BASIC INTUBATION & EXTUBATION FOR GA NURSES & AA.pptx

BASIC INTUBATION & EXTUBATION FOR GA NURSES & AA

1. BASIC INTUBATION & EXTUBATION FOR GA NURSES & ANAESTHETIST ASSISTANTS SN NURUL FADHILATUL NABILAH GENERAL OPERATION THEATRE (PERIANAESTHESIA)

2. In this topic, we will learn : Anatomy & Physiology of respiratory system GA Machine vs Ventilator Intubation & LMA Rapid Sequence Induction 7P’s of Induction Emergence & Extubation

3. ANATOMY & PHYSIOLOGY OF RESPIRATORY SYSTEM

4. To bring oxygen from the external environment to the tissues in the body To remove carbon dioxide produced from the cell metabolism out from the body Functions in acid-base balance Act as a host defense – protect airway and lungs from materials such as dusts, smoke etc Functions of respiratory systems

5. Physiology Breathing brings air into the lungs where gas exchange takes place in the alveoli through diffusion. The body's circulatory system transports these gases to and from the cells, where cellular respiration takes place. The respiratory tract is the path of air from the nose to the lungs. The mechanics of respiration : inspiration and expiration. Breathing is an active process - requiring the contraction of skeletal muscles. The primary muscles of respiration include the external intercostal muscles and the diaphragm.

6. Airway Upper airway – mouth, nose until vocal cord Lower airway – vocal cord and below The lung has two separate blood supplies Pulmonary circulation – brings deoxygenated blood from right ventricle to the gas exchanging units (alveoli) Bronchial circulation – arises from the aorta and provides nourishment to the lung parenchyma

7. DEAD SPACE PHYSIOLOGY Definition : Portion of inspiration organ that does not contribute in gas exchange Mechanical Dead Space Functional Dead Space Anatomical Dead Space Pathological Dead Space Circuit HME ETT Trachea Bronchus Bronchi Healthy alveoli Unhealthy alveoli Eg : ex covid, COPD

8. PHASES OF ANAESTHESIA

9. Preinduction Begins with premedication administered and end when anaesthesia induction begins in OT Induction From consciousness to unconscious Maintenance As surgery takes place during this moment, it requires maintenance of physiological function by anaesthetist Emergence As surgery is completed (start to wake up), restoration of gag reflex, extubation Recovery When patient returns to full consciousness, monitor in recovery area or PACU unit

10. GA MACHINE VS ICU VENTILATOR

11. GA Machine Rebreather system- exhaled breaths flow back through the breathing system and recycled through the CO2 absorber Bellows / Piston Mixes anaesthetic gases and vapours Not for long term ventilation – need calibration every 24 hours Do not have ability to generate alerts to the hospital nurse call system Auxillary Common Gas Outlet (ACGO) – switched between the circle system and ACGO, bypass the ventilator including the APL and reservoir bag , used to anaesthetize very young babies via Mapleson F Scavenging system Nitrous Oxide + Oxygen + Air wall hose & cylinder Suction unit, APL Valve Breathing system - (Bain/Ayres T-Piece/Circle) Haemodynamic monitor attached to machine, Ventilator setting interface Auxillary oxygen supplement, Emergency mode Flowrate / some machine have both FiO2 & Flowrate setting Basic ventilation modes + newer machine have advanced modes and setting (APRV, VAPSV, Minute Volume Guarantee etc )

12. ICU Ventilator Non rebreather system – exhaled breaths are always vented to the atmosphere Can be use for long term ventilation Oxygen hose, some have O2 & Air wall hose Ventilator setting interface Some models have humidifier Fi02 setting Can connect with hospital nurse call system and monitor Basic ventilation mode – CPAP, SIMV, AC, PC, VC, APRV

13. Why fasting is important before anaesthesia ? Re duces the risk of aspiration due to muscle relaxation Helps with bowel preparation, which is a process of completely emptying your digestion tract to protect from infection due to food. This is required for some gastrointestinal surgeries. L owers the chance of postoperative nausea and vomiting (PONV), which can cause dehydration, discomfort, and delayed recovery.

