Just-in-Time In Situ Simulation Training as a Preparedness Measure for the Perioperative Care of COVID-19 Patients.

Introduction: Routine workflows were redesigned during the first surge of the COVID-19 pandemic to standardize perioperative management of patients and minimize the risk of viral exposure and transmission to staff members. Just-in-time (JIT), in situ simulation training was adopted to implement urgent change, the value of which in a public health crisis has not previously been explored.

Methods: Implementation of workflow changes in the setting of the COVID-19 pandemic was accomplished through JIT, in situ simulation training, delivered over a period of 3 weeks to participants from anesthesia, nursing, and surgery, within our healthcare network.

Association Between Intraoperative Arterial Hypotension and Postoperative Delirium After Noncardiac Surgery: A Retrospective Multicenter Cohort Study.

Background: It is unclear whether intraoperative arterial hypotension is associated with postoperative delirium. We hypothesized that intraoperative hypotension within a range frequently observed in clinical practice is associated with increased odds of delirium after surgery.

Methods: Adult noncardiac surgical patients undergoing general anesthesia at 2 academic medical centers between 2005 and 2017 were included in this retrospective cohort study.

Effect of Intraoperative Arterial Hypotension on the Risk of Perioperative Stroke After Noncardiac Surgery: A Retrospective Multicenter Cohort Study.

Background: Intraoperative cerebral blood flow is mainly determined by cerebral perfusion pressure and cerebral autoregulation of vasomotor tone. About 1% of patients undergoing noncardiac surgery develop ischemic stroke. We hypothesized that intraoperative hypotension within a range frequently observed in clinical practice is associated with an increased risk of perioperative ischemic stroke within 7 days after surgery.

Neurophysiologic Intraoperative Monitoring for Spine Surgery: A Practical Guide From Past to Present.

Intraoperative neuromonitoring was introduced in the second half of the 20th century with the goal of preventing patient morbidity for patients undergoing complex operations of the central and peripheral nervous system. Since its early use for scoliosis surgery, the growth and utilization of IOM techniques expanded dramatically over the past 50 years to include spinal tumor resection and evaluation of cerebral ischemia. The importance of IOM has been broadly acknowledged, and in 1989, the American Academy of Neurology (AAN) released a statement that the use of SSEPs should be standard-of-care during spine surgery.

Perianesthetic and Anesthesia-Related Mortality in a Southeastern United States Population: A Longitudinal Review of a Prospectively Collected Quality Assurance Data Base.

Background: Perianesthetic mortality (death occurring within 48 hours of an anesthetic) continues to vary widely depending on the study population examined. The authors study in a private practice physician group that covers multiple anesthetizing locations in the Southeastern United States. This group has in place a robust quality assurance (QA) database to follow all patients undergoing anesthesia.

Is Compliance With Surgical Care Improvement Project Cardiac (SCIP-Card-2) Measures for Perioperative β-Blockers Associated With Reduced Incidence of Mortality and Cardiovascular-Related Critical Quality Indicators After Noncardiac Surgery?

Background: While continuation of β-blockers (BBs) perioperatively has become a national quality improvement measure, the relationship between BB withdrawal and mortality and cardiovascular-related critical quality indicators has not been studied in a contemporary cohort of patients undergoing noncardiac surgery.

Methods: For this retrospective study, the quality assurance database of a large community-based anesthesiology group practice was used to identify 410,288 surgical cases, 18 years of age or older, who underwent elective or emergent noncardiac surgical procedures between January 1, 2009, and December 31, 2014. Each surgical case that was withdrawn from BBs perioperatively was propensity matched by clinical and surgical characteristics to 4 cases that continued BBs perioperatively.

In Situ Ellipsometric Monitoring of Gold Nanorod Metamaterials Growth.

An in situ transmission-based system has been designed to optically monitor the ellipsometry constants of a hyperbolic plasmonic metamaterial during electrochemical growth. The metamaterial, made from an array of vertically aligned gold nanorods, has demonstrated an unprecedented ability to manipulate the polarization of light using subwavelength thickness slabs, making in situ ellipsometric data a powerful tool in the controlled design of such components. In this work, we show practical proof-of-principle of this design method and rationalize the ellipsometric output on the basis of the modal properties of the nanorod metamaterial.

Manipulating polarization of light with ultrathin epsilon-near-zero metamaterials.

One of the basic functionalities of photonic devices is the ability to manipulate the polarization state of light. Polarization components are usually implemented using the retardation effect in natural birefringent crystals and, thus, have a bulky design. Here, we have demonstrated the polarization manipulation of light by employing a thin subwavelength slab of metamaterial with an extremely anisotropic effective permittivity tensor.

The controlled fabrication and geometry tunable optics of gold nanotube arrays.

Arrays of vertically aligned gold nanotubes are fabricated over several square centimetres which display a geometry tunable plasmonic extinction peak at visible wavelengths and at normal incidence. The fabrication method gives control over nanotube dimensions with inner core diameters of 15-30 nm, wall thicknesses of 5-15 nm and nanotube lengths of up to 300 nm. It is possible to tune the position of the extinction peak through the wavelength range 600-900 nm by varying the inner core diameter and wall thickness.

High-performance biosensing using arrays of plasmonic nanotubes.

We show that aligned gold nanotube arrays capable of supporting plasmonic resonances can be used as high performance refractive index sensors in biomolecular binding reactions. A methodology to examine the sensing ability of the inside and outside walls of the nanotube structures is presented. The sensitivity of the plasmonic nanotubes is found to increase as the nanotube walls are exposed, and the sensing characteristic of the inside and outside walls is shown to be different.

