Infectious Complications of Respiratory Therapy

Abstract

Patients who require respiratory therapy are more likely than other patients to develop bacterial infections of the respiratory tract. These patients are more susceptible than healthy persons to colonization of the respiratory tract by pathogenic organisms from the environment and other persons. They also are likely to aspirate contaminated oropharyngeal secretions into the tracheobronchial tree; and they usually have impaired antibacterial defense mechanisms of the lower respiratory tract. While respiratory therapy cannot be held accountable for these abnormalities, respiratory therapy equipment and techniques play a dual role in the problem of respiratory infections, having both positive and negative effects. On the positive side, therapy aims to decrease sources of pathogens, to improve mucociliary clearance, and to enhance antibacterial defense mechanisms—by the use of humidification, aerosols, lung inflation, cough, suctioning, oxygen, and drugs that act on the airway. On the negative side, respiratory therapy equipment can act as reservoirs and agents of transmission of infectious bacteria, suctioning can compromise the mucociliary defense system, and alveolar hyperoxia can depress the antibacterial defense mecha-nisms of the lower respiratory tract. It is therefore important to adequately clean and decontaminate equipment, to schedule changes of equipment, to use certain dispos-able devices, to employ proper suctioning procedures, and to avoid alveolar hyperox-ia. Improved techniques are needed for preventing aspiration of oropharyngeal secretions and for stimulating mucociliary function and the antibacterial function of lung cells. But in the absence of such improved techniques, it is critically important that respiratory therapy equipment and techniques not actively promote the occur-rence of infections by serving as sources or vehicles of transmission of infectious organisms or by adversely affecting antibacterial defense mechanisms.