Domiciliary metaproterenol nebulization: a bacteriologic survey

Area of Science:

• Pulmonary Medicine
• Infectious Diseases
• Medical Device Contamination

Background:

• Domiciliary jet nebulization (DJN) is a common treatment for respiratory conditions.
• Concerns exist regarding the potential for microbial contamination of nebulizer equipment with daily use.

Purpose of the Study:

• To assess the risk of fungal and bacterial contamination in DJN equipment.
• To determine if contaminated equipment leads to respiratory colonization or pneumonia in long-term users.

Main Methods:

• Evaluated 23 veterans using DJN daily, initially with multi-dose saline bottles (Protocol 1) and later with 20 cc vials (Protocol 2).
• Assessed equipment contamination after nebulization in a laboratory setting (Protocol 3).
• Monitored patients for respiratory colonization and pneumonia over 9000 patient-days.

Main Results:

• Equipment contamination was high in Protocol 1 (20/23 subjects) but reduced in Protocol 2 (3/11 subjects), with saline bottles and nebulizers being common sources.
• Contamination primarily involved oropharyngeal saprophytes and gram-negative bacilli, with heavier bacterial growth in Protocol 1.
• No patients developed respiratory colonization or pneumonia during the study period.

Conclusions:

• DJN equipment, especially when using multi-dose saline bottles, is prone to bacterial contamination.
• Despite equipment contamination, daily DJN use did not result in respiratory colonization or pneumonia in this patient cohort.
• Switching to single-use vials significantly reduced equipment contamination.