1 - Medically Compromised Patients Flashcards
What are the known risk factors associated with congenital heart disease?
- Maternal rubella
- Diabetes
- Alcoholism
- Irradiation
- Drugs such as thalidomide, phenytoin sodium (Dilantin) and warfarin sodium (Coumadin)
Describe the acyanotic and cyanotic heart lesions?
- Acyanotic lesions are characterized by a connection between the systemic and pulmonary circulations or stenosis of either circulation (left to right shunts).
- All cyanotic conditions exhibit right to left shunting of desaturated blood.
- -Infants with mild cyanosis may be pink at rest but become very blue during crying or physical exertion.
- -Children with cyanotic defects are at significant risk for desaturation during general anesthesia.
What are the most common acyanotic congenital heart diseases?
- Atrial septal defect (ASD)
- Ventricular septal defect (VSD)
- Patent ductus arteriosus (PDA) caused by failure of closure of the ductus connecting the pulmonary artery with the aorta (normally closes soon after birth)
- Coarctation of the aorta
- Aortic stenosis
- Pulmonary stenosis
What are the most common cyanotic congenital heart diseases?
- Tetralogy of Fallot - includes a VSD, pulmonary stenosis, overriding aorta and right ventricular hypertrophy
- Transposition of great vessels
- Tricuspid atresia
For a pt with a congenital heart disease, what information do you need from the cardiologist and hematologist?
- Nature of diagnosis (acyanotic or cyanotic)
- Current cardiac status - BP, RR, oxygen rate, pulmonary saturations, blood gases.
- Cardiac medications
- Current INR range (normal without anticoagulant therapy is -1; target range with therapy is -2 to 3)
- Previous surgical management
- Future surgical management
- Physical activity limitations
- Risk of infective endocarditis
This information is used to:
- Assess risk of cardiac complications under GA.
- Access risk of infective endocarditis and need for antibiotic prophylaxis before invasive dental procedures.
- Access risk of hemorrhage during dental surgery.
- Develop a perioperative anticoagulant management plan.
Describe the process of how bacteremia after a dental procedure can lead to infective endocarditis?
- Coronary heart disease and rheumatic heart disease can predispose the scarred internal lining of the heart to infective endocarditis.
- Bacteremia during or after an invasive dental procedure can lead to the formation of friable vegetations of blood cells and organisms on the scar tissue.
What is the most common bacteria in infective endocarditis?
- Streptococcus viridans is most frequently responsible for chronic infective endocarditis.
- Staphylococcus aureus is often implicated in the acute fulminating form.
Besides antibiotic prophylaxis, what else can you do to help prevent antibiotic prophylaxis?
- Pre-operative antiseptic mouthwash can reduce oral bacterial load.
- Focusing on good oral hygiene practices may be more important than antibiotic prophylaxis.
When are anticoagulants used for pts with congenital heart disease?
Anticoagulants are usually prescribed for children with valvular heart disease and prosthetic valves to reduce the risk of embolization.
What are the common anticoagulant drugs?
- Oral warfarin sodium (Coumadin) - a vitamin K antagonist depleting factors II, VII, IX and X.
- Heparin sodium (Heparin) - inhibits factors IX X and XII.
What are local hemostatic measures that can be done?
- Application of topical thrombin.
- Packing of the socket with microfibrillar collagen hemostat, oxidized regenerated cellulose.
- Suturing of attached gingivae.
- Splints or stomo-adhesive bandages may also be of benefit.
- There have been recent reports of the efficacy of a “fibrin sealant” (Tisseel Duo 500) in the management of coagulopathies, but its use on moist oral mucosa is limited.
What are the common changes in anticoagulant therapy that is done before dental treatment?
- Some practitioners cease warfarin 3 to 5 days prior to the surgery date, commence enoxaparin sodium once daily via Insulfon and admit the pt to the hospital on the day of the procedure.
- -Recommencement of warfarin and weaning of enoxaparin sodium 24 hours after surgery is required to re-establish correct INR, PT and APTT. - However, recent studies on adults who had multiple dental extractions without modification of their anticoagulant therapy showed few or no post-operative complications. ADA stated in 2003 that the scientific literature does not support routine discontinuation of oral anti-coagulation therapy for dental pts bc it can place them at unnecessary medical risk. Any changes in the anticoagulation therapy must be discussed with the pt’s physician.
- American College of Chest Physicians recommends that pts who are taking vitamin K antagonists and are about to undergo minor dental procedures continue with the therapy bc it does not confer an increase in clinically important major bleeding. It further states that it is reasonable to co-administer an oral pre-hemostatic agent at the time of the procedure until more adequately powered studies are done. In pts receiving aspirin, the College recommends continuing it around the time of the procedure.