Optical nonlocalities and additional waves in epsilon-near-zero metamaterials.

We analyze the optical properties of plasmonic nanorod metamaterials in the epsilon-near-zero regime and show, both theoretically and experimentally, that the performance of these composites is strongly affected by nonlocal response of the effective permittivity tensor. We provide the evidence of interference between main and additional waves propagating in the room-temperature nanorod metamaterials and develop an analytical description of this phenomenon. Additional waves are present in the majority of low-loss epsilon-near-zero structures and should be explicitly considered when designing applications of epsilon-near-zero composites, as they represent a separate communication channel.

Polarization conversion through collective surface plasmons in metallic nanorod arrays.

For two-dimensional (2D) arrays of metallic nanorods arranged perpendicular to a substrate several methods have been proposed to determine the electromagnetic near-field distribution and the surface plasmon resonances, but an analytical approach to explain all optical features on the nanometer length scale has been missing to date. To fill this gap, we demonstrate here that the field distribution in such arrays can be understood on the basis of surface plasmon polaritons (SPPs) that propagate along the nanorods and form standing waves. Notably, SPPs couple laterally through their optical near fields, giving rise to collective surface plasmon (CSP) effects.

Optical transmission measurements of silver, silver-gold alloy and silver-gold segmented nanorods in thin film alumina.

Silver nanorods have been grown by electrodeposition into thin film porous alumina. Transmission measurements show two peaks related to the transverse and longitudinal resonance of the nanorods. The behaviour of the longitudinal resonance peak is found to vary with nanorod length and the spectral position to depend on nanorod diameter.

Adverse effects of topical papaverine on auditory nerve function.

Background: Papaverine hydrochloride is a direct-acting vasodilator used to manage vasospasm during various neurosurgical operations. Transient cranial nerve dysfunction has been described in a few cases with topical papaverine. This study supports previous reports and provides neurophysiological evidence of an adverse effect on the auditory nerve.

Towards nonlinear plasmonic devices based on metallic nanorods.

The nonlinear optical properties of gold nanorod arrays have been studied with a two-colour continuously working (CW) pump-probe spectroscopy. The hybridization of the nanorod arrays with a nonlinear polymer (poly-3BCMU) has been investigated for the purposes of active photonic component design. The sensitivity of the plasmonic resonances of the hybrid nanostructured system to pump-induced changes in the refractive index of the polymer surroundings has been used to control the optical extinction of the array.

Electronically controlled surface plasmon dispersion and optical transmission through metallic hole arrays using liquid crystal.

The enhanced optical properties of metal films periodically perforated with an array of sub-wavelength size holes have recently been widely studied in the field of surface plasmon optics. The ability to design the optical transmission of such nanostructures, which act as plasmonic crystals, by varying their geometrical parameters gives them great flexibility for numerous applications in photonics, opto-electronics, and sensing. Transforming these passive optical elements into devices that may be actively controlled has presented a new challenge.

Molecular plasmonics with tunable exciton-plasmon coupling strength in J-aggregate hybridized Au nanorod assemblies.

Controlling coherent electromagnetic interactions in molecular systems is a problem of both fundamental interest and important applicative potential in the development of photonic and opto-electronic devices. The strength of these interactions determines both the absorption and emission properties of molecules coupled to nanostructures, effectively governing the optical properties of such a composite metamaterial. Here we report on the observation of strong coupling between a plasmon supported by an assembly of oriented gold nanorods (ANR) and a molecular exciton.

Toward self-assembled ferroelectric random access memories: hard-wired switching capacitor arrays with almost Tb/in.(2) densities.

We report on the successful fabrication of arrays of switchable nanocapacitors made by harnessing the self-assembly of materials. The structures are composed of arrays of 20-40 nm diameter Pt nanowires, spaced 50-100 nm apart, electrodeposited through nanoporous alumina onto a thin film lower electrode on a silicon wafer. A thin film ferroelectric (both barium titanate (BTO) and lead zirconium titanate (PZT)) has been deposited on top of the nanowire array, followed by the deposition of thin film upper electrodes.

Intraoperative awareness in a regional medical system: a review of 3 years' data.

Background: Intraoperative awareness in patients undergoing general anesthesia is an infrequent but well-described adverse outcome. The reported incidence of this phenomenon is between 0.1% and 0.

Investigating the effects of reduced size on the properties of ferroelectrics.

A series of experiments has been undertaken to understand more about the fundamental origin of the thickness-induced permittivity collapse often observed in conventional thin film ferroelectric heterostructures. The various experiments are discussed, highlighting the eventual need to examine permittivity collapse in thin film single crystal material. It has been seen that dielectric collapse is not a direct consequence of reduced size, and neither is it a consequence of unavoidable physics associated with the ferroelectric-electrode boundary.

The relationships among pulmonary function, aerobic fitness, and cognitive functioning in older COPD patients.

Study Objectives: To study the predictive relationships among age, pulmonary function, aerobic fitness, and cognition in people with COPD.

Design: Observational study conducted during baseline testing with COPD patients who volunteered to participate in an exercise intervention.

Participants: Older adults (age, 56 to 80 years) with COPD.

Somatosensory-evoked potentials during aortic coarctation repair.

Objective: To determine the incidence of somatosensory-evoked potential (SSEP) changes and the interventions based on these changes during aortic coarctation repair.

Design: Retrospective review.

Setting: Single-institution, university hospital.