The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [321]
Xerostomia
Xerostomia is the subjective sensation of dry mouth, which does not always correlate to a reduction in saliva production (Maher 2004). It can be associated with thickened saliva, discomfort which may be burning in nature and difficulty eating or speaking (Davies 2005b). A variety of causes are known (Box 9.7).
Box 9.7 Causes of a dry mouth
Many common drugs can cause dry mouth, including analgesic agents and antidepressants.
Oxygen, due to its drying effect.
Mouth breathing.
Poor appetite.
Anxiety and depression.
Radiotherapy to the head and neck can affect the salivary glands; this may be irreversible.
Chemotherapy, which normally resolves over time.
Diseases such as Sjögren’s syndrome.
(Maher 2004)
Where possible, the cause should be treated; sips of water normally only relieve the problem briefly. Artificial saliva may be helpful and mucin-based salivary substitutes are most effective, available in gel and spray forms. Production of saliva may be stimulated by use of sugar-free chewing gum but acidic sweets should be avoided as they may cause discomfort and increase the risk of dental caries (Davies 2000). Salivary stimulants such as pilocarpine can also be useful. Studies have also demonstrated that acupuncture can be helpful (Davies 2005b).
Patients with xerostomia must pay careful attention to oral hygiene as they are at greatly increased risk of oral complications such as caries and periodontitis due to loss of the protective effect of saliva (Maher 2004).
Oral mucositis
Mucositis is inflammation of the mucous membranes of the oral cavity and gastrointestinal tract (Eilers and Million 2007). The terms ‘oral mucositis’ and ‘stomatitis’ refer to inflammation of the oral cavity. Chemotherapy and radiotherapy affect the ability of cells to reproduce and particularly affect areas which have a rapid proliferation rate such as the alimentary tract (Beck 2004). The surface epithelial layer in the oral mucosa is replaced every 7–14 days which means that the oral mucosa is particularly vulnerable to the direct effect of cell death following chemotherapy and subsequent indirect effects of treatment, such as neutropenia and thrombocytopenia, which can affect healing and vulnerability to infection (Cooley 2002, Otto 2001). The incidence of moderate to severe oral mucositis can be up to 100% in patients receiving radiotherapy to the head and neck (Peterson et al. 2009). For patients receiving standard-dose chemotherapy regimens, the incidence varies from 3% to 14% while up to 75% of patients having high-dose chemotherapy as conditioning prior to haematopoietic stem cell transplantation can experience moderate to severe oral mucositis (Peterson et al. 2009).
Mucositis is now better understood as a complex process whereby intracellular changes and reactions occur before damage to the mucosa is apparent (Sonis et al. 2004). The impact on the patient is that symptoms such as altered sensation or taste and pain may be experienced before there are obvious changes to the mucosa. This can progress to painful lesions or large ulcerated areas. Good nursing care is essential for the patient’s well-being and comfort (Eilers and Million 2007). A variety of agents have been used to prevent and treat oral mucositis, with mixed results. Several systematic reviews have been carried out and recommendations formulated (Barasch et al. 2006, Clarkson et al. 2007a, Keefe et al. 2007, Rubenstein et al. 2004, Worthington et al. 2007a).
Evidence-based approaches
Principles of care
The aims of oral care are to:
keep the oral mucosa and lips clean, soft, moist and intact
keep natural teeth free from plaque and debris
maintain denture hygiene and prevent disease