Investigation of Appropriate Scaling of Networks and Images for Convolutional Neural Network-Based Nerve Detection in Ultrasound-Guided Nerve Blocks.

Ultrasound imaging is an essential tool in anesthesiology, particularly for ultrasound-guided peripheral nerve blocks (US-PNBs). However, challenges such as speckle noise, acoustic shadows, and variability in nerve appearance complicate the accurate localization of nerve tissues. To address this issue, this study introduces a deep convolutional neural network (DCNN), specifically Scaled-YOLOv4, and investigates an appropriate network model and input image scaling for nerve detection on ultrasound images. Utilizing two datasets, a public dataset and an original dataset, we evaluated the effects of model scale and input image size on detection performance. Our findings reveal that smaller input images and larger model scales significantly improve detection accuracy. The optimal configuration of model size and input image size not only achieved high detection accuracy but also demonstrated real-time processing capabilities.

The predictive performance of propofol target-controlled infusion during robotic-assisted laparoscopic prostatectomy with CO2 pneumoperitoneum in the head-down position.

PURPOSE: Propofol clearance can be reduced when cardiac output (CO) is decreased. This clearance reduction may alter the pharmacokinetics of propofol and worsen the predictive performance of target-controlled infusion (TCI) of propofol. The head-down position (HDP) and CO2 pneumoperitoneum, which are required for robotic-assisted laparoscopic prostatectomy (RALP), may cause changes in CO. We investigated the predictive performance of propofol TCI during CO2 pneumoperitoneum in patients who underwent RALP in the HDP. METHODS: Fifteen male patients received propofol TCI using the Diprifusor model. Propofol concentrations were measured at seven time points: (T1) 15 min after anesthesia induction; (T2) before the insufflation; (T3, T4, and T5) 15, 60, and 90 min, respectively, after insufflation in the HDP; (T6) before the release of pneumoperitoneum in the HDP; and (T7) 15 min after the release of pneumoperitoneum in the supine position. Cardiac index (CI) was assessed using an arterial pulse contour CO monitor. The predictive performance of propofol TCI was evaluated by calculating the performance errors (PE) in propofol concentrations for each data point. The relationship between CI and PE was examined. Median PE (MDPE) and median absolute PE (MDAPE) were calculated as measures of bias and accuracy, respectively. RESULTS: A total of 104 blood samples were analyzed. There was significantly negative correlation between CI and PE. The predictive performance of propofol TCI during pneumoperitoneum in the HDP was acceptable (MDPE = - 1.5% and MDAPE = 18.8%). CONCLUSION: The predictive performance of propofol TCI during RALP with CO2 pneumoperitoneum in the HDP was acceptable.

The use of the Sanuki airway™ in three patients with suspected difficult airway.

The Sanuki airway is a single-use intubation oral airway designed for fiberoptic bronchoscope intubation. Sanuki airway has a bite block function and a wide lumen for the tracheal tube to pass through. Here, three cases are reported in which Sanuki airway was used for oral fiberoptic bronchoscope intubation. Case 1 is a patient who presented with reduced mouth opening and intraoral edema due to facial bone fracture. Case 2 is a patient who suffered from severe neck stiffness and had reduced mouth opening due to systemic psoriatic arthritis. Case 3 is a patient who suffered from multiple facial traumas and was in a full-stomach state. In all patients, advancing the tip of the bronchofiber into the larynx using Sanuki airway was possible under dexmedetomidine sedation, which contributed to the successful tracheal intubation. Using Sanuki airway may be considered an option for oral fiberoptic bronchoscope intubation in patients anticipated with difficult airways.

Dexmedetomidine administration in a patient with status epilepticus under color density spectral array monitoring.

BACKGROUND: Status epilepticus requires immediate treatment because treatment delay can cause permanent neurologic complications. Dexmedetomidine may be an option for the treatment of status epilepticus although its effect remains unclear with conflicting reports. CASE PRESENTATION: A 64-year-old woman with epilepsy with complex partial seizures underwent total knee arthroplasty. After emergence from general anesthesia, she developed status epilepticus and was transferred to the intensive care unit. Following initial treatment using benzodiazepines, phenytoin, and levetiracetam, dexmedetomidine (0.37 µg/kg loading in 10 min followed by 0.6 µg/kg/h) was administered and seizures terminated in 20 min. Color density spectral array using Root® with SedLine® (Masimo, Irvine, CA, USA) showed an increase in power in high frequency band of the electroencephalogram during the seizure attacks. CONCLUSION: We described a case of status epilepticus which was treated with dexmedetomidine and monitored using color density spectral array.

Correction to: Dexmedetomidine administration in a patient with status epilepticus under color density spectral array monitoring.

Following publication of the original article [1], the authors reported an error in Fig. 1b and c. A black bar and arrows were added.