The proper use of such solutions remains controversial for cardiac patients, since adverse cardiovascular effects may follow systemic absorption of the drug in some of these patients A current and highly desirable praxis among dentists is to send their cardiac patients to physicians before beginning treatment. In what concerns our previous experience, physicians invariably recommend avoiding epinephrine-containing anesthetics in cardiac patients. Nevertheless, well designed studies failed to show significant hemodynamic effects associated with the increase in plasma epinephrine levels following the administration of local anesthetics containing epinephrine 2;6;7;8; The cautious use of epinephrine-containing anesthetics has many advantages over plain lidocaine when the cardiac condition of the patient is well established and does not preclude epinephrine use.
In recent years, this view prompted the establishment of guidelines for the management of cardiac patients, so that some of these patients can also benefit from epinephrine-containing anesthetics In order to evaluate dentists' current knowledge about the use of epinephrine-containing anesthetics in cardiac patients, we carried out a questionnaire survey, comparing our findings with the recommendations found in the literature. Questionnaires were given to last term dental students from four Brazilian dental schools located in the states of Rio Grande do Sul and Santa Catarina.
The students who responded to the questionnaires were present at the end of an usual class. The survey was designed to provide anonymity for the respondent. We chose last term students because we assumed that they represent a group that follows as close as possible the academic guidelines taught in dental schools.
Furthermore, in a few months they would be making their own decisions as practitioners. The questionnaire comprised eight easily understandable clinical cases describing patients with a cardiac disease, for which the students should provide their opinion as "contraindicated" or "not contraindicated" regarding the use of epinephrine-containing local anesthetic solution.
There were three cases of ischaemic heart disease, one case of refractory arrhythmia, two cases of hypertension and two cases of congestive heart failure. According to current guidelines, heart diseases that are absolute contraindications to the use of epinephrine-containing anesthetic solutions are: unstable angina, recent myocardial infarction less than 6 months , recent coronary bypass surgery less than 6 months , refractory arrythmias, untreated or uncontrolled severe hypertension and untreated or uncontrolled congestive heart failure.
These absolute contraindications also preclude the use of other epinephrine-related vasoconstrictors, and in all of these cases, patients should be referred to a cardiologist before any dental procedure is undertaken.
In the questionnaire presented , questions 2, 3, 4, 5 and 8 are absolute contraindications that fit well the aforementioned group of heart diseases. Questionnaires were collected after class. We then pooled all the answers together, without taking into account to which dental school each student belonged. Eighty-three percent of the students were present at class and responded to the questionnaire.
Difficulties in answering the proposed questions were not reported. Table 1 summarizes the number and percentage of correct answers given by students to each case. The current recommendation for patients with a recent myocardial infarction is to postpone dental or surgical treatment for at least 6 months. It is well known that epinephrine has arrhythmogenic properties that could be life-threatening when interacting with the electrophysiological abnormalities of the infarcted myocardium.
It is also important to note that a pathophysiological continuum is found between unstable angina and myocardial infarction. This fact precludes the use of epinephrine in both groups of patients because the hemodynamic changes observed in these patients may compromise their cardiovascular status However, stable angina pectoris patients may receive regional blockades with vasoconstrictors when administered carefully and with previous aspiration 3.
Eighty-five percent of the students correctly contraindicated the use of epinephrine-containing solutions of local anesthetics in patients with a refractory arrhythmia. This condition puts patients at high medical risk and the use of local anesthetics with vasoconstrictors is therefore too risky This case seemed easy to identify as a formal contraindication to epinephrine.
The risk of severe cardiovascular or cerebrovascular complications appears too great in patients with severe or uncontrolled hypertension. Also, hypertensive patients whose blood pressure is only slightly or moderately elevated safely benefit from the use of local anesthetics with vasoconstrictors 8; Uncontrolled heart failure is a condition that may reflect many other cardiac or non-cardiac diseases. Whatever the underlying disorder responsible for this condition, there is a high risk for morbid complications.
We think that this study highlights the problems encountered in the selection of cardiac patients that could safely receive an injection of a local anesthetic solution with epinephrine for dental procedures.
The consequence of this action is a reduction in tissue perfusion which results in local ischaemia of the tissues. Noradrenaline is thus approximately 4 times less vasoconstrictive locally than adrenaline. In fact, noradrenaline could also cause a reflex stimulation of the aortic and carotid baro receptors in response to a rise in the diastolic and systolic pressures and lead to brutal bradycardia. Thus adrenaline is preferred more over noradrenaline as the preferred vasoconstrictor along with local anaesthetic solution.
The most commonly used local anaesthetic for dental surgery is 2 per cent lignocaine with 1 in 80, adrenaline. Addition of adrenaline to local anaesthetic solution is contraindicated for the following diseases like heart diseases, untreated or uncontrolled severe hypertension, uncontrolled hyperthyroidism, uncontrolled diabetes etc.
