Clinical Assessment and Guidelines
It is important to perform a history and do a focused physical exam to be sure that there aren't any medical risks that would predispose the patient to a medical emergency during the actual procedure. It is also important to talk to the patient to get a feel for the patient's psychological state. Be sure to assess the following:
Can the patient tolerate the stresses of the procedure?
Are modifications to the treatment plan necessary based upon the patient's history and physical?
Is premedication with anxiolytics required just to get the patient into the office?
In order to answer these questions, a risk assessment is performed, which requires taking a medical history and performing a physical examination.
Most of the information obtained in the medical history will be the basis for the risk assessment and it is important for the clinician to spend time talking with the patient. Information gathered in the patient history includes:
- presence of systemic diseases
- previous hospitalizations
- previous surgeries
- previous anesthetic events (how did the patient fare?)
- patient's family history for illness
- social history
- drug or tobacco use
- patient's dental history
- how the patient fared during previous dental treatment.
During the physical examination a review of systems is conducted, in order to obtain information about specific organ systems. The focused physical exam should include the following components:
- Test Results
- Assessment of physical, mental and neurological status
- Vital Signs
- Airway Assessment
- Lung Assessment
- CNS and PNS Assessment
A good history is merely confirmed by the physical examination. Begin with the basic vital signs including blood pressure, heart rate, respiratory rate, and record the height and weight of the patient.
A complete pre-operative physical exam should also include a head and neck exam, cardiovascular exam and pulmonary exam. In addition, it is also important to perform an airway exam, and that involves looking at the tongue, at the neck. During the airway exam, use the following questions to help you determine if the patient is at risk for airway obstruction during sedation:
- What is the mandibular range of motion?
- Are there tonsils present that might obstruct the airway?
- When the patient opens his/her mouth and sticks out the tongue, can you see the uvula and the pharynx?
- Is the patient obese?
- Does the patient have a fat neck, a short neck, or a large tongue that would make ventilation difficult?
During the history and physical examination, it is also important to ascertain the patient's anxiety level. Some symptoms of anxiety include sweating, dilated pupils; the patient may also be very talkative, and/or may have an increased blood pressure and heart rate.
ASA Classification System
The ASA Classification system is used by anesthesiologists to classify patients according to their medical history. It is a graded scale from one through five, with an E is added to indicate an emergency procedure.
||A normal healthy patient
||A patient with mild systemic disease
||A patient with severe systemic disease
||A patient with severe systemic disease that is a constant threat to life
||A moribund patient who is not expected to survive without the operation
||A declared brain-dead patient whose organs are being removed for donor purposes
For example, a healthy normal 18-year-old patient would be an ASA P1. If that patient was undergoing an emergency appendectomy, then the classification would be 1E
Examples of an ASA 2 would be:
- a healthy pregnant female
- any healthy patient over the age of 60
- a healthy patient but one who is extremely phobic
- someone with mild hypertension
- a well-controlled Type II diabetic.
Examples of ASA 3 patients include:
- well-controlled Type I diabetic
- has had a myocardial infarction more than six months ago
- has well-controlled chest pain
- has COPD.
Examples of ASA 4 patients include:
- has shortness of breath at rest
- has chest pain at rest
- has had a myocardial infarction within the past six months
- has uncontrolled hypertension
- COPD patient requiring constant oxygen therapy
Patients classified as ASA 1 or 2 do not require any modifications to the sedative technique. An ASA 3 patient requires more caution; modifications might be needed, such as lighter sedation or treatment in a hospital setting. An ASA 4 patient should only be treated in a hospital dental facility, and should generally undergo emergency and palliative care only.
Silverman, SJ, Bruno, JR and Foote, JW. Preoperative Evaluation. In: Fonseca, R, Walker, R and Betts, N, editors. Oral & Maxillofacial Surgery, Volume 1. Saunders: 2000. p. 13-40.