Daily toothbrushing in hospitals linked to significant drop in pneumonia cases and ICU mortality rates

By Dr. Liji Thomas, MDDec 19 2023Reviewed by Danielle Ellis, B.Sc.

Hospital-acquired pneumonia (HAP) is a significant cause of illness and death among patients requiring hospitalization. Little is known about the effectiveness of potential prevention strategies, however. A new study in JAMA Internal Medicine explored the clinical impact of daily toothbrushing on the incidence of HAP and its outcomes.

Study: Association Between Daily Toothbrushing and Hospital-Acquired Pneumonia. Image Credit: TShaKopy / Shutterstock

About one in a hundred patients in hospital develop HAP. This not only endangers their health and that of others but increases the chances of delayed recovery and treatment costs. The risk is increased among patients on mechanical ventilation (MV) who have been intubated relative to others. However, in terms of volume, non-ventilated patients make up a greater proportion of HAP cases (NV-HAP).

Both groups of patients have similar mortality rates from HAP. The lack of data on the clinical outcomes following various preventive approaches has hindered the adoption of uniform strategies to avert this risk.

Careful oral hygiene has been highlighted as a potentially very effective intervention to reduce the aspiration of oral organisms, either micro- or macro-aspirations. This is supported by the finding that the same organisms are found in the mouth and the lungs. This has led to the use of oral antiseptics, such as chlorhexidine, in patients on MV.

However, this antiseptic may be linked to higher mortality rates and has not been shown to reduce infectious complications in such patients. An alternative approach is to carefully and regularly brush the teeth, as recommended by the Society for Healthcare Epidemiology of America, excluding chlorhexidine. This is because of findings of lower ventilation-associated pneumonia and other favorable outcomes among patients who brushed their teeth regularly.

However, the small size of these studies and the lack of consensus on the association of toothbrushing with lower HAP-associated mortality, duration of MV and overall hospitalization, and antibiotic use motivated the current meta-analysis, including all relevant studies in this area.

The study included 15 randomized controlled trials (RCTs) that included, in effect, over 2,800 patients, about 80% of them admitted to the intensive care unit (ICU) and the rest in other departments. Overall, nasal and oral intubation was included, with about a fifth of patients having tracheotomies.

In most studies, chlorhexidine was used in addition to or instead of brushing in the intervention and control groups. A few used anti-plaque toothpaste, povidone-iodine, saline, or purified water instead of chlorhexidine.

What did the study show?

The results show that HAP incidence was significantly lower by over a third among those who brushed their teeth daily. This meant that for every 12 patients who brushed their teeth regularly, the incidence of pneumonia went down by 1 case.

Patients on MV experienced a reduced incidence of pneumonia by 30%, but this was not observed among those on invasive mechanical ventilation (IMV). The risk of HAP in non-ventilated patients (NV-HAP) was reduced by 15% in those admitted for medical issues but not among surgical patients.

Two studies dealt with NV-HAP revealed a 70% drop in the risk of pneumonia among patients with regular toothbrushing.

Similarly, patients had to spend less time on MV, by a mean of 1.2 days and spent on average 1.3-2 days less in the ICU. The rate of mortality among ICU patients also went down by a fifth.

Brushing teeth twice a day was found to be as effective as brushing more frequently. In most cases, the brushing was carried out by nursing staff, and only sometimes by dental professionals.

There was little effect on the length of stay in hospital outside the ICU or the duration of antibiotic use.

What are the implications?

The study appears to support extensive efforts to promote regular toothbrushing at least twice a day among hospitalized patients. "Daily toothbrushing may be associated with significantly lower rates of HAP, lower rates of ICU mortality, shorter duration of mechanical ventilation, and shorter ICU length of stay."

Compared to earlier research, this study is more comprehensive and thus better able to identify actual changes in VAP outcomes following toothbrushing. The strength of the evidence supporting the above conclusion suggests that hospital patients, especially on IMV, should have routine toothbrushing as part of their standard care in view of the documented drop in pneumonia and mortality.

Further research will be required to answer questions about the importance of the type of toothpaste used, the need for tongue cleaning, and gut cleansing or decontamination. Despite the study's limitations, it serves as evidence suggesting the need for "policies and programs to encourage daily toothbrushing in hospitalized patients, particularly those receiving mechanical ventilation."