Induction agent administration sequence and first attempt failure in emergency intubation

The traditional rapid sequence intubation approach of sedative followed by paralytic agent dates to a time where there was a prolonged onset time of  sedatives and there was concern of patients being aware and paralysed if paralytics were given prior to adequate sedation.

Agents have changed over time and more rapid onset sedating agents, may mean that we can give paralytics first, thereby aligning peak effects of drugs and minimising the apnoea time associated with sedative effect.

The Study
Catoire, p. et al. Effect of administration sequence of induction agents on first-­ attempt failure during emergency intubation: A Bayesian analysis of a prospective cohort. Acad Emerg Med. 2025;32:123–129.

This study assessed the effects of drug sequence order ie paralytic first versus sedative first, on first intubation attempt failure rate, peri-intubation hypoxemia, and complications of emergency tracheal intubation.

What They Did

This was a data analysis study from a single-center prospective cohort in the USA.

Primary Objective: To assess the “association of drug sequence order, comparing sedative-­first and paralytic-­first strategies, with the risk of first-­ attempt failure during emergency tracheal intubation.” First-attempt failure was defined as the need to insert the laryngoscope more than once to complete the intubation.

Secondary Outcomes: The association “with peri-­ procedure hypoxemia, and occurrence of a major or any complication.”

Hypoxemia was defined as a pulse oximetry < 90% occurring from induction to 1 min after the completion of intubation.
A major complication was defined as any of:

• hypoxemia,
• witnessed aspiration,
• cardiac arrest,
• oesophageal intubation, or
• first attempt failure.

A Bayesian approach was used to measure the presence and the magnitude of the effect.

N = 2216

Sedatives used were: Etomidate (88.6%), Ketamine (11.4%)
Paralytics used were: Rocuronium (77.4%), Succinylcholine (22.6%)

56.6% of patients received paralytics first and 43.4% received sedative first.

What They Found

First attempt failure rate occurred in (110 patients) 5% of cases

• 54 patients had paralytic first and
• 56 patients had sedative first.

Paralytic-first strategy was associated with an OR of 0.73 (95% Crl 0.46-1.02) with a probability of 95.7% that it was < 1

In patients who received etomidate, paralytic-­ first was associated with a lower first-­attempt failure rate than sedative-­ first subgroups, regardless of the paralytic agent used. Comparisons could not be made for patients receiving ketamine, as the groups were too small.

Discussion

This study found that a paralytic-first strategy decreased the number of first attempt intubation failures. The findings are a little different from previous studies which demonstrated no difference (1). It is a restrospective review of data from a single department using Bayesian analysis.

First attempt failure rate may be associated with adverse events and those clinical events would be of more use to us.

In many cases I already use a paralytic early in the piece and anecdotally have found a sandwich approach to be better for what we do. By this I mean, a smaller dose of Ketamine, with a short time for it to circulate, followed by a paralytic agent push( almost always use Rocuronium), followed by a bigger dose of ketamine. Then looking at the clock and intubating at 45 seconds post paralytic being given. The aim of this approach is to allign the onset of paralysis with the onset of potential apnoea from the sedation. Although I use Ketamine for the fact that it maintains airway reflexes and respiration.

References

1. Driver BE, et al. Drug order in rapid sequence intubation. Acad Emerg Med. 2019;26(9):1014-1021.