Rapid sequence intubation
- 1. Rapid Sequence Intubation Presented By Dr. Md Imtiaz Hossain Bhuiyan HDU DOCTOR| IQARUS | MedicalTreatment Facility / IQARUS - Cox’s Bazar – Bangladesh Mobile +8801324-404020| Mail: Imtiaz.Bhuiyan@iqarus.com
- 2. Introduction Rapid sequence induction is intended to achieve a definitive airway rapidly so as to minimize risk of airway soiling and achieve rapid control of ventilation. The intent is to create the best intubating conditions possible. Conduct of RSI requires a disciplined team approach with careful planning, role delineation and consideration of patient factors such as anatomy and pathology. Planning should factor into consideration difficult or failed intubation with a clearly articulated plan.
- 3. Patient Assessment The patient must be assessed as best possible for predictors of difficult intubation whilst remaining cognisant of the fact that many difficult intubations have no obvious predictors. All emergency intubations should be considered potentially difficult. Several anatomical measures have been helpful in predicting difficulty, these may be summarised in the mnemonic LEMON
- 4. Patient Assessment : LEMON L - Look for anatomical indicators of difficult intubation; large tongue, protruding teeth, beard / moustache, large breasts. E - Evaluate 3-3-2; measure mouth opening 3 fingers width, hyoid- mental distance 3 fingers width, thyro-hyoid distance 2 fingers width. Variations on these distances may predict difficulty. M - Mallampatti, in practice this may not be possible in the emergency setting as evaluation involves a cooperative seated upright patient. O - Obstruction look for evidence of airway obstruction, injury (facial or soft tissue neck), masses, swelling, foreign bodies, scarring, stridor, dysphonia N - Neck mobility, c-spine precautions, rheumatological conditions (RA, Ankylosing spondylitis, surgical fusion), previous radiotherapy.
- 6. Mallampatti Score According to the Mallampati scale, class I is present when the soft palate, uvula, and pillars are visible; class II when the soft palate and the uvula are visible; class III when only the soft palate and base of the uvula are visible; and class IV when only the hard palate is visible. A Mallampati score of III or IV is typically indicative of a higher rate of obstruction in airway as a result of enlarged tonsils or adenoids and poor Myofunctional activity (swallowing pattern and tongue position at rest) and tongue-tie.
- 7. Preparation & Equipment Patient preparation includes positioning, pre-oxygenation, ensuring adequate monitoring and lines in place. Consideration should also be given to access to the patient, ideally 360° access. The optimal position for intubation is one in which the patient’s external auditory meatus is aligned with the sternal notch in the vertical plane. This is also known as the ramped position; in obese patients this may require a number of pillows and towels positioned under shoulders and neck.
- 8. Preparation & Equipment If cervical spine injury is suspected the ramped position is not possible, a person must be allocated the role of manual in-line stabilization of the neck. This will allow the collar to be removed for intubation but still makes for a more difficult intubation than would otherwise be the case. The goal of pre-oxygenation is to maximize oxygenation and flush out nitrogen from the lungs and ensure a greater reservoir of oxygen available for gas exchange whilst apnoeic. Pre- oxygenation is generally achieved by spontaneous breathing high flow oxygen via a face mask, usually for a minimum of three minutes.
- 9. Preparation & Equipment Be aware that for effective pre-oxygenation with a bag- valve-mask apparatus a patient must be able to generate sufficient negative pressure to open the valve, for many patients this may be difficult, and a non-rebreather mask will be better. A patient with ineffective breathing may need to be assisted to achieve adequate pre-oxygenation with assisted breaths applied via B-V-M with PEEP valve (with cricoid pressure in place) or via Noninvasive Ventilation. In addition to pre-oxygenation the practice of applying high flow oxygen via nasal prongs to the apnoeic patient may buy further time for intubation prior to desaturation.
