Xirouchaki 2008.
| Methods | Single centre randomized controlled trial | |
| Participants | 208 (108 intervention; 100 control) adults ventilated for >36 hours on a controlled mode. Exclusion criteria comprised: severe acidaemia (pH>7.30); severe haemodynamic instability defined as a need for norepinephrine infusion at a rate greater than 0.5μg/kg/h, and severe bronchospasm | |
| Interventions | Intervention: Proportional Assist Ventilation + using a Puritan–Bennett 840 ventilator and a specific pre–defined written algorithm was used to set and adjust the ventilator. The initial percentage of assist was set to 60‐80%. PAV+ was continued for 48 hours unless the patients met pre‐defined criteria either for switching to CMV (failure criteria) or for breathing without ventilator assistance. Control: PSV with pre‐defined written algorithms were used to adjust the ventilator settings |
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| Outcomes | Proportion of patients meeting failure criteria in each mode during the 48 hour study period Proportion of patients meeting criteria for unassisted breathing Proportion of patients exhibiting major patient– ventilator dys‐synchronies Total amount of sedative, analgesic and vasoactive drugs during the 48 hour of observation |
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| Notes | Duration of ventilation and ICU stay provided in electronic supplement | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Randomization schedule previously generated by a statistician |
| Allocation concealment (selection bias) | Low risk | Opaque and sealed envelopes used |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | Attrition reported, no missing outcome data |
| Selective reporting (reporting bias) | Low risk | All pre‐specified outcomes are reported |
| Other bias | Low risk | No other sources of bias detected |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | Not possible due to nature of intervention |
| Blinding of outcome assessment (detection bias) All outcomes | High risk | Individuals collecting the results and outcome data were also involved in clinical management of patients |