Preanesthetic Evaluation in Dentistry

Preanesthetic Evaluation

• Determines the patient's general physical and psychological condition.
• Determines the need for medical consultation.
• Collects the history of any previous unpleasant anesthetic experience.
• Determines specific drug sensitivities.
• Assesses the need for premedication or intraoperative sedation.
• Determines the time to be allotted for the procedure.
• Determines the technique or method to be used for anesthesia.
• Aids in choice of anesthetic solution.
• Determines the need and quantity of vasoconstrictor.
• Dentists, by determining the true condition of the patient, can better plan the procedure.

Preliminary Basic Information

• Obtained by the office assistant rather than the dentist.
• Includes patient's name, age, sex, height, weight, and occupation.
• Remaining information is gathered by the dentist during the initial appointment.
• Gathering patient information gives the patient confidence that they are being surveyed.

Patient History

• Patient history should inform the dentist of the following:
• Cardiovascular status.
• Respiratory difficulties.
• Nervous system disorders.
• Metabolic deficiencies.
• Endocrine imbalances.
• Presence of allergies.
• Hematological pathologies.
• Iatrogenic conditions.
• The patient's size and age.
• Presence of emotional or psychological problems.
• Medications the patient may be taking.
• In addition to subjective questions, dentists should take the patient’s pulse and record the rate, volume, and rhythm.
• Dentists should also take and record blood pressure and respiratory rate, depth, and character.
• Observe the patient closely for any physical manifestations of systemic disorders.
• These measurements are taken during the first appointment.

Fundamentals in History Taking

• Ask clear, concise questions.
• Listen attentively.
• Observe.
• Integrate information.
• Questions should not be confusing but should elicit the most useful information.

Physical Status Classification

• The American Society of Anesthesiologists (ASA) has a grading system for relating a patient's physical status.

ASA Classification of Physical Status

• ASA I: Normal healthy patient.
• ASA II: Patient with mild systemic disease that causes only mild impairment in lifestyle.
• ASA III: Patient with moderate to severe systemic disease that severely limits daily activities.
• ASA IV: Patient with severe systemic disease that is a constant threat to life.
• ASA V: A moribund patient who is not expected to survive for 24 hours with or without treatment.
• ASA VI: Organ donation.

