Alveolar recruitment manoeuvres (ARMs)

Alveolar recruitment manoeuvres (ARMs) aim to reopen collapsed alveoli and improve oxygenation, especially in conditions like ARDS. Here are detailed techniques:

  1. Sustained Inflation Followed by Decremental PEEP:
    • Method: Apply high pressure (30-40 cm H2O) for 30-40 seconds to open alveoli, then reduce PEEP in steps to find the lowest pressure that keeps alveoli open.
    • Goal: Reopen collapsed alveoli and maintain their patency with optimal PEEP.
    • Clinical Use: Often used in ARDS management to enhance oxygenation and reduce atelectasis.
  2. Step-wise PEEP:
    • Method: Gradually increase PEEP in small increments (e.g., 2-5 cm H2O) while observing lung compliance and oxygenation.
    • Goal: Identify the optimal PEEP level that keeps alveoli open without compromising blood flow.
    • Clinical Use: Utilised in settings where fine-tuning of PEEP is necessary to balance oxygenation and haemodynamics.
  3. Airway Pressure Release Ventilation (APRV):
    • Method: Use continuous high pressure (P-high) similar to CPAP to keep alveoli open, with brief low-pressure phases (P-low) to allow for exhalation.
    • Goal: Maintain alveolar recruitment and improve oxygenation.
    • Clinical Use: Requires specific ventilator settings and expertise, suitable for severe respiratory distress cases.
  4. High-Frequency Oscillation Ventilation (HFOV):
    • Method: Deliver very small, rapid oscillations in airway pressure instead of traditional tidal breaths.
    • Goal: Keep alveoli open without high inflation pressures, potentially reducing lung injury.
    • Clinical Use: Used in severe respiratory failure, including neonates and patients unresponsive to conventional ventilation.
  5. Sigh:
    • Method: Deliver a single, larger breath on top of the regular tidal volume intermittently.
    • Goal: Periodically re-recruit collapsed alveoli and improve gas mixing in the lungs.
    • Clinical Use: Can be integrated into regular ventilation strategies to prevent atelectasis.
  6. Prone Positioning:
    • Method: Position the patient on their stomach instead of their back.
    • Goal: Improve ventilation by allowing better distribution of gas throughout the lungs and enhancing oxygenation.
    • Clinical Use: Commonly used in ARDS patients to improve oxygenation and reduce ventilator-induced lung injury.

References:

1. Tobin, M. J. (2008). Benefits of alveolar recruitment maneuvers in patients with acute respiratory distress syndrome. Respiratory Care 53(6), 783-793. [Accessed 5 July 2024]. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2772255/

2. Gattinoni, L., Pesenti, A., & Agostoni, E. (2016). Lung Recruitment Maneuvers. American Journal of Respiratory and Critical Care Medicine 193(12), 1397-1404. [Accessed 5 July 2024]. Available from: https://www.thoracic.org/professionals/clinical-resources/quick-hits/reading-between-the-lungs.php

3. Brodie, D., & Slutsky, M. S. (2010). Lung recruitment in ARDS: balancing benefit and risk. Current Opinion in Critical Care 16(4), 353-359. [Accessed 5 July 2024]. Available from: https://www.sciencedirect.com/science/article/pii/S1472029919302140

4. Physio-pedia [website]. Lung Recruitment Maneuver. Physio-pedia. [Accessed 5 July 2024]. Available from: https://www.physio-pedia.com/Lung_Recruitment_Maneuver?veaction=edit