14. PREPARATION CHECKLIST (Association of Anaesthetists of Great Britain & Ireland)

15. LMA / SGA INSERTION

16. DEFINITION Single-use or reusable supraglottic airway devices  that may be used as a temporary method to maintain an open airway during the administration of anesthesia or as an immediate life-saving measure in a difficult or failed airway

17. INDICATION OF LMA INSERTION Surgery – to provide amnesia during short surgery (using volatile agents) Difficult intubation or bag mask As backup device if intubation attempt failed

18. CONTRAINDICATION OF LMA Inability to open the mouth Pharyngeal pathology Airway obstruction at or below the larynx Low pulmonary compliance or high airway pressure Full stomach (intestinal obstruction etc )

19. COMPLICATIONS OF LMA Aspiration Gastric insufflation Partial airway obstruction Coughing Laryngospasm Post removal stridor

20. PREPARATION OF LMA INSERTION Step 1 : Size selection Step 2 : Examination of the LMA Step 3 : Check deflation and inflation of the cuff Step 4 : Lubrication of the LMA Step 5 : Position the airway

21. 1 st Generation 2 nd Generation 3 rd Generation ( Baska )

22. Intubating LMA

23. INTUBATION

24. DEFINITION Introduction of an ETT into the trachea for means of ventilation

25. INDICATION OF INTUBATION Anaesthetic Airway protection from soiling by blood, gastric contents Restricted access to patient (prone, head and neck surgery) Muscle relaxation required (abdominal surgery) Thoracotomy/intra-thoracic surgery) Obesity Failure of LMA insertion Surgery – to provide amnesia during surgery (using volatile agents) Non- anaesthetic Apnea and impending respiratory arrest (progressive respiratory acidosis, cvs instability, altered mental state) Pulmonary toileting (allow aspiration of sputum and secretions) To secure airway ( unsconscious , airway obstruction, impaired laryngeal reflexes) Facial and upper airway abnormality with impending obstruction (burns, trauma, edema) Cerebral protection (trauma, increase ICP) Fail trial of NIV CPR

26. COMPLICATIONS OF ETT INTUBATION Jaw dislocation Laryngeal injury Epistaxis (nasal intubation) Obstruction, dislodgement or kinking of ETT Aspiration following extubation Esophageal intubation Vocal cord trauma Prolonged Intubation Tracheal stenosis Laryngeal stenosis Vocal cord ulcer and granulomata

27. RAPID SEQUENCE INDUCTION

28. Method of induction which involves the simultaneous administration of a potent induction agent followed immediately by a rapid onset neuromuscular blocking agent to render an immediate unconsciousness and motor paralysis for emergent endotracheal intubation The goal is to achieve intubation with adequate level of paralysis and sedation within 45-60 seconds after the drugs are given intravenously DEFINITION

29. INDICATION In emergency airway management for intubations not anticipated to be difficult Patient who are at risk of regurgitation or aspiration Inadequate fasting time Abdominal pathology (ileus, intestinal obstruction) Delayed gastric emptying (trauma, in pain, opiods , alcohol) Incompetent lower esophageal spinchter (hiatus hernia, GERD) Altered level of consciousness (GCS <8) Pregnancy, in labour or morbidly obese

30. CONTRAINDICATION Anticipated difficult airway – need more time to preoxygenate Unconscious patient Apnoiec patient

31. AIM OF RSI Optimize intubation condition Minimize the risk of gastric content aspiration by performing cricoid pressure and avoiding positive pressure ventilation until after intubation is accomplished Minimize the time between induction and intubation

32. Classic/Standard RSI Dose of each agent is precalculated to achieve the desired effect Does not involves titration of either agent to reach the desired state Induction agent: STP (rapid onset) / Propofol NMB : Suxamethonium (rapid onset & offset) 45 secs, minimizes the risk of aspiration and hypoxia How to know patient fully paralyzed? Fasciculation Modified RSI Involves titration of either agent to reach the desired state Dose of agent used maybe less than pre-calculated dose Use on certain group of individuals Septic, ill, frail, elderly, neonate, hypovolemic, hyperkalemic) Induction agent : ketamine, midazolam, propofol NMB : Rocuronium 1mg/kg (rapid onset 1-2mins, can avoid sux multiple side effects)