Cardiovascular Status

• Groups of CV conditions of concern to dentists:
• Congenital Heart Disease.
• Result of developmental defects of the heart and major blood vessels.
• Death usually occurs early when the defect is severe and profound.
• Some severe cases may survive for up to 20 years, which is long enough that they may require dental treatment.
• General signs of congenital heart disease include retardation of growth and maturation, cyanotic skin/lips/nailbeds, and clubbed fingers.
• Activities are reduced in direct proportion to the severity of the condition.
• Local analgesia is the choice for pain control in dental management.
• Use a minimum concentration of vasoconstrictor (1:200,000 epinephrine) or eliminate entirely.
• Premedication may be used in small doses, but heavy sedation must be avoided.
• Acquired Heart Disease.
• Rheumatic Heart Disease.
• A disease of childhood and early adolescence (Rheumatic Fever).
• Affects myocardium, pericardium, and endocardium.
• Endocardial involvement produces interference in the functioning of the valves.
• Signs and symptoms include shortness of breath, dyspnea, intermittent fevers, and increased heart rate.
• Analgesia should be profound to prevent tachycardia.
• Vasoconstrictor should be kept to a minimum.
• Give Prophylactic Antibiotics before any procedure that may cause gingival bleeding for patients with a history of Rheumatic Fever. The antibiotic of choice and dose depends on the patient group.
• Atherosclerotic Heart Disease.
• Atherosclerosis refers to the hardening/thickening of the arterial walls due to plaque buildup.
• Angina Pectoris "Chest Pain" describes sudden episodes of substernal pain, often radiating down the left arm.
• Triad symptoms include the location/radiating nature of pain, short duration of the attack, and immediate causative factors (exertion, excitement, sudden exposure to cold).
• For dental management, administer 1-2 nitroglycerin tablets (0.6mg) sublingually; ask patient to inhale a broken ampule of amyl nitrate.
• Symptomatic relief should be obtained within a few minutes.
• If no relief is obtained, consider a coronary occlusion and administer oxygen along with either intramuscular or intravenous meperidine (Demerol) or morphine to ease the pain and anxiety.
• Coronary Artery Disease.
• Patients who suffer from coronary artery disease are subject to coronary artery thrombosis, also known as "heart attacks."
• Occurs commonly in patients in their late 40's, 50's, and 60's.
• Use of vasoconstrictor is NOT contraindicated; however, concentration should be kept at 1:100,000 or less, and a total controlled dose of 0.04 mg or less.
• Hypertension.
• Blood Pressure = sum of cardiac output, blood volume, blood viscosity, and vessel elasticity.
• Hypertension is technically not a disease, but rather a symptom.
• Primary/Essential Hypertension: the cause for the rise in blood pressure is unknown; responsible for the majority of cases.
• Secondary Hypertension: associated with specific disease process (renal, cardiac, etc.).
• Malignant Hypertension: fast-progressing hypertension with evidence of retinal and renal damage.
• Mild hypertension results in a diastolic pressure between 90-104 mmHg, moderate hypertension has diastolic pressure between 105-114 mmHg, while severe hypertension is diastolic pressure 115 mmHg or above.
• Patients who have moderate hypertension and exhibit no other symptoms may be treated as a normal patient.
• A diastolic pressure greater than 100 should be directed to a physician for evaluation.
• Congestive Heart Failure.
• Heart Failure is the inability of the heart to adequately meet the needs of organs and tissues for oxygen and nutrients.
• The decrease in cardiac output causes fluid to leak from capillary blood vessels, leading to edema.
• Right-sided heart failure results in edema in the abdomen and periphery (ankle edema).
• Left-sided heart failure results in pulmonary edema.
• Signs of potential pending congestive heart failure include taking glycoside medications, restricted activities, pronounced edema, and prominence of large veins in the neck.
• Patients should be treated with caution to avoid tachycardia.
• Vasoconstrictors should be kept at a minimum. - Long tiring appointments should be avoided.
• Chronic Valvular Heart Disease.
• Permanent organic deformity of one or more cardiac valves.
• Types include Mitral, Aortic, Pulmonary, and Tricuspid Valvular Disease.
• Mitral Valve Disease is usually caused by rheumatic heart disease and is the most common form of chronic valvular heart disease; it produces its most severe effects in young or early middle-aged adults.
• Aortic Valve Disease occurs much less frequently than MVD, usually in men over 50 years of age; development is slow and may be compensated for a time, later developing severe anginal pain.
• Pulmonary Valve Disease is relatively rare and usually congenital; if no other diseases complicate the condition, patients may live normal, moderately active lives, but the condition can be extremely debilitating if combined with other lesions.
• Tricuspid Valvular Disease rarely occurs as a separate lesion, but is usually associated with mitral valve lesion, and thus is invariably of rheumatic origin.
• Any patient with VHD who is able to perform an average load of daily activities, regardless of the murmur, should present no problems during ordinary treatment.
• Premedicate when indicated.
• Vasoconstrictors are not contraindicated, but should be kept at a minimum.
• Cardiac Arrhythmias.
• Normal Heart Rate: Adult is 60-80 bpm, children is 80-100 bpm, Infants is 110-130 bpm.
• Seek medical help if the heart rate is below 40 bpm or above 140 bpm.
• Interference with the initiating impulse at the sinoatrial node or with its spread throughout the conductive system will produce an arrhythmia.
• Almost every patient who is able to go about their daily activities without stress/strain, shortness of breath, or undue fatigue is a satisfactory candidate for regional analgesia, otherwise patients should be treated with caution.
• No regional analgesia is contraindicated for the patient who has a cardiac condition; it is primarily a question of concentration and total volume of both anesthetics and vasoconstrictor.

Additional Considerations

• The patient's condition should be understood through consultation with a physician when indicated.
• The procedure should be planned to fit the individual patient's condition.
• If fearful and apprehensive, the patient is to be moderately premedicated and/or sedated during the appointment.
• Keep appointments short to prevent undue tiring.
• Use the least possible amount of anesthetic solution.
• Vasoconstrictors, although not contraindicated, should be kept at a minimum, or they can be eliminated if necessary.
• The patient may be given oxygen by nasal cannula during the procedure.