The effect of clonidine, an alpha 2-adrenoceptor agonist, on intravenous (IV) sedation with midazolam was studied. Subjects were eight healthy adults; IV sedation was performed twice on each subject. In the control (CO) group, midazolam alone was administered. In the clonidine (CL) group, the subjects were given about 5 micrograms/kg of clonidine orally 2 hr before the initiation of sedation with midazolam. The following parameters were determined: dose of midazolam, changes in vital signs, recovery time, amnesia, and side effects. The average sedating dose of midazolam was 0.078 and 0.043 mg/kg in the CO and CL groups, respectively. Recovery times determined by stabilometry were 150 and 120 min in the CO and CL groups, respectively. Based on these results, the combined use of clonidine can reduce the dose of midazolam and shorten the recovery time. It is suggested that clonidine may be useful in IV sedation with midazolam.

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The results of the present study of the pharmacokinetics of articaine in children show serum concentrations comparable to those in adults. The maximum values are distinctly lower with the 2% articaine solution. The t max found in our investigation was distinctly earlier than in comparable investigations on adults, whereas the plasma clearance was increased. There is no need to fix a lower mg/kg articaine dose limit for children because of age-related differences in the pharmacokinetics. The use of 2% articaine in pediatric dentistry is particularly advantageous because of the lower C max and the shorter half-life.

This study examined the effects of age on the behavior of mice administered one of two benzodiazepines with and without nitrous oxide. Young (3 wk +/- 3 days) and adolescent (7 wk +/- 3 days) male DBA-2 mice were administered oral diazepam (2.0 or 3.5 mg/kg), midazolam (0.75 or 1.2 mg/kg), or a placebo in combination with 50% nitrous oxide/50% oxygen, or room air. The mouse staircase model was used, where the number of rears (NR) served as an index of anxiety, and the number of steps ascended (NSA) as an index of sedation. No significant differences in the responses between the ages were noted. Nitrous oxide seemed to increase the NR and NSA, whereas the benzodiazepines alone did not affect behavior. These DBA-2 mice may represent a strain that is less sensitive to the anxiolytic-sedative effects of the benzodiazepines than are other strains.

A patient developed skin erythema and wheals within 1 h after local dental anesthesia with articaine hydrochloride. Pretreatment with oral terfenadine or topical betamethasone dipropionate prevented her reaction to articaine. In contrast, neither pretreatment with oral aspirin nor topical capsaicin affected her reaction to articaine. The results of radioallergosorbent tests (RAST) to articaine and a passive transfer test were negative. The reaction was probably caused by a complement-mediated mechanism leading to the degranulation of mast cells. The patient tolerated local anesthesia with lidocaine.

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These results were all obtained by dental anesthesiologists in our clinic actually conducting conscious sedation while observing the patients' response and appearance. Consequently, the anesthesiologist's preferences and skill seem to influence the drugs chosen and the method of use. In reviewing these 300 cases, we found many in which the procedure was completed within 40 min, and effective sedation could be achieved by intravenous sedation using a single benzodiazepine. When a variety of dental treatments are scheduled, tooth extraction is usually performed last. Since the depth of sedation in such cases has become shallow, carelessly performed local anesthetic injections lead to undesirable results. Aside from the nature and duration of treatment, when sedation was employed because of patients' problems, such as anxiety concerning the procedure, good sedation was often achieved with a benzodiazepine, even for relatively lengthy treatments. When a benzodiazepine failed to achieve good sedation on first administration in patients scheduled for repeated sedation, additional drugs are sometimes required from the second time onward. In patients with a gag reflex, conscious sedation with a benzodiazepine alone, and without a comprehensive sedation plan, often ends in failure, and ultimately high doses of multiple drugs have been used in some patients. In some cases, patient management was impossible without general anesthesia.

I believe that dentists have made important contributions to anesthesiology and patient care. Medical anesthesiology is now being required to provide more same-day or ambulatory care. Where it was once good sport to criticize dentists providing brief anesthesia services for their patients, it has now become appropriate for physician anesthesiologists to use shorter-acting agents, improved physiologic monitoring, reversal agents, and early discharge as part of their care of patients. Anecdotes are informative and often provide us with nostalgic recognition and a smile. Ask yourself how you would have responded to the needs of your patients if you were practicing 40 or more yrs ago. We owe a major debt of gratitude to our gallant forebearers and an acknowledgement saying "Well done," and "God bless."