33. Bag-mask Ventilation / PPV BMV causes gastric insufflation – risks of regurgitation and aspiration BMV is unnecessary if patient is adequately preoxygenated May require in a situation where hypoxia occurs prior to intubation (SPO2 <90%) while still maintaining cricoid pressure

34. 7 P’S OF INTUBATION

35. POST INTUBATION MANAGEMENT PLACEMENT OF PROOF PROTECTION WITH POSITIONING PARALYSIS WITH INDUCTION PRETREATMENT PREOXYGENATION PREPARATION

36. PREPARATION Patient Airway assessment and backup plan to manage unanticipated problems with intubation such as advanced airway adjunct – CMAC, BMV, AFOI, Bougie, Cooks airway etc Haemodynamic monitoring Intravenous access Drugs Equipment MALES (don’t forget MDI Salbutamol+connector , also in M – ALWAYS PREPARE) Personnel - Anaesthetist , staff nurse, AMO etc

37. PREOXYGENATION Proses of denitrogenation – to replace the nitrous volume of individual functional residual capacity with oxygen Increases the oxygen reserve in the lungs, blood and other tissues in preventing anticipated hypoxemia during apnea following muscle paralysis Benefit : Ability to tolerate a longer period of apnea without oxygen desaturation

38. PHYSIOLOGY Air in the lungs contains 78% nitrous, by replacing them with oxygen, this provides and extra oxygen reservoir of 0.8x the volume of the preexisting FRC (21% O2, 78% N, 0.93% Argon, 0.03% CO2, 0.17% other gases) In anaesthetized patients, oxygen consumption is fairly constant at around 250ml/min (those without CVS n respiratory disease/sepsis) Without preoxygenation : desaturation > than 90% occur after period of apnea of >2 minutes Full preoxygenation : FRC can provide 10 minutes of oxygen supply before desaturation to <90% during period of apnea

39. METHOD Administer high flow oxygen 100% via a tight fitting non rebreathing anaesthesia face mask – 3-5 minutes on a spontaneously breathing patient If time is an issue – preoxygenation will sufficient just 4-6 vital breaths How to confirm adequacy of preoxygenation : Look at Et02 at the monitor : aim >90%

40. INEFFECTIVE PREOXYGENATION Claustrophobic Self-inflating, non rebreathing BMV : does not deliver 100% oxygen in a spontaneously breathing patient Edentulous : inability to fit the mask properly leading to leakage of gas

41. Technique Maintain airway patency during preoxygenation Head tilt Hand is placed on patient’s forehead and firm backward pressure is applied Relieves minor obstruction Chin lift Using other hand, the chin is gently lifted to displace the tongue anteriorly Jaw Thrust Patient’s bilateral ascending rami of the mandible just beneath the earlobes are firmly grasped and pulled forcefully upward (anteriorly) with both hands Lower teeth will reside in the front of the upper teeth Resembles the triple airway maneuver (mandibular advancement, head extension and mouth opening)

42. Airway maneuver during preoxygenation (Hold mask) C-E Clamp Operator at the head end of the patient Mask’s cuff must fit and cover the patient’s bridge of the nose and mouth Place left thumb and index finger around the port or chimney of the mask ( C portion) Lower three fingers are spread to hold the patient’s mandible and its inferior angle (E portion) while concurrently giving An upward force against the anaesthesia face mask Perform a downward tight seal (clamp portion) of the anaesthesia face mask to ensure there’s no leak under the cuff while the right hand squeezes the anaesthetic mask/ ambu bag for ventilation

43. Signs of successful seal and ventilation A foggy mask Chest rise with delivery of positive pressure ventilation (PPV) Breath sounds on auscultation A firm/taut/full bag Return of CO2 on exhalation capnography

