Are there specific proning positions that are recommended when trying to maximize awake oxygenation of patients on nasal cannulas

Posted on April 15, 2020 by Raymond Cho

Summary

  • There is no robust evidence for awake proning but several small studies and reports in patients with COVID-19 have reported that proning may improve oxygenation and reduce the need for intubations.
  • The general proning protocol uses 4 positions changing positions Q 30min-2H (essentially spinning patients in a circle).
  • If troubleshooting is insufficient to elevate SpO2, O2 modality should be escalated according to Ding et al.’s escalating protocol.

I.   Evidence for awake prone positioning

  • Prone position (PP) of intubated patients is a widely used technique used in the ICU that has been shown to improve oxygenation and mortality (1). The physiology of proning should work regardless of intubation status as proning improves secretion clearance, recruits posterior lung regions to reduce atelectasis and therefore, improves V/Q matching (2).
  • Ding et al. proposed a stepwise approach to awake proning using 4 support strategies, which are listed here in order of efficacy on PaO2/FiO2: high-flow nasal cannula (HFNC) < HFNC + PP < non-invasive ventilation (NIV) < NIV + PP. They decreased their intubation rate from a predicted 75% of patients with ARDS to 45% in 20 patients (3).
  • A case series by Perez-Nieto et al. reported that intubation was avoided in 4 out of 6 patients with non-infective ARDS using HFNC/NIV and PP for 2-3 h every 12 hours for 2 days (4). 
  • Scaravilli et. al. performed a retrospective feasibility study on 15 awake patients on the effects of PP on oxygenation. There were no complications and oxygenation improved temporarily in PP (pre-prone PaO2/FIO2: 124 ± 50 mmHg, prone P2O2/FIO2: 187 ± 72 mmHg) (5).

II.   Proning protocols and methods

  • Indicactions: isolated hypoxemic respiratory failure without substantial dyspnea (i.e. no multi-organ failure, potential to avoid intubation, normal mental status, no anticipated difficult airway, no hypercapnia), able to follow instructions, patients who do not wish to be intubated, bridge for oxygenation when intubation is not immediately available (1).
  • Contraindications (6)
    • Absolute: respiratory distress, immediate indication for intubation, hemodynamic instability (SBP < 90), agitation or AMS, unstable spine/thoracic/abdominal injury.
    • Relative: facial injury, uncontrolled neuro issues, obesity, pregnancy, pressure ulcers.
  • COVID Awake Repositioning/Proning Protocol (CARP) (7,8)
    • Timed position changes – ask patient to switch every 30min-2hrs between:
  1. Prone in bed
  2. Right lateral recumbent
  3. Upright 60-90°
  4. Left lateral recumbent
  5. Repeat
  6. Trendelenburg position may also be attempted if O2 saturation is not improving.
    • Troubleshooting: if the patient experiences O2 desaturation, ensure O2 is still hooked onto the wall, ask the patient to try a different position or escalate O2 modality.
  • Intensive Care Society Guidance for Prone Positioning of the Conscious COVID Patient 2020 (similar to CARP) (6)
    • See link for flow diagram decision tool for conscious proning.
    • In summary:
      1. Assist patient to prone position using pillows to support the chest, reverse trendelenburg for comfort, monitor O2 sat for 15 min each position change.
      2. Position changes as above using CARP protocol.
      3. If SpO2 92-96%, continue position changes Q 30min-2H.
      4. If SpO2 drops, ensure O2 connection to wall/patient, increase O2, change position and escalate to critical care if troubleshooting unsuccessful.
  • Massachusetts General Awake Prone Positioning Nursing Guidelines
    • Massachusetts General’s nursing guidelines for non-intubated patients allow for more flexibility, suggesting patients should stay for 1 hour in PP and be encouraged to stay prone for as long as tolerated. The goal is to stay prone more often than not (9).
  • Ding et al.’s study (mentioned above) used an escalating protocol for O2 therapy (2,3). 
    • Patients with stable SpO2 > 90% were placed on HFNC in a supine position.
    • If SpO2 desaturates under 90%, patients  would be placed in PP with HFNC.
    • If SpO2 continues to desaturate under 90%, patients are placed supine with NIV.
    • If SpO2 still desaturates under 90%, patients are placed in PP with NIV.
    • Intubation is then considered if there is no improvement.

In short: HFNC → HFNC + PP → NIV → NIV + PP → Intubation

Questions? Comments? Does this need to be updated? Do you have valuable points to add ? Please email ask.reakt@ubc.ca.

References

  1. Farkas J. PulmCrit Wee – Proning the Non-Intubated patient [Internet]. PulmCrit. EMCrit; 2016 [cited 2020Apr15]. Available from: https://emcrit.org/pulmcrit/proning-nonintubated/
  2. Farkas J. COVID-19 [Internet]. EMCrit Project. 2020 [cited 2020Apr15]. Available from: https://emcrit.org/ibcc/covid19/
  3. Ding L, Wang L, Ma W, He H. Efficacy and safety of early prone positioning combined with HFNC or NIV in moderate to severe ARDS: a multi-center prospective cohort study. Critical Care [Internet]. 2020Jan30 [cited 2020Apr15];24(1). Available from: https://ccforum.biomedcentral.com/articles/10.1186/s13054-020-2738-5
  4. Pérez-Nieto OR, Guerrero-Gutiérrez MA, Deloya-Tomas E, Ñamendys-Silva SA. Prone positioning combined with high-flow nasal cannula in severe noninfectious ARDS. Critical Care [Internet]. 2020Mar23 [cited 2020Apr15];24(1). Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7092599/
  5. Scaravilli V, Grasselli G, Castagna L, Zanella A, Isgrò S, Lucchini A, et al. Prone positioning improves oxygenation in spontaneously breathing nonintubated patients with hypoxemic acute respiratory failure: A retrospective study. Journal of Critical Care [Internet]. 2015Dec;30(6):1390–4. Available from: https://www.sciencedirect.com/science/article/abs/pii/S0883944115003755?via=ihub
  6. Bamford P, Bentley A, Dean J, Whitmore D, Wilson-Baig N. ICS Guidance for Prone Positioning of the Conscious COVID Patient 2020 [Internet]. Intensive Care Society. EMCrit Project; 2020 [cited 2020Apr15]. Available from: https://emcrit.org/wp-content/uploads/2020/04/2020-04-12-Guidance-for-conscious-proning.pdf
  7. Weingart S. COVID19 – Awake Pronation – A guest write-up by David Gordon, MD [Internet]. EMCrit Project. 2020 [cited 2020Apr15]. Available from: https://emcrit.org/emcrit/awake-pronation/ 
  8. COVID Awake Repositioning / Proning Protocol (CARP) [Internet]. EMCrit Project. 2020 [cited 2020Apr15]. Available from: https://emcrit.org/wp-content/uploads/2020/04/COVID-CARP-Protocol-postable.pdf
  9. Ananian L, Hardin C, Lux L, Ronin J, Prout L. Massachusetts General Hospital Prone Positioning for Non-Intubated Patients Guideline [Internet]. Massachusetts General . 2020 [cited 2020Apr15]. Available from: https://www.massgeneral.org/assets/MGH/pdf/news/coronavirus/prone-positioning-protocol-for-non-intubated-patients.pdf

Disclaimer

The above is intended to serve as a rapidly-created, accessible source of information curated by medical students and healthcare professionals. It is for educational purposes only and is not a complete reference resource. It is not professional medical advice, and is not a substitute for the discretion, judgment, and duties of healthcare professionals. You are solely responsible for evaluating the information above.