Tracheal Deviation and Airway Management: Clinical Considerations From a Cadaver.

Severe tracheal deviation detected on preoperative chest radiographs is one of the risk factors for difficult tracheal intubation and difficulty in ventilation using an endotracheal tube after tracheal intubation when managing the airway through tracheal intubation under general anesthesia. In this report, we describe the cadaver of an 81-year-old woman with marked tracheal deviation due to meandering multiple aortas. This report details the importance of anatomical knowledge in developing a detailed airway management plan. The deviated trachea was removed from the cadaver and the tracheal tube was inserted at the glottis to the proximal end of the glottal marker. The tube tip was in contact with the tracheal wall, suggesting ventilation difficulty during intubation. The tortuous brachiocephalic artery passed in front of the trachea, which posed a risk of massive aortic hemorrhage and postoperative trachea-brachiocephalic artery fistula during percutaneous tracheostomy for emergency airway management. The anatomical location of the trachea and carotid artery must be confirmed before surgery/anesthesia to ensure safe airway management.

Alternating Current Iontophoresis for Control of Postoperative Pain.

Control of early postoperative pain entails the use of various medications including acetaminophen, nonsteroidal anti-inflammatory drugs, selective cyclooxygenase-2 inhibitors, tramadol, and opioids. However, these medications should be carefully administered in patients with aspirin-exacerbated respiratory disease because some medications may trigger adverse reactions after maxillofacial surgeries. The goal of postoperative pain control in patients with aspirin-exacerbated respiratory disease is to eliminate pain without complications. Local anesthesia is an efficient tool for the control of postoperative pain after maxillofacial surgeries. We utilized a transdermal drug delivery system, iontophoresis by alternating current, in order to develop an alternative technique for administering local anesthetic to control postoperative pain in 2 patients with aspirin-exacerbated respiratory disease. A visual analogue scale was used to objectively measure the severity of pain. A 55-year-old woman who underwent mandibular wisdom tooth extraction and an 18-year-old woman who underwent sagittal split ramus osteotomy of the mandible both complained of pain multiple times. After application of iontophoresis, the visual analogue scale score was reduced to zero and postoperative pain could be controlled. There were no adverse events such as bronchospasm or skin irritation after the application of iontophoresis by alternating current.

Drug delivery and transmission of lidocaine using iontophoresis in combination with direct and alternating currents.

The present study investigates how effectively lidocaine ions are transported across a cellophane membrane through the application of either a direct current (DC) or alternating current (AC). The cellophane membrane was set on a parallelplate- type acrylic cell with platinum electrodes at both ends, filled with a donor cell of a 1 % aqueous solution of lidocaine and a receptor cell with distilled water. Lidocaine concentrations were measured for 60 min while the following voltages were applied, with changes every 10 min: 3 V DC and 7.5 V sine wave AC; frequency at 1 kHz. As a result, lidocaine concentrations in the receptor cell increased in a time-dependent manner. Significant increases in lidocaine concentrations were observed in groups where the voltage combination consisted of DC 30 min/AC 30 min, DC 50 min/AC 10 min, DC 60 min and AC 10 min/DC 50 min, compared with the passive diffusion group or in groups where voltage application was performed for 20, 30 , 40, 50 and 60 min. Significant increases were also observed in groups where the voltage combination consisted of A C 6 0 min, D C 10 min/AC 5 0 min, AC 3 0 min/ DC 30 min and AC 50 min/DC 10 min, compared with the passive diffusion group or in groups where voltage application was performed for 40, 50 and 60 min. These results suggest that lidocaine was delivered more rapidly with DC than with AC, and that its ions are transported faster when voltage is switched from DC to AC than from AC to DC, which is presumably due to the contribution of electrorepulsion by DC voltage application and the vibration energy infiltration mechanism owning to AC. Iontophoresis in combination with DC and AC was found to enable highly efficient drug delivery that shares the benefits of both forms of current application.