bluuebunny/crossref_metadata_2025 huggingface dataset:
Preservation of Fertility or Ovarian Function in Patients with Breast Cancer or Gynecologic and Internal Malignancies
Authors: Stachs Angrit , Hartmann Steffi , Gerber Bernd
Published: August 2017

Because of the efficacy of systemic therapies, neoplasias which occur in pediatric and adolescent patients and in young adults have high cure rates. This means that fulfilling their wish to have children has become a more pressing concern, particularly among young women with malignant tumors. Premature ovarian failure is also a not insignificant problem as it has a lasting detrimental effect on quality of life. Every oncology patient who may potentially wish to have children should be informed about their options for preserving fertility prior to starting treatment. The rates of patient who received detailed briefing on this point remain low. This review presents the effects of different chemotherapeutic drugs on gonadal function together with an overview of currently valid recommendations on fertility preservation. Risk groups are defined and the specific approaches for malignancies of various organ systems are described. Cryopreservation of oocytes, fertilized embryos and ovarian tissue are fertility-preserving options for girls/young women. The data on the benefits of administering GnRH analogs for ovarian protection prior to starting chemotherapy are not clear. In postpubertal boys or male cancer patients, the standard approach is to cryopreserve sperm before starting therapy. The cryopreservation of testicular tissue is possible for prepubertal boys, however in-vitro sperm maturation is still in its experimental stages. This review also presents existing drug options for the preservation of ovarian function in oncology patients prior to chemotherapy, particularly for patients with (hormone-sensitive) breast cancer, and looks at the special issues of fertility-preserving surgery and radiation therapy in patients with gynecologic malignancies.
Therapie der pulmonal arteriellen Hypertonie
Authors: Rosenkranz Stephan , Ghofrani H. Ardeschir , Hoeper Marius M.
Published: August 2017

Die Betreuung von Patienten mit pulmonal arterieller Hypertonie (PAH) basiert auf einer komplexen Strategie, welche neben dem Einsatz
gezielter PAH-Medikamente auch Allgemeinmaßnahmen und supportive Therapien einschließt. Gezielte PAH-Therapien umfassen
Endothelin-Rezeptor-Antagonisten, Phosphodiesterase 5-Inhibitoren, Stimulatoren der löslichen Guanylatzyklase, Prostazyklin-Analoga und
Prostazyklin-Rezeptor-Agonisten, die als Mono- oder Kombinationstherapien eingesetzt werden. Vor Einleitung einer gezielten PAH-Therapie
sollten die Patienten zur Diagnosesicherung und Klassifikation in einem Expertenzentrum vorgestellt werden. Therapieentscheidungen basieren
auf der initialen Ermittlung der Krankheitsschwere und einer individuellen Risikostratifizierung, dem Vorhandensein von Komorbiditäten und
Risikofaktoren, dem Therapieansprechen und dem Krankheitsverlauf. Die aktuellen ESC/ERS-Leitlinien und die Empfehlungen der Kölner
Konsensus-Konferenz betonen den Stellenwert von Kombinationstherapien, wobei je nach Vorhandensein kardialer und/oder pulmonaler
Begleiterkrankungen zwischen „typischer" und „atypischer" PAH unterschieden werden sollte. Allgemeinmaßnahmen und supportive Therapien haben
zum Teil erheblichen Einfluss auf die Morbidität und Mortalität und sind daher integraler Bestandteil der Behandlung und Versorgung von
PAH-Patienten.
The mechanism for large-volume fluid pumping via reversible snap-through of dielectric elastomer
Authors: Li Zhe , Wang Yingxi , Foo Choon Chiang , Godaba Hareesh , Zhu Jian , Yap Choon Hwai
Published: August 2017

