ethylene Glycol
Renal failure
Diarrhoea causing loss of HCO3

Question 11

What are some of the causes of metabolic alkalosis?

Answer 11

Vomiting
Mineralcorticoid excess
Burns
Intake of base

Question 12

What are some of the causes of respiratory acidosis?

Answer 12

Lung disease most common cause - COPD and asthma
Neuromuscular - Guillian Barre
Sedatives and anesthetics

Question 13

What are some of the causes of respiratory alkalosis?

Answer 13

Hyperventilation
From mild asthma or anxiety
Could be from CNS cause e.g. stroke