Types of hypoxia Flashcards
T1RF
hypoxia without hypercapnia, PaO2 <8kPa with normal or low co2, v/q mismatch → severe pneumonia, lung injury or pulmonary oedema , high altitude, alveolar failure or vasculature failure
T2RF
Hypoxia + hypercapnia
metabolic acidosis
Lack of bicarbonate
T2RF o2 target
88-92%
Normal v/q
0.8
types of hypoxia
- Inadequate oxygenation of blood in the lungs - deficiency of o2 in inspired air or hypoventilation
- Pulmonary disease - airways resistance or failure of respiratory membrane diffusion
- Venous to arterial shunts (R → L) - septal defects
- Inadequate o2 transport to tissues - anaemia, circulatory failure, oedema
- Inadequate tissue use of o2 - burns victim
Causes of cyanide toxicity
Gold mining, jewellery cleaner, nylon, pesticide, fruit pits
How does cyanide cause acidosis?
inactivates mitochondrial oxidative phosphorylation → inhibits cellular respiration → anaerobic respiration → increaesd lactic acid
How to treat cyanide toxicity
Amyl nitrate + sodium thiosulfate + sodium nitrite creates methemoglobinemia
Hypoxia sx
Cyanosis
Reduced work capacity of muscles
Depressed mental activity
Ischaemia
causes of t1RF
V/q mismatch
Hypoventilation
Diffusion problems
Shunt
Causes of T2RF
increased resistance
Reduced breathing effort
Chronic bronchitis
Neuromuscular damage
COPD blood gases
Low pao2
High paco2
High HCO3
Normal pH
Chronic bronchitis sx
Productive cough and sputum Haemoptysis Cyanosed Peripheral oedema Obese
Emphysema sx
Minimal cough Pink skin, pursed-lip breathing Accessory muscle use cachexia Tachypnoea