Giant deformation of dielectric elastomers (DEs) via electromechanical instability (or the “snap-through” phenomenon) is a promising mechanism for large-volume fluid pumping. Snap-through of a DE membrane coupled with compressible air has been previously investigated. However, the physics behind reversible snap-through of a DE diaphragm coupled with incompressible fluid for the purpose of fluid pumping has not been well investigated, and the conditions required for reversible snap-through in a hydraulic system are unknown. In this study, we have proposed a concept for large-volume fluid pumping by harnessing reversible snap-through of the dielectric elastomer. The occurrence of snap-through was theoretically modeled and experimentally verified. Both the theoretical and experimental pressure-volume curves of the DE membrane under different actuation voltages were used to design the work loop of the pump, and the theoretical work loop agreed with the experimental work loop. Furthermore, the feasibility of reversible snap-through was experimentally verified, and specific conditions were found necessary for this to occur, such as a minimum actuation voltage, an optimal range of hydraulic pressure exerted on the DE membrane and a suitable actuation frequency. Under optimal working conditions, we demonstrated a pumping volume of up to 110 ml per cycle, which was significantly larger than that without snap-through. Furthermore, we have achieved fluid pumping from a region of low pressure to another region of high pressure. Findings of this study would be useful for real world applications such as the blood pump.
A curved resonant flexoelectric actuator
Authors: Zhang Shuwen , Liu Kaiyuan , Xu Minglong , Shen Shengping
Published: August 2017

Flexoelectricity is an electro-mechanical coupling effect that exists in all dielectrics and has the potential to replace piezoelectric actuating on the microscale. In this letter, a curved flexoelectric actuator with non-polarized polyvinylidene fluoride is presented and shown to exhibit good electro-mechanical properties. This provides experimental support for a body of theoretical research into converse flexoelectricity in polymeric materials. In addition, this work demonstrates the feasibility of lead-free microscale actuating without piezoelectricity.
Rapid evaporation-driven chemical pre-concentration and separation on paper
Authors: Syms Richard
Published: August 2017

Airflow-enhanced evaporation is investigated as a method for rapid chemical preconcentration on a thin porous substrate. The mechanism is described by combining 1D models of capillary rise, chromatography, and pervaporation concentration. It is shown that the effective length of the column can be shorter than its actual length, allowing concentrate to be held at a stagnation point and then released for separation, and that the Péclet number, which determines the concentration performance, is determined only by the substrate properties. The differential equations are solved dynamically, and it is shown that faster concentration can be achieved during capillary filling. Experiments are carried out using chromatography paper in a ducted airflow, and concentration is quantified by optical imaging of water-soluble food dyes. Good agreement with the model is obtained, and concentration factors of ≈100 are achieved in 10 min using Brilliant Blue FCF. Partial separation of Brilliant Blue from Tartrazine is demonstrated immediately following concentration, on a single unpatterned substrate. The mechanism may provide a method for improving the sensitivity of lab-on-paper devices.
Characterization of polarizing semiconductor radiation detectors by laser-induced transient currents
Authors: Musiienko A. , Grill R. , Pekárek J. , Belas E. , Praus P. , Pipek J. , Dědič V. , Elhadidy H.
Published: August 2017

A method is presented for the determination of the carrier drift mobility, lifetime, electric field distribution, and the dynamics of space charge formation, including the detrapping energy and capture cross-section of the dominant trap level in polarizing semiconductor radiation detectors. The procedure stems from the laser-induced transient current measurements done at a steady-state and pulsed biasing and at variable temperature. The approach allows us the direct determination of detector parameters from measured data without a complex mathematical treatment. The detrimental effect of surface carrier recombination often hampering the evaluation of detector properties is eliminated. Lifetime worsening caused by the space charge formation is included. The usefulness of the procedure is demonstrated on a CdTe radiation detector.
Magnetic vortex nucleation/annihilation in artificial-ferrimagnet microdisks
Authors: Lapa Pavel N. , Ding Junjia , Phatak Charudatta , Pearson John E. , Jiang J. S. , Hoffmann Axel , Novosad Valentine
Published: August 2017

