Airway management in simulated restricted access to a patient - can manikin-based studies provide relevant data?

Table 1 Mean time used to insert supraglottic devices and endotracheal tube in simulated optimal and restricted access

Device	Manikin	Scenario	Number	Successful	Mean time (seconds)	SD
iGel ™	Ambu ™	A (optimal)	20	All	9.9	4.5
iGel ™	Ambu ™	B (restricted)	20	All	12.3	3.6
LTSII ™	Ambu ™	A (optimal)	20	All	12.8	2.9
LTSII ™	Ambu ™	B (restricted)	20	All	10.6	3.2
Macintosh #3	TrueCorp ™	A (optimal)	20	Yes	12.1	3.3
			0	No
Macintosh #3	TrueCorp ™	B (restricted)	16	Yes	28.0	13.0
			4	No
P-values for comparing same device in scenario A versus B
Mean time with iGel in scenario A vs scenario B				p = 0.09	NS
Mean time with LTSII in scenario A vs scenario B				p = 0.01	S
Mean time with Macintosh laryngoscope (blade #3) in scenario A vs Scenario B				p < 0.01	S
P-value for comparing devices with each other in scenario A
Mean time with iGel vs LTSII				p = 0.69	NS
Mean time with Macintosh #3 vs iGel				p = 0.88	NS
Mean time with Macintosh #3 vs LTSII				p = 0.19	NS
P-values for comparing differen devices with each other in scenario B
Mean time with iGel vs LTSII				p = 0.50	NS
Mean time with Macintosh #3 vs iGel				p < 0.001	S
Mean time with Macintosh #3 vs LTSII				p < 0.001	S
NS = Non-significant, S = significant

Legend (table 1): The success rates and mean time (seconds) used to insert the supraglottic device and endotracheal tube in simulated optimal (scenario A) and restricted (scenario B) access conditions. Relevant P-values are listed. Specific comment for Macintosh #3 in scenario B: three HEMS physician chose to use digital technique when inserting the endotracheal tube. In 13 cases classic laryngoscopy technique succeeded. In the remaining four cases of attempted direct laryngoscopy no endotracheal tube was placed within the time limit of 60 seconds.