Table 1.

Effect of bolus volume and external cricoid pressure on UES nadir relaxation pressure

External Cricoid Pressure	DS	5 ml	10 ml
0 mmHg	1.9 ± 1.1	5.8 ± 1.2†	7.4 ± 1.0†
20 mmHg	4.3 ± 1.1*	9.4 ± 1.3*†	11.1 ± 1.0*†
30 mmHg	5.3 ± 1.1*	10.3 ± 1.2*†	12.1 ± 1.3*†
40 mmHg	8.6 ± 1.1*	11.4 ± 1.1*†	12.4 ± 1.1*†

Values are mean mmHg ± SE.

^*P < 0.05 compared with no external cricoid pressure at each tested bolus volume;

^†P < 0.05 compared with dry swallow (DS) at each tested external cricoid pressure.