What are some common medications to improve cardiac function and reduce congestive heart failure in children?
Oral elixirs including Digoxin and Furosemide, usually with sucrose or sorbitol base.
Why are children with congenital heart disease more likely to develop dental caries in primary teeth?
- Enamel is often hypoplastic and susceptible to early childhood caries.
- High-caloric diet.
- Use of sucrose-rich medications.
- Medications may induce xerostomia.
- Parental indulgence with sweets, juices, sodas, etc.
How would non-compliance with preventive advice alter treatment planning?
It may be necessary to extract all carious teeth, especially those with pulpal involvement, to reduce the risk of infection and infective endocarditis.
For a pt with cystic fibrosis what questions do you ask about the medical history?
- When was the diagnosis made?
- Who are the lead pediatrician and other pediatricians who are involve din the pt’s care and what are their addresses?
- What is the frequency of outpatient appointments?
- What is the frequency of admissions?
- What are the frequency and severity of chest infections?
- What is the microbiology of chest infections? (Infection by pseudomonas is an indication that lung function is severely compromised)
- What are the current medications?
- Is an indwelling catheter (central line) present?
- What is the pt’s experience with general anesthesia?
- Is there a possibility of future radical treatment? (Heart-lung transplant may be considered in pts with terminal respiratory failure)
- Are there any special dietary requirements/modifications?
What is the genetics of cystic fibrosis?
Basic defect is a failure to code for cystic fibrosis transmembrane regulator (CFTR) protein which regulates electrolyte and water transport across cell membranes.
What is the test for cystic fibrosis?
The optimal diagnostic test is the measurement of sweat electrolyte levels.
What is affected in cystic fibrosis?
- Respiratory issues:
- -Viscous secretions accumulate in smaller airways which are prone to infection.
- -Children are on long-term antibiotics to prevent chest infections, which must be treated aggressively.
- -Healing occurs with scarring, further compromising the airway.
- -Regular physiotehrapy is required to encourage physical removal of secretions.
- -Many children have reversible airway obstructions treated by salbutamol and steroid inhalers. - Gastrointestinal issues:
- -Damage to pancreas results in pancreatic enzyme insufficiency, thus oral pancreatic supplements are required with all meals.
- -Fat-soluble vitamin supplements are taken due to the pt’s reduced ability to absorb the vitamins.
- -Incidence of celiac disease and Crohn’s disease seems to be increased in CF pts.
What are the long-term complications of cystic fibrosis?
- Diabetes
- Liver disease
- Pneumothroax
- Sinusitis
- Nasal polyps
- Osteopenia
- Failure to thrive
- Infertility
What is the management of cystic fibrosis?
- Proactive treatment of airway infection
- Encouragement of good nutrition
- Active lifestyle
-For pts in late respiratory failure, heart-lung transplants are an option but are available in only a minority of cases.
What are the oral manifestations in cystic fibrosis pts?
- Dental caries is lower than in healthy controls (despite a high-carbohydrate diet) - this is due to long-term antibiotic therapy, high salivary pH and raised salivary calcium levels
- Increased levels of calculus and lower gingival health - pts have altered amounts of calcium and phosphate in their saliva. Pancreatin may have a role in decreasing calculus formation and reducing dental caries in these pts.
- Higher prevalence of enamel defects - due to severe systemic upset in infancy, especially in cases in which pts are diagnosed late.
What is the dental treatment considerations for cystic fibrosis pts?
- General anesthesia is strongly contra-indicated bc of the compromised airway and increased incidence of post-operative chest infections.
- Consult with pediatrician to decide on which antibiotic to give for acute dental conditions. The choice of antibiotic should take into account the current regime and the types of antibiotics that may be required for future treatment.
- High priority for dental prevention bc the condition makes treatment of dental disease more difficult.
- Liver disease may be a feature of older children with CF, resulting in complications involving bleeding, infection and drug metabolism.
- Nitrous oxide sedation may be contra-indicated in these children and should only be carried out after consultation with the pediatrician to establish respiratory capacity. The procedure should be carried out in a hospital environment. Careful monitoring of oxygen saturation levels is essential.
What precautions are required for treatment under general anesthesia in cystic fibrosis pts?
The precautions for treatment under general anesthesia are:
- Avoid general anesthesia if possible.
- Make sure that there are no signs of pulmonary infection. May require sputum culture.
- Chest radiograph.
- Blood gases.
- Pulmonary function testing.