- 10. Preparation & Patient All personnel should be assigned specific roles and confirmation that they understand these roles be sought. Roles may include, depending on numbers available: Intubator : Makes plan, executes intubation / airway procedures, maintains situational awareness. Airway assistant: Runs check list with intubator , passes equipment and anticipates next step according to plan, monitors time and patient. Drug administration: Very explicit instructions must be given explaining what is in syringe, what volume is to be given (mark the syringe if necessary), ensure line free flowing and drugs do not flow back up into bag. Instruct regarding order of administration, speed and flushing.
- 11. Preparation & Patient Cricoid pressure: May not be used, often obscures airway, of doubtful benefit, if used have low threshold for removal when difficulties occur. Ensure operator knows how to perform, when to apply and when to release.
- 12. Cricoid Cartilage (Anatomical Position)
- 13. Cricoid pressure for RSI:
- 14. Continue: MILS (Manual In-Line Stabilization ): Ensure operator knows how to perform and is positioned such that will not interfere with access to airway, may be preferable with a caudal position. Scribe Runner
- 15. Induction & Paralyzing Induction agent and paralysis are given in pre-determined doses rapidly with generous flushes in between: If cricoid pressure is to be used it should commence as soon as there is loss of consciousness. If suxamethonium is used onset of paralysis will be indicated by fasciculation (this may be subtle) Do not ventilate the patient at this point.
- 16. Intubation and Confirmation of Placement Intubation should proceed promptly with a focus on maintaining oxygenation and prompt progression to failed or difficult intubation drill if failing. Tube placement is confirmed by a continuous ETCO2 waveform and seeing the tube pass through the cords. Both axillae and stomach should be auscultated in addition to checking ETCO2 waveform.
- 17. Anaesthetic Drugs - Induction agents Anaesthetic Drugs Induction agents Thiopentone – dose 1–3mg/kg Traditional gold standard for RSI due to rapid onset and predictable degree of anaesthesia. Side Effects hypotension Benefits head injuries (lowers ICP; anticonvulsant)
- 18. Anaesthetic Drugs - Induction agents Anaesthetic Drugs Induction agents Propofol – dose 0.5–2mg/kg Profound respiratory depressant. Side Effects More hypotensive compared with thiopentone (therefore not suitable for most emergency inductions). Benefits Useful as ongoing sedation for ventilated patient if plan is to awaken soon after admission.
- 19. Propofol - Rapid Sequence Intubation (Visual Presentation)
- 20. Anaesthetic Drugs - Induction agents Anaesthetic Drugs Induction agents Ketamine – dose 1-2mg/kg Dissociative anaesthetic (causes state of profound analgesia and anaesthesia where patient may appear awake). Airway reflexes are NOT preserved at induction doses. Mode of Action Causes increase in sympathetic activity resulting in increased BP , increased ICP and bronchodilation Indications Acute asthma, Profound hypovolaemic shock (eg. AAA). Contraindications Head injuries (relative) IHD.
- 21. Ketamine - Rapid Sequence Intubation (Visual Presentation)
- 22. Anaesthetic Drugs - Induction agents Fentanyl - dose 3μg/kg Short-acting opiate; profound respiratory depressant. Useful in combination with other induction agents (allows smaller doses to be used, causing less hypotension) Contraindications Avoid in shocked patients who are relying on their sympathetic to maintain their BP as fentanyl Abolishes this and can result in severe hypotension Advantage Prevents the rise in ICP from laryngoscopy in head injured patients Side Effects High doses can cause chest wall muscle rigidity and difficulty in ventilation (treat with suxamethonium).
- 23. Anaesthetic Drugs - Sedation agents Anaesthetic Drugs - Sedation agents Midazolam – dose 0.15mg/kg Slow onset of action and hypotension has resulted in it no longer being considered suitable for RSI. Side Effects Has amnestic and anticonvulsant properties. Advantage Useful in ongoing sedation of ventilated patient.
