High tidal volume mechanical ventilation-induced lung injury in rats is greater after acid instillation than after sepsis-induced acute lung injury, but does not increase systemic inflammation: an experimental study

Table 1 Hemodynamics and arterial blood gas analysis.

		Baseline	T = 0 hr	T = 2 hr	T = 4 hr
Mean arterial pressure (mmHg)	LVt acid^#	81 ± 4.0	84 ± 3.9	91 ± 3.8	77 ± 2.6*
	HVt acid^#	77 ± 3.4	88 ± 5.5	87 ± 2.7	72 ± 2.3
	LVt sepsis	75 ± 1.7	74 ± 2.6	68 ± 2.2	69 ± 2.5
	HVt sepsis	74 ± 2.2	80 ± 2.2	66 ± 2.1	65 ± 0.9
Heart rate (bpm)	LVt acid	269 ± 10	267 ± 11	332 ± 10	336 ± 12
	HVt acid	289 ± 8	249 ± 14	328 ± 7	345 ± 11
	LVt sepsis	322 ± 9^$	322 ± 9	346 ± 15	353 ± 8
	HVt sepsis	350 ± 14^$	360 ± 12	361 ± 10	350 ± 9
pH	LVt acid	7.41 ± 0.02	7.39 ± 0.01	7.37 ± 0.01	7.35 ± 0.01
	HVt acid	7.41 ± 0.02	7.38 ± 0.01	7.40 ± 0.01	7.30 ± 0.02
	LVt sepsis	7.44 ± 0.01	7.42 ± 0.01	7.38 ± 0.02	7.33 ± 0.02
	HVt sepsis	7.44 ± 0.01	7.44 ± 0.01	7.41 ± 0.02	7.38 ± 0.02
P_aCO₂ (mmHg)	LVt acid	39.4 ± 1.1	42.9 ± 1.8	42.4 ± 1.4	42.2 ± 1.4
	HVt acid	40.0 ± 1.2	43.8 ± 2.3	40.3 ± 1.3	45.8 ± 2.1
	LVt sepsis	37.1 ± 0.8	38.7 ± 1.78	38.0 ± 1.0	42.2 ± 1.0
	HVt sepsis	37.0 ± 1.5	38.7 ± 1.6	36.0 ± 0.7	36.0 ± 0.6

Mean arterial pressure (MAP) and heart rate in rats during 4 h of mechanical ventilation after acid instillation or during sepsis with low tidal volume (LVt) (6 mL/kg), with a positive end-expiratory pressure (PEEP) of 5 cm H₂O or high tidal volume (HVt) (15 mL/kg) without PEEP. Data represent mean ± SEM. ^# p < 0.001 for model compared to sepsis during the experiment, * p = 0.01 compared to HVt sepsis, ^$ p = 0.001 for model compared to acid only at baseline.

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