Lung Function and Organ Dysfunctions in 178 Patients Requiring Mechanical Ventilation During The 2009 Influenza A (H1N1) Pandemic

Table 2 Variables related to mechanical ventilation in all patients, and comparison between survivors and non-survivors.

	Day 0				Day 3				Day 7				Day 10
	All	S	NonS	P	All	S	NonS	P	All	S	NonS	P	All	S	NonS	P
N	178	93	85		152	89	63		129	80	42		73	38	35
Tidal volume (ml/kg of IBW)	7.8 ± 2	8.0 ± 2	7.7 ± 2	.35	7.9 ± 2	8.0 ± 2	7.8 ± 2	.46	7.9 ± 2	8.2 ± 2	7.5 ± 1	.02	8.1 ± 2	8.3 ± 2	7.9 ± 2	.35
Plateau pressure (cmH₂O)	26 ± 7	25 ± 6	27 ± 8	.09	24 ± 7	24 ± 6	26 ± 8	.10	24 ± 7	23 ± 6	27 ± 8	.01	25 ± 8	24 ± 7	26 ± 8	.16
PEEP. (cm H₂O)	10 (7 to 14)	10 (7 to 14)	10 (8 to 14)	.34	10 (7 to 14)	10 (7 to 12)	12 (7 to 14)	.05	10 (6 to 14)	8 ^a (5 to 12)	12 (8 to 15)	.003	10 (6 to 14)	8 ^b (6 to 12)	12 (8 to 15)	.008
Driving Pressure (cm H₂O)	16 ± 6	15 ± 5	17 ± 6	_..05	15 ± 6	14 ± 5	16 ± 6	.16	15 ± 6	14 ± 5	16 ± 7	.26	15 ± 7	14 ± 5	16 ± 8	.21
Respiratory rate (cycles/min)	21 ± 5	21 ± 5	21 ± 4	.66	21 ± 5	20 ± 4	22 ± 5	.22	21 ± 5	20 ± 4	22 ± 5	.15	20 ± 6	20 ± 5	23 ± 6	.03
PaO₂/FIO₂	136 (85 to 204)	146 (110 to 215)	125 (71 to 197)	.02	178 ^a (125 to 251)	220 ^a (156 to 287)	134 (84 to 185)	< 0.001	195 ^a (142 to 260)	230 ^a (172 to 292)	144 (88 to 190)	< 0.001	172 ^a (109 to 235)	212 ^a (164 to 270)	123 (80 to 160)	< 0.001
FIO₂ (%)	80 (25 to 100)	70 (50 to 100)	100 (70 to 100)	< 0.001	60 ^a (40 to 70)	50 ^a (40 to 60)	65 ^a (50 to 100)	< 0.001	50 ^a (40 to 65)	50 ^a (40 to 55)	60^a (45 to 85)	< 0.001	50 ^a (41 to 70)	47 ^a (40 to 50)	80 ^a (50 to 100)	< 0.001

Data are presented as means ± standard deviations, and medians and (IQR)
Vt, Tidal volume. IBW, predicted body weight. S, Survivors. NonS, Non-survivors. P, Intergroup comparisons (between survivors vs. non-survivors) at each day are shown.
For intragroup comparisons over time: Days 3, 7 and 10 are compared to Day 0 values, in all patients, in survivors and in non-survivors.
^a P <.001; ^b P <.01

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