Table 1.

— Summary of Direct Measurements of Total and Peripheral Airways Resistance in Human Lungs

	Control		Emphysema		Chronic Bronchitisa
Source	Total	Peripheral	Total	Peripheral	Total	Peripheral
Hogg et al7	0.69±0.04	0.18±0.04	3.66±0.99	2.97±0.93	...	...
Van Brabandt et al23	1.52±0.27	1.24±0.27	10.47±3.79	9.44±3.42	...	...
Yanai et al14
Inspiration	3.1±0.1	0.7±0.3	5.9±0.8	2.8±0.4	8.7±1.1	4.6±0.5
Expiration	4.0±0.3	1.1±0.4	7.3±1.1	3.7±0.6	10.6±1.8	5.9±0.8
Wagner et al24/1990	...	0.15±0.03	...	...	...	...
Wagner et al25/1998	...	0.18±0.05	...	...	...	...

Mean±SE. All units are cm H₂O/L/s. The original Macklem and Mead data can be found in Reference 13. References in the Source column refer to studies where direct measurements of peripheral airways resistance have been reported.

^aAlthough the authors referred to these cases as chronic bronchitis, the obstruction was most likely attributable to the bronchiolitis present in some but not all cases of chronic bronchitis.¹⁴