Yuka Honda

Female Patients Require a Higher Propofol Infusion Rate for Sedation.

Sedation may minimize physiologic and behavioral stress responses. In our facility, the infusion rate of propofol is adjusted according to the bispectral index (BIS) in all cases of implant-related surgery; multivariate analysis of retrospective data enabled us to extract independent factors that affect the dose of propofol in sedation that are considered useful indicators for achieving adequate sedation. The study population comprised all patients undergoing implant-related surgery under intravenous sedation in Okayama University Hospital from April 2009 to March 2013. The infusion rate of propofol was adjusted to maintain the BIS value at 70-80. The outcome was the average infusion rate of propofol, and potential predictor variables were age, sex, body weight, treatment time, and amount of midazolam. Independent variables that affected the average infusion rate of propofol were extracted with multiple regression analysis. One hundred twenty-five subjects were enrolled. In the multiple regression analysis, female sex was shown to be significantly associated with a higher average infusion rate of propofol. Females may require a higher infusion rate of propofol than males to achieve adequate sedation while undergoing implant-related surgery.

Independent Factors Affecting Recovery Time After Sedation in Patients with Intellectual Disabilities

Purpose : The purpose of this study was to identify independent factors associated with prolonged recovery time after intravenous sedation for dental treatment in patients with intellectual disabilities. Methods : This study was designed as a prospective cohort study. Participants were patients with intellectual disabilities, for whom sedation for dental treatment was planned in Okayama University Hospital. The outcome variable was recovery time. The predictor variables were patient background, antiepileptic and psychotropic drugs, and anesthesia-related variables. Factors affecting the outcome were examined with multiple regression analysis. Results : We enrolled 260 cases in this study. Oral midazolam was a strong independent determinant in prolonged recovery time. Teeth extraction, short treatment time and lower body mass index were significant independent predictors of prolonged recovery time. Conclusion : Oral midazolam is a clear independent determinant of prolonged recovery time after sedation, while psychotropic drugs and antiepileptic drugs were not independent determinants in this study.

Effect of a low dose of midazolam on high blood pressure in dental patients: a randomised, double-blind, placebo-controlled, two-centre study

Some patients have transient hypertension before dental treatment as a result of anxiety and stress. Midazolam is an anxiolytic, and thought to be effective for the management of this sort of transient hypertension. We have evaluated in a randomised, controlled trial whether a low dose of midazolam can lower blood pressure in dental patients to an acceptable level without excessive sedation. Suitable patients were randomised to be given midazolam (trial group) or physiological saline (control group) intravenously. Blood pressure, heart rate, degree of anxiety, and amount of sedation were measured before and after injection. After injection, blood pressure in the trial group significantly decreased to clinically acceptable levels compared with controls. The degree of anxiety in the trial group was also significantly less than that in the control group, but there were no significant differences in sedation. These results suggest that injection of a low dose of midazolam stabilises the blood pressure of dental patients with transient hypertension.

Clinical analysis of analgesics and steroids use for extraction of teeth in patients with intellectual disability under general anesthesia

Background: The extraction of lower wisdom teeth is often performed under general anesthesia in patients with intellectual disabilities. However, the choice of analgesics has not yet been investigated. Objective: To analyze the use of analgesics during general anesthesia for extraction including lower wisdom teeth in patients with intellectual disabilities. Methods: This research is a retrospective observational study. The study population was composed of all patients presenting for extraction of lower wisdom teeth under ambulatory general anesthesia in the clinic of Special Needs Dentistry in Okayama University Hospital from April 2011 to March 2016. The distribution of the combination of analgesics and the relationship between the use of analgesics and the type of extraction were investigated. Results: One hundred and twelve cases were enrolled in this study. Intravenous injections of flurbiprofen, acetaminophen and betamethasone were used in 96 (85.7%), 12 (10.7%) and 26 cases (23.2%), respectively. Flurbiprofen is a non-steroid anti-inflammatory drugs (NSAIDs). Acetaminophen is an old analgesic, but an injection of acetaminophen is new, which was released in 2013 in Japan. And betamethasone is not an analgesic, but a steroid. Betamethasone was used in combination with other analgesics, and was used at a higher dose in a case in which four wisdom teeth were extracted. Conclusion: Flurbiprofen was the main analgesic used for extraction of wisdom teeth under general anesthesia in patients with intellectual disabilities. Betamethasone was used to support flurbiprofen or acetaminophen for extractions of multiple wisdom teeth, with the aim of controlling swelling rather than relieving pain.