The maximum doses are contained in 20 ml of local anaesthetic, epinephrine 1: , or levonordefrin ,; each ml of solution contains 0. Cardiac patients are at higher risk from the massive release of endogenous catecholamines associated with the mismanagement of pain control and anxiety than they are from the small quantities of vasoconstrictors usually used in dentistry.
Unstable angina is characterized by recent worsening of symptoms and poor response to medical treatment. In normotensive healthy subjects injection of a moderate quantity of local anaesthetic with vasoconstrictor can lead to significant increase in cardiac stroke volume and oxygen consumption.
An aspiration test should be done and the smallest effective dose should be administered for carrying out emergency dental procedures in these patients 1 If emergency dental treatment is necessary, medical consultation is required and treatment should be aimed mainly at eliminating pain. Epinephrine dosages should be limited to one to two cartridges of , solution 0. Similarly, in patients with stable angina, vasoconstrictors should be limited to one to two cartridges 2.
The current recommendation for patient with a history of recent myocardial infarction is to postpone dental treatment for at least 3 to 6 months.
Because of their chronotropic, inotropic, and arrhythmogenic properties, epinephrine and other vasoconstrictors are strictly contraindicated for patients recovering from myocardial infarction supported by the fact that after a myocardial infarction, higher risk of reinfarction is reported during surgery with the patient.
In the postrecovery period local anesthetic with vasoconstrictor should be employed only in patients whose heart condition has been followed closely and judged stable by the treating cardiologist. In case of six months after the stroke, doses of epinephrine should be limited to less than 0. Both the injection of local anesthetic with vasoconstrictor and regular dental treatments could indeed be risky within 3 months after coronary artery bypass surgery.
This corresponds to the delicate healing period during which significant ischemic alterations can take place. Ventricular tachycardia and ventricular fibrillation are among other dangerous types of arrhythmias associated with an increased risk of sudden death and thus represent one of the major contraindications to the use of vasoconstrictors in dentistry. After many studies with varying number of subjects it has been found that that the blood pressure of the patients of the group without vasoconstrictor are significantly worse, in terms of control of the pain and stress, than those of the group with vasoconstrictor when the subjects were injected with local anaesthesia without and with vasoconstrictors respectively prior to tooth extraction 1.
It is attributed to the bad anaesthesia obtained due to using local anesthesia without a vasoconstrictor which led to more stress during the extraction of teeth leading to increase in the endogenous catecholamines. Thus there is no contraindication to use of a LA associated with adrenaline when a prolonged and deep local anaesthesia is needed in hypertensive subjects provided the hypertension is stabilized by an antihypertensive treatment.
The maximum recommended dose is 0. Several studies have clearly shown that u ncontrolled congestive heart failure carries a poor. Thyrotoxicosis is responsible for tachycardia, hypertension, and an increase in cardiac output. Studies have shown that hyper- and hypothyroid patients do not present major disorders when they are subjected to corrective treatment and put in the presence of catecholamines before the beginning of this treatment.
Although the existing data remain equivocal, it is recommended that the use of vasoconstrictors in local anesthetics be avoided in untreated or poorly-controlled hyperthyroid patients 2. The action of epinephrine directly opposes that of insulin. Patients should be placed supine with the legs raised and the airway secured. Ventilation and circulation should be assessed. If body temperature suddenly increases while the patient is unconscious, potential thyroid storm should be considered.
This is not due to reduced oxygen levels, and basic first aid may not be adequate. In this case, call for emergency transport [ 8 ]. The dentists should have good prior knowledge of medical history for thyroid disease patients, in order to prepare for emergencies, including potential thyroid storm. When treating hyperthyroid patients, monitoring for systemic complications or altered consciousness due to stress is necessary, and clinicians should be capable of active emergency management.
National Center for Biotechnology Information , U. J Dent Anesth Pain Med. Published online Jun Find articles by Kyung-Jin Lee. Find articles by Wonse Park. Find articles by Nan-Sim Pang. Find articles by Jin-Hyung Cho. Find articles by Kee-Deog Kim.
Find articles by Bock Young Jung. Find articles by Eun-Jung Kwak. Author information Article notes Copyright and License information Disclaimer. Corresponding author. Abstract The prevalence of thyroid disease, particularly hyperthyroidism, has rapidly increased in Korea in the past 10 years. Keywords: Dental emergency, Graves' disease, Hyperthyroidism. Table 1 ASA categorization based on thyroid malfunction and physical status. Open in a separate window. Table 2 The results of thyroid test.
Examination Results Reference values 9. References 1. Pimentel L, Hansen KN. Thyroid disease in the emergency department: a clinical and laboratory review. J Emerg Med. Little JW. Thyroid disorders. Part I: hyperthyroidism. Part II: hypothyroidism and thyroiditis. The diagnosis and management of hyperthyroidism in Korea: consensus report of the korean thyroid association. Endocrinol Metab. Diagnosis and classification of Graves' disease.
Autoimmun Rev. Thyroid and the heart. Am J Med. Haas DA. An update on local anesthetics in dentistry.
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