Two Definitions of Successful First-Attempt Intubation: Which Is Better?

Successful intubation on the first attempt is a term used in research and in emergency medicine quality control reports. However, the definition of this marker varies and therefore may not provide a complete picture of outcomes.

The traditional definition of successful intubation on the first attempt is the successful placement during just one laryngoscope placement. The drawback of this definition is that it only includes the first step of the intubation process, laryngoscopy, while not including the second step of the process, endotracheal tube (ETT) delivery and placement. A second definition including the second step of the process may, therefore, be more informative to clinicians. In applying the first definition, there is a risk that multiple attempts at placing an ETT have occurred and are not acknowledged—these multiple attempts may result in complications and would negate the information assumed from the moniker successful intubation on the first attempt.

Two Definitions of Intubation Have Never Been Compared

To help determine the significance of using one of these definitions over the other, Stacy A. Trent, MD, MPH, and colleagues pursued a secondary analysis of data from two multicenter randomized trials of critically ill adults admitted to the ED or ICU and applied two of the definitions of successful intubation on the first attempt to determine which is most effective.

As pointed out by Dr. Trent and colleagues in Annals of Emergency Medicine, “These two definitions of successful intubation on the first attempt have never been compared. We sought to compare these two definitions and assess whether emergency intubations with 1 insertion of the laryngoscope followed by 1 successful insertion of an ETT are associated with a shorter duration of intubation and fewer serious complications than intubations with 1 insertion of the laryngoscope followed by multiple ETT insertions.”

The study included 1,863 patients who were over the age of 18 and underwent orotracheal intubations with a laryngoscope, all of whom were drawn from the BOugie or stylet in Patients UnderGoing Intubation Emergently (BOUGIE) trial and the PREventing Cardiovascular CollaPse with Administration of Fluid REsuscitation During Induction and Intubation (PREPARE II) trial. The primary outcome of the study was successful intubation on the first attempt, which was defined in two different ways, as discussed above. The secondary outcome was the duration of the intubation as well as complications resulting from the intubation.

First Attempt Occurred Less Frequently When Second Definition Was Applied

It was observed that first attempt success occurred less frequently when the second definition was applied (ie, 1 laryngoscope and 1 ETT insertion) as compared with the first definition (ie, 1 laryngoscope and any number of ETT attempts) (81.2% vs 86%, respectively; −4.9% difference; 95% CI, −3.9 to −5.9%; Table). For patients who underwent successful intubation on the first attempt according to the first definition, the median interval (ie, 155 seconds) was 35 seconds longer (95% CI, 9 to 61 s) than when successful intubation on the first attempt occurred according to the second definition (ie, median 120 s).

In terms of serious complications occurring during the intubation process, 23.1% of patients successfully intubated according to the second definition (1 laryngoscope and 1 ETT insertion) compared with 26.9% of patients successfully intubated according to the first definition (1 laryngoscope insertion) experienced serious complications (% difference −3.8%; 95% CI, −13.8% to 5.7%). As Dr. Trent and colleagues conclude, “our observations suggest that the definition of successful intubation on the first attempt should be placement of an ETT in the trachea using 1 laryngoscope insertion followed by a single ETT insertion.”