Duration of mechanical ventilation and oxygen therapy
Five studies reported duration of mechanical ventilation, and four studies reported duration of oxygen therapy. We observed that the duration of mechanical ventilation (OR -0.72, 95%CI: -0.92 - -0.51,P<0.001) and oxygen therapy duration (OR -6.05, 95%CI: -6.56 - -5.54, P<0.001) were considerably lower in the prophylactic caffeine group than in the control group. The random-effects model was employed because moderate heterogeneity in duration of mechanical ventilation was identified among the included studies (I2=52.2%, P=0.079, Figure 3B). We used a fixed-effects model to evaluate the meta-analysis of the duration of oxygen therapy (I2=23.5%, P=0.270, Figures 3C).