By Philip Neuwirth, BS, MICP, CCEMTP, FP-C
Patients complaining of shortness of breath (SOB) generally present with a few main complaints, such as an increased work of breathing (e.g. obstructed lung disease), chest tightness/pain, or the sensation of not getting enough air. What is your patient’s first reaction to shortness of breath? They sit-up! And, in severe cases, they start “tripoding”. Why? Sitting up or tripoding optimizes respiratory mechanics by (1) increasing lung volume, (2) increasing functional residual capacity (the amount of air left over after a passive exhalation), (3) aligns the oral, pharyngeal and laryngeal axes of the upper airway into better alignment and (4) in obese patients, decreases pressure on the diaphragm making lung excursion easier. All of these factors make oxygenation better. So, why have we been pre-oxygenating and intubating patients supine? Laying a patient flat to pre-oxygenate and intubate is rarely a good idea.
Back-Up, Head Elevated (BUHE) position or sometime referred to as HELP (Head-up, Head Elevated for Help) position for intubation is gaining momentum. A study by Khandelwal, Khorsand, Mitchell, Joffe, (2016), evaluated 528 adult patients undergoing emergent tracheal intubation outside of the operating room by the anesthesiology-based team. Intubation-related complications included: difficult intubation (>3 attempts), hypoxemia (prolonged attempt >10 min), esophageal intubation, and/or pulmonary aspiration. Intubated-related complications occurred in 22.6% managed in the supine position compared with 9.3% patients managed in the BUHE [>30 degrees] position, signifying a 13.3% absolute difference. The study had a few limitations, including (1) the intubation data was self-reported and subject to reporting bias, (2) it was retrospective, (3) those intubating in the BUHE position were more experienced providers, and (4) it did not include pre-hospital or ED intubations. However, the study concluded intubating patients in the back-up head-elevated position during emergent intubation was associated with reduced chance of airway-related complications.
The BUHE position is not necessarily new; several other studies looked an alternative positioning during rapid sequence induction/intubation. Most of the studies explored whether BUHE improved pre-oxygenation and safe apnea time compared to patients managed supine. A study by Ramkumar, Umesh, Philip (2011), concluded that BUHE increased safe apnea time compared to patients lying supine. A study by Lee, Kang, Kim (2007), indicated that BUHE demonstrated improved laryngoscopic views. The authors concluded that “During laryngoscopy, the laryngeal view, as assessed by POGO (percentage of glottic opening) scores, improves significantly on the 25-degree back-up position when compared with the flat position” (Lee et al., 2007, pg 586). Dr Richard Levitan, www.airwaycam.com teaches, the best position to kill someone from an airway perspective is flat on their back; he calls it the COFFIN position.
Obviously, HEMS clinicians are limited in height, and would not be able to raise the head of the bed 25-30 degrees and still have room to intubate. So, depending on your environment, raising the head of the bed even 10-15 degrees may be beneficial. In the obese patient, extra blankets, pillows, etc., may have to be used to help align the patient’s ear (external auditory meatus) to the level of the sternal notch from the side (sagittal view). This will bring the oral, pharyngeal and laryngeal axes of the upper airway into better alignment, allowing for more laminar air flow and less resistance to ventilation.
Obese patients, patients with co-morbidities and patients assessed as a difficult airway should be pre-oxygenated and intubated in the BUHE or semi-fowlers position (absent of circulatory shock or spinal injury). Consider the BUHE position for pre-oxygenation and intubation in ALL patients absent of circulatory shock or spinal injury. BUHE improves oxygenation, ventilation, laryngoscopic views and decreases complications (i.e., difficult intubation, hypoxemia, esophageal intubation, passive regurgitation, and pulmonary aspiration).
Snyder, S., Kivlehan, S., Collopy, K., (2014, January) 10 Tips for Effective Airway Management and Ventilation. Retrieved from: http://www.emsworld.com
Khandelwal, N., Khorsand, S., Mitchell, S., Joffe, A. (2016, April). Head-Elevated Patient Positioning Decreases Complications of Emergent Tracheal Intubation in the Ward and Intensive Care unit. Anesth Analg, 122(4): 1101-7.doi: 10.1213/ANE.0000000000001184
Lane S., Saunders D., Schofield, A., Padmanabhan, R., Hildreth, A., Laws, D. (2005) A Prospective, Randomized Controlled Trial Comparing the Efficacy of Pre-Oxygenation in the 20 Degrees Head-up vs. Supine Position. Anesthesia(60), 1064-7. DOI: 10.1111/j.1365-2044.2005.04374.x
Lee B., Kang J., Kim D., (2007). Laryngeal exposure during laryngoscopy is better in the 25 degrees back-up position than in the supine position. Br J Anaesth, 99(4), 581-6. Br. J. Anaesth. 99 (4):581-586.doi: 10.1093/bja/aem095
Ramkumar V., Umesh G., Philip FA. (2011, April). Preoxygenation with 20º head-up tilt provides longer duration of non-hypoxic apnea than conventional preoxygenation in non-obese healthy adults. J Anesth (25), 189-94. doi: 10.1007/s00540-011-1098-3.