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Three Part Question

In [adults in cardiac arrests requiring airway management] are [i-gels better than LMAs] at [delivering patient outcomes]?

Clinical Scenario

You arrive at a crash call on the ward. CPR is in progress and you are asked to manage the airway, but you are not trained in placing endotracheal tubes. You have been told that i-gels are easy to place but are unsure whether an LMA may be a more reliable way of securing the patient's airway. Which supraglottic airway device should you reach for?

Search Strategy

PubMed website search. Aug 2008 - current.

(((((((adult) OR adults)) AND ((((((resuscitation) OR Cardiopulmonary resuscitation) OR Cardiopulmonary arrest) OR Cardiorespiratory resuscitation) OR Cardiorespiratory arrest) OR CPR))) AND ((i-gel) OR i-gels)) AND ((((LMA) OR LMAs) OR laryngeal mask airway) OR laryngeal mask airways))

Search Outcome

39 papers of which 3 titles found to be relevant. Manikin and cadaveric studies excluded.
On screening of abstracts, 1 title was discarded as it was a feasibility protocol relating to another of the relevant papers.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Benger et al. 2016	615 adult out of hospital cardiac arrests in which resuscitation was attempted. i-gel (n=232), LMA Supreme (n=174) and usual practice (n=209) compared.	Prospective feasibility study, cluster randomized	ROSC	i-gel: 30.8%; LMA 31.2%; usual practice 32.7%. Authors concluded no difference.	Only one third of eligible paramedics recruited, so may not be representative. Paramedics not blinded. Cluster randomized as felt to be more feasible. LMA arm discontinued after 10 months and 33 patients switched to usual practice arm. 20% protocol non-adherence (16% no airway management given/wrong device initially used, 4% no data). Usual practice arm not standardised (mixture of supraglottic airway devices, tracheal intubation, bag mask ventilation).
			Survival to hospital admission	i-gel: 22.0%; LMA 17.6%; usual practice 21.0%. Authors concluded no difference.
			Survival to discharge	i-gel: 10.3%; LMA 8.0%; usual practice 9.1%. Authors concluded no difference.
			90 day survival	i-gel: 9.5%; LMA 6.9%; usual practice 8.6%. Authors concluded no difference.
			90 day Delayed Matching to Sample Score (all delays)	i-gel 11.8 (±2.4); LMA 10.7 (±1.6); usual practice 9.9 (±2.0). No difference.
			90 day Depression, Anxiety and Stress Scale	i-gel 27.1 (±30.2); LMA 18.3 (±16.3); usual practice 15.4 (±20.0). No difference.
			90 day SF-36 physical (QoL measure)	i-gel 43.9 (±11.4;) LMA 41.5 (±11.3); usual practice 49.2 (±7.6). No difference.
			90 day SF-36 mental (QoL measure)	i-gel 47.7 (±11.1); LMA 50.4 (±8.2); usual practice 46.9 (±13.7). No difference.
Middleton et al. 2014	51 out of hospital cardiac arrests aged 12 years or over	Single centre, prospective randomized controlled trial	Successful insertion n/N (%)	i-gel 18/20 (90); LMA 16/28 (57)	Sample size smaller than power calculation recommended (50 patients per group for two-sided 5% significance and 80% power) due to slow enrolment. Open label trial. Single centre.
			Number of attempts Q2 (Q1–Q3)	i-gel 1 (1-1); LMA 1 (1-2); p = 0.67
			Ease of insertion Q2 (Q1–Q3)	i-gel 2 (1.0 - 2.75); LMA 3 (2 - 4); p <0.001
			ROSC n/N (%)	i-gel 7/20 (35); LMA 7/28 (25); p = 0.66

Comment(s)

No significant difference in patient outcomes when i-gels or LMAs are used to manage the airway in cardiac arrest. Only two studies were found which looked at data from adult cardiac arrests, rather than manikin or cadaveric studies. No studies were found which looked at in-hospital cardiac arrests. The Middleton paper, though a small sample, shows that the i-gel has an overall greater success rate of insertion than the LMA and is subjectively easier to insert according to paramedics. Given that there is no difference in short-term (ROSC, survival to hospital admission) or long-term (90 day survival, DMS as a surrogate for overall cognition, and quality of life measures) patient outcomes, it seems reasonable to favour the i-gel if one finds them easier to insert.

Clinical Bottom Line

No significant difference in short- or long-term patient outcomes in i-gel use vs. LMA. i-gels are subjectively easier to insert than LMAs and have a greater overall success rate in a study of 51 patients.

References

1. Benger J, Coates D, Davies S, Greenwood R, Nolan J, Rhys M, Thomas M, Voss S. Randomised comparison of the effectiveness of the laryngeal mask airway supreme, i-gel and current practice in the initial airway management of out of hospital cardiac arrest: a feasibility study. Br J Anaesth. 2016 Feb;116(2):262-8
2. Middleton PM, Simpson PM, Thomas RE, Bendall JC Higher insertion success with the i-gel supraglottic airway in out-of-hospital cardiac arrest: a randomised controlled trial. Resuscitation 2014 Jul;85(7):893-7