Rapid sequence airway (RSA) and PALM

Reviewed and revised 7 March 2015

OVERVIEW

Rapid sequence airway (RSA)

• Rapid sequence airway (RSA) is a modified form of rapid sequence intubation that uses an LMA inserted following induction (+/- administration of neuromuscular blockade) to maximise peri-intubation oxygenation prior to endotracheal tube insertion
• Apneic oxygenation with nasal prongs or CPAP, and delayed sequence intubation (DSI) are alternative strategies for difficult to pre-oxygenate patients

Pharmacologically assisted laryngeal mask insertion (PALM)

• PALM is a related technique called pharmacologically assisted laryngeal mask insertion, which involves the use of induction agents to facilitate LMA placement in lieu of rapid sequence intubation
• unlike the RSA approach, neuromuscular blockade is not administered as part of the PALM approach
• it is included in the UK Faculty of Prehospital Care Guidelines, but the consensus was not supported by the Royal College of Anaesthetists
• its role is primarily in the pre-hospital environment in rare circumstances with the following criteria according to UK Faculty of Prehospital Care Guidelines:
  • hypoxic patient for whom rapid sequence intubation (RSI) is not possible and other basic measures have been exhausted e.g. polytrauma patients with a reduced level of consciousness and ongoing airway obstruction, or airway soiling from facial injuries
  • used as a rescue technique, not as a primary airway management strategy
  • should be checklist driven
  • should involve use of at least a second generation supraglottic airway device (SAD)
  • ETCO2 monitoring is mandatory
  • should only be carried out by trained, competent practitioners (training should in-hospital insertion of SADs, simulation training and training in the transfer of critically ill patients)

These techniques are controversial, and are primarily considered in the prehospital environment where RSI is also controversial in certain circumstances (e.g. level of training, relative merits of less invasive airway measures and potential for delayed transfer).

PROS AND CONS OF RSA

(compared to standard RSI)

Advantages

• maintains patent airway for apnoeic oxygenation
• allows CPAP to maintain oxygenation during apnea
• allows PPV to prevent respiratory acidosis during apnea
• allows gastric decompression via gastric port on LMA prior to intubation (benefit is questionable)
• has been used

Disadvantages

• more complex
• LMA difficult to insert/ use in selected patients (RODS: Restricted mouth opening, Obstruction, Distorted airway, Stiff lungs or c-spine)
• requires ablation of airway reflexes (by deep sedation or paralysis) in an inadequately preoxygenated patient before an LMA can be inserted
• LMA does not provide definitive protection against aspiration
• minimal experience and evidence base is scant (few case reports)

Similar pros and cons apply to PALM, though the risks are greater as there is a longer and indefinite period until a definitive airway will be obtained

VIDEO

RSA approach demonstrated by Darren Braude:

References and Links

LITFL

• CCC — Laryngeal mask airway (LMA)
• CCC — Preoxygenation
• CCC — Delayed sequence intubation
• CCC — Apnoeic oxygenation

Journal articles

• Braude D, Richards M. Rapid Sequence Airway (RSA)–a novel approach to prehospital airway management. Prehosp Emerg Care. 2007 Apr-Jun;11(2):250-2. PMID: 17454819.
• Braude D, Southard A, Bajema T, Sims E, Martinez J. Rapid sequence airway using the LMA-Supreme as a primary airway for 9 h in a multi-system trauma patient. Resuscitation. 2010 Sep;81(9):1217. PMID: 20599313.
• Moss R, Porter K, Greaves I; Consensus Group Faculty of Pre-Hospital Care. Pharmacologically assisted laryngeal mask insertion: a consensus statement. Emerg Med J. 2013 Dec;30(12):1073-5. PMID: 24232013.
• Southard A, Braude D, Swenson K, Sullivan A (2010) Using Rapid Sequence Airway to Facilitate Preoxygenation and Gastric Decompression Prior to Emergent Intubation. J Anesthe Clinic Res 1:113. [Free Full Text]

FOAM and web resources

• PHARM Podcast 11 – Rapid Sequence Airway with Dr Darren Braude (2012)
• Minh Le Cong and Nicholas Chrimes — RSA: A 4 Day Twitter Conversation (2013)
• Resus.ME — Guidelines on Prehospital Drug-assisted LMA insertion (2013)