General anaesthesia Dept of Surgery.pptx

General Anesthesia concepts and basics

1. GENERAL ANAESTHESIA Krishnap riya K Roll no 122

2. General Anaesthesia Triad of: Amnesia: loss of memory Analgesia:pain relief Muscle relaxation

3. Agents used : Intravenous agents Propofol . Thiopentone Etomide . Ketamine Inhalational agents Sevoflurane- inhalational induction

4. Advantages Non pungent Useful in Children Needle phobic adult Airway difficulty anticipated patients Disadvantages High risk of developing airway obstruction

5. Techniques 1.Rapid sequence induction (RSI) 2.Total intravenous induction (TIVA)

6. RSI Uses predetermined dose of intravenous anaesthetic agent+rapidly acting Muscle relaxant Used in individuals with high risk of regurgitation Secures airway quickly Needed in: Emergency surgery Non Emergency Surgery patient with delayed stomach empying

7. TIVA Uses propofol and ultrashort acting opioid remifenta nil Advantages : Lack cumulative effect Better hemodynamic stability Excellent recovery profile Used routinely in: Neurosurgery Airway laser surgery Cardiopulmonary bypass Day case anaesthesia

8. Maint enance of anaesthesia done using continuous infusion of intravenous agents -propofol or inhaled vapour-isoflurane,sevoflurane,desflurane NITROUS OXIDE have weak anaesthetic and analgesic property Postoperative nausea and vomiting Increases size of air bubbles Mutagenic Greenhouse gas

9. Management of ventilation during anaesthesia General anaesthesia Loss of Muscle tone Unable to keep the air way open with the use of muscle relaxant,patient unable to breathe by their own,so need artificial ventilation

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11. Supraglottic airways 1.Laryngeal mask airway(LMA) - first generation supraglottic airway -mask with an inflatable cuff is inserted via the mouth and produces a seal around the gl ottic opening -less irritating -less traumatic to patients airway -can be easily taught to Non anaesthetist and paramedics -used as emergency airway management tool

12. Types First generation LMA Classic LMA Flexible LMA Second generation LMA - good safety and efficacy than 1st generation ProSeal LMA i-gel Modified versions of LMA In cubating LMA(ILMA)

13. Endotracheal intubation - feasible in most patient -But complications are present

14. Muscle relaxation Neuromuscular blocking agents blockage of neuromuscular transmission Relaxation of muscles Easy surgical access

15. 2 Types 1.Depolarising agents Depolarising agents Bind to nicotinic acetylcholine receceptors Opening of cation channels Depolari zation Rapid relaxation of muscles

16. 2.Non Depolarising agents Non Depolarising agents Competitive blockade of postsynaptic receptors at NMJ Longer,predictable activity. Reqire careful monitoring

17. Ventilation during anaesthesia Mechanical ventil ation required when i)patient‘s spontaneous ventilation is inadequate ii)patient is not breathing because of effect of anaesthetic,analgesicagents or muscle relaxants

18. Monitoring and care during anaesthesia Cardiovascular paramet er monitoring are required in surgery Vascular ECG Blood pressure Adequacy of ventilation Inspired oxygen concentration Oxygen saturation by pulse oximetery End tidal carbon dioxide concentration

19. Others are Monitoring of temperature, ventilation parameter and delivery of anaesthetic agent routinely used Measurement of urine output and central venous pressure recommended for major surgery

20. THANK YOU