The topological nature of the magnetic-vortex state gives rise to peculiar magnetization reversal observed in magnetic microdisks. Interestingly, magnetostatic and exchange, energies which, drive this reversal can be effectively controlled in artificial ferrimagnet heterostructures composed of rare-earth and transition metals. [Py(t)/Gd(t)]25 (t = 1 or 2 nm) superlattices demonstrate a pronounced change of the magnetization and exchange stiffness in a 10–300 K temperature range as well as very small magnetic anisotropy. Due to these properties, the magnetization of cylindrical microdisks composed of these artificial ferrimagnets can be transformed from the vortex to uniformly magnetized states in a permanent magnetic field by changing the temperature. We explored the behavior of magnetization in 1.5-μm [Py(t)/Gd(t)]25 (t = 1 or 2 nm) disks at different temperatures and magnetic fields and observed that due to the energy barrier separating vortex and uniformly magnetized states, the vortex nucleation and annihilation occur at different temperatures. This causes the temperature dependences of the magnetization in these Py/Gd disks to demonstrate a unique hysteretic behavior in a narrow temperature range. It was discovered that for the [Py(2 nm)/Gd(2 nm)]25 microdisks, the vortex can be metastable within a certain temperature range.
Relativistic self-focusing of an intense laser pulse with hot magnetized plasma in the presence of a helical magnetostatic wiggler
Authors: Abedi-Varaki M. , Jafari S.
Published: August 2017

In this paper, we study the nonlinear interaction of a circularly polarized laser pulse propagating through a hot magnetized plasma in the presence of a helical magnetostatic wiggler. A non-linear equation that describes the spot-size of the laser beam for both left- and right-hand polarizations has been derived. Non-linear dispersion relation describing the evolution of the laser frequency propagating through the hot magnetized plasma has been obtained. The effect of the wiggler magnetic field strength on the evolution of the laser spot-size has been discussed. The results indicate that for the right-hand polarization with increasing wiggler magnetic field strength, the laser spot-size decreases and the laser pulse becomes more focused. On the contrary, for the left-hand polarization, the self-focusing decreases with increasing wiggler magnetic field strength. Besides, it was found that in the right-hand polarization, the laser spot-size increases with the increasing plasma temperature, and the laser beam becomes more defocused. Furthermore, for the left-hand polarization, the laser self-focusing increases with the decreasing plasma temperature. Further numerical results revealed that by increasing the wiggler field strength, the normalized laser power increases significantly.
Measurement and structure of spiral wave response functions
Authors: Dierckx Hans , Verschelde Henri , Panfilov Alexander V.
Published: August 2017

The rotating spiral waves that emerge in diverse natural and man-made systems typically exhibit a particle-like behaviour since their adjoint critical eigenmodes (response functions) are often seen to be localised around the spiral core. We present a simple method to numerically compute response functions for circular-core and meandering spirals by recording their drift response to many elementary perturbations. Although our method is computationally more expensive than solving the adjoint system, our technique is fully parallellisable, does not suffer from memory limitations and can be applied to experiments. For a cardiac tissue model with the linear spiral core, we find that the response functions are localised near the turning points of the trajectory.
Highly trabeculated structure of the human endocardium underlies asymmetrical response to low-energy monophasic shocks
Authors: Connolly Adam , Robson Matthew D. , Schneider Jürgen , Burton Rebecca , Plank Gernot , Bishop Martin J.
Published: August 2017

Novel low-energy defibrillation therapies are thought to be driven by virtual-electrodes (VEs), due to the interaction of applied monophasic electric shocks with fine-scale anatomical structures within the heart. Significant inter-species differences in the cardiac (micro)-anatomy exist, however, particularly with respect to the degree of endocardial trabeculations, which may underlie important differences in response to low-energy defibrillation protocols. Understanding the interaction of monophasic electric fields with the specific human micro-anatomy is therefore imperative in facilitating the translation and optimisation of these promising experimental therapies to the clinic. In this study, we sought to investigate how electric fields from implanted devices interact with the highly trabeculated human endocardial surface to better understand shock success in order to help optimise future clinical protocols. A bi-ventricular human computational model was constructed from high resolution (350 μm) ex-vivo MR data, including anatomically accurate endocardial structures. Monophasic shocks were applied between a basal right ventricular catheter and an exterior ground. Shocks of varying strengths were applied with both anodal [positive right ventricle (RV) electrode] and cathodal (negative RV electrode) polarities at different states of tissue refractoriness and during induced arrhythmias. Anodal shocks induced isolated positive VEs at the distal side of “detached” trabeculations, which rapidly spread into hyperpolarised tissue on the surrounding endocardial surfaces following the shock. Anodal shocks thus depolarised more tissue 10 ms after the shock than cathodal shocks where the propagation of activation from VEs induced on the proximal side of “detached” trabeculations was prevented due to refractory endocardium. Anodal shocks increased arrhythmia complexity more than cathodal shocks during failed anti-arrhythmia shocks. In conclusion, multiple detached trabeculations in the human ventricle interact with anodal stimuli to induce multiple secondary sources from VEs, facilitating more rapid shock-induced ventricular excitation compared to cathodal shocks. Such a mechanism may help explain inter-species differences in response to shocks and help to develop novel defibrillation strategies.
A new way to derive the Taub-NUT metric with positive cosmological constant
Authors: Osuga Kento , Page Don N.
Published: August 2017