The successful use of conscious sedation in patients physically dependent on centrally acting drugs is problematic for the dental anesthesiologist because of the concomitant development of tolerance to standard sedative agents. Dosage requirements necessary to adequately sedate these patients are often higher than recommended and carry an increased risk of drug overdose. The following report summarizes our experience with 18 drug-dependent patients in whom hypnosis was employed in conjunction with a standard sedation regimen. Attempts to complete various dental procedures while employing sedation alone on these patients had previously failed. All patients exhibited highly fearful or phobic behavior toward dental treatment as assessed by the Corah Dental Anxiety Scale. If an intravenous sedative regimen (midazolam or diazepam plus methohexital) was employed, hypnotic induction preceded the administration of the sedative drugs. If an intramuscular sedative regimen was employed (meperidine plus promethazine), the hypnotic induction took place after drug administration. With the combined hypno-sedative approach, treatment outcomes were judged to be good or excellent in 11 of 18 patients. Interestingly, in five of seven patients for whom the treatment outcome was rated poor or fair, the possibility of tolerance or cross-tolerance existed between a drug being abused and the sedative regimen. In contrast, this possibility existed in only 1 of 11 patients with good or excellent treatment outcomes. We conclude that hypnosis can augment the effects of sedation in this patient population. However, it is also important to choose a sedative regimen where tolerance is unlikely to exist.

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Neostigmine is commonly used to reverse neuromuscular blockade. A side effect can be parasympathetic stimulation, which may result in heart block. Renal failure can decrease the clearance and increase the half-life of the drug, thus increasing the likelihood of a vagomimetic response. A case is presented where a child with renal failure developed a type I second-degree heart block after neostigmine was given.

A 21-yr-old female suffering from osteogenesis imperfecta was anesthetized for correction of maxillary and mandibular deformities that had restricted her chewing. Preoperative assessment revealed a difficult intubation, restrictive lung disease secondary to bony deformities, and multiple repairs of fractures. Management of anesthesia for this operation--which is very rarely carried out in this disorder--is described along with a review of the problems of anesthesia associated with osteogenesis imperfecta.

This investigation compared the use of a 5% eutectic mixture of local anesthetics (EMLA) cream to a "standard" intraoral topical anesthetic (5% lidocaine) as a means of anesthetizing the gingival sulcus in a double-blind, split-mouth study with human volunteers. A 5-min application of EMLA in a customized intraoral splint resulted in a significant increase in the depth of probing of the gingival sulcus without discomfort compared to a similar application of 5% lidocaine. Following application of EMLA, the pain-free probing depth measured at three sites in the upper premolar region increased by a mean total of 2.8 mm compared to an increase of 1.9 mm with lidocaine. This study suggests EMLA may be advantageous in providing periodontal anesthesia where manipulation of the gingiva is necessary.

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The addition of a benzodiazepine antagonist to the dental anesthesiologist's armamentarium should provide added safety for conscious sedation using benzodiazepines. A double-blind, placebo-controlled clinical trial of flumazenil, the first available benzodiazepine antagonist, was performed to evaluate its safety and efficacy following conscious sedation induced by diazepam and fentanyl. Flumazenil was found to reverse rapidly much of the central nervous system depression induced by fentanyl and diazepam conscious sedation. Flumazenil appears to be a valuable adjunct for dentists who administer intravenous benzodiazepines for conscious sedation.

Horace Wells first used nitrous oxide for anesthetic purposes in December 1844. Although his life ended tragically in 1848--and before he received official recognition for his work--Wells' significance in the history of anesthesiology is now firmly established. One hundred fifty yr later, the story of his discovery may also be seen as having significance in terms of ethical issues in health care, particularly as regards clinical decision making. Wells' story provides an example of how the moral dimensions of actions taken in the health care setting can be understood only in the context of the individual, clinical, institutional, and political arenas in which they occur. Resolving ethical conflicts and dilemmas thus requires clinicians to pay attention to such factors as personal, professional, institutional, and broader social, political, and economic considerations that influence what one believes to be "best" in given circumstances.

Since Gardner first used arteriotomy during anesthesia to improve visibility in the surgical field, various techniques and pharmacological agents have been tried for the same purpose. With reports documenting the spread of acquired immune deficiency syndrome through blood transfusions, prevention of homologous blood transfusions during surgery has also become a major concern. Induced hypotension has been used to reduce blood loss and thereby address both issues. In orthognathic surgery, induced hypotension during anesthesia has been used for similar reasons. It is recommended that hypotensive anesthesia be adjusted in relation to the patient's preoperative blood pressure rather than to a specific target pressure and be limited to that level necessary to reduce bleeding in the surgical field and in duration to that part of the surgical procedure deemed to benefit by it. A mean arterial blood pressure (MAP) 30% below a patient's usual MAP, with a minimum MAP of 50 mm Hg in ASA Class I patients and a MAP not less than 80 mm Hg in the elderly, is suggested to be clinically acceptable. Various pharmacological agents have been used for induced hypotension during orthognathic surgery. In addition, there are many drugs that have been used in other types of surgery that could be used in orthognathic surgery to induce hypotension. Recent reports using control groups do not show significant differences in morbidity and mortality attributable to induced hypotension during anesthesia. Appropriate patient evaluation and selection, proper positioning and monitoring, and adequate fluid therapy are stressed as important considerations in patients undergoing induced hypotension during orthognathic surgery.