Clinical Assessment and Guidelines
Special Cases to Consider
Cardiac Disease
Cardiac disease can be congenital, such as congenital valvular disease or it could be acquired, such as acquired valvular disease, with rheumatic heart disease. Patients with coronary artery disease who may have angina pectoris or have a history of myocardial infarction. Patients may also have congestive heart failure, and may have arrhythmias.
With patients with coronary artery disease, the goal is to decrease the oxygen requirements of the heart. Stress reduction is critical, and the administration of supplemental oxygen is important. This is where conscious sedation can become very critical in whether or not a patient can be treated, as benzodiazapines will increase sympathetic outflow. These patients may require shorter appointments as well.
Does the patient have a cardiac pacemaker? It is important to ascertain the need for stress reduction to minimize rhythm abnormalities during treatment; it is also important to find out whether an implantable defibrillator has been installed.
It is important to ascertain the following:
- Date and type of cardiac surgeries, if any.
- Has the patient had an M.I. before they had their cardiac surgery?
- PatientŐs pre and post-surgical symptoms and limitations.
- Changes in patientsŐ symptoms following cardiac surgery.
Rheumatic Fever
Patients with a history of rheumatic fever may have had rheumatic heart disease and valvular disease. These patients may develop congestive heart failure from their valvular disease and may have undergone a valve replacement. If the patient has had a valve replacement, it is important to ascertain whether the patient is anticoagulated. In addition, it is always important to cover these patients for SBE with appropriate antibiotics.
It is important to ascertain the following:
- Whether the patient anticoagulated.
- If/when the patient had valve surgery.
- What antibiotics are needed to cover the patient's heart.
Patient's with a CVA have other considerations. Hypoxemia and hypoxia places these patients at greater risk for a repeat CVA; therefore a light sedation and inhalation technique, perhaps with nitrous oxide, is the best approach for these patients. Be very careful when deciding to sedate a patient with a history of multiple TIAs, as such patients are at high risk of develop a CVA if they become hypoxic in your chair.
Pulmonary Disease
There are two global categories of pulmonary disease: restrictive pulmonary disease, such as scoliosis, kyphosis and thoracic cage deformatives, and obstructive diseases, such as asthma and COPD.
Asthma is a disease of obstruction of the lower airways. Patients are at risk when a histamine is released, which might occur with the administration of certain narcotics and barbiturates. In patients with significant asthma, it is important to avoid barbiturates and certain narcotics which can cause histamine release.
Patients with COPD, generally with emphysema, have a decreased respiratory reserve. Many of these patients tend to be barrel-chested, and they may come into your office on supplemental oxygen. These patients should be sedated carefully and very lightly, because they are no longer breathing based upon their CO2 drive, but based upon their PA O2.
In patients with asthma, it is important to ascertain the frequency of the asthma, the severity of the asthma, and the causative factors. Be sure to ask about:
- Medications the patient is currently taking.
- Whether the patient has had multiple emergency room visits or has ever been intubated for the asthma. (If so, when?)
- Whether the patient has been on systemic steroids for the asthma. (If so, when was the last steroid administration?)
Hypertension
Sedation can be very useful in lowering the blood pressure in the anxious patient. However, hypertensive patients are also at higher risk for a hypertensive crisis, defined by a systolic rate within 250 mm hg and/or a diastolic rate within 130 millimeters; in case of a hypertensive crisis should be transported to the local emergency room, and the patient's physician called.
It is important to ascertain the following:
- How well blood pressure is controlled.
- Current medications.
- Patient's baseline blood pressure.
Diabetes
Diabetics: how well controlled is the diabetes? Is the patient a Type I insulin dependant? Is the patient a Type II diabetic? Does the patient have associated coronary artery disease? These are all important considerations in doing a risk assessment. Of course, there are other diseases as well, such as thyroid disease, renal disease and liver disease, which are extremely important.
Renal Disease
Renal disease for altered excretion of drugs that we administer and their metabolites. The liver, of course, is very important because that is where metabolism occurs of most of these agents. Plasma proteins are manufactured in the liver, which bind these drugs in the circulatory system, and, of course, patients with significant liver disease will also have coagulopothies. G.I. disease with altered absorption is also important to be aware of.
Pregnancy
Teratogens during the first trimester, when the embryo is developing vasso constrictors, may cause vasso constriction of the placental circulation. Nitrous oxide and oxygen are generally safe to use during the second trimester.