We investigate a biaxial Bianchi IX model with positive cosmological constant, which is sometimes called the Λ-Taub-NUT spacetime, whose exact solution is well known. The minisuperspace of biaxial Bianchi IX models admits two non-trivial Killing tensors that play an important role for deriving the Taub-NUT metric.
Correlation of oxygen vacancies to various properties of amorphous zinc tin oxide films
Authors: Sung Nark-Eon , Lee Han-Koo , Chae Keun Hwa , Singh Jitendra Pal , Lee Ik-Jae
Published: August 2017

Amorphous ZnO-SnO2 (a-ZTO) films were deposited on quartz substrates at working pressures of 5 ≤ PW ≤ 12 mTorr using radio frequency sputtering. PW affected the occurrence of oxygen deficiencies in the films. X-ray photoemission spectroscopy, near edge X-ray absorption fine structure (NEXAFS), and ultraviolet photoelectron spectroscopy-based spectroscopy analyses showed that oxygen vacancies (OVs) influence the evolution of the optical and electrical properties of a-ZTO films. NEXAFS reflects the onset of OVs. Low PW contributes to the evolution of a chemical structure with numerous OVs. This result can be applied to improve the electro-optical properties of a-ZTO films. As PW decreased, the carrier concentration increased, carrier mobility increased, and film resistivity decreased. Average optical transmittance in the visible region was >90%, and increased as PW decreased.
Nickel effect on root-meristem cell division in Plantago lanceolata (Plantaginaceae) seedlings
Authors: Pavlova Dolja
Published: August 2017

The toxic effect of nickel (Ni) on cell division on root-meristem cells in seedlings of Plantago lanceolata L. was studied and compared. Seed material was collected from serpentine and non-serpentine populations of the species distributed in the Rhodope Mountains, Bulgaria. The root-tip meristem cells of germinated seeds were treated with different solutions of 0.01, 0.025, 0.05, 0.1 mM Ni as NiSO4 6H2O with distilled water for 24 h and 48 h respectively. The mitotic index decreased when Ni concentrations and exposure time increased in both type of samples. Significant differences in the mitotic indexes were found between the controls and the roots treated with Ni. The mitotic index was higher in root-meristem cells of serpentine seedlings. C-mitosis, anaphase bridges, chromosome stickiness, laggards and extrusion of nuclear material into the cytoplasm were observed in the root-tip cells treated with Ni. The percentage of aberrations generally increased in a concentration- and time-dependent manner. The percentage of the extruded nuclei was higher in cells treated with 0.05 and 0.1 mM Ni. It can be concluded that P. lanceolata seedlings on serpentine can tolerate higher Ni concentrations than can non-serpentine seedlings.
Single-cell functional and chemosensitive profiling of combinatorial colorectal therapy in zebrafish xenografts
Authors: Fior Rita , Póvoa Vanda , Mendes Raquel V. , Carvalho Tânia , Gomes António , Figueiredo Nuno , Ferreira Miguel Godinho
Published: August 2017

