Makindo Medical Notes

Patients do not die from a failure to intubate. They die from HYPOXIA due to failure to stop trying to intubate.

About

• Administration of a potent IV induction agent followed immediately by a rapidly acting neuromuscular blocking agent to induce unconsciousness and motor paralysis to facilitate tracheal intubation.
• RSI is the standard technique for definitive emergency airway management in the emergency department to allow intubation while minimising the risk of pulmonary aspiration.

Reasons for Rapid Sequence Induction (RSI)

• Airway Protection: To prevent aspiration of gastric contents in patients at high risk of aspiration (e.g., trauma, decreased level of consciousness, or gastrointestinal bleeding).
• Emergency Airway Management: In patients requiring urgent intubation due to respiratory failure, hypoxia, or impending airway obstruction.
• Severe Trauma: For head injury, spinal injury, or multisystem trauma where airway control is crucial to prevent hypoxia.
• Decreased Level of Consciousness: In patients with altered mental status or coma where airway reflexes are compromised.
• Inadequate Oxygenation or Ventilation: In patients with respiratory distress or failure, RSI ensures rapid and controlled airway management.
• Severe Sepsis or Shock: When patients need immediate airway control due to hemodynamic instability.
• Acute Poisoning or Overdose: When airway management is necessary due to respiratory depression or compromised airway reflexes.
• Burns or Airway Edema: Inhalation injuries or facial burns can lead to airway swelling, necessitating early intubation.
• Inability to Protect Airway: In cases such as stroke, seizures, or neuromuscular disorders where patients cannot maintain airway patency.

Difficult Airways

Induction Agents Used

• Thiopentone: Historically the gold standard induction agent for RSI because of its rapid action and efficacy, but it can cause depressed cardiac and respiratory function.
• Propofol: Has a rapid onset of action and potently attenuates pharyngeal, laryngeal, and tracheal reflexes. However, it causes significant reduction in systemic vascular resistance (SVR) and blood pressure (BP).
• Etomidate: Increasingly used for RSI of ED patients due to its rapid onset of anaesthesia, haemodynamic stability, cerebral protective properties, and lack of respiratory depression.

Paralysis with Induction

• Suxamethonium: The most commonly used neuromuscular blocking agent (NMB) for emergency RSI, having a rapid onset and short half-life.
• The dose of suxamethonium in RSI is 1.5 mg/kg.

Issues

• All induction agents have the potential to cause myocardial depression and secondary hypotension.

Pre-oxygenation

• Pre-oxygenation involves providing high concentration oxygen to the patient for ideally 5 minutes prior to the procedure.
• This builds up a reservoir of oxygen in the lungs to allow a period of apnoea during RSI.
• If 5 minutes of preoxygenation is not possible, 8 vital capacity breaths (the largest breaths the patient can take) should be performed.
• This helps patients with normal lungs maintain oxygen saturations over 90% for several minutes.

Environment

• Clinical area: resuscitation room.
• Monitoring: ECG monitor, BP, SpO₂, capnography.
• Intravenous access: Preferably two IV lines.
• Position: The patient should be positioned to optimise access for intubation.
• Drugs: Should be drawn up in labelled syringes and checked by medical staff.

Equipment

• Two functioning laryngoscopes with appropriate blades.
• Endotracheal tubes: Test cuff inflation and have smaller sizes ready. Male size: 8 to 9 mm, Female size: 7 to 8 mm.

Placement and Proof

• Intubation should be performed carefully and gently. The larynx is visualised and the endotracheal tube (ETT) is placed. The stylet, if used, is then removed and the cuff inflated.
• Tube position is confirmed by visualising the passage of the ETT between the cords, listening to both sides of the chest, and over the stomach.
• Assess end-tidal CO₂, the most reliable method for confirming correct tube placement.
• Cricoid pressure should be discontinued once the intubator confirms correct tube placement.
• If intubation cannot be achieved, oxygenation should be maintained using basic airway manoeuvres and bag-mask ventilation. Further attempts at intubation can then be made safely.
• If intubation fails, revert to basic airway management using bag-mask-valve ventilation with 100% oxygen until a definitive airway can be secured.

Post-Placement

• After tube placement is confirmed, secure the ET tube with ties or tape. Measure and report the patient's blood pressure to the team leader.
• Mechanical ventilation should be initiated. Obtain a chest X-ray to confirm ET tube position and assess the lungs.

Priorities in the Failed Airway Situation

• Call for the most senior assistance available (e.g., Consultant in A&E, ICU, Anaesthetics, ENT, +/- difficult airway trolley).
• Assess whether oxygenation is adequate.
• If oxygenation is adequate and the patient can maintain saturation >90% with bag-mask ventilation, alternative techniques (e.g., fibreoptic scope) may be used.
• If oxygenation cannot be maintained, revert to GOOD basics while preparing for a surgical airway.
• Use high-flow oxygen via anaesthetic circuit or BVM, suction/OPA/NPA, proper head positioning, and 2-person ventilation technique. Consider using an LMA.

Failed Intubation

• If intubation fails, provide high concentration oxygen and revert to GOOD basic airway opening manoeuvres, using assistance and adjuncts as necessary.
• If oxygen saturation improves and remains >90%, the expert may attempt further intubation, considering changes in technique, equipment, or patient positioning.
• If oxygen saturation cannot be maintained despite optimum basic airway management, prepare for a surgical airway (needle or surgical cricothyroidotomy).

Post-Intubation Management

• After confirming tube placement, secure the ET tube and measure blood pressure. Report findings to the team leader.
• Initiate mechanical ventilation and obtain a chest X-ray to confirm tube position and assess lung status.

References

• Guidelines on RSI