The influence of the addition of rinsing with a 0.05% chlorhexidine-containing solution to usual daily oral hygiene care on the incidence of aspiration pneumonia in physically-impaired care home residents with dysphagia.

In care homes pneumonia is the second most common infection, after urinary
tract infections, and the leading cause of death from infection (Pace and
McCullough, 2010). In care homes, the incidence of pneumonia is ten times
higher than the incidence in the community (Oh et al, 2004). Care home
residents have a higher risk of developing aspiration pneumonia than
community-dwelling older people (Shariatzadeh et al, 2006).
Care home residents are often dependent on nurses for daily oral hygiene care.
It has been found that care home residents have poor oral hygiene, both for
teeth and removable dentures (De Visschere et al, 2006). The accumulation of
oral plaque emerges and inadequate oral hygiene care increases colonization of
respiratory pathogens in oral plaque (Scannapieco, 1999). Not the type of oral
bacteria, but the amount of bacteria aspirated is an important factor in the
development of pneumonia (Ingles et al, 1993). Oral hygiene care, such as tooth
brushing after each meal, cleaning dentures once daily and professional oral
health care once weekly reduces the number of oral bacteria (Yoneyama et al,
2002; Bassim et al, 2008; Ishikawa et al, 2008). However, it is not clear which
oral health care intervention is most efficacious in reducing the risk of
aspiration pneumonia.
The mechanism of aspiration pneumonia onset is unknown. Scannapieco
(1999) described four feasible mechanisms for oral bacteria causing respiratory
infections. Colonization of pulmonary pathogens in the oral biofilm and
aspiration of these pathogens into the lungs, is the first mechanism. The
second mechanism is that in saliva present periodontal-disease-associated
enzymes may modify mucosal surfaces and facilitate the adherence of respiratory
pathogens which can be aspirated into the lungs. The third mechanism is
periodontal-disease-associated enzymes destroying protective salivary
pellicles. Fourth, cytokines from infected periodontal tissues may alter
respiratory epithelium, which results in respiratory pathogen colonization and
an increased risk of infection. However, until now no evidence for one of these
hypotheses has been found. The difference in diagnosing an aspiration pneumonia
or a pneumonia is clinically not possible. Therefore the diagnose pneumonia
will be used.
Recently, the literature published between January 2000 and April 2009
was systematically reviewed on the risk factors of aspiration pneumonia in
frail older people (van der Maarel-Wierink et al, 2011a). The following risk
factors could be identified: age, male gender, lung diseases, dysphagia,
diabetes mellitus, severe dementia, ACE DD genotype, bad oral health,
malnutrition, Parkinson*s disease and the use of antipsychotic drugs and proton
pump inhibitors. The presence of two or more of the risk factors could be an
indicator that specific preventive oral health care is needed (van der
Maarel-Wierink et al, 2011a). A combination of frequent toothbrushing and a
pharmacological intervention, such as the use of an antiseptic mouthwash, was
suggested as an adequate intervention (van der Maarel-Wierink et al, 2012).
A meta-analysis confirmed dysphagia being a significant risk factor for
aspiration pneumonia in frail older people (OR = 9.84; 95% CI = 4.15 - 23.33),
specifically in stroke patients: OR = 12.93; 95% CI = 8.61-19.44 (van der
Maarel-Wierink et al, 2011b). Data from another study demonstrated that
completely dependent residents had a 42 times and to a great extent dependent
residents a 13 times higher risk of subjective dysphagia than independent
residents (van der Maarel-Wierink et al, 2012).
Although oral hygiene care is known to prevent aspiration pneumonia, it
is not yet clear which oral hygiene care intervention is most efficacious in
reducing the risk of aspiration pneumonia (van der Maarel-Wierink et al,
2011b). The combination of usual oral hygiene care and a pharmacological
intervention, using a chlorhexidine-containing solution, might be an adequate
method. Twice-daily oropharyngeal cleansing with a 0.2% chlorhexidine gluconate
solution has proven to reduce the risk of nosocomial pneumonia in patients
residing at intensive care units, not specifically older patients (Panchabhai
et al, 2009).
A randomized controlled trial is needed to find out whether oral hygiene care
with a chlorhexidine-containing solution in addition to usual oral hygiene care
reduces the incidence of pneumonia in physically-impaired care home residents
with dysphagia.

