The Effect of Dexmedetomidine on Oral Mucosal Blood Flow and the Absorption of Lidocaine.

Dexmedetomidine (DEX) is a sedative and analgesic agent that acts via the alpha-2 adrenoreceptor and is associated with reduced anesthetic requirements, as well as attenuated blood pressure and heart rate in response to stressful events. A previous study reported that cat gingival blood flow was controlled via sympathetic alpha-adrenergic fibers involved in vasoconstriction. In the present study, experiment 1 focused on the relationship between the effects of DEX on alpha adrenoreceptors and vasoconstriction in the tissues of the oral cavity and compared the palatal mucosal blood flow (PMBF) in rabbits between general anesthesia with sevoflurane and sedation with DEX. We found that the PMBF was decreased by DEX presumably because of the vasoconstriction of oral mucosal vessels following alpha-2 adrenoreceptor stimulation by DEX. To assess if this vasoconstriction would allow decreased use of locally administered epinephrine during DEX infusion, experiment 2 in the present study monitored the serum lidocaine concentration in rabbits to compare the absorption of lidocaine without epinephrine during general anesthesia with sevoflurane and sedation with DEX. The depression of PMBF by DEX did not affect the absorption of lidocaine. We hypothesize that this is because lidocaine dilates the blood vessels, counteracting the effects of DEX. In conclusion, despite decreased palatal blood flow with DEX infusion, local anesthetics with vasoconstrictors should be used in implant and oral surgery even with administered DEX.

Intravenous sedation for implant surgery: midazolam, butorphanol, and dexmedetomidine versus midazolam, butorphanol, and propofol.

We compared the amnesic action, recovery process, and satisfaction of patients and surgeons after the use of 2 different sedation regimens for 40 patients undergoing scheduled implant surgery. Butorphanol, midazolam, dexmedetomidine (BMD) was administered to 20 patients who were maintained with continuous infusion of dexmedetomidine after the induction with butorphanol and midazolam, and butorphanol, midazolam, propofol (BMP) was administered to 20 patients who were maintained with continuous infusion of propofol after the induction with butorphanol and midazolam. To assess the amnesic action, the memory of local anesthesia, auditory memory, and visual memory were evaluated. The Trieger Dot Test (TDT) was applied during the recovery process. A questionnaire regarding the patient's feelings of the management of sedation was taken from each patient and was also filled out by the surgeon. The comparison between groups was analyzed by the Mann-Whitney U test. No significant differences in the amnesic action and the TDT were noted. Both methods also satisfied the patients and surgeons, as determined by the questionnaire results. In conclusion, both sedation regimens are appropriate for implant surgery.

Effects of a transmitted light device for pediatric peripheral venipuncture and intravenous cannulation.

Pediatric peripheral venipuncture and intravenous cannulation are difficult. However, successful venipuncture and intravenous cannulation are absolutely required for pediatric clinical risk management. This study assessed the success rate of venipuncture and intravenous cannulation when transmitted light was applied to the pediatric dorsum manus. The subjects included 100 young children who were scheduled for dental treatment or oral surgery under general anesthesia. Anesthesia was induced, and insertion of an intravenous catheter into the dorsum manus was attempted with or without using transmitted light. The patients were evaluated to determine whether the venipuncture was successful, and whether the intravenous cannulation of the external catheter was successful. The success rate of venipuncture was 100% when transmitted light was used, and 83% when the transmitted light was not used (P = 0.000016). In addition, the success rate of intravenous cannulation was 88% when transmitted light was used, and 55% when the transmitted light was not used (P = 0.0000002). The shape of the vein in the dorsum manus can be clearly recognized when transmitted light is used. The use of light significantly increased the success rate of intravenous cannulation, because it allowed direct confirmation of the direction to push the intravenous catheter forward. The use of transmitted light allows for more successful venipuncture and intravenous cannulation in young children.