Preoperative Assessment and Resuscitation

1. Airway Preoperative Assessment and Resuscitation Dr Mark Lambert FRCA Specialty Registrar in Anaesthesia University College London Hospitals

2. Managing the airway • It’s as easy as… • A – Airway • B – Breathing • C - Circulation

3. Airway • First in the hierarchy of survival • Anaesthetists have the leading role for airway management in hospitals • Most airways are easy!

5. Learning outcomes • Recognise airway anatomy • Prepare a framework for managing the airway in theatres • Discriminate easy and difficult airways • Outline plans for failed airway management

6. Anatomy

7. The Glottis

8. Why do anaesthetists need to manage the airway? • Anaesthetic drugs • Depress/abolish airway reflexes • Cause relaxation of upper airway muscle tone • Cause respiratory depression / apnoea • In an emergency • Acute airway obstruction • Failure to oxygenate/ventilate

9. A typical anaesthetic • Mrs Miggins is about to have her hip fixed • You give your best anaesthetic • 5 seconds later : she’s asleep • 15 seconds later : apnoea • What are you going to do next?

10. Ventilate Call for help Fibreoptic laryngoscopy Put in an LMA Go for coffee Tracheostomy Cricothyroidotomy Intubate Ask your ODA/ODP/anaesthetic nurse to bail you out Start the crossword

11. But always make sure that you can… Oxygenate

12. Facemask ventilation • Important (and harder than it looks) • One person / two person • Adjuncts • There’s always a backup self-inflating bag in theatre and the anaesthetic room in case of anaesthetic machine failure

13. Facemask ventilation adjuncts • Oropharyngeal airway • Size : Incisor to angle of jaw (or ask your ODA)

14. Facemask ventilation adjuncts • Nasopharyngeal airway • Size : Patient’s little finger • Use plenty of lube (and go carefully if you suspect basal skull fracture)

15. Back to Mrs Miggins • She’s easy to facemask ventilate • Will we hold a mask on her face for the entire case? • Other airway options include • Laryngeal mask airway • Endotracheal tube

16. Laryngeal mask airway (LMA) • Blind insertion • Cuff to improve fit • Hands free • Sits above the glottis • Variety of second generation devices available but all work on a similar principle

17. LMA position • Like a facemask over the larynx • Doesn’t protect against aspiration of gastric contents

18. Endotracheal tube • “A secure airway is a cuffed tube in the trachea” • Allows ventilation • Protects against aspiration • Normally placed under direct vision (laryngoscopy)

19. Laryngoscopy • Uses a metal blade with a light source to create a direct line of sight to the glottis • Can be stressful (for you and the patient) • Laryngoscopes come in a variety of shapes and sizes

20. The view from a laryngoscope

21. Recognising when airway management is going to be difficult • History • Previous anaesthetic problems • Congenital disorders associated with difficult airway (Anatomy) • Co-morbid conditions (Pathology) • Examination • General appearance • Specific tests • Special investigations • Rarely used (nasal endoscopy/CT)

22. Specific airway tests • Mallampati • Mouth opening • Neck movement • Thyromental distance • Jaw protrusion

23. Sometimes it’s obvious

24. But…. • Tests are notoriously unreliable and focus on difficult intubation • Difficult facemask ventilation is often more worrying than difficult intubation • Beards / big neck / high BMI / Elderly • Trust your instincts! • Ask for senior advice or help early

25. Planning for failure • Always have a plan B for managing the airway (and communicate this to the rest of the team) • If not possible to place an endotracheal tube what next? • Plan B – LMA (and call for help) • Plan C – Facemask ventilation + Guedel • Plan D – Emergency cricothyroid puncture • Guidelines exist to help plan for the unexpected but it’s much easier if you’ve identified trouble beforehand

27. Extubation • Taking the airway device out can be as risky as putting the device in • Increasing recognition of this • Improved training • Guidelines (Difficult airway society) • If you had difficulties at intubation then extubation also likely to be troublesome…

28. Key Points • Always think ‘oxygenation’ • Consider whether mask ventilation or intubation (or both!) will be a problem • Trust your instincts • Have a back-up plan ready and make sure everyone else knows what it is

29. Learning outcomes • Recognise airway anatomy • Prepare a framework for managing the airway in theatres • Discriminate easy and difficult airways • Outline plans for failed airway management

30. Please ask your questions now…. Thank you