The new era of pretracheal/precordial stethoscopes.

Vigilance is the motto for the American Society of Anesthesiologists. Vigilance over the sedated pediatric dental patient is essential for safe and successful treatment. Especially important is vigilance over the patient’s airway. If airway compromise can be quickly detected and corrected, then the likelihood of the patient experiencing a decrease in oxygen saturation will be low. Hypoxia caused by airway obstruction is a challenge faced by every pediatric dentist who chooses sedation as an alternative mode of treatment. Airway obstruction may be caused by several factors: poor patient positioning, blockage of the oropharynx by the tongue, fluids accumulating in the back of the throat, excess secretions, or collapse of soft tissues due to decreased muscle tone. These factors can lead to laryngospasm or bronchospasm, thus further compromising the airway. While it has been reported that some pediatric dentists and pediatric dentistry training programs have decreased their use of sedation, many practitioners still view the use of sedative agents as acceptable treatment for the pre-cooperative child. The pediatric dentist today has an array of monitoring devices to protect the sedated patient. These monitors have been reviewed and discussed in great detail in the literature. Pulse oximeters and capnographs are two electronic monitors that have been described as the “favorites.” While these devices have brought many advances to the dental and medical fields, they are not without their limitations, especially when dealing with pediatric dental sedations (Table 1). AAPD Guidelines for the Elective Use of Conscious Sedation, Deep Sedation and General Anesthesia in Pediatric Dental Patients (revised May, 1998), requires that patients be monitored continuously for patient responsiveness and airway patency. One of the most useful devices in the armamentarium of the pediatric dentist for continuous monitoring of the airway is the pretracheal/precordial stethoscope. The use of the stethoscope in the monitoring of the anesthetized patient can be traced back to Cushing in 1909. The pretracheal/precordial stethoscope is a simple, yet highly effective device for the monitoring of respiratory and cardiac sounds. Traditionally, the device was comprised of an earpiece (universal or custom) which was connected to a weighted chestpiece through rubber or plastic tubing. The conventional stethoscopes operated on the basis of acoustic transmission, with the chestpiece placed above the patient’s sternal notch. AAPD Guidelines also state that “a precordial/pretracheal stethoscope shall be used for obtaining additional information on heart and respiratory rates and for monitoring airway patency during Level 3 sedations.” The use and effectiveness of the pretracheal/precordial stethoscope has received mixed reviews in the literature. It has even been observed that one trend among anesthesiology trainees and providers is to replace (rather than supplement) pulse oximetry and capnography with the pretracheal/precordial stethoscope. Monitor Advantages Limitations