A "Heads Up" Approach to Intubation

Case Presentation

A 42 year old woman with morbid obesity, HTN, type 2 diabetes, and OSA, presents to the ED with isolated head trauma and a GCS of 6. The team decides to intubate for airway protection prior to CT scan. As the induction and paralytic agents are being drawn up, the junior resident prepares to manage the airway. The senior resident asks what position she plans to use for intubation.

Clinical Question:

Is the back-up head-elevated (BUHE) position superior to the supine position for intubation?

The BUHE position involves putting the patient in Trendelenburg position, then elevating the head of the bed by at least 20 degrees, and finally ensuring the ear and sternal notch are aligned by putting blankets under the patient’s shoulders. The BUHE position is illustrated below.

Summary of Evidence:

[if !supportLists]• [endif]A retrospective study concluded that the BUHE position resulted in fewer intubation-related complications such as difficult intubation, hypoxemia, esophageal intubation, or pulmonary aspiration (1)

[if !supportLists]• [endif]The drawbacks of this study are that it was retrospective and not prospective, intubations were performed with anesthesiologists in either the OR or recovery settings, and only involved direct laryngoscope intubations. The study also did not conclude if there were any long-term or mortality benefits for the patients (1)

[if !supportLists]• Another study had blinded independent investigators grade the laryngeal view of morbidly obese patients who had been intubated with either the sniff position or ramped-up position (involving head-elevation). They concluded that the ramped-up position had superior views of the glottic structures in the morbidly obese population (2)

[if !supportLists]• [endif]Studies by Altermatt et al and Dixon et al both concluded that preoxygenation and intubation in the BUHE position was associated with increased apnea time to desaturation (less than 92%) in obese and morbidly obese patients, respectively (5, 6)

[if !supportLists]• [endif]Studies by Lane et al and Ramkumar et al have shown that BUHE positioning results in significantly improved arterial oxygen tensions after preoxygenation as well as greater times to oxygen desaturation of 92% or lower after being intubated and disconnected from the ventilator (3, 4)

[if !supportLists]• [endif]The physiologic rationale behind enhanced preoxygenation suggests that dependent lung tissue undergoes atelectasis once the patient is paralyzed, and the BUHE position has less dependent lung tissue (3, 4). BUHE position therefore would allow for better preoxygenation because it offers decreased venous return and preload, increased lung volumes, and has less dependent alveoli (1, 3, 4)

Recommendations:

[if !supportLists]• [endif]The most important point to address is that all of these studies have two main differences from this case presentation: intubations were performed outside of the emergency setting. This raises legitimate concern as to applicability of this research to the case.

[if !supportLists]• [endif]Further studies need to be done in the ED setting. Additionally, studies on long-term outcomes and mortality would enhance the understanding of BUHE position’s benefit for patients.

[if !supportLists]• [endif]However, it is reasonable to apply research across medical fields and the studies relevant to BUHE position have not demonstrated any harm for patients. The physiological rationale pertaining to the improved preoxygenation and intubations outcomes should apply to patients in the emergency department as well.

[if !supportLists]• [endif]Therefore, I recommend BUHE intubation position to the ED resident in this case, because it is associated with superior views in obese patients, better outcomes, and fewer intubation-related complications.

References:

[if !supportLists]1. [endif]Khandelwal, Nita, et al. “Head-Elevated Patient Positioning Decreases Complications of Emergent Tracheal Intubation in the Ward and Intensive Care Unit.” Anesthesia & Analgesia, vol. 122, no. 4, 2016, pp. 1101–1107., doi:10.1213/ane.0000000000001184.

[if !supportLists]2. [endif]Collins, Jeremy S., et al. “Laryngoscopy and Morbid Obesity: a Comparison of the ‘Sniff’ and ‘Ramped’ Positions.” Obesity Surgery, vol. 14, no. 9, Jan. 2004, pp. 1171–1175., doi:10.1381/0960892042386869.

[if !supportLists]3. [endif]Lane, S., et al. “A Prospective, Randomised Controlled Trial Comparing the Efficacy of Pre-Oxygenation in the 20° Head-Upvssupine Position*.” Anaesthesia, vol. 60, no. 11, 2005, pp. 1064–1067., doi:10.1111/j.1365-2044.2005.04374.x.

[if !supportLists]4. [endif]Ramkumar, Venkateswaran, et al. “Preoxygenation with 20º Head-up Tilt Provides Longer Duration of Non-Hypoxic Apnea than Conventional Preoxygenation in Non-Obese Healthy Adults.” Journal of Anesthesia, vol. 25, no. 2, Apr. 2011, pp. 189–194., doi:10.1007/s00540-011-1098-3.

[if !supportLists]5. [endif]Altermatt, F. R. “Pre-Oxygenation in the Obese Patient: Effects of Position on Tolerance to Apnoea.” British Journal of Anaesthesia, vol. 95, no. 5, 2005, pp. 706–709., doi:10.1093/bja/aei231.

[if !supportLists]6. [endif]Dixon, Benjamin J., et al. “Preoxygenation Is More Effective in the 25° Head-up Position Than in the Supine Position in Severely Obese Patients:A Randomized Controlled Study.” Anesthesiology: The Journal of the American Society of Anesthesiologists, The American Society of Anesthesiologists, 1 June 2005, anesthesiology.pubs.asahq.org/article.aspx?articleid=1942533.