Dr Rob Stephens Thanks to Drs James Holding and Maryam Jadidi

1. Dr Rob Stephens Thanks to Drs James Holding and Maryam Jadidi

2. Contents Introduction – the classical triad Introduction – general principles Hypnotic Agents Neuromuscular Paralysis Reversal of Neuromuscular Paralysis Analgesia Cardiovascular Drugs – up and down Fluids and Gasses are drugs too!

3. Introduction • ‘Anaesthesia’ classically • Hypnotic agent- unconsciousness • Gas or IV • Analgesia • Neuromuscular Paralysis • Induction, Maintenance, Emergence, Recovery

4. Introduction - Principles • Pharmacokinetics • What the body does to the drug • Absorption, distribution, metabolism, elimination • Pharmacodynamics • What the drug does to the body – ie it’s effects • CVS, RS, GI, NS, Other , Side effects

5. 2013 Anaesthesia • Intravenous induction • Short acting opiate - e.g. fentanyl • Hypnotic ‘anaesthetic’ - e.g. propofol • Set up of anaesthetic maintenance - e.g. sevoflurane vapour in oxygen and air • Specific muscle paralysis may be needed • Definitive analgesia • Anti-emetic • Others

6. Hypnosis: Propofol

7. Maintenance Concepts of partial pressure and MAC • Sevoflurane (SEVO) – MAC = 2.2 • Used for gaseous induction. • Isoflurane (ISO) – MAC = 1.1 • Desflurane (DES) – MAC = 6 • The most insoluble – so the fastest to equilibrate – but a respiratory irritant, so unsuitable for gaseous induction. • Nitrous Oxide – a gas. MAC = 105 • Oxygen /Air • Propofol and Remifentanil

8. Muscle Paralysis

9. Neuromuscular blockers • Depolarising • Suxamethonium • Non-depolarising • Atracurium • Vecuronium • Rocuronium

10. Nicotinic ACh Receptor

11. Reversal of Paralysis • Neostigmine • Blocks cholinesterase • Stimulates nicotinic and muscarinic • Given with an anticholinergic • Sugammadex

12. Analgesia • Systemic • Simple- paracetamol 1g • NSAID – Diclofenac etc • Opioids eg morphine 2mg bolus • Others – Ketamine • Regional – spinal / epidural / blocks • Local - infiltration

13. Opiates Morphine Diamorphine Fentanyl Alfentanil Remifentanil Tramadol

14. Uppers • Anticholinergics • Atropine • Glycopyrulate 200-600μg • Symatheto-mimetics •  agonists • Phenylepherine • Metaraminol 0.25-0.5 mg • Ephedrine • A mixed  and  adreno agonist • 3mg

15. Downers More anaesthetic or opiate / analgesia Short acting -blockers (labetalol, esmolol) GTN Clonidine - 2 agonist clonidine

16. Antiemetics

17. Antiemetics • Cyclizine anti-histamine • S/E – tachycardia and other anti-cholinergic effects • Ondansatron 5-HT3 receptor antagonists • S/E – constipation + long QT • Prochlorperazine (‘Stematil’) – DA and mACh receptor antagonist • S/E – extrapyramidal • Dexamethasone glucocorticoid • S/E – deranged glucose control

18. Fluids and Gasses are drugs too! • Oxygen is a ‘drug’ • Intravenous fluids • Colloids • Crystalloids • Blood and products

19. General Advice • Can always give more – can’t take away • Caution in • Unwell • Elderly • Hypovolaemic • Lots of ways to anaesthetise- don’t worry

20. Summary • Classical Triad Anaesthesia • Temporal sequence • Usual sequence