# Rapid Sequence Induction

## Overview

This module describes how to intubate patients with a high risk of aspiration using rapid sequence induction (RSI). This technique protects the airway by minimising the time between induction and airway protection. The triad of RSI is pre-oxygenation, cricoid pressure, and fast acting drugs.

## Indications

## Contraindications

## Patient information and consent

When doing this procedure in an unresponsive patient, consent is generally implied. Patients with “Do Not Resuscitate” (DNR) orders, “Not For Max” orders, or living wills that specify that no resuscitation may be performed, may not be intubated. In elective patients, consent must be signed.

## Preparation

This procedure requires one, or preferably two assistants, and:

A difficult airway trolley should also be available with supraglottic devices.

## Site & Positioning

The patient should be in the “sniffing” position, with the ear aligned to the sternal notch. This may require building a ramp with pillows and blankets to raise the patient’s head.

## Procedure

Although RSI aims to avoid BVMR ventilation during preoxygenation and prior to the tube cuff being inflated, BVMR ventilation must be employed should hypoxia occur, even at the risk of aspiration. To minimise risk of gastric insufflation and resultant aspiration:

1. Maintain cricoid pressure
2. Insert oropharyngeal airway device
3. Keep BVMR pressures (adjusted on APL valve) at 10-15 cmH20 (the gastroesophageal valve opens at 20 cmH20) — colloquially referred to as ‘gentlation’.

Use medical asepsis with non-sterile gloves. Wear N95 masks as for aerosol-generating procedures.

## Troubleshooting

I can’t visualise the cords.

Always re-oxygenate the patient between attempts, providing breaths with the BVMR. Call for a senior. If not able to oxygenate, consider a supraglottic airway.

To optimise visualisation, position the patient with ear in line with sternal notch.

1. Check that your laryngoscope provides sufficient light
2. Check your viewing angle. Try straightening your back and bobbing your head up and down
3. Make sure that your laryngoscope is lifting the jaw, not acting as a lever
4. Ask your assistant to apply backwards, upwards, rightwards pressure to the cricoid cartilage
5. Reposition the blade, which may be too deep
6. Use a different size or shape of laryngoscope blade
7. Ask a more experienced colleague or senior to attempt intubation
8. Use a videolaryngoscope if available and you are familiar
9. Re-optimise the patient if unstable or induction/paralytic effects are wearing off

I can’t oxygenate the patient with BVMR breaths.

1. Call for help
2. Reposition the patient using basic head-tilt chin-lift or jaw thrust
3. Ensure an NPA or OPA is in situ when using BVMR
4. Use two handed mask seal
5. Increase PEEP
6. Rule out pneumothorax
7. Insert an LMA if not successful with mask ventilation

I can’t oxygenate the patient, and intubation or difficult airway devices have failed or are unavailable.

This is a can't intubate- can't oxygenate scenario, and front of neck access may be indicated.

I’m not sure how to draw up ketamine.

Ketamine is available in different concentrations; 10, 50, and 100 mg/ml. It is easiest to work with a 10 mg/ml solution, which comes as a 20 ml vial and can be used undiluted. If you have a 50 mg/ml vial (comes in a 10 ml vial), draw up 2 ml in a 10 ml syringe and add 8 ml of normal saline, making a 10 mg/ml solution.

For the 100 mg/ml solution (comes in a 10 ml vial), draw up 1 ml ketamine and add 9 ml normal saline in a 10 ml syringe, making a 10 mg/ml solution. For a 70 kg patient, you may need to draw up two 10 ml syringes, or one 20 ml syringe with 2 ml of ketamine.

Diluting high concentrations of ketamine is safe practice and avoids accidental misdosing.

## Risks

## References