title: Saline instillation before tracheal suctioning decreases the incidence of ventilator-associated pneumonia.
abstract: OBJECTIVE
  To compare the incidence of ventilator-associated pneumonia (VAP) with or without isotonic saline instillation before tracheal suctioning. As a secondary objective, we compared the incidence of endotracheal tube occlusion and atelectasis.
  
  
  METHODS
  Randomized clinical trial.
  
  
  METHODS
  The study was conducted in a medical surgical intensive care unit of an oncologic hospital. We selected consecutive patients needing mechanical ventilation for >72 hrs. Patients were allocated into two groups: a saline group that received instillation of 8 mL of saline before tracheal suctioning and a control group which did not. VAP was diagnosed based on clinical suspicion and confirmed by bronchoalveolar lavage quantitative culture. The incidence of atelectasis on daily chest radiography and endotracheal tube occlusions were recorded. The sample size was calculated to a power of 80% and a type I error probability of 5%.
  
  
  RESULTS
  One hundred thirty patients were assigned to the saline group and 132 to the control group. The baseline demographic variables were similar between groups. The rate of clinically suspected VAP was similar in both groups. The incidence of microbiological proven VAP was significantly lower in the saline group (23.5% x 10.8%; p = 0.008) (incidence density/1.000 days of ventilation 21.22 x 9.62; p < 0.01). Using the Kaplan-Meier curve analysis, the proportion of patients remaining without VAP was higher in the saline group (p = 0.02, log-rank test). The relative risk reduction of VAP in the saline instillation group was 54% (95% confidence interval, 18%-74%) and the number needed to treat was eight (95% confidence interval, 5-27). The incidence of atelectases and endotracheal tube occlusion were similar between groups.
  
  
  CONCLUSIONS
  Instillation of isotonic saline before tracheal suctioning decreases the incidence of microbiological proven VAP.
authors.affiliation: Hospital A C Camargo, Sao Paulo, SP, Brazil. pedro.caruso@hcnet.usp.br
authors.forename: Pedro
authors.initials: P
authors.lastname: Caruso
authors.forename: Silvia
authors.initials: S
authors.lastname: Denari
authors.forename: Soraia A L
authors.initials: SA
authors.lastname: Ruiz
authors.forename: Sergio E
authors.initials: SE
authors.lastname: Demarzo
authors.forename: Daniel
authors.initials: D
authors.lastname: Deheinzelin
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D007322:Instillation, Drug; D007442:Intubation, Intratracheal / Q000009:adverse effects; D007552:Isotonic Solutions / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D053717:Pneumonia, Ventilator-Associated / Q000453:epidemiology* / Q000517:prevention & control*; D001261:Pulmonary Atelectasis / Q000453:epidemiology / Q000517:prevention & control; D012965:Sodium Chloride / Q000008:administration & dosage*; D013396:Suction; D014132:Trachea
chemical_list: D007552:Isotonic Solutions; D012965:Sodium Chloride