In mechanically ventilated (MV) patients, occurrence of a ‘microbial shift’ in dental plaque to include respiratory pathogens has been suggested. These microorganisms may subsequently cause ventilator-associated pneumonia. The causes of microbial change are unclear, but could relate to poor oral hygiene, reduced salivary flow or other perturbations to the oral environment related to underlying condition or treatment. The aim of this study was to examine occurrence of microbial changes and possible underlying factors in MV patients.
Method:
Dental plaque and saliva were collected from 50 MV patients (3 times during the first week of intubation, and weekly until hospital discharge). Microbial culture and identification was undertaken on dental plaque, whilst total volume and protein quantity was determined for saliva.
Result:
Pseudomonas aeruginosa was detected in dental plaque of 18% of MV patients (66.6% not positive at admission), whilst 42% of MV patients (17.4% not positive at admission) had S. aureus. Reduction in saliva volume and total protein concentration was evident in >75% of patients whilst undergoing MV. Saliva volume increased in 22% of patients post extubation.
Conclusion:
Microbial shift occurred in dental plaque of MV patients to include respiratory pathogens. Initial salivary analysis indicated that saliva volume and total protein concentration decreased during mechanical ventilation which could promote this microbial change. The results highlight the importance of oral care in MV patients to reduce the risk of harboring respiratory pathogens within the mouth.