Routine and emergency management guidelines for the dental patient with renal disease and kidney transplant part 2

Treatment in a theatre environment

The special care practitioner may consider that some patients in end stage renal failure should have their oral care provided in a theatre environment where they can be monitored more closely by the medical team. Additionally, anxiety management strategy should be considered for renal patients. Discussion with a consultant anaesthetist, ideally the one who will be present at the time of treatment, should be part of the planning process.

Dialysis fistulas and grafts should be protected against pressure during lengthy interventions or general anaesthesia; they should not be used for vascular access unless in an emergency, for example, a cardiac arrest. Patients already on dialysis may benefit from observation overnight and arrangements must be made for their dialysis treatment whilst in hospital. Patients on peritoneal dialysis (PD) may be unable to perform the dialysis themselves if compromised by sedation and analgesia, and will therefore need assistance.

A suggested process of assessment, preventive regimes and advice regarding necessary work-up when undertaking oral care procedures in renal patients are summarized in Tables 1-3.

Dental care in pre-dialysis patients

There is no universally accepted definition of what is a pre-dialysis patient. Most people would use the term for patients in whom renal replacement therapy will be required within a year. These patients pose a particular challenge as they are going through a phase of transition towards dialysis dependency. This brings about changes in their life pattern, possible worsening of symptoms and an impaired ability to function. Dental problems may not be a high priority for these patients and may therefore often be ignored.

Conversely, many patients with early renal failure are treated successfully in general dental practice. The main problems for the general dental practitioner are:

These issues usually occur once a patient has progressed to CKD stage 3 or beyond and further work-up may be required to ensure safety of the patient when undergoing certain dental procedures.

Nephrotoxic and non-steroidal anti-inflammatory drugs should be avoided in pre-dialysis patients. This includes COX-2 inhibitors (the Coxibs).1 The use of paracetamol and local anaesthetic solution is generally safe. Mepridine should not be used as it can result in seizures in CKD patients because of the accumulation of toxic metabolites. Antibiotics are generally safe, as long as dose adjustment is made for the degree of renal dysfunction according to GFR (Table 4) and formulations containing potassium salts are avoided. Hypertension is also common at this stage and often requires a combination of three to five anti-hypertensive drugs to control blood pressure. Patients should be advised to take their morning medication before the dental procedure.

Achieving adequate haemostasis can be a concern following dental procedures. This may be multi-factorial and use of anti-coagulant drugs is often implicated. These drugs should be temporarily discontinued only after liaison with a physician or nephrologist. Dental practitioners may wish to seek advice from a renal physician prior to elective procedures in renal patients who appear chronically ill. Uraemia-induced bleeding disorder is rare and usually only seen in CKD stage 5. Its presence is suggested by a prolonged bleeding time while INR and aPTT remain normal. This can be treated with desmopressin (DDAVP), which is usually effective for up to 4 hours. The usual dose is 0.3 mcg/kg, given subcutaneously or intravenously. This needs special expertise and dentists should seek advice.

Anaemia with haemoglobin of less than 10 g/dl may be a relative contra-indication for general anaesthesia and can be corrected within a few weeks with iron infusions and erythropoietin injections.

Endocarditis in renal patients carries a higher mortality, but the current recommendations of NICE2 highlight that antibiotic prophylaxis is not required for patients undergoing dental procedures. The basis for this recommendation is that no consistent association has been shown between dental procedures and increased risk of infective endocarditis (IE). The recommendation also stems from recent research that demonstrated transient bacteraemia due to normal oral commensals, even after simple daily procedures such as brushing the teeth.3 Moreover, antibiotics are not proven to reduce the risk of IE and are themselves not without side-effects and risk of anaphylaxis. The use of indwelling lines and grafts for dialysis (as opposed to native dialysis fistulas) were identified as risk factors.4 There are no specific recommendations for renal patients, although endocarditis in these patients carries high mortality rates.5 We would recommend close liaison between dentist and nephrologist so that a joint decision can be made, based on the extent of the planned dental procedure as well as the individual patient profile, for example age co-morbidity and degree of immunosuppression.

Dental care in dialysis patients

Signs and symptoms related to oral disease are common in dialysis patients, and occur more frequently in those who have diabetes as well. The high prevalence of uraemic fetor, xerostomia, saburral tongue and candidiasis could be early warning signs of the possibility of non-diagnosed advanced renal disease in diabetic patients.6 Dental infections may have the potential of causing bacteraemia and thus infecting tunnelled lined and AV grafts.7 However, there may be considerable variations in treatment regimes between countries, depending on the health system and how dental care is provided. In this regard, a study from the Netherlands demonstrated no difference in oral health between patients on dialysis and controls.8

The most common concern that dental surgeons have to deal with is the enhanced bleeding tendency during procedures. In patients who are on maintenance haemodialysis, uraemic platelet dysfunction should not be a major issue. However, the timing of the procedure should be carefully selected, and procedures should generally be performed on non-dialysis days. Patients are usually heparinized during dialysis to prevent blood clotting in the dialyzers. Heparin has a half-life of 1–2 hours and the effect therefore usually wears off in 6–10 hours. Patients who are adequately dialyzed on peritoneal dialysis generally do not have enhanced bleeding tendency, and dental procedures need not be specifically timed, although liaison with the nephrologist is recommended. Patients, who normally perform peritoneal dialysis themselves at home, may temporarily need help if they are compromised by sedation or pain.