Significance

Despite advances in targeted cancer treatments, we still lack methods to predict how a specific cancer will respond to a given therapy. As a consequence, patients go through rounds of trial-and-error approaches based on guidelines to find the best treatment, often subjected to unnecessary toxicity. Using cell lines, we used zebrafish larvae xenografts as sensors for cancer behavior and therapy guideline screening. Our data show not only sufficient resolution to distinguish functional tumor behaviors in just 4 days but also differential sensitivity to colorectal cancer therapy. As proof-of-principle, we provide evidence for similar behavior response to therapies in patients as in zebrafish patient-derived xenografts. Altogether, our results suggest zebrafish larvae xenografts as a promising in vivo screening platform for precision medicine.
Motile cilia create fluid-mechanical microhabitats for the active recruitment of the host microbiome
Authors: Nawroth Janna C. , Guo Hanliang , Koch Eric , Heath-Heckman Elizabeth A. C. , Hermanson John C. , Ruby Edward G. , Dabiri John O. , Kanso Eva , McFall-Ngai Margaret
Published: August 2017

Significance

Recent findings demonstrate that microbiome communities often reside on mucociliated surfaces. While mucociliary clearance of bacteria from such surfaces has been extensively studied, the process of bacterial recruitment has remained unexplored. Here, using a simple model system, we show that ciliated surfaces, in addition to their clearance function, can create fluid-mechanical microhabitats with distinct transport and mixing properties that facilitate the active recruitment of symbiotic candidates from a background of suspended particles. Although each specific system will have unique properties, because ciliary structure and function are highly conserved, studies of models will contribute to an understanding of rules governing the selective behavior of ciliated surfaces.
Microstructure and mechanical properties of in situ formed TiC-reinforced Ti–6Al–4V matrix composites
Authors: Wei Wen-Hou , Shao Ze-Ning , Shen Jun , Duan Xuan-Ming
Published: August 2017

Carbon nanotubes were blended into a Ti–6Al–4V matrix to synthesize titanium carbide (TiC) in situ, via spark plasma sintering. The microstructure and mechanical properties of both the monolithic Ti–6Al–4V alloys and the TiC/Ti–6Al–4V composites were studied to evaluate the strengthening effects of TiC on the Ti–6Al–4V matrix. The morphologies obtained by scanning electronic microscopy and optical microscopy indicated that the grain size of both the Ti–6Al–4V alloy and the TiC/Ti–6Al–4V composite decreased with increasing planetary ball-milling (PBM) speed, leading to an increase in the hardness of the investigated materials. The compressive yield strength of the monolithic Ti–6Al–4V alloys and the TiC/Ti–6Al–4V composites initially increased and then decreased with increasing PBM speed. The strengthening and fracture mechanisms were studied.
Retrospective Analysis of Seasonal Ocean Growth Rates of Two Sea Winter Atlantic Salmon in Eastern Maine Using Historic Scales
Authors: Izzo Lisa K. , Zydlewski Joseph
Published: August 2017

Substantial declines of anadromous Atlantic Salmon Salmo salar have occurred throughout its range, with many populations at the southern extent of the distribution currently extirpated or endangered. While both one sea winter (1SW) and two sea winter (2SW) spawner numbers for the North American stocks have declined since the 1950s, the decline has been most severe in 2SW spawners. The first months at sea are considered a period of high mortality. However, early ocean mortality alone cannot explain the more pronounced decline of 2SW spawners, suggesting that the second year at sea may be more critical than previously thought. Atlantic Salmon scales collected by anglers and the state agency from 1946 to 2013 from five rivers in eastern Maine were used to estimate smolt age and ocean age of returning adults. Additionally, seasonal growth rates of maiden 2SW spawners were estimated using intercirculi measurements and linear back-calculation methods. Generalized linear mixed models (Gaussian family, log link function) were used to investigate the influence of average sea surface temperature, accumulated thermal units, the Atlantic Multidecadal Oscillation (AMO) and North Atlantic Oscillation indices, smolt age, smolt length, postsmolt growth, and river of origin on growth rate during the oceanic migration of North American Atlantic Salmon. Results suggest that different factors influence salmon growth throughout their oceanic migration, and previous growth can be a strong predictor of future size. Growth was negatively impacted by the phase of the AMO, which has been linked to salmon abundance trends, in early spring following the postsmolt period. This is likely when the 1SW and 2SW stock components separate, and our results suggest that this period may be of interest in future work examining the disproportionate decline in 2SW spawners.
Cysteine residues in the cytoplasmic carboxy terminus of connexins dictate gap junction plaque stability
Authors: Stout Randy F. , Spray David C.
Published: August 2017

