Caruso 2009.

Methods	Study design: 2‐arm RCT Location: Brazil Number of centres: 1 Study period: August 2001 to December 2004 Funding source: Not stated
Participants	Setting: Closed medical surgical ICU unit in oncologic hospital Inclusion criteria: Patients aged > 18 years expected to need mechanical ventilation for > 72 hours through orotracheal or tracheotomy tube Exclusion criteria: Previous mechanical ventilation within past month, mechanical ventilation for > 6 hours prior to study enrolment, contraindication to bronchoscopy and expected to die or stop treatment within 48 hours Number randomised: 262 Number evaluated: 262 Baseline characteristics: ‐ Intervention group: Age: 65 ± 14 years; M/F: 66/64 ‐ Control group: Age: 63 ± 6 years; M/F: 70/62
Interventions	Comparison: Saline rinse versus usual care Experimental group (n = 130): Instillation of 8 ml of isotonic saline prior to tracheal suctioning, which was conducted by respiratory therapists Control group (n = 132): Tracheal suction alone with no saline instillation Aspirations were carried out when 1 of the following occurred: visible airway secretion into endotracheal tube, discomfort or participant asynchrony, noisy breathing, increased peak expiratory pressures, or decreased tidal volume during ventilation attributed to airway secretion
Outcomes	1. Incidence of VAP 2. Duration of ventilation in ICU 3. Length of stay in ICU 4. ICU mortality 5. Tracheal colonisation 6. Suctions per day, chest radiographs
Notes	Sample size calculation: Estimated that 130 participants per group required to give 80% power with α = 5% to detect a decrease in VAP from 30% to 15%
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"randomised" No details of method of sequence generation provided in report
Allocation concealment (selection bias)	Unclear risk	Not described
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Attending physicians and nurses blinded to study group. Intervention carried out by respiratory therapists available on ICU 24/7
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessment conducted by physicians and nurses blinded to allocated treatment
Incomplete outcome data (attrition bias) All outcomes	Low risk	All randomised participants included in outcome evaluation
Selective reporting (reporting bias)	Low risk	All planned outcomes reported in full
Other bias	Low risk	No other sources of bias identified