Table 4.

Effect of Pharyngeal Stimulus Volume on Respiratory and Pharyngeal Responses during Multiple-Pharyngeal Swallowing Sequences

Characteristic	0.1 mL (n=98 stimuli)	0.3 mL (n=99 stimuli)	0.5 mL (n=53 stimuli)	P-value
Respiratory Response
Deglutition apnea, %	97	98	98	1.0
Deglutition apnea duration, sec	3.2 ± 1.2	4.5 ± 0.6	5.1 ± 0.7	0.4
Respiratory response latency, sec	2.6 ± 0.8	4.5 ± 0.4	4.7 ± 0.5	0.06
Respiratory response duration, sec	13.2 ± 6.9	25.0 ± 2.8	28.5 ± 4.3	0.2
Respiratory Response duration, sec	15.7 ± 7.1	29.5 ± 3.0	33.2 ± 4.5	0.1
Composite Pharyngeal Response
Prevalence, n(%)	16(16)†‡	95(96)	49(92)	<0.01
Peak recruitment, #	2.1 ± 0.6†‡	6.2 ± 0.4‡	9.0 ± 0.5†	<0.01
Response duration, sec	7.3 ± 3.0‡	14.5 ± 1.2	19.6 ± 1.7	<0.01
Frequency, Hz	0.9 ± 0.07†‡	0.6 ± 0.02	0.5 ± 0.04	<0.01
Peak variability, sec	2.0 ± 0.5	1.6 ± 0.1	1.4 ± 0.2	0.5
Peak stability	0.5 ± 0.1	0.5 ± 0.03	0.5 ± 0.04	0.9

Data presented as n(%) or mean ± SEM or,

^†p<0.05 vs 0.3 mL,

^‡p<0.05 vs 0.5 mL,

Both maturations were included however P-values were calculated controlling for maturation. Results for deglutition apnea prevalence and duration apply to only to those responses where pharyngeal swallowing response was observed, whereas other respiratory characteristics apply to the total stimuli administered.