Rapid Sequence Intubation (RSI)

by Qais Abuagla

Introduction

Airway management is one of the most important skills for an Emergency Department practitioner to master because failure to secure an airway can lead to mortality or morbidity. Therefore, all junior doctors and trainees should be aware of this procedure in the early of their career.

RSI is an advanced airway management technique that induces immediate unresponsiveness (induction agent) and muscular relaxation (neuromuscular blocking agent). It is the method of choice for intubations in the Emergency Department due to its high success rates and the fewest complications.

Indications for RSI

Failure of airway maintenance or protection or anticipated deteriorated clinical course
Failure of ventilation or oxygenation
Minimize oxygen consumption and optimize oxygen delivery (e.g., sepsis)
Prevent secondary brain injury or terminate seizure (status epilepticus)

Contraindication

Absolute

Total upper airway obstruction
Total loss of facial/oropharyngeal landmarks

Relative

Anticipating difficult airway
Cardiac/respiratory arrest (this will go to crash intubation)

Steps of RSI (7 Ps)

Preparation & Plan
Preoxygenation
Pre-treatment
Paralysis and induction
Protection and positioning
Placement with proof
Post-intubation management

1. Preparation

Equipment (tube, blade, Oxygen, suction, capnography, monitoring (ECG, BP, SpO2))
- Peds tube size: (age+4) /4 or use Braselow tape
- The depth of the tube: size x 3
Asses for difficult airway, and set plan B for failed airway
- Assessment of airway: Anticipating difficulty in establishing an airway in emergency patients is the first step in avoiding major complications. This helps us to think about alternatives of RSI. For example, neuromuscular paralysis should generally be avoided in patients with a high level of intubation difficulty.
- LEMON
  - L – Look externally: Look for external markers of difficult intubation; these may include the following body habitus, head and neck anatomy (short neck), mouth (small opening, loose teeth or prominent teeth), jaw abnormalities (significant malocclusion), and beards.
  - E – Evaluate 3-3-2: 3-3-2 rule is to assess the patient’s airway geometry to determine his or her suitability for direct laryngoscopy. Can the patient fit 3 fingers between the incisors? For optimum glottis visualization, an adequate mouth opening is required. Is the mandible length 3 fingers from the mentum to the hyoid bone? Submandibular space is adequate to accommodate the tongue making the visualization of the glottis easy. Is the larynx low enough in the neck to be accessible? The distance from the hyoid to the thyroid. 2 fingers are what we are looking for.
    - M – Mallampati: Oral access is assessed with the Mallampati scale. Visibility of the oral pharynx ranges from complete visualization, including the tonsillar pillars (class I), to no visualization at all, with the tongue pressed against the hard palate (class IV). Class I and class II predict adequate oral access, class III predicts moderate difficulty, and class IV predicts a high degree of difficulty.

- - O – Obstruction or obesity. Upper airway obstruction can make visualization of the glottis, or intubation itself, mechanically impossible. This may present as stridor, inability to swallow secretions or alteration in voice quality. Conditions such as epiglottitis, head and neck cancer, Ludwig’s angina, neck hematoma, foreign body or thermal injury can compromise laryngoscopy, the passage of the endotracheal tube (ETT), BMV, or all three.
  - N – The NECK mobility. Neck mobility is desirable for any intubation technique and is essential for positioning the patient for optimal direct laryngoscopy. Neck extension is the most important maneuver, and simple extension may be as effective as the “sniffing” position in achieving an optimal laryngeal view. Neck mobility can be significantly reduced in patients with trauma (cervical collar) or the elderly and those with arthritis.

Video – Equipment and Preparation

2. Preoxygenation

Three minutes on 100% nonrebreather mask or six vital capacity breaths provides 8 minutes of adequate oxygenation during apnea, but this time period decreases in pregnancy, obesity, and extreme of ages.

Maintaining SpO2 > 90% differs between patients.

Healthy 70 kg adult 8 minutes
Moderately ill adult 5 minutes
10 kg child 4 minutes
Obese adult 3 minutes
Very ill patient <2 minutes

3. Pretreatment

It is used to blunt the adverse effect of laryngoscopy and intubation but scant evidence

Medication of pretreatment

Atropine
- 0.02 mg/kg IV
- For all children <10 to prevent bradycardia
Fentanyl
- 2-3 mcg/kg IV
- For elevated ICP, myocardial ischemia, aortic dissection, subarachnoid hemorrhage
Lidocaine
- 1.5mg/kg
- For increased ICP and bronchospasm

Indication for pretreatment: PREMED

Pediatric
Resistance (asthma)
Elevated ICP
MI
Elevated BP
Dissection

4. Paralysis and Induction

You don’t want an awake paralyzed patient!!

