[Emergencies evolving from local anesthesia].

Local anesthesia is without doubt the most frequently used drug in dentistry and in medicine. In spite of records of safety set by using these drugs, there is evidence to adverse reactions ranging from 2.5%-11%. Most of the reactions originate from the autonomic system. A recent, well-planned study indicates that adverse reactions are highly correlated to the medical status of the patient: the higher the medical risk, the greater the chance to experience an adverse reaction. This study also found that adverse reactions highly correlated to the concentration of adrenalin. Another recent study found a direct relationship between adverse reactions and the level of anxiety experienced by the patient and to the dental procedure. Most of the reactions in this study occurred either immediately at injection time and within 2 hours following the injection. Since the beginning of last century, vasoconstrictors have been added to local anesthesia solutions in order to reduce toxicity and prologue activity of the LA. However, today it is commonly agreed that this addition to local anesthesia should not be administered to cardiac patients especially those suffering from refractory dysrhythmias, angina pectoris, post myocardial infarction (6 months) and uncontrolled hypertension. Other contraindications to vasoconstrictors are endocrine disorders such as hyperthyroidism, hyperfunction of the medullary adrenal (pheochromocytoma) and uncontrolled diabetes mellitus. Cross reactivity of local anesthetic solutions can occur with MAO inhibitors, non specific beta adrenergic blockers, tricyclic antidepressants, phenothiazides and cocaine abusers. Noradrenaline added to local anesthetics as a vasoconstrictor has been described as a trigger to a great increase in blood pressure and therefore has been forbidden for use in many countries. This paper describes 4 cases of severe complications following the injections of local anesthesia of which three ended in fatality.

Dental treatment in very high risk patients with active ischemic heart disease.

A new method of predental treatment and management for patients with active ischemic heart disease is reported. Patients with unstable angina pectoris or who have just had a myocardial infarction underwent full treatment for pain-induced dental problems, with the use of an incremental three-level antiangina and antianxiety medication: before dental treatment; in the waiting room, and c) during dental treatment. The setting was a tertiary referral oral medical service and hospital dental clinic. Twenty-six patients were treated, 16 men, 10 women, ranging in age from 45 to 68 years. Ten patients with unstable angina pectoris and 16 patients less than 3 months after a myocardial infarction. All patients underwent comprehensive dental treatment. Good cardiovascular control was achieved, and all the procedures were uneventfully completed. This study indicates the need to reconsider the absolute versus relative contraindications for dental treatment in patients with active ischemic heart disease and recommends the use of a gradual three-level therapy.