Perioperative oxygen therapy / fasting guidelines Flashcards
1
Q
Describe the importance of oxygen delivery in minimising operative risk?
A
- Maximising oxygenation to tissues during surgery reduces:
- Post-op complications
- Long hospital stays
- Mortality
2
Q
How can oxygen delivery to the tissues be calculated?
A
- Do2 = CO * Cao2
- Do2 = Oxygen delivery
- CO = Cardiac output
- Cao2 = Oxygen content of arterial blood
3
Q
Name a condition which should be correct post-op to optimise oxygen delivery to the tissues?
A
Anaemia
4
Q
What can be used to guide perioperative oxygen therapy?
A
- Goal direct haemodynamic therapy (HT)
- Uses CO monitoring to guide supplemental oxygen and IV fluids
- Useful in those with anaemia and poor CV and respiratory function
5
Q
Describe the use of cardiopulmonary function testing as part of the preoperative assessment?
A
- Useful for calculating the anaerobic threshold
- Point where anaerobic metabolism occurs due to inadequate oxygen delivery
6
Q
What is the purpose of pre-operative fasting?
A
- Ensure an empty stomach
- Minimise risk of regurgitation and aspiration during the induction of anaesthesia
- Extended periods of pre-op fasting are not usualy required
- Component of ‘enhanced recovery after surgery’
7
Q
What are the optimum fasting timings?
A
- No food 6 hours before
- No clear fluids for 2 hours before
- Chewing gum not permitted on day of the surgery
8
Q
In what situations can an empty stomach not be guaranteed despite fasting guidelines being followed?
A
- Pregnancy
- Gastric outlet or bowel obstruction
- Any condition which causes functional gastroparesis
- Delayed gastric emptying in long-standing diabetes
NG tube may be indicated in these patients **
9
Q
What can goal direct haemodynamic therapy be used for?
A
- Guidance for:
- IV fluids
- Inotropic therapy
- Blood transfusions
- Supplemental oxygen
