COVID 19 - Mouth Care for the Critically Ill Patient

Add to favourites

Dental Plaque accumulates rapidly in the mouths of critically ill patients and, as the amount of plaque increases, colonisation by microbial pathogens is likely. Plaque still forms in the mouths of people on nil-by-mouth, PEG-fed and oxygen therapy. ​​

In addition, intubation and critical illness reduce oral immunity, may be associated with mechanical injury of the mouth and respiratory tract, increase the likelihood of dry mouth and the presence of the endotracheal tube also makes access for oral care more difficult.

Mouth care is an essential aspect of palliative care in all settings and should be considered part of daily routine patient care for these individuals.

Regular effective mouthcare should be planned for all patients.

1. Assessment of the mouth

This is required to ascertain the type of mouth care required and is dependent on whether a patient has natural teeth, no natural teeth, dentures or a mixture of these. It will also identify the presence of some common oral conditions that may require more targeted care.

  • Ensure comfort and minimise pain when carrying out an assessment by lubricating cracked lips with a water-based product.
  • Petroleum lip balms should be avoided due to flammability and aspiration risk.
  • Previous applications of water-based lubricants should be gently removed before replacing.
  • Remove dentures before examining the mouth or performing routine mouth care.
  • Check the lining of the mouth is clean.
  • Look for signs of dryness, coating, ulceration or infection.
2. Management of Oral Hygiene

All Patients

  • Looking after oral soft tissues is just as important as looking after the teeth.
  • Keep mouth and lips clean, moist and intact by removal of plaque and debris.
  • Gentle tongue brushing should also be encouraged to reduce halitosis and prevent tongue coating.
  • In the unconscious patient, wetted nonfraying gauze wrapped around a gloved finger can be used to remove debris. 
  • Apply water-based gel to dry lips after oral care.
  • Good hydration is essential

Patients with natural teeth

  • Clean natural teeth with fluoride toothpaste (1350 to 1500ppm fluoride) at least twice daily if tolerated.
  • Mechanical brushing of teeth and gums to remove plaque and debris is as important as application of toothpaste or chlorhexidine digluconate 1%w/w dental gel.
  • Encourage patients to spit out excess toothpaste after brushing.
  • The mouth should not be rinsed with water after brushing.
  • Remove partial dentures and clean separately.
  • Very soft toothbrushes (for example silk toothbrush or baby toothbrush) can be used to perform oral daily care for patients with a painful mouth.

Denture care

  • Brush dentures at least twice a day over a sink of water to guard against splashing and prevent them from breaking if they are dropped.
  • Use of a personal toothbrush and running water are adequate for the physical cleaning of dentures. Denture cream or unperfumed soap may be used but not regular toothpaste.
  • Remove dentures at night and soak in a suitable cleansing solution for
    20 minutes, then overnight in plain water. Recommended soaking solutions are:
    • dilute sodium hypochlorite solution for plastic dentures
    • chlorhexidine gluconate 0.2% solution for dentures with metal parts.
    • Check dentures for cracks, sharp edges and missing teeth daily

Palliative Care

  • Carry out mouth care as often as necessary to maintain a clean mouth.
  • In people who are conscious, the mouth can be moistened every 30 minutes with water from a water spray or dropper or ice chips can be placed in the mouth.
  • In unconscious people, moisten the mouth frequently, when possible, with water from a water spray, dropper or ice chips placed in the mouth.
  • To prevent cracking of the lips, a water-soluble lubricant should be applied.

Ventilated Patients

  • Effective oral hygiene is important for ventilated patients in intensive care to reduce ventilator-associated bacterial pneumonia. Cleaning of the teeth and gums with chlorhexidine mouthwash or gel, cleaning of teeth and gums with gauze can be effective.
  • Lubricating the patient’s lips every 6 hours with water-based saliva replacement gel or aqueous cream (petroleum gel should not be used in the vicinity of oxygen)
  • Performing mouth and pharynx suction every 2 hours or when needed.



