Author: Fiqry Fadhlillah / Editor: Beth Newstead / Codes: CAP15, CAP35, CAP6, CMP2, CMP6 / Published: 16/12/2019 / Review Date: 16/12/2021
Intubation forms an integral role in the treatment of the critically ill or injured patients presenting to the ED with a failed or at-risk airway. The acuity of their presentation may often necessitate a rapid placement of an endotracheal tube (ETT). There are many different strategies to achieve this; one such technique is rapid sequence induction (RSI). RSI is designed to minimise the time between loss of airway reflexes and placement of an ETT in the trachea. It minimises the risk of aspiration in patients who are inadequately starved, have impaired gastric emptying or are known to have gastric reflux. The term ‘rapid sequence induction’ emphasises the use of a sequential technique in achieving rapid intubation by minimising the time delay between loss of airway reflexes and tube placement.
Rapid sequence induction (RSI) is an established method of inducing anaesthesia in patients who are at risk of aspiration of gastric contents into the lungs. It involves inducing loss of consciousness whilst cricoid pressure is applied followed by intubation without face mask ventilation.
An induction agent (e.g. propofol) induces a state of immediate unresponsiveness. This is then followed by the administration of a neuromuscular blocking agent to induce paralysis. The combination of drugs ceases spontaneous ventilation in the patient and allows for better view of the vocal cords. RSI is useful in patients with an intact gag reflex, a full stomach and a life threatening injury or illness requiring immediate airway control.
There are considerable variations in medications used for induction and paralysis. In the UK, propofol and ketamine remain the two most commonly used induction agents. There is now a shift of use of paralytic agent, from suxamethonium to rocuronium. In a recent analysis of 4275 intubations performed in the ED (USA), suxamethonium and rocuronium exhibited no differences in first-pass success (87.0% versus 87.5%) or adverse events (14.7% versus 14.8%) (April MD et al). This study only examined patients receiving either suxamethonium or rocuronium.
The most common induction agents used are:
|Drug||How to make up||Final concentration|
|Propofol 1%||Neat into 20ml syringe||10mg/ml|
|Ketamine 500mg/10ml||Neat into 10ml syringe||50mg/ml|
|Thiopentone 500mg vial||Add 20ml water into 20ml syringe||25mg/ml|
|Etomidate 20mg/10ml||Neat into 10ml syringe||2mg/ml|
The most common paralysing agents used are:
|Drug||How to make up||Final concentration|
|Suxamethonium 50mg/ml||Neat 1 ampoule into 2ml syringe||50mg/ml|
|Rocuronium 50mg/5ml||Neat 2 ampoules into 10ml syringe||10mg/ml|
|Atracurium 50mg/5ml||Neat 2 ampoules into 10ml syringe||10mg/ml|
|Vecuronium 10 mg||Add 5ml water into 5ml syringe||2mg/ml|
The assessment of an airway should involve the use of the LEMON criteria:
- Look externally (facial trauma, large incisors, beard, large tongue)
- Evaluate the 3-3-2 rule (incisor distance 3 finger breadths, hyoid-mental distance 3 finger breadths and thyro-hyoid distance 2 finger breadths)
- Neck mobility
Emergency intubations are not without the risk of complications, not least due to the emergency nature of the procedure. A growing body of evidence suggests that the risk accompanying an invasive airway technique may even outweigh its intended benefits of protecting the airway and achieving adequate ventilation. The AIRWAYS-2 and PART studies, both published in the same 2018 issue of the Journal of the American Medical Association (JAMA), concluded that intubation is not superior to placing a supraglottic airway device (SAD) in the out-of-hospital (atraumatic) cardiac arrest setting; and that SAD may be at least as good, if not better than attempts at inserting an ETT.