Whilst contra-indicated in pre-dialysis patients, NSAIDS can be used in dialysis patients9 provided there is no ongoing issue with gastritis or peptic ulceration. However, they can still impair any residual urine output (some dialysis patients may still have good urine output, and paracetamol and opioids are therefore preferable). Other drugs, including antibiotics, can be used with dose adjustments, depending on whether the patient is on haemo- or peritoneal dialysis (Table 4).

Dental care in kidney and kidney-pancreas transplant candidates

This is another controversial issue at the interface between nephrology and dentistry. Again, data are sparse and there are no universally accepted recommendations. Rustemeyer and Bremerich10 studied 204 transplant candidates for solid organ transplantation who had been referred for dental work-up. They demonstrated that as many as 70% of transplant candidates required dental procedures prior to transplant listing; as any untreated potential focus of infection can cause problems once these patients are on immunosuppressives post-transplant. Notably, under conditions of immunosuppression post-transplant, there is an increased risk that a source of infection can flare up and lead to widespread local and systemic infection. Most transplant patients are also on corticosteroids, which may delay wound healing. As such, dental treatment should be undertaken prior to transplantation. Therefore the authors recommend that a thorough oral and radiographic examination should be a part of the pre-transplant work-up for all patients.

Dental care after kidney and kidney-pancreas transplantation

Gingival hyperplasia is a common dental problem in transplant recipients. This has an increased prevalence in patients who are immunosuppressed with ciclosporin and is aggravated by concomitant use of calcium channel blockers for hypertension.11 Counselling regarding oral hygiene and the use of a chlorhexidine gluconate 0.2% mouthrinse is often effective in mild cases.12 Stopping the calcium antagonist can be beneficial. More severe cases will need conversion of the immunosuppression to tacrolimus. However, the data on tacrolimus are controversial. The drug has been reported to increase,13 as well as reduce the risk of14 gingival hyperplasia. Surgical or laser excision of gingival tissue may be required for cosmetic or functional reasons.

Oral ulceration can occur frequently in patients on an immunosuppression regimen based on mammalian target-of-rapamycin (mTOR) inhibitors. These drugs, such as sirolimus and everolimus, have a unique mode of action and the occurrence of oral ulcers usually reflects high drug levels. These ulcers respond well to dose adjustment.

Another common finding is oral candidiasis. Oral candidiasis can be seen in many transplant patients. Lesions include pseudo-membranous, erythematous and chronic atrophic candidiasis.15 All azole anti-fungals interact with ciclosporin as well as tacrolimus at cytochrome P450 enzymes, thus inhibiting their metabolism with a resultant increase in serum levels. As such, anti-fungals should not be prescribed without advice from a renal physician. Fluconazole may be prescribed if indicated, but the dose should be adjusted and ciclosporin levels closely monitored for a possible elevation. Amphothericin lozenges are a safe alternative in mild disease.

Amongst topical anti-fungals, clotrimazole is not absorbed from intact or inflamed skin into the circulation. Terbinafine (Lamisil) has less than 5% absorption with no significant drug interactions. Although little of miconazole (Daktarin) cream is absorbed through the skin when applied topically, miconazole (Daktarin) oral gel may be swallowed and can get into the systemic circulation in sufficient amounts to interact with, and cause a possible increase in, drug levels of ciclosporin, tacrolimus and sirolimus. Close monitoring and possible dose reduction of ciclosporin is recommended in such cases. However, an interaction with intravaginal miconazole would not normally be expected because its systemic absorption is usually very low (less than 2%).16 In summary, there is little systemic absorption from these topical preparations, with the exception of miconazole oral gel. In addition, there is a potential interaction with ciclosporin and miconazole oral gel.

Long-term immunosuppression also predisposes transplant patients to malignancies, such as squamous cell carcinoma of the oral cavity, which may develop in areas of gingival hypertrophy.17 Human herpesvirus 8 (HHV-8) associated with Kaposi's sarcoma has an increased incidence in transplant recipients. Lymphoma associated with the Epstein-Barr virus is also seen in transplant patients and may occasionally affect the oral mucosa,18 manifesting as hairy cell leukoplakia.15 It is therefore important that there is a low threshold for biopsy if new intra-oral lesions occur in transplant patients.

Transplant patients are recommended to have an annual dermatological review owing to the increased risk of carcinoma. If a dental practitioner encounters a suspicious lesion on the face or lips of patients, an urgent referral should be made.

Conclusion

Patients with renal failure often have a complex medical history and pose specific problems to the dental team. Many patients with mild renal disease are treated successfully in general dental practice, while patients with advanced stages of renal failure and co-morbidity may be more suitable for the specialist in special care dentistry. In these patients, the dosage of many drugs needs to be adjusted according to the residual kidney function, while other drugs, such as the NSAIDs, should be avoided altogether. The risk of endocarditis is also markedly increased compared to the general population, although specific guidelines for these patients do not exist. Dialysis patients may pose specific problems to the dental team and close liaison between renal and dental teams is recommended.

Before any dental treatment is undertaken it is important that a risk assessment of all renal patients is undertaken, as such specific problems can be identified and discussed with the nephrology team. This will enhance the patient experience and reduce the risk of possible complications.