Ramped Position Doesn't Work? Let's Do a Check-UP On This Study

Let's Check-UP on this study
Clay Smith

Here is a podcast I did with Chip Lange, TOTAL EM on this article.

Ramped position for intubation has been studied in the operating room (OR) and found to improve functional residual capacity (FRC), reduce oxygen desaturation, and improve glottic view.  But how does it perform outside the OR?  This was a RCT of ramped vs sniffing position for ICU patients, most of which were intubated for hypoxia or altered mental status.  They found no difference in lowest oxygen saturation with the ramped position, though there was a nonsignificant trend across all subgroups favoring the ramped position group.  However, difficulty of intubation was greater in the ramped position, across the spectrum of BMI, with more attempts and use of the bougie.  This could have been due to the relative inexperience of the intubators.

Of greatest concern, they performed the ramped position differently than the anesthesia studies.  Here is a sample ramped position picture and description from this article.

"The patient will be moved toward the head of the bed until the head and neck are resting on the edge of the mattress. Keeping the lower half of the bed flat, the head of the bed will be raised to an angle of 25°. The patients face will be parallel to the ceiling with neck in slight extension, torso at 25°, and legs parallel to the ceiling."

"The patient will be moved toward the head of the bed until the head and neck are resting on the edge of the mattress. Keeping the lower half of the bed flat, the head of the bed will be raised to an angle of 25°. The patients face will be parallel to the ceiling with neck in slight extension, torso at 25°, and legs parallel to the ceiling."

Compare this picture with an image showing the traditional table-ramp position in this anesthesia study.

Ramped position is described in anesthesia literature as: "combined shoulder-head elevation, so that the sternum aligned with the external auditory meatus."

Ramped position is described in anesthesia literature as: "combined shoulder-head elevation, so that the sternum aligned with the external auditory meatus."

I wonder if the ramped position in the Check-UP study produced excessive cervical extension rather than head elevation, which may have degraded laryngoscopic view, as in the MRI image below.

Left: neck hyperextension Right: sniffing position. Adapted from Br J Anaesth, click image for source link.

Left: neck hyperextension
Right: sniffing position.

Adapted from Br J Anaesth, click image for source link.

The ideal ramped position should simply be the sniffing position with head of bed elevation.

Spoon Feed
For less experienced intubators in the ICU, ramped position offered no benefit over the sniffing position.  However, I'm concerned this article doesn't reflect the ramped position used by anesthesia and that we use in the ED.  With avoidance of neck hyperextension, I think the ramped position remains advantageous, especially in morbidly obese patients.  EM Nerd has an excellent deep dive on this article.  Also, don't miss the podcast!

Source
A Multicenter, Randomized Trial of Ramped Position versus Sniffing Position during Endotracheal Intubation of Critically Ill Adults. Chest. 2017 May 6. pii: S0012-3692(17)30881-4. doi: 10.1016/j.chest.2017.03.061. [Epub ahead of print]

Peer Review Comments
Thomas Davis
The OR data are quite convincing that ramped is safer--possibly even for preoxygenation alone followed by intubation in the traditional supine position. Most studies, though, did intubate in the ramped position which the anesthesiologists anecdotally found to offer superior glottic views. However, they were all much more experienced proceduralists than the fellows in the Check-UP study. Therefore, if you do choose to develop this technique and eventually make it your go-to method, here's a pro tip from the discussion sections of several anesthesiology articles: make sure you use a foot stool.