implementation of a complete system of physical evaluation for all prospective dental patients could prevent up to 90% of life-threatening situations. The remaining 10% would occur in spite of all preventive efforts.
- Determine the patient’s ability to physically/psychologically tolerate the stress involved in the planned treatment.
- Determine whether treatment modifications are required to enable the patient to better tolerate the stress involved in the planned treatment.
- Determine whether the use of sedation is warranted:
- Determine which sedation technique is most appropriate.
- Determine whether contraindications exist to any drugs to be used in the planned treatment.
Physical evaluation in dentistry consists–minimally–of the medical history questionnaire, physical examination, and dialogue history.
Medical history questionnaire
There are two basic types: the short-form medical history, and the long-form medical history. Any medical history questionnaire can be extremely valuable or entirely worthless. The ultimate value of the questionnaire resides in the doctor’s ability to interpret the significance of the answers provided and to elicit additional information through dialogue history and physical examination.
For the health history to be of value, patients must (1) be aware of their state of health and of any existing medical conditions and (2) be willing to share this information with their dentist. Most patients will not knowingly deceive their dentist by omitting important information from their medical history questionnaires.
Because the patient-completed medical history questionnaires are not always reliable, the doctor must seek additional sources of information concerning the patient’s physical status. The physical examination provides much of this information. Physical examination in dentistry consists of the following steps:
- Monitoring of vital signs
- Blood pressure
- Heart rate (pulse) and rhythm
- Respiratory rate
- Body Mass Index
- Visual inspection of the patient
- Functional tests as indicated
- Auscultation, monitoring (via electrocardiogram), and laboratory tests of the heart and lungs as indicated
ASA Physical Status Classification System
- ASA 1: A normal, healthy patient without systemic disease
- ASA 2: A patient with mild systemic disease
- ASA 3: A patient with severe systemic disease
- ASA 4: A patient with an incapacitating systemic disease that is a constant threat to life
- ASA 5: A moribund patient not expected to survive without the operation
- ASA 6: A declared brain-dead patient whose organs are being removed for donor purposes
- ASA E: Emergency operation of any variety, with E preceding the number to indicate the patient’s physical status (for example, ASA E-3)
When the ASA system was adopted for use in a typical outpatient dental setting, the ASA 5 classification was eliminated.
ASA 1 patients are considered normal and healthy. Review of their medical history, physical evaluation, and all other evaluation parameters indicate no obvious abnormalities. Major organs and organ systems—the heart, lungs, liver, kidneys, and CNS—appear to be in good health. ASA 1 patients are able to walk up one flight of stairs or two level city blocks without distress. Physiologically, ASA 1 patients should be able to tolerate whatever stress is associated with their planned dental treatment without added risk of serious complications. Psychologically, such patients also should have little or no difficulty “handling” the planned treatment. Healthy patients with little or no dental anxiety are assigned an ASA 1 classification representing a “green traffic light” for
treatment. Treatment modification is usually not required for these patients.
An ASA 2 patient has a mild systemic disease or is a healthy (ASA 1) patient who demonstrates extreme anxiety and fear in the dental environment. ASA 2 patients are able to walk up one flight of stairs or two level city blocks before distress causes them to stop. ASA 2 patients generally are less stress tolerant than ASA 1 patients; however, they still represent a small risk during their dental treatment. Routine (elective) dental care is indicated as long as some thought is given to possible treatment modification or considerations warranted by the patient’s medical condition. Examples of such considerations or modifications include the use of prophylactic antibiotics or sedative techniques, limits on the duration of treatment, and possible medical consultation.
An ASA 2 classification should serve as a “yellow traffic light,” a warning to the doctor to proceed, but with caution. Elective dental care is warranted because of the minimal increase in risk to the patient during therapy. Treatment modifications should be considered.
Examples of ASA 2 conditions/patients include the following:
- Type 2 diabetes (well controlled)
- Epilepsy (well controlled)
- Asthma (well controlled)
- Hyperthyroid or hypothyroid disorders (well controlled) in which patients are under a physician’s care and currently have normal thyroid function (considered euthyroid)
- ASA 1 patients presenting with upper respiratory tract infections
- Healthy (ASA 1) pregnant patient
- Otherwise healthy patients with allergies, especially to drugs
- Otherwise healthy patients with extreme dental fears
- Adults with blood pressures between 140 and 159 mm Hg systolic and/or 90 to 94 mm Hg diastolic
- BMI between 30.0 and 39.9 (assess for presence of comorbidities)
Generally, the ASA 2 patient is able to perform normal activities without experiencing distress (e.g., undue fatigue, dyspnea, or precordial pain).
