Respiratory system compliance at the same PEEP level is similar in COVID and non-COVID ARDS

Respiratory Research

Table 1 Patient characteristics

	Non-COVID ARDS	COVID ARDS	p value	COVID ARDS, matched cohort	p value*
Number of patients	91	276		91
Age, years	69 [59, 77]	68 [60, 73]	0.30	67 [63, 73]	0.40
Male sex	61 (67)	207 (75)	0.18	71 (78)	0.14
Respiratory rate, breaths·minute⁻¹	21 [18, 25]	22 [20, 25]	0.16	22 [20, 24]	0.47
PEEP, cmH₂O	8 [6, 10]	10 [8, 14]	< 0.001	10 [8, 12]	< 0.001
pH	7.34 [7.26, 7.43]	7.32 [7.23, 7.39]	0.02	7.34 [7.23, 7.39]	0.13
PaCO₂, mmHg	44 [36, 53]	51 [44, 62]	< 0.001	49 [44, 60]	< 0.001
BMI, kg/m²	26 [22, 29]	28 [26, 32]	< 0.001	27 [25, 31]	0.005
V_T, ml·kg IBW	6.4 [5.8, 7.1]	6.0 [5.4, 6.5]	< 0.001	5.9 [5.4, 6.3]	< 0.001
PaO₂/FiO₂	117 [89, 172]	103 [77, 138]	0.017	108 [80, 144]	0.12
Predicted FRC, liters	3.1 [2.7, 3.6]	3.1 [2.6, 3.4]	0.07	3.10 [2.7, 3.6]	0.71
Ventilatory Ratio	1.7 [1.3, 1.9]	1.9 [1.5, 2.2]	0.001	1.8 [1.5, 2.1]	0.027
Best C_rs, ml/cmH₂O	38 [29, 50]	40 [30, 48]	0.98	40 [30, 49]	0.82
Best minimum PEEP, cmH₂O	6 [4, 8]	6 [2, 10]	0.64	4 [2, 8]	0.012

Data are shown as median [interquartile range], or count (percentage)
The last column (*) shows the comparison between non-COVID ARDS and COVID ARDS patients matched for predicted FRC. Best compliance is the highest C_rs obtained at the tested PEEP levels
Best minimum PEEP is the lowest PEEP level associated with the highest C_rs
PEEP positive end expiratory pressure, BMI body mass index, V_T tidal volume, IBW ideal body weight, FRC functional residual capacity, C_rs respiratory system compliance, ARDS acute respiratory distress syndrome

ISSN: 1465-993X