hiv. the human immunodeficiency virus retrovirus rna virus protein coat (hiv antigens) reverse...
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HIVHIV
The Human immunodeficiency virus
RetrovirusRNA virusProtein coat (HIV antigens)Reverse transcriptase turn RNA into DNAHIV integrase incorporates viral DNA into host genomeTranscribed by host/viral enzymesViral assembly and shedding with protease
Pathophysiology
Transmission : - sexual - nonsexual
Categorization of HIV exposures
Group 1 HIV antibody positive – asymptomatic Group 2 ARC, CD4 < 400 symptoms (fever, malaise, lymphadenopathy, diarrhea), opportunistic infections
Categorization of HIV exposures
Group 3 AIDS; CD4 < 200 Kaposi’s sarcoma, lymphoma, pneumonia, cervical carcinoma, etc.
Signs and symptoms
Initial exposure or infection Flulike symptoms-fever, weakness, 10
to 14 days Asymptomatic stage
serologic evidence of infection no signs or symptoms
Signs and symptoms
Symptomatic stage serologic evidence of infection T4/T8 ratio reduced to about 1 persistent lymphadenopathy oral candidiasis constitutional symptoms : night sweats, diarrhea, weight loss,
fever malaise, weakness
Signs and symptoms
Advanced symptomatic stage serologic evidence of infection T4/T8 ratio < 0.5 HIV encephalopathy HIV wasting syndrome major opportunistic infections Neoplasms : kaposi’s sarcoma,
lymphoma
Laboratory blood, semen, breast milk, tears,
saliva With or without clinical : antibodies Advanced HIV :
altered ratio T4/T8 decreased total number of
lymphocytes trombocytopenia, anemia alteration in Ab system Cutaneous anergy
Laboratory test
ELISA : sensitive, high rate of false positive screen
Second test : Western blot Combination of test : > 99%
accurate Positive : exposed to AIDS virus potentially infectious PCR
Laboratory test
Status and potential risk of surgery Viral load CD4 lymphocyte count
Laboratory test
Viral load Current viral activity Disease progression
> 30,000 – 50,000 HIV RNA copies/ml plasma poor prognosis
< 5000 HIV RNA copies/ml plasma better short-term prognosis
Laboratory test
CD4 lymphocyte Degree of immunologic destruction
AIDS : low lymphocyte count and depressed CD4 T-cells CD4 : CD8 ratio of 1:0 or less
Opportunistic infection
Pneumocystis carinii pneumonia (PCP) Protozoan parasite Invade lungs (rarely LN) Symptoms : fever, cough, difficulty
breathing, weight loss, night sweats, fatigue
Prophylaxis : TMP-SMX,
Opportunistic infection
Toxoplasmosis Protozoa Infection of CNS Symptoms : neurologic headaches, dizziness, seizures
Opportunistic infection
Cryptosporidiosis Protozoa Affect GI tract Nausea, vomiting, diarrhea, malaise,
fever, weight loss
Opportunistic infection
Candidiasis Oral and systemic Infect mucous membrane : mouth,
vagina, esophagus, GI tract, skin Systemic Tx. Fluconazole or
ketoconazole
Opportunistic infection
Cryptococcus and histoplasma Yeastlike fungi Infect lung and brain, other tissue Fever, weight loss, neurologic
symptoms, difficulty breathing, mucosal lesion, headache, N/V, malaise
Tx. : fluconazole, ketoconazole, amphotericin B
Opportunistic infection
Tuberculosis Mycobacterium tubercullosis S/S : lymphadenopathy, cough, fever
weight loss, diarrhea, night sweats, malaise
Skin test Tx : Isoniazid (INH), Rifampin,
ethambutol, streptomycin
Opportunistic infection
Tuberculosis Multiantibioticresistant form of TB Mycobacterium avium Mycobacterium intracellulare
Tx. : ciprofloxacin, amikacin sulfate, ethambutol
Opportunistic infection
Cytomegalovirus 90% of HIV Oral cavity : deep, non-healing
ulcerations Retinitis Esophagitis Colitis
Tx. : Ganciclovir
Opportunistic infection
Herpes simplex/ herpes zoster Infect epithelial tissue and nerve
ending Symptoms: painful inflammatory
blisters follow a sensory nerve
tract Tx./prophylaxis : acyclovir
Opportunistic infection
Epstein-Barr virus Associated with oral hairy leukoplakia
in HIV/AIDS Acyclovir or ganciclovir
Opportunistic infection
Human papillomavirus Oral cavity Clinical : oral warts
Tx. excision
HAART therapy
Highly Active Anti-Retroviral Therapy Is essentially triple (or even
quadruple therapy) Two nucleoside reverse transcriptase
inhibitors (NRTIs) combined with either a protease inhibitor (PI) or a non-nucleoside reverse transcriptase inhibitor (NNRTI)
Nucleoside reverse transcriptase inhibitors(NRTIs)
Zidovudine AZT Dideoxyinosine DDI Dideoxycytidine DDC Stavudine d4T Lamivudine 3TC Etc.
