Читать книгу A Practical Approach to Special Care in Dentistry - Группа авторов - Страница 199

1 What could have led to this patient having HCV infection?The patient received a blood transfusion in the 1980sThis was before the introduction of HCV screening of donated blood in 1991–2

2 The patient requests that the #26 is extracted immediately and does not want any delay. Why is this not advisable?You need further information from his physician regarding the severity/impact of his HCV infectionThe patient has an increased bleeding risk due to his thrombocytopenia and the likelihood that his HCV infection has also impaired the hepatic synthesis of coagulation factorsAntibiotic prophylaxis is mandatory (splenectomised)

3 What could be causing this patient's thrombocytopenia?The pathophysiology of thrombocytopenia in relation to HCV infection is complexFigure 4.3.1 Orthopantomogram demonstrating unrestorable caries in #26.Hypersplenism may contribute to thrombocytopenia but this patient has had a splenectomyHence, in his case, contributory factors include:Bone marrow suppression resulting from HCV itselfAberrations of the immune system resulting in the formation of antiplatelet antibodies and/or immune complexes that bind to platelets and facilitate their premature clearanceThrombopoietin (TPO) deficiency secondary to liver dysfunction

4 What laboratory test results would you need before proceeding with the dental extraction?Full blood count to confirm the platelet countCoagulation study to check the prothrombin time/INR and partial thromboplastin time

5 What factors are considered important in assessing the risk of managing this patient?SocialReduced co‐operation due to anxiety‐depressive syndromeHistory of dental anxiety/bad experience of dentistryAlprazolam may impair judgement/cause drowsiness – the patient should not drive and he may not be able to give informed consentMedicalLow compliance with medical management with no active antiviral treatment – HCV loads likely to be highBleeding tendencyIncreased risk of infection due to the splenectomyCompromised respiratory capacityRisk of a hypertensive crisis (exacerbated by dental anxiety)Drug selection and interactionsDentalPoor oral healthAcute infection of #26 may prevent effective anaesthesiaLack of regular brushing/mouth cleaning (increases the risk of postoperative infection)Dry mouth as a result of alprazolamFollow‐up jeopardised by patient's dental history and depressive symptoms

6 The patient requests sedation due to his dental anxiety. What should you consider?In moderate hepatic impairment, benzodiazepines should not be administered (except for lorazepam in liaison with the physician)Benzodiazepines should also be avoided for patients with chronic obstructive pulmonary diseaseThe patient is already taking alprazolam (a benzodiazepine)The use of nitrous oxide may be a better option

7 You are unable to achieve effective anaesthesia to enable extraction of the #26. How would you proceed?Prescribe antibiotics: amoxicillin (full dosage) and metronidazole (reduced dosage) may be prescribed but clavulanic acid and azithromycin should be avoidedIncision and drainage should be considered

8 What analgesic would you recommend after extracting the tooth root remains?In moderate hepatic impairment, the recommendation is to use metamizole or paracetamol at reduced dosages (<2 g/24 hours)Non‐steroidal anti‐inflammatory drugs with antiplatelet action should be avoided for this patient due to his tendency to bleedPeripheral thrombocytopenia is an adverse effect of metamizole (unavailable in some countries), which is therefore not recommended when there is baseline thrombocytopenia