Randomized controlled trial of 152 children (experimental group = 96; control group = 56), 4 to 11 years of age, “to determine if phentolamine mesylate accelerated the return of normal soft tissue sensation by means of standardized lip palpation for mandibular and maxillary procedures and of tongue sensation by means of standardized tongue palpation for mandibular procedures.”

“The proposed mechanism of action of phentolamine mesylate, which is a vasodilator, with respect to local anesthesia reversal is that increased local blood flow accelerates the clearance of local anesthetic from the submucosal tissue to the bloodstream.”

All subjects received local anesthetic injections of 2% lidocaine with 1:100,000 epinephrine for dental procedures. Experimental group subjects received a phentolamine mesylate injection in the same site “as the local anesthetic was administered in a 1:1 cartridge ratio after the procedure was completed.” Subjects who received one-half cartridge of local anesthesia were given 0.2 mg of phentolamine mesylate while those who received a full cartridge of local anesthesia were given 0.4 mg of phentolamine mesylate.

The median recovery time to normal lip sensation was shorter (60 minutes) in the experimental group as compared to the control group (135 minutes). “The authors noted no differences in adverse events, pain, analgesic use or vital signs, and no subjects failed to complete the study.”

The authors concluded that phentolamine mesylate “can help dental clinicians shorten the post-treatment duration of soft-tissue anesthesia and can reduce the number of post-treatment lip and tongue injuries in children.”

Reviewer's note: Local anesthetic reversal with phentolamine mesylate requires another injection, a definite drawback for its application in children.

“Supplemental oxygen not only does not prevent oxygen desaturation but also delays the recognition of apnea”

The role of supplemental oxygen on the time interval between apnea simulation to bag-mask ventilation was analyzed in a pediatric sedation case scenario on a 6-year-old patient using a simulator mannequin.

The authors in their review cite that respiratory depression and airway obstruction are the primary causes of adverse events associated with pediatric sedation. They further noted that “when supplemental oxygen is administered, hemoglobin saturation measurements do not provide sufficient feedback to gauge the adequacy of ventilation.”

The authors observed that “there is no basis in the data collected to support or to reject recommendations for capnometry. The utility of capnometry as a monitoring tool depends on reliable capnographic pattern recognition by the clinicians using it.”

The authors concluded that “hypoventilation and apnea are detected more quickly when patients undergoing sedation breathe only air.”

N.B. Only the previous two issues of the coverpage are available here. Abstracts from earlier issues can be viewed in Archives.