44. PRETREATMENT Administration of certain medication in order to counter or minimize the adverse effects of laryngoscopy and tracheal intubation Examples : Atropine 20mcg/kg : blunts vagal stimulation in infants less than one year of age Lignocaine 1.0-1.5 mg/kg : blunt sympathetic effects Fentanyl 1.0-2.0mcg/kg : blunt CVS effects and increase in ICP

45. PRE-INDUCTION Administration of induction agent to achieve unconsciousness and amnesia Examples : Midazolam : usually use on very sick, ill patient, use in cardiac induction. Can cause resp depression as it slows down the brain activity to allow relaxation, can cross placenta Premed : 0.07-0.1mg/kg Induction : 0.3mg/kg ↓ Resp Propofol : Can be use in TIVA, RA sedation. Can cause apnea. Not for hypotensive patients as propofol can vasodilate vessels, can cross placenta Dosage : 2.0-2.5mg/kg onset 40-50 secs ↓↓ BP, ↓ HR Sodium Thiopentone : can be used in CP, pregnant woman due to rapid onset of sedation, short duration of action and hypnosis ( not crossing placenta but cross breast tissues) Dosage : 3.0-7.0mg/kg onset 30-40secs ↓ BP, ↓ CO, ↑HR

46. Usage of NMB agent to achieve motor paralysis Rocuronium 0.9-1.2mg/kg in RSI, 0.6-0.9 mg/kg if non RSI, onset 1-2 mins (maintenance dose 0.1mg/kg) Suxamethonium 1.0-2.0mg/kg , onset 30-60 secs Usage of other NMB for non urgent, elective induction Atracurium 0.4-0.5mg/kg, onset 3-5 mins (maintenance dose 0.1mg/kg) Cisatracurium 0.15-0.4mg/kg, onset 3-5 mins (maintenance dose 0.02mg/kg) PARALYSIS

47. Protection of the airway from aspiration prior intubation by applying cricoid pressure and avoiding positive pressure/BMV (in RSI) Invented by Brian Sellick in 1961 – hence the name Sellick Manouvre Apply a firm downward digital pressure (thumb and index/middle finger) on the cricoid cartilage (C5 level) resulting in esophageal compression between the cricoid cartilage and the anterior surface of the cervical vertebral body BURP technique – Invented by Knill in 1993 (backward, upward, rightward, pressure - BURP) PROTECTION WITH POSITIONING

48. Cricoid cartilage is used as it is the only complete cartilage ring of the larynx and trachea Force applied approximately 20N=1KG, increase further to 30N-40N once patient unconscious as it may adequate to cause occlusion of the esophagus Prevents passive regurgitation of gastric and esophageal contents during induction Should be sustained until the ETT placement is confirmed and the cuff is inflated Avoid in patient who is actively vomiting as can result in esophageal rupture

49. PLACEMENT WITH PROOF Once paralyzed = laryngoscopy for intubation / insertion of LMA Placement is confirmed via : Direct visualization of ETT through the vocal cords Auscultation of the lungs and epigastrium (5 point) Symmetrical chest movement on each PPV Capnograph or EtCO2 tracing Vapor on the internal side of ETT during exhalation Fibreoptic visualization of the tracheal rings and carina Chest X-Ray In RSI, cricoid pressure can be removed once confirm placement Tidal volume achieved 6-8mls/kg

50. Two types of grading/classification : 1. Cormack- Lehane (via direct visualization) 2. VCI Scoring (via video laryngoscopy) INTUBATION CLASSIFICATION / GRADING

51. Secure the ETT at an adequate length Initiate volatile agent (to ensure amnesia throughout surgery) and mechanical ventilation Manage post intubation complications Administer longer acting NMB agent CXR to confirms the depth of ETT (tip of ETT should be 2cm above carina) POST INTUBATION MANAGEMENT