The 4thNational Audit Project of the Royal College of Anaesthetists and Difficult Airway Society (NAP4) was designed, in part, to look at airway management in ED and highlight any deficiencies that have or could have led to serious harm. Analysis of cases highlighted the following gaps in care:
- Poor or delayed recognition of at-risk or deteriorating patients
- Inadequate preparation
- Insufficiently trained staff
- Inadequate equipment
Steps in RSI
- Verbalise time out
- Ensure designation of roles intubator, drug delivery, managing equipment, monitoring patients vital signs
- Check drugs, equipment
- Ensure plan discussed
- Give induction agent
- Give paralytic agent
- Wait 45-60 seconds after paralytic agent
- Pass endotracheal tube
- Move to plans B, C or D as needed
- Confirm end-tidal CO2, lung sounds, chest rise and misting of tube
The Difficult Airway Society, Intensive Care Society, FICM and the Royal College of Anaesthetists published a 2018 guideline on the management of tracheal intubations in critically ill adults.
As a minimum, the following personnel should be present during an intubation:
In the event of a failed or difficult airway, the following steps should be followed:
RSIs can be difficult in a number of scenarios:
- Rapidly deteriorating patient
- Non-cooperative or combative patients
- Structural airway problems/distortion (e.g. short neck, trauma)
- Full stomach (increased risk of regurgitation, vomiting, aspiration)
- Secretions, vomitus, blood
- Difficult ventilation
- Haemodynamic instability
Always ensure that the following medications are within reach:
|Drug||Use||How to make up||Final concentration||Suggested initial dose|
|Atropine||Bradycardia||Neat from pre-filed syringe||
|Neat into 2ml syringe||600mcg/ml||600mcg|
|Glycopyrronium||Bradycardia||Neat into 5ml syringe||200mcg/ml||200mcg|
|Metaraminol 10mg||Hypotension||1 vial Add N Saline to make 20ml||0.5mg/ml||0.5mg|
|Ephedrine 30mg||Hypotension||1 vial Add N Saline to make 10ml||3mg/ml||6-9mg|
|Sugamaddex 500mg/5ml||Reversal of NMB||Neat into 5ml syringe||100mg/ml||16mg/kg (immediate reversal)|
- Walls RM. Rapid Sequence intubation comes of age. Ann Emerg Med 1996;28:7981.
- Sellick BA. Cricoid pressure to control regurgitation of stomach contents during induction of anaesthesia. Lancet 1961;2:404-406.
- Butler JM, Clancy M, Robinson N, Driscoll P. An observational survey of emergency department rapid sequence intubation. Emerg Med J. 2001 Sep;18(5):343-8.
- April MD, Arana A, Pallin DJ, Schauer SG, Fantegrossi A, Fernandez J, et al. Emergency Department Intubation Success With Succinylcholine Versus Rocuronium: A National Emergency Airway Registry Study. Ann Emerg Med. 2018 Dec;72(6):645-653.
- Benger JR, Kirby K, Black S, Brett S, Clout M, Lazaroo M, et al. Effect of a Strategy of a Supraglottic Airway Device vs Tracheal Intubation During Out-of-Hospital Cardiac Arrest on Functional Outcome: The AIRWAYS-2 Randomized Clinical Trial. JAMA. 2018;320(8):779-791.
- Wang HE, Schmicker RH, Daya MR, Stephens SW, Idris AH, Carlson JN, et al. Effect of a Strategy of Initial Laryngeal Tube Insertion vs Endotracheal Intubation on 72-Hour Survival in Adults with Out-of-Hospital Cardiac Arrest: A Randomized Clinical Trial. JAMA. 2018;320(8):769-778.
- Cook TM, Woodall N, Frerk C; Fourth National Audit Project. Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 1: anaesthesia. Br J Anaesth. 2011 May;106(5):617-31.
- Higgs A, McGrath BA, Goddard C, Rangasami J, Suntharalingam G, Gale R, et al. Guidelines for the management of tracheal intubation in critically ill adults. Br J Anaesth. 2018 Feb;120(2):323-352. doi: 10.1016/j.bja.2017.10.021. Epub 2017 Nov 26.