ASA 3 patients have a severe systemic disease that limits their activity but does not incapacitate them. At rest, ASA 3 patients do not exhibit signs and symptoms of distress and can function normally; however, distress is exhibited when these patients encounter either physiologic or psychological stress. For example, a dental-phobic anginal patient may be normal (no chest pain) in the reception area but develops chest pain when placed in the dental chair. ASA 3 patients are able to negotiate one flight of stairs or two level city blocks, but will have to stop and rest at least once while en route. Like ASA 2 patients, these are “yellow traffic light” patients (e.g., proceed with caution). Elective dental care is not contraindicated, but this patient’s risk during treatment is increased. Serious consideration should be given to the possible use of treatment modifications.
Examples of ASA 3 conditions/patients include the following:
- Angina pectoris (stable)
- Status post–myocardial infarction: more than 6 months prior to dental appointment and with no significant residual signs or symptoms
- Status post–myocardial infarction: less than 6 months prior to dental appointment where the degree of myocardial damage is minimal (requires medical consultation) and with no significant residual signs or symptoms
- Status post-CVA: more than 6 months prior to dental appointment and with minimal residual signs and symptoms
- Type 1 diabetes (well controlled)
- HF with orthopnea and ankle edema
- COPD: emphysema or chronic bronchitis
- Exercise-induced asthma
- Epilepsy (less well controlled)
- Hyperthyroid or hypothyroid disorders (patient is symptomatic)
- Patients who are functionally anephric (renal dialysis patients)
- Adults with blood pressures 160 to 199 mm Hg systolic and/or 95 to 114 mm Hg diastolic
- BMI of 40.0 or greater (may be ASA 3 or 4 depending on presence and severity of comorbidities)
ASA 3 patients can usually perform normal activities without experiencing distress (e.g., undue fatigue, dyspnea, or precordial pain) but will need to stop and rest during an activity should they become distressed.
ASA 4 patients have an incapacitating systemic disease that is a constant threat to their lives. They have severe medical problems that are of greater significance to their health than the planned elective dental treatment. Whenever possible, elective dental care should be postponed until the patient’s medical condition has improved at least to an ASA 3 classification.
ASA 4 patients are unable to walk up one flight of stairs or two level city blocks. Distress is present even at rest. These patients present in the dental office exhibiting clinical signs and symptoms of their underlying disease. An ASA 4 classification should represent a “red traffic light,” a warning that the risk involved in treatment of the patient is too great to permit elective care. The management of dental emergencies, such as infection and pain, should be treated as conservatively as possible in the dental office until the patient’s physical condition improves.
Whenever possible, such emergency dental treatment should be noninvasive, consisting of the prescription of medications such as analgesics for pain and antibiotics or infection. In situations in which immediate intervention is deemed necessary (e.g., incision and drainage, extraction, pulpal extirpation), the patient should receive such care within the confines of an acute care facility (i.e., hospital), if possible, or within the confines of a dental office equipped to recognize and manage emergency situations that might arise. Although hospitalized patients are still at risk, their chance of survival may be greater in the event an acute medical emergency arises as well-trained personnel should be more readily available.
Examples of ASA 4 conditions include the following:
- Unstable angina pectoris (preinfarction angina)
- Myocardial infarction: within the past 6 months
- CVA: within the past 6 months
- Adult blood pressure greater than 200 mm Hg or 115 mm Hg
- Severe HF or COPD (requiring O2 supplementation or confinement in a wheelchair)
- Uncontrolled epilepsy (with a history of hospitalization)
- Uncontrolled type 1 diabetes (with a history of hospitalization)
- BMI of 40.0 or greater (may be ASA 3 or 4 depending on presence and severity of comorbidities)
ASA 5 patients are moribund and are not expected to survive more than 24 hours without the planned surgery. ASA 5 patients almost always are hospitalized (patient located in hospital, nursing home, or hospice facility), terminally ill patients. They may be referred to as DNAR (do not attempt resuscitation) or “no code” patients. Resuscitation efforts are not instituted if respiratory or cardiac arrest occurs. Elective dental treatment definitely is contraindicated; however, emergency care in the realm of palliative treatment (that is, relief of pain and infection) may be necessary. An ASA 5 classification should represent a “red traffic light” for dental care.
Examples of ASA 5 conditions include the following:
- End-stage hepatic disease
- End-stage cancer
- End-stage infectious disease
- End-stage cardiovascular disease
- End-stage respiratory disease