The interest in research on oral care in intensive care unit (ICU) patients has emerged
largely from the 2000s onward after years of being a rather ignored topic in health
science. Since, the focus has been on its potential contribution to preventing pneumonia
by eliminating contaminated oral pathogens that might invade the lower respiratory
tract. Accumulating evidence of the effectiveness of oral care with chlorhexidine
gluconate (CHG) in preventing ventilator-associated pneumonia (VAP) or postoperative
pneumonia [1, 2] has led to adopting CHG oral care as the gold standard for intubated
patients. Recently, however, potential adverse effects of CHG on the oral mucosa [3]
and reduced bacterial susceptibility [4] have been reported, as well as an even more
alarming potential association of CHG oral care with an increased risk of mortality
[5–8]. Although the latter association results from retrospective studies or meta-analyses,
righteous calls for caution and for a thorough re-evaluation of the established gold
standard have been launched [9, 10].
It is not unlikely that the findings presented above could instigate questioning the
safety of oral care in the ICU. Additionally, doubt could be casted on its value as
the beneficial effect on the risk of VAP of other oral hygiene measures not involving
CHG, such as swabbing and toothbrushing, is not supported by the evidence [11].
Oral care does, however, not need to reduce the risk of pneumonia to be pivotal. As
in healthy individuals, mouth care is an indispensable basic hygiene requirement for
each ICU patient, intubated or not. Appropriate oral care counters discomfort caused
by xerostomia, a sore mouth or ulcerated lips, and promotes oral health by preventing
caries and decay of teeth, bacterial or candidal stomatitis, gingivitis, and periodontitis
which has been associated with systemic diseases such as bacteraemia, rheumatoid arthritis
and cardiovascular diseases, including stroke [12]. Oral health is therefore just
as important an endpoint of oral care as VAP prevention. A potential risk reduction
in pneumonia should rather be considered as a favourable side effect of oral care
and not as the primary goal.
Moreover, oral care aiming at oral health does not necessarily involve CHG use. Toothpaste
and an appropriate brush adequately clean teeth and gums. The oral cavity can be cleansed
mechanically and/or chemically with non-CHG containing mouthwashes, and saliva substitutes,
stimulants and moisturizing gels are not CHG-based [13]. There are no substantiated
arguments to question the legitimacy of oral care for safety concerns due to potential
CHG-associated harm.
The above plea for proper daily oral care may not seem to leave room for doubting
the viewpoint that less daily oral care in the ICU could be more. However, there are
no evidence-based standards available to date that define the interventions, methods
and frequency to provide ICU patients with optimal oral health. In the clinical environment,
this lack of evidence is reflected by a huge variety of practices that differ between,
and even within, healthcare facilities, and of oral care protocols that are based
on expert opinion only. It seems obvious that toothbrushing is an essential component
of these protocols owing to its potential to effectively decrease dental plaque reservoirs
[13], but the rationale for the incorporation of some other interventions is far less
obvious, e.g. the use of foam sticks and specific oral care solutions. While lacking
proof of evidence of their effectiveness, these interventions are not rarely costly
and labour-intensive. As such, and until solid evidence will determine best practices,
many oral care protocols could benefit from critical reconsideration aiming at a rational
downsizing of unsubstantiated resources without affecting the quality of care. From
this perspective, less daily oral care in the ICU could indeed be more.
As a striking example, the most appropriate frequency of oral care is a well-known
matter of debate. Since there is no evidence for choosing one frequency over another,
intervals vary extensively among protocols, both for intubated and non-intubated patients.
Protocols generally include an intervention (toothbrushing and/or swabbing and/or
oral moistening) minimally twice a day. Particularly for intubated patients, the suggested
regimens range widely, i.e. from two times daily up to six times daily. To change
such generic, costly and demanding care routines into individualized care that is
tailored to the patients’ specific needs it might be suggested to use an oral assessment
score to determine mouth care regimes. Most assessment tools have, however, been developed
for use in the care-dependent elderly. Recently, Ames and colleagues [14] developed
an assessment scale specifically for critically ill intubated and non-intubated patients
that, moreover, includes an interpretation of the timing of oral care based on the
score. Although the authors report no measures of reliability or validity of the instrument,
their tool might be a first step towards better matching timing and frequency of oral
care to the specific needs of individual ICU patients and to turn ‘more’ into a ‘less’
of at least equal quality.
We warmly invite researchers to contribute to the acquisition of evidence-based insights
in what should be recommended as optimal oral hygiene in the ICU in order to eliminate
expensive but redundant interventions from daily practice and to provide patients
with optimal oral health. Well-designed, appropriately sampled multicenter trials
are needed to tackle what we consider to be research priorities in this field (Table
1) [15]. Additionally, we welcome all further evidence clarifying the contribution
of oral care interventions to the prevention of pneumonia and the current concerns
regarding the safety of CHG oral care.
Table 1
Research priorities in the field of oral hygiene for ICU patients
Topic
Focus and outcome
Suggested approach and points of interest
Oral assessment
Oral assessment tool for ICU patients
Outcome: separate tools for intubated and non-intubated patients, respectively
Development—reliability and validity testing. Multidisciplinary cooperation with dental
professionals
Type of toothbrush
Manual versus powered
Bristle size, shape and type
Outcome: plaque reduction
Randomized controlled trial (RCT). Blinding not possible—cave performance bias, same
oral care regimens in comparable groups. Independent blinded assessment of outcomes
and assessment of compliance highly recommended. Consider use of split-mouth design
Mouthwashes
Chlorhexidine gluconate
Outcome: safety
Preclinical trials on toxicity and pharmacokinetics. No RCTs given the current state
of the science
Alternatives to CHG including povidone iodine, saline, bicarbonate, triclosan and
furacilin
Outcome: effectiveness in chemically cleaning the oral cavity
Separate randomized controlled trials or multiple-armed RCTs or factorial design.
Cave, the latter rely on the assumption of no interaction between treatment arms.
Avoid split mouth design due to the high possibility of carry-across effects
Solutions for moistening the oral cavity
Saliva substitutes and oral moisturizers
Outcome: effectiveness in hydrating the oral cavity and lips
Same as above
Frequency
Optimal frequency for various aspects of daily oral hygiene (teeth brushing, moisturizing,
mouthwash)
Outcome: oral health as measured through specific, valid and reliable oral assessment
tools for intubated and non-intubated ICU patients, respectively
Valid and reliable oral assessment tool needs to be developed first. Then, separate
randomized controlled trials or multiple armed RCTs or factorial design. Cave, the
latter rely on the assumption of no interaction between treatment arms
Best practices for ICU patients with specific oral needs
Best oral hygiene practices for patients with, e.g. dental prostheses, following maxillofacial
surgery, oral health problems, …
Multidisciplinary cooperation with dental professionals
In conclusion, the current state of the science does not allow to determine whether
less daily oral hygiene could indeed be more. While awaiting solid evidence that will
elucidate this uncertainty, we consider an individualized oral care approach that
takes into account the patients’ risk profile and ability to maintain oral health
themselves the best option.