Interpreting ABG 2 Flashcards
Normal pH
7.35 to 7.45
Normal PaO2
11.5 to 14.5
Normal PaCO2
3.5 to 5.5 kPa
Normal HCO3
24-28
Metabolic acidosis indicator
Low HCO3-
Metabolic alkalosis indicator
High HCO3-
Respiratory acidosis indicator
High CO2
Respiratory alkalosis indicator
Low CO2
T2RF
Decreased PaO2, increased PaCO2
T1RF
Decreased PaO2
Main cause of T1RF
V/Q mismatch
- Type 1 diabetes, pyrexial and vomiting
- pH is low
- PCO2 is low
- pO2 is okay
- HCO3- is low
- DKA - diabetic keto-acidosis - ketonaemia, acidaemia, hyperglycaemia
- High ketonaemia, high blood glucose and low bicarbonate
- DKA is acidosis, dehydrated, excess potassium in blood but total body potassium deficit
- No insulin so little K+ shift into cell but large shift out in urine
- Kussmaul breathing: deep and laboured breathing with tachypnoea
- Ketosis and acidosis respiratory compensation to decrease PaCO2
Fluid and electrolyte shifts in DKA
Absent insulin - hypergylcaemia - glycosuria - osmotic diuresis (electrolyte loss) - dehydration (renal failure)
- High pH
- High PCO2
- Normal pO2
- High bicarbonate
He is in metabolic alkalosis - he is vomiting up any stomach contents due to pyloric ulcer
He will be dehydrated and hypochloraemic (HCl) lost - kidneys will try and retain H+ instead so losing K+
Treated with IV fluid - 0.9% saline to rehydrate and provide chloride to correct balance
Why does a pyloric ulcer result in alkalosis?
Getting rid of all acid
