Considerations for Satisfactory Sedation during Dental Implant Surgery.

Implant surgery is a lengthy dental procedure, and sedation is often used to reduce discomfort. The effectiveness of sedation has traditionally been evaluated in terms of patient and surgeon satisfaction, but the most important goal is not to induce a deep sleep in the patient, but rather to ensure that the surgery is performed safely and as planned. Additionally, adequate pain control is a necessary requirement for patient and surgeon satisfaction. Most patients undergoing implant surgery are middle-aged or older, and a relatively large number of them have cardiovascular disease. Infiltration anesthesia using articaine or lidocaine in combination with adrenaline is widely used, but its use in patients with cardiovascular disease is limited because of adrenaline's effects on the cardiovascular system. The use of long-acting local anesthetics and the potential efficacy of ultrasound-guided jaw nerve block have been investigated to enhance analgesia without resorting to adrenaline. Midazolam and propofol are usually used for sedation, but dexmedetomidine, which causes less respiratory depression, and the ultrashort-acting benzodiazepine remimazolam are emerging as potential alternatives. Monitoring of anesthetic depth using electroencephalography is effective in maintaining a constant level of sedation. In addition, sedation promotes the stabilization of heart rate and blood pressure, reducing the risks associated with adrenaline and allowing for safer management.

Perioperative Management of a Patient With Tongue Cancer Who Developed Pneumomediastinum Following Tracheostomy Performed to Secure the Airway.

Prior to a scheduled operation for a 45-year-old male patient with tongue cancer, a tracheotomy performed under intravenous sedation to prevent asphyxia due to extensive bleeding resulted in pneumomediastinum and subcutaneous emphysema. The planned operations were postponed until reduction of the pneumomediastinum was confirmed. During operation, airway pressure was kept low to prevent tension pneumomediastinum along with a sufficient depth of anesthesia, controlled analgesia, and continuous administration of muscle relaxants. Postoperatively, sedation was used to avoid stress and complications with the vascular anastomosis site. In this case, air leakage into the soft tissues was one of the possible causes of the event associated with increased airway pressure. Although the incidence of such complications is relatively low, caution should be exercised after tracheostomy.

Coronary Spasm During Postoperative Sedation With Dexmedetomidine.

This is a case report of an 81-year-old woman who underwent tracheostomy, bilateral cervical dissection, partial tongue resection, radial forearm free flap reconstruction, and split-thickness skin grafting under general anesthesia. After successful surgery, she was moderately sedated postoperatively with intravenous dexmedetomidine (DEX) and fentanyl. The fentanyl was discontinued 5 hours postoperatively. Eight hours after the operation, an atrioventricular junctional rhythm, a 2-mm elevation of the ST segment, and biphasic T waves were detected in lead II that lasted approximately 3 minutes. Hypotension and bradycardia were observed simultaneously with the abnormal electrocardiogram. The next day, a cardiologist examined the patient and suggested that coronary spasm had occurred based on those findings. The transient coronary spasm was likely caused by a combination of various factors including surgical stress and altered autonomic function. However, it is possible that stimulation of α-2 adrenergic receptors induced by DEX may also be linked to the coronary vasospasm that occurred.

Transient ventricular bigeminy during emergence from general anesthesia in a pediatric patient with catecholaminergic polymorphic ventricular tachycardia.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare genetic disease that is characterized by ventricular arrhythmias and sudden death, induced by exogenous and endogenous catecholamine. We performed general anesthesia for dental treatment of multiple teeth in a 7-year-old boy with CPVT. To avoid sympathetic tone, anesthesia was maintained by total intravenous anesthesia, but ventricular bigeminy was induced by stimulation on emergence form general anesthesia. Although bigeminy in the present case might have been less likely to induce a fatal arrhythmia, we should keep in mind that a small amount of sympathetic tone may induce arrhythmias in a patient with CPVT.

Combined Use of a Gum Elastic Bougie and Video Laryngoscopy for Intubating a Patient With an Unexpected Laryngeal Papilloma.

This is a case report of a 75-year-old man scheduled for apical resection and cystectomy of odontogenic cysts involving both maxillary central incisors who presented with a previously unknown laryngeal mass that was discovered prior to intubation. Following induction and easy mask ventilation, direct laryngoscopy revealed a large mass on the right side of the glottis that impeded passage of a standard oral endotracheal tube. Successful atraumatic intubation was performed with the combination of a video laryngoscope (King Vision, Ambu Inc, Ballerup, Denmark) and a gum elastic bougie (GEB). Although a GEB may not be used routinely for tracheal intubation, it facilitated smooth advancement of the endotracheal tube without damaging the laryngeal mass when used in combination with video laryngoscopy.

Difficult Nasal Intubation Using Airway Scope® for a Child With Large Tumor.

We report a case of difficult nasal intubation utilizing a Pentax-Airway scope® AWS-100. A 4-month-old female with a rapidly growing melanotic neuroectodermal tumor was scheduled for resection under general anesthesia. The tumor was a large rubbery mass located in the middle of the mandible. For nasal intubation using the AWS, guidance of the tube toward the glottis was attempted using pediatric Magill forceps. Although we could hold the tube with the Magill forceps, it was difficult to insert the tube into the trachea due to the limited space in her hypopharynx. We then used a standard laryngoscope with a Miller straight blade for direct visual laryngoscopy and successfully intubated the patient with the aid of the pediatric Magill forceps. We often experience difficulty navigating a nasal endotracheal tube toward the glottis even when a clear glottic view is obtained with video laryngoscopes, especially in children with a small oropharyngeal space. However, some reports have been shown that video laryngoscopes are useful for intubation of the difficult airway and causes less stress to the upper airway than direct visual laryngoscopy. Video laryngoscopy can be an excellent way to provide nasal intubation in some but not all children.

NGF is Induced by Lidocaine in Human Skin Fibroblast Cells In Vitro.

We incubated skin fibroblasts with various concentrations of lidocaine for 3, 24, and 48 hours and found that the NGF mRNA expression levels significantly increased after incubation for 3 hours, indicating that the incubation for 3 hours activated the signaling that induce the NGF mRNA expression.

Trigeminal neuralgia: differences in magnetic resonance imaging characteristics of neurovascular compression between symptomatic and asymptomatic nerves.

OBJECTIVES: Neurovascular compression (NVC) of the trigeminal nerve is the primary cause of trigeminal neuralgia (TN) but is known to occur in both symptomatic and asymptomatic nerves. The purposes of this study were to evaluate the relationship between the magnetic resonance imaging (MRI) findings regarding the site of NVC and the manifestation of TN symptoms. METHODS: In 147 patients with unilateral TN, the presence or absence of NVC was evaluated on MRI in both symptomatic and asymptomatic nerves. In cases with NVC, the shortest distance from the trigeminal nerve root to the responsible vessel was measured. RESULTS: The mean distance from the trigeminal nerve root to the site of NVC in asymptomatic nerves (3.85 ± 2.69 mm) was significantly greater than that in symptomatic nerves (0.94 ± 1.27 mm). When the distance was 3 mm or less, the rate of the manifestation of TN symptoms was 83.1% (103/124). On the other hand, it was only 19.6% (9/46) in cases with a distance of greater than 3 mm. CONCLUSIONS: Whether or not NVC of the trigeminal nerve was symptomatic was closely related to the distance from the trigeminal nerve root to the responsible blood vessel.