Do endotracheal tubes with suction above the cuff decrease the rate of ventilator-associated pneumonia, and are they cost-effective?

1. Department of Pulmonology, Faculdade de Medicina, Universidade de São Paulo USP São Paulo (SP), Brazil. 2. Faculdade de Medicina, Universidade de São Paulo USP São Paulo (SP), Brazil. Endotracheal tube-associated pneumonia and ventilator-associated pneumonia (VAP) occur in approximately 10% to 25% of patients who require invasive mechanical ventilation for more than 24 hours; the incidence density rate varies between 9 and 15 cases per 1,000 days of mechanical ventilation. Mortality rates associated with VAP vary with the criteria used for diagnosis: the rates are lower if only clinical criteria are used, such as purulent discharge, fever or hypothermia, leukocytosis or leukopenia and progressive or new radiological infiltrate; the rates are progressively higher if microbiological criteria are used, such as a quantitatively positive bronchoalveolar lavage culture, and if gas exchange deteriorates to the point of requiring an increase in the fraction of inspired oxygen (FIO2) and in positive end-expiratory pressure (PEEP). (1,2) Recently, Su et al. reported that serum levels of soluble triggering factor receptor expressed on myeloid cells (sTREMs) are important for diagnosing VAP in septic patients and that the serum levels of procalcitonin and the value of the clinical pulmonary infection score (CPIS) are important prognostic factors. (3) Preventive measures have been shown to be effective in decreasing VAP occurrence and are increasingly being used and becoming more widespread in intensive care units (ICUs). These measures include raising the headboard angle of the patient’s bed to 30°-45°, applying oral hygiene using chlorhexidine, daily awakening of the patient (stopping sedation once a day), using effective protocols for weaning from mechanical ventilation, observing hand hygiene for health professionals, using tracheal tubes impregnated with antiseptics, using tubes that allow the aspiration of secretions above the cuff and, increasingly, using non-invasive ventilation. (4) The rationale for using tracheal tubes that allow the aspiration of secretions that accumulate above the cuff of the tracheal tube is that these secretions spread through microchannels present in the tube cuffs and are eventually aspirated into the patients’ lungs, contributing to the occurrence of VAP. Tubes with suction above the cuff allow for the intermittent aspiration of these secretions, either with high pressure or continuously with pressures up to 20 mmHg, maintaining space above the cuff free of secretions and reducing the occurrence of microaspirations. Prospective and controlled studies in critically ill patients comparing the use of tubes with the possibility of suction above the cuff and traditional tracheal tubes have indicated decreased VAP incidence with the use of subglottic suction or suction above the cuff. An analysis of 2,213 patients from a total of 10 randomized trials using tracheal tubes with suction above the cuff exhibited a significant reduction in the incidence of VAP (relative risk: 0.56, 95% confidence interval [95% CI]: 0.45-0.69, p<0.00001) and early-onset Conflicts of interest: None.