Table 2.

Overall characteristics of LCR following 16-day exposure to cigarette smoke

	Control	Exposure
%dec RR	51 (18)	67 (15)*
Apnea duration, s	4.5 (8.3)	7.8 (8.5)*
No. of apneas	1.1 (2.7)	2.2 (4.7)*‡
%dec HR	21 (11)	28 (14)
Bradycardia duration, s	0.2 (0.7)	0.3 (0.7)
No. of bradycardias	0.2 (0.7)	0.5 (1)†
Minimum HR, min−1	142 (9)	144 (7)
%inc MAP	23 (16)	18(10)
Respiratory LCR duration, s	13.2 (10)	14.8 (8.8)
Total Ta EMG duration, s	2.2 (2.9)	2.5 (2.9)
%dec Saturation	3 (3)	3 (3)
Saturation, area under 90%	0.04 (0.2)	0.06 (0.3)
Saturation, area under 85%	0.01 (0.08)	0.02 (0.14)
No. of swallows	12 (10)	8 (7)†
Arousal no. of LCR with arousal/total no. of LCR	76/89	83/116†
Coughs (no. of LCR with cough/total no. of LCR	14/94	11/116
Awakening (no. of LCR with awakening/total no. of LCR)	48/76	55/83

Values are means (SD). Results are means from all laryngeal stimulations (all solutions and all states of alertness) for each group. Values in the control group were available only in 5 lambs for percent increase in MAP (%inc MAP) and saturation indexes and in 6 lambs for the number of swallows and total duration of electrical activity of the thyroarytenoid muscle (Ta EMG duration). %dec HR, %dec RR, and %dec saturation, percent decrease in HR, RR, or O₂ saturation, respectively; LCR, laryngeal chemoreflexes.

^*P < 0.05;

^†P < 0.1 vs. control.

^‡Significant interaction between sleep state and solution (see Table 3 for details).