Fig. 4From: Could remifentanil reduce duration of mechanical ventilation in comparison with other opioids for mechanically ventilated patients? A systematic review and meta-analysisFunnel plots. Funnel plots were generally asymmetrical. The hollow dots and dotted line indicate individual studies and 95% confidence intervals, respectively. a Funnel plot of duration of mechanical ventilation. b Funnel plot of ICU-LOS. c Funnel plot of time to extubation after cessation of sedationBack to article page