Clinical review: Airway hygiene in the intensive care unit

Clearance of airway secretions, or airway hygiene, is a normal physiological process needed for the preservation of airway patency and the prevention of respiratory tract infection. Impaired clearance of airway secretions can result in atelectasis and pneumonia, and may contribute to respiratory failure prompting admission to an intensive care unit (ICU).Physical methods to augment the clearance of secretions are often used in the ICU. This review focuses on mechanical methods and pharmacological agents commonly used to maintain airway hygiene in the ICU, and their effect on clinical outcomes of critically ill patients. The impact of oral hygiene, tracheal suctioning, bronchoscopy, mucus-controlling agents, and kinetic therapy on the incidence of nosocomial respiratory infections, length of stay in the hospital and the ICU, and mortality will be discussed. Where possible, we have distilled available data into recommendations for airway hygiene in ICU patients.Literature for this article was identified by searching the PubMed database (1966 to present). English-language articles of relevance were selected and reviewed. Additional resources were obtained through the bibliographies of reviewed articles. The following search terms were used: airway hygiene, oral hygiene, mucociliary clearance, tracheal suctioning, bronchoscopy, mucolytics, chest physiotherapy, kinetic therapy, continuous lateral rotational therapy, selective digestive decontamination, nosocomial pneumonia, hospital-acquired pneumonia, ventilator-associated pneumonia, and pneumonia.A summary of recommendations and associated strength of supporting evidence for strategies used in the reduction of nosocomial pneumonia is shown in Table 1. The following grading system described by Kollef [1] was used to assess strength of evidence: A, supported by at least two randomized, controlled investigations; B, supported by at least one randomized, controlled investigation; C, supported by nonrandomized, concurrent-c