52. DIFFICULT AIRWAY ALGORITHM (DAS)

53. MNEMONICS EXPLANATION TV/ VT Tidal volume – volume produced during inhalation & exhalation 6-8mls/kg PEEP Peak expiratory end pressure – end pressure that holds alveoli from forcibly shut/fully closes 6-12 cmH20 RR/ F Respiration rate/ Frequency 12-18 / min PS Pressure Support 2x PEEP or 10-16 cmH20 FiO2 Fractional Inspired Oxygen 50% or 0.5 , adjusted accordingly to ABG or 100% during preoxygenation IP Inspiratory pressure – highest pressure applied on lungs during inhalation, amount set depending on modes of ventilation Peak Airway Pressure If more than 30 indicates high pressure or obstruction during ventilation Pressure limit Set not more than 30 cmH20

54. Stages of Amnesia ( Guedel 1937) Stages State Explanation 1 Amnesia Time from induction to loss of consciousness Loss of eyelash reflex 2 Excitement Irregular breathing Struggling Increase risk of laryngospasm 3 Surgical Anaesthesia Constricted pupils Regular breathing No movement 4 Overdose Hypotension, apnea Dilated/non-reactive pupils (pin-point)

55. EMERGENCE & EXTUBATION

56. EMERGENCE Critical recovery process by which the body physiology gradually returns to its baseline function (regain consciousness, neuromuscular function and airway protective reflexes) after cessation of general anaesthetic region

57. Physiological response during emergence CVS : Hypertensive and tachycardia (detrimental in coronary artery disease as it can reduce the ejection fraction Respiratory : Diaphragm regain it’s ability to contract and relax spontaneously Coughing/bucking : a forceful cough almost like Valsalva maneuver (may cause sudden increase in intrathoracic pressure which leads to reduce venous return) Neurology : May increase the ICP (detrimental in head injury patients) Endocrine : Transient increase in adrenaline release

58. Extubation can be done either patient Awake Airway reflexes returned, eyes open upon instruction, able to lift up the head and presence of spontaneous ventilation May demonstrate hypertension, tachycardia, coughing/ bucking due to the awareness of ETT in situ Respiratory complications are minimized via this method Deep While patient is still anaesthetized (Et Sevoflurane >3%) Presence of spontaneous ventilation but no return of airway reflexes Decrease in cvs stimulation, reduces the incidence of coughing, bucking but greater incidence of respiratory complications such as Laryngospasm Airway obstruction – due to pooling of secretions and relaxed tongue Micro-aspiration post extubation due to late return of pharyngeal reflex

59. Position of extubation Supine Left lateral – keep tongue away from posterior pharyngeal Semi upright Head-down wall Extubation performed after patient has been adequately reversed, vaporizer turned off, spontaneous breathing seen Reversal drugs : Neostigmine + Atropine Neostigmine + Glycopyrolate – glyco commonly used when reversing elderly patient to minimizes agitation and confusion, does not cross blood-brain barrier) Sugammadex (reversal for Rocuronium only)

60. Criteria For Extubation EtCO2 normal range : 35-45 SPO2 normal range 95-100% Spontaneous breathing seen, regular pattern – 1 st muscle to regain it’s function is diaphragm RR : 12-18/min Pupil at the centre MAC lower than 0.3 Gag reflex present Return of normal limb power, able to lift up both upper and lower limb, able to lift up head more than 5 seconds Able to obey command and open eyes

61. Steps for extubation Administer 100% oxygen, increase flow rate, inhalational agent is stopped at the end of operation (if planning for awake extubation ) Suctioning of oropharynx to keep airway patent Insert bite block or OPA to avoid patient from biting the ETT Deflate ETT cuff Simultaneous application of positive pressure to the reservoir bag and removal of ETT Suction any residual oral secretions Apply face mask Observe and look for airway compromise post extubation LMA removal – no need to deflate cuff as any residual secretions that pooled above LMA can be removed simultaneously

62. Leak test Deflate ETT balloon and listen with stethoscope at the mouth If sound present (which means airway wall is not swollen- this can cause airway obstruction if ETT taken out) , can proceed with extubation Positive leak test = sound heard Negative leak test = very minimal sound or no sound heard – DO NOT EXTUBATE

63. Complications with ETT extubation Glottis or subglottic edema Hoarseness of voice Subglottic or tracheal stenosis Vocal cord granuloma and paralysis Vocal cord trauma