Inflammatory Cellular Response to Mechanical Ventilation in Elastase-Induced Experimental Emphysema: Role of Preexisting Alveolar Macrophages Infiltration

Table 1

Respiratory mechanics data during mechanical ventilation in D14 and D21 Saline and Elastase mice.

	Saline MV			Elastase MV
	H0’	H1	H2	H0’	H1	H2
D14
Ppeak, cmH20	9.4±0.9	10.5±1.2	11.2±1.7	7.9±1.3	8.4±1.0	9.3±1.8
Pmean, cmH20	6.3±0.3	6.9±0.7	7.4±0.9	6.0±0.4	6.2±0.4^£	6.5±0.8
Compliance, 10^−3mL/cmH20	41.0±8.0	33.0±6.0	28.0±6.0	62.0±13.0	46.0±11.0	39.0±10.0
Resistance, 10^−2cmH20.s/mL	70.0±21.0	75.0±23.0	72.0±26.0	72.0±8.0	80.0±11.0	79.0±9.0
∆Compliance, %			-33.3±9.6			-39.1±4.3^£
D21
Ppeak, cmH20	8.7±1.0	9.8±0.9	10.7±1.0	8.0±0.7	8.7±1.1	9.8±1.9
Pmean, cmH20	6.3±0.9	6.8±0.8	7.2±0.7	6.1±0.6	6.2±0.7	6.5±0.7^£
Compliance, 10^−3mL/cmH20	44.0±8.0	36.0±6.0	28.0±4.0	60.0±20.0	43.0±12.0	32.0±10.0^£
Resistance, 10^−2cmH20.s/mL	69.0±17.0	79.0±19.0	77.0±12.0	76.0±12.0	76.0±23.0	88.0±20.0
∆Compliance, %			-34.3±6.4			-40.8±14.8

Values are expressed as medians ± interquartile range. n = 6 animals/group at D14, 13 animals/group at D21. ^£, , , and denote p value <0.10 (marginally significant), <0.05, <0.01, and <0.001, respectively, for the Mann-Whitney pairwise comparisons (following Kruskal-Wallis test), Elastase MV versus Saline MV. Definition of abbreviations: MV: mechanical ventilation; H0’: after volume history standardization consisting of three inflations to a transrespiratory pressure of 30 cmH₂O; H1: after one hour; H2: at the end of MV; Ppeak: peak airway pressure; Pmean: mean airway pressure; Compliance, Resistance: dynamic compliance and resistance of the respiratory system calculated using the single frequency forced oscillation technique; ∆Compliance: percentage of compliance decrease during mechanical ventilation, between H0’ and H2.