Gap junctions are cellular contact sites composed of clustered connexin transmembrane proteins that act in dual capacities as channels for direct intercellular exchange of small molecules and as structural adhesion complexes known as gap junction nexuses. Depending on the connexin isoform, the cluster of channels (the gap junction plaque) can be stably or fluidly arranged. Here we used confocal microscopy and mutational analysis to identify the residues within the connexin proteins that determine gap junction plaque stability. We found that stability is altered by changing redox balance using a reducing agent—indicating gap junction nexus stability is modifiable. Stability of the arrangement of connexins is thought to regulate intercellular communication by establishing an ordered supramolecular platform. By identifying the residues that establish plaque stability, these studies lay the groundwork for exploration of mechanisms by which gap junction nexus stability modulates intercellular communication.
Myocardial Ischemia
Authors: Bennett Jeremy , Siegrist Kara
Published: August 2017

Coronary artery disease is a prevalent and growing problem in the United States leading to significant morbidity and mortality including myocardial ischemia and infarction. Diagnosis and treatment of myocardial ischemia under general anesthesia can present unique challenges for the anesthesiologist including interpretation of diagnostic monitoring data and options for therapeutic interventions. There are many complex factors that determine myocardial oxygen supply and demand; when these become imbalanced, myocardial ischemia occurs that can progress to infarction. Maintaining a high-degree of suspicion for myocardial events in the perioperative period is paramount to good patient outcomes. In fact, perioperative myocardial injury within 30 days of surgery, if considered as a disease entity, would be the third leading cause of death in the United States. This chapters reviews the diagnosis and treatment of such events.
Aortic Disruption
Authors: Kingeter Adam J. , Sileshi Bantayehu
Published: August 2017

This chapter covers the mechanism, classification, presenting signs, and basic principles of management for aortic dissection. Aortic disruption occurs when a tear develops in the aortic intima with passage of blood into the new space between the intima and media. A hypothetical patient presenting with signs of dissection is presented first, followed by sections covering classification systems of dissection, risk factors for dissection, and basic principles of management. Acute stabilization, diagnostic imaging, definitive management, and long-term follow up of patient management are discussed. In addition the dissection location and its implication on principles of management and outcome are covered. The chapter concludes with some discussion questions covering frequently encountered aspects of management touched on in the chapter.
Physiologic Airflow Disruption
Authors: Sentissi Kinza , Yacoubian Stephanie
Published: August 2017

Airflow disruption can be triggered through multiple mechanisms. The obstruction can stem from within the airway lumen, airway walls, or the tissues surrounding it. This section focuses on airflow disruption initiated by bronchospasm, obstructive lung disease, asthma and status asthmaticus. Bronchospasm presents with increased airway resistance secondary to airway hyperreactivity or anaphylaxis. Asthma and chronic obstructive pulmonary disease (COPD) are obstructive and inflammatory lung pathologies. Airflow disruption in asthma is reversible between exacerbations. The airway obstruction in COPD is not fully reversible. Status asthmaticus is the most severe presentation of asthma and can be life threatening. Poorly controlled obstructive lung disease can result in perioperative complications. Patients should therefore be medically optimized before undergoing operative procedures.
Introduction to Metabolic and Endocrine Diseases
Authors: Dierdorf Stephen F.
Published: August 2017