Non-Nucleoside reverse transcriptase inhibitors (NNRTIs)
Delavirdine DLV Efavirenz EFV Nevirapine NVP Copravirine CPV Etc.
Protease inhibitors (PIs)
Affect s posttranslational modification (late stage) of HIV replication
Ritonavir RTV Indinavir IDV Amprenavir APV Etc.
Entry inhibitors (or fusion inhibitors)
Block viral entry into cells
Fuzeon (enfuvirtide, T-20)
Goal of therapy
Maximal and durable suppression of viral load in blood
Restoration and/or preservation of immunological function
Reduction of HIV-related morbidity and mortality
Thailand
GPO-vir This is a generic drug combination
of d4T (stavudine) 3TC (lamivudine) NVP (nevirapine)
Side effects
anemia : major (toxic to bone marrow and blood cellls) blood transfusion in severe case leukopenia and granulocytopenia : predispose to infections, fatigue, muscle
pain, rashes, nausea, diarrhea and headaches hepatotoxicity, peripheral neuropathy and
pancreatitis
Side effects (oro-facial)
Taste perversion Ritinovir (PI)
Circumoral paresthesia Amprenivir (PI) Ritinovir (PI)
Stevens johnson syndrome (EM) Neviripine (NNRTI) Amprenivir (PI)
Side effects (oro-facial)
Stomatitis, oral ulceration Abacavir (NRTI)
Thrombocytopenia, anemia Indinavir (PI) zidovudine (NRTI)
Parotid swelling (lipomatosis) Protease inhibitor
Xerostomia DDI Protease inhibitors
Treatment planning
Current CD4 lymphocyte count Viral load Presence and status of
opportunistic infections Medications
Dental Treatment
Exposed to AIDS virus, HIV seropositive but asymptomatic, ARC : CD4> 400
receive all indicated dental Tx.
Dental Treatment
Symptomatic , early stage of AIDS (CD4< 200) : increased susceptibility to
opportunistic infections prophylactic drugs receive most dental care (after R/O neutropenia,
thrombocytopenia)Complex Tx. : prognosis of medical
condition
Treatment planning
Medicated with drug, prophylactic for opportunistic infection
allergic reaction, toxic drug reaction, hepatotoxicity, immunosuppression, anemia, serious drug interaction
Consultation, investigation (bleeding time, WBC)
Dental management
severe thrombocytopenia
platelet replacement before surgery
Prophylactic antibiotics : severe immune neutropenia (< 500 cells/mm)
In general , only urgent Tx. needs for patient with advanced AIDS
Drug interaction
Acetaminophen : caution with AZT
(granulocytopenia, anemia may be intensified)
Aspirin : avoid in thrombocytopenia Antacids, phenytoin, cimetidine,
rifampin : avoid in ketoconazole (altered absorption and metabolism)
Cerebrovascular Cerebrovascular accidentaccident
Stroke (CVA, apoplexy)
Serious, often fatalcerebrovascular diseaseNot fatal : some degree debilitated in motor function, speech or mentation
Stroke : generic name
neurologic deficit sudden interruption of oxygenated bl to brain
focal necrosis of brain tissue
Interruption of blood supply :
Occlusive - thrombosis of cerebral vessel (65%-80%) - cerebral embolism hemorrhage - intracranial hemorrhage
Cerebrovascular disease
Atherosclerosis
(most common)hypertensive vascular disease
cardiac pathosis (MI, AF)
Factors (increased risk for Factors (increased risk for stroke)stroke)
Occurrence of TIAs Hypertension DM Elevated blood lipid
levels Antiphospholipid
antibodies Black male
Previous stroke Cardiac abnormalities Atherosclerosis Elevated hematocrit level Increasing age
