Cardiac arrest: intubation: laryngeal masks were easier and faster to insert than endotracheal tubes

Clinical bottom line (level 2b)

  1. Paramedics or respiratory therapists who used a laryngeal mask compared with an endotracheal tube were more likely to succeed (NNT = 2 at 5 minutes) .
  2. Insertion of a laryngeal mask took less time (roughly 3 minutes), required fewer attempts (roughly 1 fewer) and was considered to be easier to perform.
Reinhart and Simmons: Annals of Emergency Medicine 1994; 24 (2): 260-263
Expires October 2003

The study

Single-blinded concealed quasi-randomised trial with intention-to-treat
Setting: operating rooms, acute hospital, USA

19 patients undergoing elective surgery, who were intubated by 7 paramedics and 12 respiratory therapists.
Note:
  • All participants had received formal training in endotracheal intubation. Participants watched a 20 minute training videotape on laryngeal mask insertion, and had an opportunity to handle one.
  • Both the endotracheal tube or the laryngeal mask were inserted in each patient, but in a random order.


    • Control Group: (n = 19, 19 analysed): endotracheal tube
    Experimental Group: (n = 19, 19 analysed): laryngeal mask

    100% followed for 5 minutes
    Outcome notes:
    • failed insertion : oxygen saturation fell below 90% during attempt

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    failed insertion 5 minutes 10
    (52.6%)    		 0
    (0.0%)    		 100%
    (% to %)    		 52.6%
    (30.2% to 75.1%)    		 2
    (1 to 3)

    Outcome Control Group
    (SD)    		 Experimental Group
    (SD)    		 Mean Difference
    (95% CI)
    time to perform technique (sec) 206
    (139)     		38.9
    (8.30)     		170
    (100 to 230)
    number of attempts 1.0
    (0.0)     		2.2
    (0.87)     		1.2
    (0.80 to 1.5)
    technique difficulty on a visual analog scale (mm) 67.3
    (26.6)     		8.60
    (6.54)     		59
    (46 to 71)

    Comments

    1. Note this was not performed in emergency situations. The rate of aspiration following laryngeal mask insertion in elective conditions is very low, but the rate in emergency situations has not been determined.
    2. In ALS teaching, the LMA is considered as the better alternative to a bag and mask but the ET tube is the gold standard of airway protection and management.

    Citation

    1. Reinhart DJ, and Simmons G: Comparison of placement of laryngeal mask airway with endotracheal tube by paramedics and respiratory therapists. Annals of Emergency Medicine 1994; 24 (2): 260-263
    Contributor: Chris Ball and Clare Wotton, October 1999
    Reviewer: Clare Liddy

    Clinical Question.
    Patient paramedics or respiratory therapists
    Intervention or Exposure laryngeal mask intubation
    Comparison endotracheal tube
    Outcome successful intubation, time to intubation, ease of intubation