- 24. Anaesthetic Drugs - Sedation agents Anaesthetic Drugs - Sedation agents Morphine – dose 0.1–0.2mg/kg Sometimes used as an adjunct to other induction agents. Side Effects Less reliable respiratory depression and suppression of airway slow onset and hypotension Has meant it is no longer recommended for RSI. Useful with midazolam as ongoing sedation of ventilated patient.
- 25. Anaesthetic Drugs - Neuromuscular blockers Suxamethonium – dose 1-2mg/kg Non-competitive depolarizing neuromuscular blocker. IV administration leads to fasciculations 10–15 sec. Maximum paralysis 30–60 sec Return of spontaneous respirations 3–5 mins Full ventilatory capacity 8-10 mins.
- 26. Anaesthetic Drugs - Neuromuscular blockers – side effects Side effects of Suxamethonium Fasciculations leading to increased intragastric, intraocular & intracranial pressures (possible clinical significance). Increased serum K+ (up to 0.5mmol/L in average patient; up to 5-10mmol/L in patients with burns or crush injuries >48 hrs, or those with NM disorders. Patients with renal failure who are not hyperkaliaemic can be given suxamethonium) Bradycardia (especially children or repeated doses in adults)
- 27. Side effects of Suxamethonium Scoline apnoea (congenital absence of pseudocholinesterase results in prolongation of paralysis (hrs) – not a in most patients ventilated for transport as usually ventilated longer than this). Malignant hyperthermia (genetic skeletal muscle abnormality triggered by inhalational anaesthetics and suxamethonium to muscle rigidity and breakdown, autonomic instability, hyperkalemia and acute renal failure. Often fatal.) Treated with dantrolene.
- 28. Succinylcholine or Suxamethonium chloride Rapid Sequence Intubation (Visual Presentation)
- 29. Anaesthetic Drugs - Neuromuscular blockers Rocuronium – dose 1-1.5mg/kg (in RSI); 0.15mg/kg (Ongoing Relaxation) Competitive, non-depolarizing blocker. Indications as above but more rapid onset makes it an attractive option where suxamethonium contraindicated and rapid intubation conditions desirable. Intubating conditions in 60 sec.
- 30. Anesthetic Drugs - Neuromuscular blockers Rocuronium Duration 10-40 minutes. Sugammadex, used for rapid reversal. Preference for rocuronium over suxamethonium is a clinical based on a number of factors including patient issues, clinician experience and need to secure an airway by either oral or surgical means regardless. Minimal side effects.
- 31. Rapid Sequence Induction &Intubation (Rocuronium)
- 32. Anaesthetic Drugs - Neuromuscular blockers Vecuronium – 0.1mg/kg (Ongoing Relaxation) Competitive, non-depolarizing blocker Indications: intubation in patients where suxamethonium contraindicated, ongoing relaxation in ventilated patient IV administration→ onset of paralysis 90 sec
- 33. Frequently Asked Question? Scenario 1: A 17 years old boy came to ER department with A severe RTA with massive loss of blood. His BP is 80/60 mm of Hg. He also diagnosed Asthma 3 years ago. In this patient, Which induction agent is more preparable? Ans: Ketamine
- 34. Scenario 2 : A 33years old female lady came to our Iqarus MTF diagnosed as a case of Confirmed COVID-19, Temp 96.7 degree F, Pulse 60bpm, Spo2 81% in room air with breathing difficulties , RR 18bpmBp 126/65mmHg. Her body weight is 120kg. If there is need to do intubation of this patient what will be the drug of choice? Ans : Thiopentone / Thiopental Sodium
- 35. References 1. IQARUS guideline from QMS 2. WHO guideline of critical care management ( COVID-19 ) 3. USA guideline: https://www.covid19treatmentguidelines.nih.gov/management/ critical-care/ 4. National guideline on case management of COVID-19: http://www.mohfw.gov.bd/index.php?option=com_docman&tas k=doc_download&gid=22424&lang=en