- Vigorous course of pre-op and post-op chest physiotherapy to clear as much of the secretions as possible.
- Check for diabetes (blood glucose) and liver disease (LFTs) pre-op.
- Check current antibiotic regimen.
- Peri-operative frequent suctioning and removal of secretions.
- Nasal polyps are a contra-indication to nasal intubation.
For a pt with hemophilia, what questions do you ask about the medical history?
- Type and severity of hemophilia
- Hemophilia team contact information
- Compliance with medications
- Frequency and management of bleeding episodes
- Inhibitor status
- History of blood borne disease such as HIV infection or hepatitis due to blood transfusions
- Limitations or restrictions on activities
Describe the heredity of hemophilia?
- Hemophilia A and hemophilia B are X-linked recessive traits.
- Hemophilia C is an autosomal recessive trait (most frequently presenting in Ashkenazi Jews).
Describe the effect effect on bleeding of hemophilia?
Hemophilia presents as impaired secondary hemostasis (stabilization of the platelet plug with fibrin) while primary hemostasis (platelet plug formation) is normal.
Hemophilia A - factor VIII deficiency
Hemophilia B - factor IX deficiency
Hemophilia C - factor XI deficiency
How is the severity of hemophilia classified?
Classified by level of factor activity:
- Normal: 55% to 100%
- Mild: >5%
- Moderate: 1% to 5%
- Severe:
What are the medications that can be used in hemophilia management?
- Antifibrinolytic medications - aminocaproic acid (AMICAR) or tranexamic acid (Cyklokapron).
- Desmopressin - increases plasma levels of factor VIII (may be useful in mild hemophilia A).
When should a hemophilia pt be treated under general anesthesia?
- Most pts can receive outpatient dental treatment.
2. Pts with extensive treatment needs, and moderate or severe hemophilia should be considered for treatment under GA.
For a hemophilia pt, what local anesthetic injections can be administered without factor replacement?
Buccal, intrapapillary and PDL infiltrations can be administered without factor replacement.
Intfiltrations into a highly vascularized area or into loose connective tissue and posterior superior alveolar and inferior alveolar nerve blocks.
If factor replacement is required for the local anesthetic injection for the hemophilia pt, what should be done?
Due to the risk of dissecting hematoma formation and potential airway compromise, factor replacement should be raised to 30% to 40% before infiltration into a highly vascular area or loose connective tissue as well as before PSA or IANB.
What alternative pain medications should be used for hemophilia pts?
- Don’t use aspirin and other NSAIDs - may aggravate bleeding.
- Codeine and acetaminophin are safe alternatives.
What lab test is affected by hemophilia?
The activated partial thromboplastin time is usually two to three times the upper limit of normal.
What is the significance of inhibitors in hemophilia?
Bleeding episodes continue despite appropriate factor replacement levels. Care for these pts may include use of a bypassing agent such as VIIa or activated prothrombin complex concentration.
What is the most common acute childhood leukemia?
ALL accounts for 80% to 85% of acute childhood leukemias with a peak incidence at four years of age.
How is ALL defined?
Defined by the presence of more than 25% lymphoblasts in the bone marrow.
How is ALL treated?
Therapy is tailored to the risk of relapse dependent on cytogenetic markers, and includes a combination of induction chemotherapy, central nervous system prophylaxis, and maintenance chemotherapy for 2.5 to 3.5 years.
How can cranial radiation be avoided in ALL treatment?
Intrathecal therapy (commonly methotrexate) has been used to replace cranial irradiation.
What is the cure rate for ALL?
Cure rates for standard risk ALL are now over 90% on current protocols. If relapse occurs, 40% to 50% can be cured with chemotherapy and/or hematopoietic stem cell transplantation, which is reserved for very-high-risk or relapse patients.
How is the prognosis of ALL determined?
Prognosis depends on age of onset, initial white cell count, cytogenetic abnormalities, and other features.
Why should you avoid alcohol products in pts with mucositis?
Avoid using alcohol-containing products when mucositis is present (it will sting and burn the mucosal tissues).
What antimicrobial therapy can you prescribe before dental treatment under general anesthesia?
Prescribe 0.2% chlorhexidine gel application four times daily prior to procedure.
How should the pt perform oral care during cancer treatment?
- Aggressive oral hygiene with a soft toothbrush or an electric brush should be done throughout treatment, regardless of the child’s hematological status.
- Ultrasonic brushes and flossing can be used if the patient is properly trained.
- Avoid using toothpicks and water irrigation devices during periods of immunosuppression.
- Patients should brush or at least rinse the mouth with water after taking oral medications or nutritional supplements.
