Physiology of anaesthesia Flashcards
Central Nervous System function
divided up into the somatic system (involving voluntary actions such as those of skeletal muscle) and autonomic system (involving involuntary actions such as those of the viscera)
effects of anaesthesia on Central Nervous System
Side effects of general anaesthesia for this system. Reversible depression resulting in a loss of consciousness, depresses cardiac and respiratory control centres and removes reflexes.
Cardiovascular System Function
transport oxygen and nutrients to the tissue and transport waste away from the tissue
Effects of anaesthesia on Cardiovascular System
Some anaesthetic drugs cause vasodilatation to blood vessels . This results in hypotension which reduces blood supply to organs. The vasodilation can also contribute to hypothermia
Respiratory System Function
transfer oxygen to the blood and remove carbon dioxide from the blood
Effects of anaesthesia on Respiratory System
Anaesthetics depress this system causing :
Bradypnoea, Reduced sensitivity to blood carbon dioxide, hypercapnia, reduced ventilation and hypoxia
Liver Function
This organ is involved in the metabolism of many anaesthetic agents including propofol and ketamine.
Effects on anaesthetics on liver
- Anaesthetic agents can directly affect the hepatic blood supply.
- Hepatic artery and the portal vein provide blood supply to this organ.
- Stress of Induction can initially increase heart rate
Kidney Function
o Excrete waste products
o Filter blood
o Regulates fluid balance: water/electrolytes
o Secrete hormone erythropoietin
o Maintains blood pressure
Effects of Anaesthesia on Kidneys
Side effect of anaesthesia medication can be hypotension. This causes reduction in blood supply to kidneys which can cause damage and impair excretion of anaesthetic agents.
