Effects of higher PEEP and recruitment manoeuvres on mortality in patients with ARDS: a systematic review, meta-analysis, meta-regression and trial sequential analysis of randomized controlled trials

Intensive Care Medicine Experimental

Table 2 Baseline characteristics of patients included in the meta-analysis

Parameter	Intervention (n = 1918)	Control (n = 1952)
Age, years	55.7 (3.2) [n = 1919]	56.1 (5.3) [n = 1952]
Women, No (%)	732 (38) [n = 1918]	750 (38) [n = 1952]
PaO₂/FIO₂ at enrolment, mmHg	135.8 (14.4) [n = 1859]	134.7 (17.4) [n = 1892]
Respiratory system compliance, mL/cmH₂O	32.9 (5.1) [n = 969]	32.0 (4.4) [n = 975]
Causes of lung injury
Pneumonia, No. (%)	920 (49) [n = 1878]	933 (49) [n = 1911]
Aspiration, No. (%)	175 (13) [n = 1373]	185 (13) [n = 1376]
Sepsis, No. (%)	495 (26) [n = 1908]	538 (28) [n = 1942]
Multiple trauma, No. (%)	54 (4) [n = 1394]	72 (5) [n = 1432]
Ventilation parameters
Tidal volume, mL/kg of predicted body weight	7.3 (1.1) [n = 1909]	7.4 (1.2) [n = 1942]
Set PEEP, cmH₂O	11.2 (1.8) [n = 1643]	11.1 (2.1) [n = 1679]
Driving pressure, cmH₂O	15.4 (2.4) [n = 1575]	15.2 (2.1) [n = 1615]
Plateau pressure, cmH₂O	27.0 (2.8) [n = 1575]	26.8 (2.7) [n = 1615]

Data are mean (standard deviation) or frequency (proportion). Number of patients for each variable is also reported, as data was missing or not reported as mean in all studies. Values are estimated means (standard deviations) calculated with a mixed-effects model using the DerSimonian-Laird method. PEEP positive end-expiratory pressure