Capnography Prevents Hypoxia during Sedation for Dental Treatment: A Randomized Controlled Trial:

Intravenous sedation is useful for dental treatment in patients with intellectual disabilities. However, it is often necessary to manage such patients with deep sedation because their cooperation cannot be obtained. During deep sedation, undetected hypoventilation can lead to severe complications, such as hypoxia. Recently, capnographic monitoring has been advocated as a useful technique for preventing hypoxia during sedation. This randomized control trial evaluated whether the use of capnography reduces the incidence of hypoxia during the deep sedation of patients for dental treatment. This study involved patients with intellectual disabilities who underwent dental treatment under sedation. The subjects were randomized to the intervention group (I-group) or control group (C-group). All of the patients underwent routine monitoring, as well as bispectral index (BIS) and capnographic monitoring; however, only an independent observer had access to the patients’ capnographic data during the dental procedures. Sedation was maintained at a BIS of 50 to 70 by administration of propofol. In the I-group, the independent observer signaled to the dental anesthesiologist if the capnogram indicated that the patient had been suffering from alveolar hypoventilation or apnea for >15 s. In the C-group, the observer signaled to the dental anesthesiologist if the capnogram indicated that the patient had been suffering from alveolar hypoventilation or apnea for >60 s. In both groups, the dental anesthesiologists responded to the signals using appropriate airway management strategies. The primary endpoint of this study was the incidence of hypoxia during dental treatment, which was defined as oxygen saturation of <95%. Hypoxemic episodes occurred in 13.4% and 34.8% of cases in the I-group and C-group, respectively. The incidence of hypoxia was significantly lower in the I-group. These results suggest that capnographic monitoring during deep sedation for dental treatment prevents hypoxemic episodes by allowing the early detection of hypoventilation. Knowledge Transfer Statement: This is the first randomized controlled trial to examine whether the use of capnography reduces the incidence of hypoxia during deep sedation for dental treatment. The findings of this study can be used by clinicians to aid decision-making regarding dental sedation standards at individual clinics. Moreover, they can be used as high-level evidence during the production or updating of clinical guidelines for dental sedation by leading associations.

The inhibitory effect of locally injected dexmedetomidine on carrageenan-induced nociception in rats

Recent studies showed that the administration of dexmedetomidine relieved hyperalgesia in the presence of neuropathic pain. These findings have led to the hypothesis that the local administration of dexmedetomidine is useful for relieving acute inflammatory nociception, such as postoperative pain. Thus, we evaluated the inhibitory effect of locally injected dexmedetomidine on acute inflammatory nociception. Acute inflammatory nociception was induced by an intraplantar injection of 1% carrageenan into the hindpaws of rats, and dexmedetomidine was also injected combined with carrageenan. The paw withdrawal threshold based on von Frey filament stimulation was measured until 12 h after injection. We compared the area under the time-curve (AUC) between carrageenan and carrageenan with dexmedetomidine. To clarify that the action of dexmedetomidine was via α2-adrenoceptors, we evaluated the effect of yohimbine, a selective antagonist of α2-adrenoceptors, on the anti-nociception of dexmedetomidine. As the results, the intraplantar injection of carrageenan with over 10 μM dexmedetomidine significantly increased AUC, compared to that with only carrageenan injection. This effect of dexmedetomidine was reversed by the addition of yohimbine to carrageenan and dexmedetomidine. These results demonstrated that the locally injected dexmedetomidine was effective against carrageenan-induced inflammatory nociception via α2-adrenoceptors. The findings suggest that the local injection of dexmedetomidine is useful for relieving local acute inflammatory nociception.