. 2000 Dec 1;529(Pt 2):493–504. doi: 10.1111/j.1469-7793.2000.00493.x

Table 1.

Group mean data

	MSNA (% change)	ΔMAP (mmHg)	ΔHeart rate (beats min⁻¹)	V_T (1)	f_b (breaths min⁻¹)	T₁/T_Tot	Peak PμM (cm H₂O)	∫P_M	∫P_M× f_b	V_T/T_I (1 s⁻¹)	P_co₂ (mmHg)
Eupnoea	0	0	0	0.673 ± 0.196	13.3 ± 4.6	0.38 ± 0.03	−0.68 ± 0.28	−0.68 ± 0.39	−7.52 ± 4.18	0.36 ± 0.06	37.8 ± 2.3
Protocol 1A
Min 1	−3.2 ± 37.3	0.9 ± 4.1	20.6 ± 9.5^*	1.056 ± 0.282^†	14.9 ± 0.1	0.71 ± 0.05^†	−68.3 ± 18.0^*	−140.9 ± 25.5^*	2073 ± 404^*	0.38 ± 0.11	38.2 ± 5.0
Min 2	22.2 ± 33.6	10.1 ± 4.4	22.1 ± 9.6^*	1.107 ± 0.295^†	15.0 ± 0.2	0.73 ± 0.05^†	−70.4 ± 17.9^*	−145.9 ± 29.4^*	−2177 ± 444^*	0.38 ± 0.11	40.2 ± 4.6
End	76.9 ± 51.1^*	12.4 ± 7.4	27.0 ± 11.3^*	1.044 ± 0.360^†	15.1 ± 0.5	0.71 ± 0.05^†	−71.8 ± 17.5^*	−131.3 ± 27.4^*	−1970 ± 414^*	0.37 ± 0.13	41.3 ± 4.5
Protocol 1B
Min 1	−5.5 ± 21.4	1.0 ± 4.2	6.0 ± 5.4	1.106 ± 0.315^†	15.0 ± 1.4	0.64 ± 0.05^†	−2.0 ± 0.9	−1.7 ± 0.8^†	−25.1 ± 11.2^†	0.43 ± 0.12	40.1 ± 4.4
Min 2	−7.7 ± 18.6	1.4 ± 4.2	5.7 ± 5.9	1.134 ± 0.288^†	15.0 ± 1.2	0.65 ± 0.03^†	−2.2 ± 0.9	−1.7 ± 0.8^†	−26.3 ± 10.8^†	0.43 ± 0.09	41.0 ± 5.5
End	−5.5 ± 19.0	1.1 ± 3.6	4.1 ± 4.7	1.114 ± 0.267^†	14.9 ± 1.1	0.66 ± 0.05^†	−2.1 ± 0.7	−1.9 ± 0.8^†	−27.4 ± 11.4^†	0.42 ± 0.10	40.6 ± 4.4
Protocol 2A
Min 1	−12.1 ± 37.2	3.8 ± 1.2^†	20.5 ± 5.9^†	1.221 ± 0.055^†	42.5 ± 2.3^†	0.49 ± 0.01^†	−11.0 ± 1.9^†	−4.9 ± 0.5^†	−206.1 ± 31.6^†	1.78 ± 0.17^†	38.0 ± 6.5
Min 2	0.4 ± 18.6	8.0 ± 3.3^†	16.3 ± 8.9^†	1.237 ± 0.083^†	42.6 ± 2.6^†	0.49 ± 0.01^†	−10.2 ± 2.7^†	−4.7 ± 1.3^†	−199.0 ± 62.1^†	1.79 ± 0.20^†	38.1 ± 4.9
Protocol 2B
Min 1	−9.8 ± 28.5	−1.8 ± 7.5	6.3 ± 7.8	0.933 ± 0.218	12.0 ± 0.1	0.38 ± 0.08	−94.7 ± 27.1^†	−116.0 ± 32.3^†	−1379 ± 380^†	0.49 ± 0.05^†	38.5 ± 3.6^†
Min 2	4.4 ± 25.1	0.5 ± 5.1	9.3 ± 5.0	0.970 ± 0.215^†	12.0 ± 0.1	0.38 ± 0.08	−99.3 ± 28.6^†	−125.0 ± 30.4^†	−1503 ± 348^†	0.51 ± 0.04^†	40.5 ± 4.4
Protocol 2C
Min 1	−15.7 ± 16.6	−0.3 ± 4.5	−0.7 ± 2.1	1.270 ± 0.404	12.1 ± 0.1	0.35 ± 0.04	−1.9 ± 0.6	−1.7 ± 1.1	−20.2 ± 13.0^†	0.67 ± 0.09^†	36.1 ± 0.4
Min 2	2.9 ± 6.0	0.3 ± 2.1	−0.7 ± 2.5	1.187 ± 0.215	11.9 ± 0.3	0.34 ± 0.08	−2.0 ± 0.9	−1.9 ± 1.1	−23.4 ± 13.8^†	0.68 ± 0.14^†	39.0 ± 4.1

Values are means ± S.D. Protocol 1A: 60% MIP + 0.70 duty cycle, fatiguing (n = 7). Protocol 1B: 2% MIP + 0.70 duty cycle, non-fatiguin (n = 7). Protocol 2A: hyperpnoean, non-fatiguing (n = 6). Protocol 2B: 95% MIP + 0.35 duty cycle, non-fatiguing (n = 4). Protocol 2C: 2% MIP + 0.35 duty cycle, non-fatiguin (n = 3).

Significantly different from eupnoea, and from non-fatiguing trial at 2% MIP + 0.70 duty cycle (protocol 1B; P < 0.05).

^†

Significantly different from eupnoea (P < 0.05). End-tidal P_o₂ averaged 110 mmHg for protocols 1A and 1B and 350 mmHg for protocols 2A, 2B and 2C. ∫P_M, integrated mouth pressure; ∫P_M × f_b, average ∫P_M per breath multiplied by breathing frequency.