First induction agent is given, then it is followed by a paralytic agent. The induction agents main aim is to induce rapid loss of consciousness to facilitate ease of intubation.

Medication for induction

Etomidate
- 0.2-0.3 mg/kg IV
- Rapid action, and short duration. It has no analgesic effect.
- It’s the most hemodynamically stable induction agent. This is an advantage over other agents in shock, anaphylaxis or any case where the further drop in blood pressure can be catastrophic.
- Etomidate has a potential cerebroprotective effect as it decreases cerebral metabolic oxygen consumption and reduces cerebral blood flow and intracranial hypertension while maintaining cerebral perfusion pressure
- Side effects are nausea, vomiting, myoclonus and adrenal cortical depression with multiple doses.
Ketamine
- 1-2mg/kg IV, 4-5mg/kg IM.
- NMDA receptor antagonist.
- Ketamine produces a loss of awareness within 30 seconds, peaks in approximately 1 minute, and has a clinical duration of 10 to 15 minutes.
- Many protective reflexes are preserved with Ketamine, including airway reflexes. Ketamine has a direct bronchodilator effect and causes catecholamine release. Therefore, it is mainly used in patients with asthma, anaphylaxis and hemodynamically unstable patients. Because of its features, it’s an excellent alternative to etomidate.
- Side effects are the raise of BP (avoid in elderly) and emergence phenomena (visual, auditory, proprioceptive and confessional illusions which may progress to delirium after waking up from sedation)
Propofol
- 1.5 to 2.0 mg/kg IV,
- It produces significant venous dilation, myocardial depression and can reduce cerebral perfusion pressure.
- Because of the propensity of propofol to cause hypotension, through both vasodilation and direct myocardial depression, the dosage is reduced, or the drug is avoided altogether in hemodynamically compromised patients.
Other agents: Benzodiazepines like midazolam and barbiturates like thiopental and methohexital

Paralytic agents

Neuromuscular blocking agent (NMB) are mainly divided into depolarizing agents (DPA) and non-depolarizing agents (NDPA)

Succinylcholine
- 1.5 -2 mg/kg.
- It is the only DPA used in the emergency room having a rapid onset and short half-life. It takes 45-60 seconds to induce paralysis and takes 8-10 min to recover.
- It can rise serum potassium levels, and is contraindicated in the following circumstances:
  - Hyperkalemia
  - Patient ≥5 hours post burn
  - Patient ≥5 days post crush injury or denervation
  - Neuromuscular diseases (amyotrophic lateral sclerosis, multiple sclerosis, muscular dystrophy)
  - Denervation (stroke, spinal cord injury) >5 days until 6 months post injury
  - Intra-abdominal sepsis >5 days until resolution
Rocuronium
- 1-1.2 mg/kg.
- NDPA.
- It has a comparable time to paralysis but a longer recovery time of 35-45 minutes. It can be reversed by Sugammadex which can be an advantage in some circumstances.

5. Protection and Positioning

In-line Stabilization: In cases of trauma in which cervical spine injury is suspected and not yet ruled out, protection of the cervical spine is a priority and intubation must be performed without movement of the head. An assistant is required to maintain inline stabilization. This allows the cervical collar to be opened giving better access. The head and neck are maintained in the neutral position.

If no cervical spine injury is suspected flexing the neck and extending the head to the so-called sniffing position helps to align the axes and facilitates visualization of the glottic opening.

6. Placement with proof

Intubation should be performed carefully and gently. After flaccidity is achieved laryngoscopy glottis is visualized, the clinician places the endotracheal tube between the cords, inflates the cuff, withdraws the stylet, and confirms placement.

Confirmation of proper endotracheal tube (ETT) placement is crucial; unrecognized esophageal intubation leads to devastating complications.

Confirm the placement by a combination of

Visualizing the passage of the ET tube between the cords
Listening to both sides of the chest and over the stomach
End-tidal CO2 (EtCO2) determination (either colorimetric or quantitative).

7. Post-intubation management

After intubating the patient, the tube is tied or taped in place. Maintaining sedation is essential; infusions should be prepared and started as soon as possible. A post-procedural chest x-ray is obtained to confirm the depth of tube placement and to evaluate for evidence of barotrauma as a consequence of positive pressure ventilation. Oro-Gastric tube and urinary catheter insertion used to decompress the stomach and monitor urine output respectively.