Table 2: Comparison of chest compression quality and characteristics of pauses^a in the manual and mechanical phases of 202 device-assisted arrests.

Variable	Manual Phase^b	Mechanical Phase^b	p-value^c
CPR Time^d (min:sec)	3:13 (1:40-4:53)	23:24 (13:22-33:22)	< 0.001
Compression rate (per min)	121 (109-131)	102 (102-102)	< 0.001
Compression fraction^d (%)	77 (68-85)	89 (86-92)	< 0.001
Pauses
Duration (sec)
All Pauses	9.9 (7.5-15.0)	13.7 (10.8-18.0)	< 0.001
Peri-Shock Pauses	22.0 (18.0-28.0)	24.0 (19.5-30.0)	0.72
Non-Shock Pauses	9.1 (6.8-13.0)	13.0 (10.4-16.8)	< 0.001

^aThe main pause for application of the mechanical device was excluded from analysis;

^bResults are expressed as median (IQR);

^cp-value for Wilcoxon signed -rank test;

^dSee Methods for definition;

CPR = cardiopulmonary resuscitation