Table 2.

Quantification of respiratory variables during the three patterns of flow limitation

	Breath 1	Breath 2	Breath 3	Breath 4	Breath 5	Breath 6
Starling resistor
Ti, s	1.83	1.78	1.97	1.79	1.86	1.79
Ti/Ttot	0.52	0.49	0.50	0.49	0.52	0.52
Peak flow, l/s	0.34	0.31	0.29	0.32	0.31	0.31
Mean flow, l/s	0.25	0.23	0.22	0.24	0.23	0.22
Tidal volume, liter	0.45	0.41	0.43	0.42	0.42	0.40
Respiratory rate, beat/min	17.05	16.48	15.28	16.23	16.82	17.36
Instantaneous ventilation, l/min	7.70	6.79	6.57	6.87	7.06	6.96
Negative effort dependence within a breath only
Ti, s	1.80	1.84	1.94	1.95	2.10	2.24
Ti/Ttot	0.38	0.40	0.40	0.47	0.48	0.49
Peak flow, l/s	0.27	0.26	0.25	0.25	0.23	0.24
Mean flow, l/s	0.21	0.18	0.18	0.17	0.15	0.14
Tidal volume, liter	0.38	0.34	0.35	0.34	0.32	0.32
Respiratory rate, beat/min	12.38	13.62	13.26	13.14	13.75	12.91
Instantaneous ventilation, l/min	4.69	4.56	4.68	4.42	4.35	4.07
Negative effort dependence within and across breaths
Ti, s	1.27	1.52	1.46	1.76	2.01	1.96
Ti/Ttot	0.41	0.55	0.55	0.59	0.61	0.67
Peak flow, l/s	0.20	0.10	0.06	0.06	0.01	0.01
Mean flow, l/s	0.10	0.09	0.08	0.06	0.03	0.02
Tidal volume, liter	0.16	0.17	0.15	0.15	0.09	0.03
Respiratory rate, beat/min	19.49	21.75	22.40	20.09	18.28	20.40
Instantaneous ventilation, l/min	3.08	3.74	3.34	2.93	1.55	0.55

Breaths 1–6 are highlighted breaths from Fig. 6, A–C. Flow-limited Starling resistor breaths have similar peak flow, similar mean flow, and preserved tidal volume and minute ventilation. Negative effort dependence within a breath only has similar peak flow, but decreasing mean flow; ventilation is relatively preserved through increase in the duty ratio (Ti/Ttot). In contrast, in negative effort dependence across breaths, the increase in the duty ratio does not compensate for decreasing peak and mean flows.