Primary objective:
To assess the influence of the addition of rinsing with a 0.05%
chlorhexidine-containing solution to usual daily oral hygiene care on the
incidence of pneumonia in physically-impaired care home residents with
dysphagia.

Secondary objective:
To assess the correlation between some medical, physical, and oral conditions
and the incidence of aspiration pneumonia in physically-impaired, older care
home residents with dysphagia who rinse with a 0.05% chlorhexidine-containing
solution or a placebo in addition to usual daily oral hygiene care.

The primary and secondary objective of the study are expressed by 2 research
questions:
1) Is there any statistically significant difference with regard to the
incidence of pneumonia in physically-impaired care home residents with
dysphagia, who in addition to usual daily oral hygiene care rinse with a 0.05%
chlorhexidine-containing solution or a placebo?

2) Is there any statistically significant correlation between on the one hand
age, gender, diseases diagnosed, care dependency, medication use, number of
teeth and implants present, and presence of removable dentures and on the other
hand the incidence of pneumonia in physically-impaired care home residents with
dysphagia who rinse with a 0.05% chlorhexidine-containing solution or a placebo
in addition to usual daily oral hygiene care?

The study design is a randomized controlled trial, with care home wards as
units of randomization. Care home wards will randomly be allocated to either
the intervention group or the control group, while the groups will be balanced
for dysphagia severity and care dependency. Care home residents fulfilling the
inclusion criteria as well as participating physicians, speech therapists, oral
health care providers, nurses, examiner and assistant examiners will be blinded
to the assignment in order to prevent bias. The applied solutions will be
labelled using encrypted codes which refer to the chlorhexidine-containing
solution or the placebo. To prevent bias, the placebo will have the same
wrapping, colour, odour, and taste as the chlorhexidine-containing solution.

The intervention consists of applying a 0.05% chlorhexidine-containing solution
twice daily immediately after the usual oral hygiene care, whereas the control
group receives a placebo. The placebo has the same wrapping, colour, odour, and
taste, and contains the same ingredients as the chlorhexidine-containing
solution, except the chlorhexidine.

The application method of the 0.05% chlorhexidine-containing solution is
depending on the severity of the dysphagia. Residents who tolerate thin liquids
have to rinse with the 0.05% chlorhexidine-containing solution for 30 seconds
twice daily immediately after the usual oral hygiene care. Residents with
severe dysphagia who cannot tolerate thin liquids have to clean their teeth,
gums, tongue, palate, and buccal mucosa with a gauze containing 0.05%
chlorhexidine-containing solution twice daily immediately after the usual oral
hygiene care.

Rinsing with a chlorhexidine-containing solution gives very rarely allergic
and/or hypersensitivity reactions. Other side effects are discoloration of
teeth, removable dentures, mucosa or tongue, temporary taste disorder, swelling
of salivary glands, and pain. However, these are side-effects of 0.2%
chlorhexidine-containing solutions and rarely of lower-concentration
chlorhexidine-containing solutions, whereas the concentration used in this
study is 0.05%. The (reversible) tooth and removable denture discoloration is
stronger in the presence of tannins in the mouth, such as after drinking tea,
coffee or wine. Oral ingestion of chlorhexidine is usually well tolerated
because of the negligible systemic absorption.
The benefit for the residents in the intervention group may be a better oral
hygiene status and oral health condition, and consequently, a reduction of the
incidence of pneumonia. No strenuous physical examinations will be carried out
and participating residents have to provide informed consent. When the
symptoms of pneumonia occur, the resident will be physically examined by a
physician. Only a short oral examination by an oral health care provider and
determining dysphagia by a speech therapist will be carried out.