Acid-Base Disorders, Blood Gas Analysis

Question 1

Acid-Base evaluation

Answer 1

Importance: info about the acid-base status & function of the vital buffer systems.

Sample: anticoagulated blood.
Arterial -> resp.function assesments
Venous/Arterial -> metabolic status of the animal.

Method: ion selective electrodes (correction to patient’s T).

1. Evaluate whether there is acidosis / alkalosis (decompensated/comp)
2. Search for the cause of the pH alteration (metab/resp.)
3. If compensatory effect is visible.
4. Example that can cause the changes.

Question 2

Buffer solution

Answer 2

A weak acid / base and 1 of its salts.
It can maintain a nearly constant pH.
It resists pH changes

Most important physico-chem buffer system = carbonate-bicarbonate

Vital buffer system: kidneys - lungs

Question 3

Blood-Gas analysis

Answer 3

Goal: assess effectiveness of gas-exchange (paO2, paCO2).

Sample: arterial samples (precise), venous blood (how much O2 is consumed). Anticoagulated blood (& closed sampling- “Astrup technique”)

Method: ion specific electrodes (corrected to the T of the patient).

Interpretation: hypoventilation / hyperventilation (hypoxaemia/hyperoxaemia, hypocapnia/hypercapnia).