3. Management of dry/coated mouth care
  • Oral care should be offered at least four times daily or as tolerated. Some patients may need more frequent care.
  • Where possible, identify and manage the underlying cause, for example review medication, manage anxiety, treat intraoral infection, humidify oxygen and if appropriate encourage hydration.
  • Gently remove coatings, debris and plaque from soft tissues, lips and mucosa.
  • Failing to gently remove dried secretions, debris and plaque gently can cause pain, ulceration, bleeding and predispose to infection.
  • Use damp non-fraying gauze (which has been thoroughly wetted in clean, running water) wrapped round a gloved finger to gently soak coated areas, provided it is safe to do so.
  • Damp gauze (as above) or a moistened soft toothbrush can then be used to gently remove coatings and debris. The gauze should be changed when required and several pieces of gauze may be required to clean the mouth.
  • Encourage hydration. Cold, unsweetened drinks (such as sips of water) should be taken frequently throughout the day if possible. Sucking crushed ice may provide relief.
  • Saline mouthwashes may help to clean the mouth. Patients may use 0.9% sodium chloride from a vial to be followed by rinsing with cold or warm water.
  • Saliva stimulation (for example sugar-free chewing gum, sugar-free boiled sweets, pastilles, mints) should be considered if the patient is able to comply.
  • Saliva substitutes (for example oral gel, spray or mouth rinse) may be used if other measures are insufficient.
  • Fluoride mouthwash (0.05%) can be used at a different time from brushing.
4. Management of Pain relating to soft tissues

Mouth ulcers

Pain from these may be relieved by benzydamine 0.15% oral mouthwash or benzydamine 0.15% oromucosal spray. The mouthwash may be diluted 1:1 with water if stinging occurs. Other agents include choline salicylate or a variety of proprietary preparations for use in the mouth containing the local anaesthetic, lidocaine.


This is a condition characterised by pain and inflammation of the mucous membrane which may present as painful mouth ulceration affecting any or all intra-oral surfaces. Consider oral mucositis as a possible cause, particularly in patients receiving chemotherapy or radiotherapy. Salt water mouthwashes are effective in maintaining oral hygiene and are advised for the prevention and management of mucositis. They should be used at least four times in 24 hours to clean the mouth and remove debris.

Chlorhexidene gluconate 0.2% mouthwash can be considered to treat secondary infections or when pain limits other mouth care methods; 10ml used twice daily may be useful to inhibit plaque formation in patients unable to tolerate other mouth care measures. Dilute 1:1 with water if it stings. Alcohol-free preparations are available.

If the patient is unable to rinse and expectorate or there is an aspiration risk, soak gauze in chlorhexidine gluconate 0.2% mouthwash and gently wipe over coated surfaces, teeth and gums.

Oral thrush

The most common types are candidiasis, denture stomatitis and angular cheilitis (soreness, redness and fissures at corners of mouth). Risk factors include wearing dentures, concomitant antibiotic or steroid use and xerostomia.

It is important to maintain oral hygiene.

Systemic treatment such as fluconazole. Topical miconazole oral gel 2% may also be used particularly for treating angular cheilitis. (For both of these, not in patients taking warfarin or statins because of risk of serious drug interaction)

In patients where this treatment is contra-indicated, or for mild oral candidiasis in non‑immunocompromised patients, nystatin oral suspension can be considered.

N.B. If a fungal infection is present, dentures must be cleaned thoroughly – soak in chlorhexidine 0.2% mouthwash (if dentures have metal components) or dilute sodium hypochlorite for 20 minutes twice a day. Toothbrushes should also be replaced.

5. Viral Infections

Herpes simplex is the most common viral infection.

  • Treat infections inside the mouth with oral aciclovir: 200mg five times a day for at least 5 days (or until healing is complete). Soluble preparations are available.
  • The dose of aciclovir may be doubled or intravenous treatment considered if the patient is immunocompromised or if absorption is impaired. In this case seek advice. Doses may need to be reduced in renal impairment.
  • The use of antimicrobial mouthwashes (either chlorhexidine 0.2% mouthwash or hydrogen peroxide mouthwash, 6%) controls plaque accumulation if toothbrushing is painful and also helps to control secondary infection in general.
  • Immunocompetent patients in the early stages of an uncomplicated herpes simplex infection in the lips (cold sore) should receive a topical antiviral preparation, for example acyclovir 5% cream applied 5 times a day for 5 days.
  • Provide supportive therapy: encourage fluid intake, keep mouth moist, apply water-based lubricant, antipyretic medication and analgesia.
  • Viral infections are highly contagious. Strict adherence to infection control measures is essential.
References 2020. Caring for Smiles | Turas | Learn. [online] Available at: [Accessed 6 April 2020].

Health Improvement Scotland. 2020. Scottish Palliative Care Guidelines. [online] Available at: [Accessed 6 April 2020].

Hua, F., Xie, H., Worthington, H., Furness, S., Zhang, Q. and Li, C., 2016. Oral hygiene care for critically ill patients to prevent ventilator-associated pneumonia. Cochrane Database of Systematic Reviews, [online] Available at: http://Oral hygiene care for critically ill patients to prevent ventilator‐associated pneumonia.