A Practical Approach to Special Care in Dentistry. Группа авторов

patient.

      Dental Management

       Dental management considerations include prevention of transmission of the viral infection in the dental clinic, preventing and treating associated increased bleeding risk during invasive procedures, and avoiding the prescription of drugs metabolised by the liver (Tables 4.3.1 and 4.3.2)

Section II: Background Information and Guidelines

      Definition

Hepatitis is an inflammatory process of the liver that is generally caused by viruses, toxins (typically alcohol and drugs) or autoimmune disorders. Viral hepatitis is caused by the action of viruses of the hepatitis virus family (HAV, HBV, HCV, HDV, HEV, HGV, SEN, TTV [Torque teno virus]), Herpes virus (Cytomegalovirus, Epstein–Barr virus, Herpes simplex) and others (Coxsackie B) (Table 4.3.3).

      HBV and HCV infections are of special interest in dentistry because they can become chronic, causing hepatic dysfunction. Furthermore, these viruses can be transmitted by contaminated blood or other bodily fluids (including saliva). It is currently estimated that more than 240 million individuals are chronic carriers of HBV and more than 70 million are carriers of HCV.

      Aetiopathogenesis

       HBV and HCV are non‐cytopathic viruses

       The liver damage they cause is therefore considered to be a consequence of an immunopathological process

       Chronic hepatitis is characterised by an ineffective response by T‐cells, which are unable to complete the viral clearance and therefore result in continuous cycles of low‐level cell destruction

      Clinical Presentation

       Hepatitis viruses result in both acute and chronic disease

       Acute phaseCan be asymptomatic or subclinicalNon‐specific symptoms of asthenia (weakness), anorexia and mild fever can sometimes occurHepatic damage impedes bilirubin conjugation; when bilirubin accumulates above 40 μmol/L, it expresses clinically as jaundice, pruritus, choluria and acholia (Figure 4.3.3)

       Chronic phaseFollowing the initial infection, approximately 80% of individuals do not exhibit any symptomsTable 4.3.1 Considerations for dental management.Risk assessmentBleeding risk (thrombocytopenia, impaired production of clotting factors)Impaired drug metabolismThe transmission rate by the percutaneous pathway:HBV risk varies depending on e‐antigen (HBeAg) status of source person; if HBeAg positive, the risk is up to 30%, if HBeAg negative, risk is 1–6%HCV risk is 1.8%Criteria for referralDuring the acute phase of the infection, emergency dental treatment should only be performed in the hospital settingMost patients with chronic hepatitis can be treated in a conventional dental clinicAccess/positionA number of barriers to treatment have been identified for these patients, including the anxiety caused by the dental settingSchedule the appointment for the last session of the day to minimise the risk of cross‐transmissionCommunicationSome patients with chronic viral hepatitis who undergo dental treatment do not report their condition, for fear of discriminatory attitudes by health professionalsConsent/capacityPatients need to be warned of the potential complications resulting from viral hepatic infection, which may require adaptation such as:Implementation of bleeding prevention protocolsPrescription of drugs that are not metabolised by the liverAnaesthesia/sedationLocal anaesthesiaMinimise the risk of pricking with contaminated needles after infiltrative anaesthesia (e.g. single‐use devices)Caution is advised when using lidocaine and mepivacaine (prilocaine and articaine may be preferable)SedationDrug sedation with benzodiazepines in patients with mild hepatic failure may be performed by reducing the dosageFor patients with moderate–severe hepatic failure, benzodiazepines should be avoidedGeneral anaesthesiaA comprehensive assessment in conjunction with the anaesthetist is essentialThe patient's physician should be consulted and investigations undertaken to assess the risk of bleeding and infection, and whether there are any concurrent infections which would compromise the procedureDental treatmentBeforeUniversal cross‐infection control measures should be appliedRecent blood tests results should be available including:Full blood count (risk of thrombocytopenia)Coagulation study (hepatitis/cirrhosis can reduce clotting factors)DuringInvasive procedures can cause prolonged bleeding, which typically is controlled with local haemostasis measuresAfterIf the bleeding does not stop, the administration of vitamin K may be consideredAvoid drugs that are metabolised in the liver (Table 4.3.2)Drug prescriptionIn general, drugs may be prescribed during short periods at normal dosages, except in cases of moderate–severe hepatic dysfunction (Table 4.3.2)Education/preventionHBVThe vaccine against hepatitis B offers 98–100% protection and is mandatory for dentistsPractitioners infected by HBV who are HBeAg positive or have more than 1000 HBV‐RNA copies/mL of blood should not perform procedures with a potential risk of exposure to the virusIn the event of accidental exposure to HBV of an unvaccinated individual, the administration of immunoglobulin (HBIg) and/or starting the vaccination within 24 hours should be assessedHCVThere is no effective vaccine against hepatitis CPractitioners infected by HCV should not perform procedures with a potential risk of exposure to the virusIn the event of accidental exposure to HCV, the prophylactic administration of antivirals is not recommendedHowever, early treatment of the acute infection can prevent chronicityThe dental clinic can also be used as a primary screening centre with the new rapid detection tests for HCV antibodies in salivaTable 4.3.2 Prescription of drugs for patients with moderate to severe hepatic failure.Type of drugRecommendationAntibioticsPenicillin VAmoxicillinAmoxicillin/clavulanic acidClindamycinMetronidazoleAzithromycinClarithromycinNo dosage adjustment requiredNo dosage adjustment requiredContraindicatedReduce dosage (150 mg/8 h)Reduce dosage (250 mg/8 h)ContraindicatedReduce dosage (250 mg/8 h)Analgesics ParacetamolMetamizoleIbuprofenDiclofenacNaproxenCodeineTramadolReduce dosage (<2 g/24 h)No dosage adjustment required (under review)ContraindicatedContraindicatedContraindicatedContraindicatedContraindicatedCorticosteroids Sedatives HydroxyzineDiphenhydramineDiazepamMidazolamLorazepamAlprazolamContraindicatedContraindicatedContraindicatedContraindicatedNo dosage adjustment requiredContraindicatedTable 4.3.3 Characteristics of the most common types of viral hepatitis.Hepatitis A virus (HAV)Hepatitis B virus (HBV)Hepatitis C virus (HCV)Type of virusPicornaviridae (RNA)Hepadnaviridae (DNA)Flaviviridae (RNA)Prevalence range^*50‐90%0.7‐6.2%0.6‐6.7%Main transmission pathwayFecal‐oral and sexualParenteral and sexualParenteralTransmission in the dental clinic–YesYesChronicity rate–5%70%Vaccine availableYesYes–Hepatitis D virus (HDV) Hepatitis E virus (HEV) Hepatitis G virus (HGV) Type of virusDelta virus (RNA)Calicivirus (RNA)Flaviviridae (RNA)Prevalence range^*1‐40%0‐25%1‐4%Main transmission pathwayParenteral and sexualFecal‐oralParenteralTransmission in the dental clinicYes––Chronicity rate5‐95%^†––Vaccine availableYes (anti‐HBV)–‐^* The wide ranges represent the difference between areas of very low prevalence and endemic areas.^† 5% in previously negative HBV (co‐infection) and 95% in previously positive HBV (superinfection).Figure