Essentials of airway management, oxygenation, and ventilation: part 2: advanced airway devices: supraglottic airways.

Offices and outpatient dental facilities must be properly equipped with devices for airway management, oxygenation, and ventilation. Part 1 in this series on emergency airway management focused on basic and fundamental considerations for supplying supplemental oxygen to the spontaneously breathing patient and utilizing a bag-valve-mask system including nasopharyngeal and oropharyngeal airways to deliver oxygen under positive pressure to the apneic patient. This article will review the evolution and use of advanced airway devices, specifically supraglottic airways, with the emphasis on the laryngeal mask airway, as the next intervention in difficult airway and ventilation management. The final part of the series (part 3) will address airway evaluation, equipment and devices for tracheal intubation, and invasive airway procedures.

Image processing algorithms for retinal montage synthesis, mapping, and real-time location determination.

Although laser retinal surgery is the best available treatment for choridal neovascularization, the current procedure has a low success rate (50%). Challenges, such as motion-compensated beam steering, ensuring complete coverage and minimizing incidental photodamage, can be overcome with improved instrumentation. This paper presents core image processing algorithms for 1) rapid identification of branching and crossover points of the retinal vasculature; 2) automatic montaging of video retinal angiograms; 3) real-time location determination and tracking using a combination of feature-tagged point-matching and dynamic-pixel templates. These algorithms tradeoff conflicting needs for accuracy, robustness to image variations (due to movements and the difficulty of providing steady illumination) and noise, and operational speed in the context of available hardware. The algorithm for locating vasculature landmarks performed robustly at a speed of 16-30 video image frames/s depending upon the field on a Silicon Graphics workstation. The montaging algorithm performed at a speed of 1.6-4 s for merging 5-12 frames. The tracking algorithm was validated by manually locating six landmark points on an image sequence with 180 frames, demonstrating a mean-squared error of 1.35 pixels. It successfully detected and rejected instances when the image dimmed, faded, lost contrast, or lost focus.

The respiratory effects of drugs used for conscious sedation and general anesthesia.

This review article illustrates that all medications used for conscious sedation can depress ventilation. The dental practitioner should not abandon the use of these agents to control fear and anxiety during dental treatment; rather, the dentist should administer the agents cautiously and monitor respiratory status throughout the dental procedure. In this regard, pulse oximetry is a welcomed advance in monitoring as it acts to warn the unknowing clinician that he is approaching a "cliff" (the steep portion of the oxyhemoglobin curve).

Management of nausea and vomiting: physiological, pharmacological, and therapeutic considerations.

Most incidences of nausea and vomiting can be avoided by careful movement of the patient from a supine position to walking, sound hemostatic principles, and prudent postoperative medication prescribing habits. However, when therapeutic intervention becomes necessary, the clinician should ascertain the probable source of vomiting center activation before selecting a particular pharmacological agent. Although many agents are available, there is little evidence of superior efficacy for agents other than those listed in Table 3.

Management of immediate allergic reactions.

Allergic and pseudoallergic reactions can be associated with all drug classes used in dental practice. A thorough medical history is essential to avoid challenging a patient with an agent for which they have proven intolerance. Despite this precaution, the dentist must be prepared to manage an immediate reaction, should it occur. In all cases, management should begin with standard ABC assessment and oxygen supplementation. The administration of either diphenhydramine or epinephrine is predicated on the severity of the reaction. Suggestions regarding dosages and routes of administration are summarized in Table 4. The duration of action for epinephrine is relatively brief (10 to 30 minutes), and dosages may need to be repeated if symptoms recur. Following stabilization, patients who have experienced anaphylactoid reactions should be transported by EMS to the closest emergency room for definitive management. A treatment algorithm summarizing management of allergic reactions is presented in Figure 1.

Assessment and management of cardiovascular urgencies and emergencies: cognitive and technical considerations.

Cardiovascular emergencies represent the most feared complications in dental practice. Not only do they present the greatest possibility for morbidity and mortality, but their pathogenesis and treatment are poorly understood. This article reviews fundamental physiologic and pathological concepts that will guide the clinician toward a more cognitive approach to patient assessment and management. The treatment algorithms presented develop rationally from these fundamental scientific principles.

Management of respiratory complications in clinical dental practice. Pathophysiological and technical considerations.

Preoperative assessment and continuous support of respiratory function are essential components of medical care during dental treatment. This article describes the principles of respiratory support and reviews the pathophysiology and management of common disorders that may present acute complications during daily dental practice.

Pharmacological considerations for conscious sedation: clinical applications of receptor function.

Most drugs used in conscious sedation regimens act by reasonably well-defined receptor mechanisms. The variety of clinical effects produced by these agents is generally extensive, and often can be explained by their activity at more than one receptor type. Rote memorization of drug effects is a futile exercise, especially when one considers the number of new agents introduced each year. An appreciation of receptors and their effects is a more logical approach. This article reviews fundamental concepts of receptor dynamics that are applicable to agents used for conscious sedation. Using this approach, the effects and indications for various agents can be predicted based on their activity at specific receptor sites.

Continuing education in preoperative sedation: perspectives on educational methodology.

Preoperative sedation is a vital component of general dental practice. The final goal and supporting objectives for training programs have been developed. An emphasis must now be placed on effective methods for accomplishing this goal. The design found in the American Heart Association's ACLS training program may serve as an excellent model for future curriculum development.

Considerations for selecting effective analgesic regimens in dental practice.

A variety of analgesic regimens can be developed, based on sound pharmacological principles, in response to the empirical estimate of pain intensity. Including optimal doses of nonopioids to reduce the amount of opioid required is recommended. Furthermore, when pain is anticipated, the nonopioid regimen can be administered on a regular schedule rather than as needed. Preventing pain is better than attempting to reduce it after full intensity has been reached. Careful selection of an effective regimen can prevent breakthrough pain, along with stress and anxiety, which are factors that often require desperate attempts for relief. Options for the dentist to consider are summarized in Table 5 and may be simulated through substitution of other NSAID or opioid equivalents.

Pain management in adult dental patients: the art and science of successful regimens.

Pain is a protective mechanism for the body; it occurs whenever any tissues are being damaged, and it causes the individual to react to remove the pain stimulus. Most ailments of the body cause pain, and the ability to diagnose different diseases depends to a considerable extent on the physician's knowledge of the various qualities of pain. In dentistry, pain may be expected, i.e., caused by dental procedures, and its management should commence preoperatively. This article is a review of pharmacologic pain management in adult dental patients. It discusses the pharmacology and therapeutic utilization of opioid and nonopioid analgesics and the selection of single and combined analgesic regimens.