Pathophysiology
Pathologic change from : infarction intracerebral hemorrhage subarachnoidal
hemorrhage
Infarction
Cause : atherosclerotic thrombi or emboli of cardiac origin Extent of infarction : site of occlusion, size of occluded vessel, duration of occlusion, collateral
circulation Neurologic abnormalities : artery involved
Intracerebral hemorrhage
Cause : hypertensive atherosclerosis
microaneurysms of arterioles Rupture
Subarachnoid hemorrhage
Cause : rupture of a aneurysm at
the bifurcation of a major cerebral artery
Sequelae and complications
Most serious : death (38% - 47% within a month) Mortality rate related to type of stroke 80% : intracerebral hemorrhage 50% : subarachnoid hemorrhage 30% : occlusion of major vessel by thrombus
Survive : neurological deficit or disability of
varying degree and duration 10% recover with no impairment 40% mild residual ability 40% disabled + require special service 10% require institutionalization
residual deficit: size and location of infarct and
hemorrhageDeficit : Unilateral paralysis Numbness Sensory impairment Dysphasia Blindness Diplopia Dizziness Dysarthria
bResidual problem : Difficulty in walking, using the hands, performing skilled act or speaking
Clinical presentationClinical presentation
S/S 1. Transient ischemic attack (TIA) 2. Reversible ischemic
neurological deficit (RIND) 3. Stroke in evolution 4. Completed stroke
TIA
Mini stroke Cause : temporary disturbance in blood
supply to localized area of brain Numbness of face, arm or leg one side
(hemiplegia), weakness, tingling, numbness, speech disturbance < 10 min.
Major stroke proceded by 1 or 2 stroke within several days
RIND
Neurologic deficit similar to TIA Not clear within 24 hr. Eventual recovery
Stroke in evolution
Cause : occlusion or hemorrhage Deficit present for several hour Continue to worsen
Stroke in evolution
Signs: hemiplegia, temporary loss of speech, trouble in speaking or understanding
speech, temporary dimness or loss of vision
one eye, unexplained dizziness, unsteadiness
or suden fall
treatment
On respirator On Anticoaggulant
Heparin coumadin
Tx. of hypertension, DM, heart disease
On aspirin
Dental management Identification of risk factors a. hypertension b. DM c. coronary atherosclerosis d. elevated blood cholesterol or lipid
level e. cigarette smoking f. TIA or previous stroke g. increasing age Encourage to control risk factors – refer
Dental management
Hx. of stroke a. high risk – caution b. urgent dental care only during first 6 mo. c. TIAs or RINDs – no elective care
Dental management Hx. of stroke d. anticoagulant drugs : bleeding
problem 1. Aspirin : preTx. bleeding time < 20 min
2. Coumarin : pre Tx. : PT < 2 times or INR < 3.0 if PT > 2 –2.5 times or INR > 3.0-3.5 consult to reduce dose
Dental management Hx. of stroke d. anticoagulant drugs
3. Heparin IV – palliative emergency dental care
or discontinue 6-12 hr. prior to Sx. (with physician’s approval ); restart after clot
form (6 hr. later) Heparin (subcutaneous) – no changes
required 4. Use measures to minimize hemorrhage 5. Hemostatic agents
Dental management
Short stress free, midmorning appointment
Monitor blood pressure minimum amount of LA with
vasoconstrictor LA with 1:100,000 or 1:200,000 epi (4 ml or less) No epinephrine in retraction cord