Vapor Pressures of Anesthetic Agents at Temperatures Below 0°C and a Novel Anesthetic Delivery Device.

At room temperature, the vapor pressures of desflurane, isoflurane, and sevoflurane are well above the clinically useful range. We hypothesized that therapeutic concentrations of these agents could be achieved at temperatures below 0°C, but the vapor pressure-temperature relationship is unknown below 0. Second, we hypothesized that this relationship could be exploited to deliver therapeutic-range concentrations of anesthetic vapor. We therefore set out to determine the low temperature-vapor pressure relationships of each anesthetic agent, thereby identifying the saturated vapor concentration of each agent at any temperature below 0°C. To test our hypothesis, we measured the saturated vapor concentration at 1 atm of pressure for temperatures between -60 and 0°C, thus developing an empiric relationship for each agent. There was consistency in repeated experiments for all 3 agents. To test the empiric data, we constructed a digitally controlled thermoelectric anesthetic vaporizer, characterized the device, and used it to deliver anesthetic vapor to laboratory mice. We report, for the first time, the temperature-vapor pressure relationship at temperatures below 0°C for desflurane, isoflurane, and sevoflurane as well as the TMAC of these agents: the temperature at which the vapor pressure is equal to the minimum alveolar concentration. We describe the construction and limited validation of an anesthetic vaporizer prototype on the basis of this principle. We conclude that clinically relevant concentrations of volatile anesthetics may be achieved at low temperatures.

Local read haplotagging enables accurate long-read small variant calling.

Long-read sequencing technology has enabled variant detection in difficult-to-map regions of the genome and enabled rapid genetic diagnosis in clinical settings. Rapidly evolving third-generation sequencing platforms like Pacific Biosciences (PacBio) and Oxford Nanopore Technologies (ONT) are introducing newer platforms and data types. It has been demonstrated that variant calling methods based on deep neural networks can use local haplotyping information with long-reads to improve the genotyping accuracy. However, using local haplotype information creates an overhead as variant calling needs to be performed multiple times which ultimately makes it difficult to extend to new data types and platforms as they get introduced. In this work, we have developed a local haplotype approximate method that enables state-of-the-art variant calling performance with multiple sequencing platforms including PacBio Revio system, ONT R10.4 simplex and duplex data. This addition of local haplotype approximation simplifies long-read variant calling with DeepVariant.

Stent assisted coil embolization of unruptured middle cerebral artery aneurysms.

BACKGROUND: Due to anatomic features, including wide necks and incorporation of important branches, endovascular coiling of middle cerebral artery (MCA) aneurysms has proved challenging. Stent assisted embolization may increase the likelihood of successful treatment. METHODS: Consecutive patients undergoing stent assisted coil embolization utilizing the Neuroform stent from 2004 to 2009 were identified by hospital billing records. Procedural and clinical information-including procedure related mortality and morbidity and long term outcomes-were then obtained by retrospective chart review. RESULTS: Treatment was successful in 22/23 (96%) patients. Median age was 61 years and 16/22 (73%) were women. Aneurysm size was: <5 mm in 5/22 (23%); 5-9 mm in 14/22 (64%); and ≥10 mm in 3/22 (14%) patients. There were four periprocedural complications (including one stroke and one intraprocedural rupture), none associated with neurological dysfunction. Angiographic follow-up was available in 18/22 (82%) and clinical follow-up in 19/22 (86%) patients, both at a median of 1 year (mean 1.2 years) after coiling. Aneurysm occlusion was complete in 12/18 (67%), a neck remnant was present in 3/18 (17%) and persistent aneurysmal filling was present in 3/18 (17%) patients, requiring retreatment in 1/18 (6%) patient. In-stent stenosis of 50%, which was asymptomatic, occurred in 1/18 (6%) patient. No subarachnoid hemorrhages and no ischemic events related to the procedure were observed during follow-up. CONCLUSION: In this small series, the technical success rate was 96%, there were no transient or permanent neurological complications and complete aneurysmal occlusion was achieved in two-thirds of treated aneurysms on follow-up angiography. These results suggest that in appropriately selected patients, stent assisted coil embolization of MCA aneurysms can be performed with a high degree of safety and acceptable durability.