Patients may have metabolic and endocrine dysfunction that is primary and results in surgical pathology, or the surgical condition can produce metabolic changes that influence the administration of anesthesia. These disorders can vary with incidence of occurrence from commonly encountered situations such as hyperkalemia, to more rare disorders such as the porphyrias. Knowledge of the metabolic/endocrine derangements can lead to treatment that can be life-saving during the perioperative period. While it is important to periodically review the new developments in metabolism and endocrinology disorders, it is also helpful to review the long standing accepted treatments of the more unusual disorders. This will help to improve the application of appropriate treatment steps in the perioperative care of the patient.
Myxedema Coma
Authors: Allison Jacquelyn E. , Dunlap Julie D.
Published: August 2017

Thyroid hormones influence every metabolic function of the body. Inadequate amounts of circulating thyroid hormone cause dysfunction of two systems in particular that result in abnormal responses to anesthesia: the central nervous system and the cardiovascular system. Physiologic compensation for the slow onset of hypothyroidism can mask the degree of dysfunction and make diagnosis challenging. Stressors associated with surgery and anesthesia can aggravate coexisting hypothyroidism and trigger severe life-threatening hypothyroidism (myxedema). This chapter reviews the pathophysiology involved in hypothyroidism, identifies populations at risk for myxedema coma, and provides a stepwise treatment plan for these patients.
Hyperkalemia/Hypokalemia
Authors: Dierdorf Stephen F.
Published: August 2017

Disorders of potassium regulation (hyperkalemia/hypokalemia) are common in clinical medicine. Patients with neuromuscular disorders may develop hyperkalemia in response to inhaled, halogenated anesthetics and/or succinylcholine. This is most likely to occur in patients with occult myopathies. Potassium abnormalities have a wide range of potential implications for patient outcome. For instance, acute hyperkalemia has profound effects on the cardiac action potential that can lead to life-threatening dysrhythmias. In contrast is chronic hypokalemia, which occurs in 10% to 40% of patients receiving thiazide diuretics. In most cases, chronic hypokalemia does not cause perioperative complications unless intraoperative management alters potassium balance. In this chapter we present two clinical case scenarios which center around the underlying processes, detection, and treatment of each of these disorders.
High or Total Spinal/Epidural
Authors: Peralta Feyce
Published: August 2017

High or total spinal/epidural blockade occurs due to excess spread of local anesthetic within the neuraxial space. While this is an infrequent complication, it can cause respiratory and hemodynamic instability in obstetric patients. If high/total spinal/epidural occurs prior to delivery, such derangements may lead to fetal intolerance and need for emergency delivery. Clinicians should suspect risk for high block when patients lose upper extremity motor function and complain of dysphonia or dyspnea. Intubation and respiratory and hemodynamic support along with adequate sedation should be given until the block recedes. Preventative measures include strict epidural catheter aspiration practice and incremental epidural dosing strategies.
Peripartum Embolism
Authors: Lange Elizabeth M. S. , Toledo Paloma
Published: August 2017

Embolic disease during pregnancy is a significant contributor to maternal morbidity and mortality. The most common type of embolism is venous air embolism, but this is rarely symptomatic or hemodynamically significant. However, both thromboembolism and amniotic fluid embolism (AFE) are associated with significant maternal risk, and in the case of AFE, frequent major hemodynamic sequelae and fatal results ensue. As each class of embolic disease has slightly different risk factors, pathophysiology, clinical presentation, and treatment, they will each be discussed in separate sections in this chapter with an overview of these components.
Stroke/Subarachnoid Hemorrhage and Pregnancy
Authors: Wood Cristina
Published: August 2017

Death from neurological causes is a massive issue in maternal mortality, and the rate of deaths from neurological causes has remained essentially unchanged for the past thirty years. Two of the most common neurological causes of death are stroke and intracranial hemorrhage. These medical emergencies can be more challenging to diagnose and treat in the parturient. This is largely due to the physiologic changes that occur during pregnancy and in the postpartum period, but fetal considerations are also a factor. This chapter focuses on the pathophysiology, assessment, and management of stroke and subarachnoid hemorrhage in pregnancy. A thorough understanding of each of these components is necessary to ensure appropriate and timely care delivery for optimal outcome in the setting of these neurologic emergencies.
Diabetic Emergencies in Pregnancy
Authors: Guletz Maribeth , Minehart Rebecca
Published: August 2017

Diabetes in pregnancy is rising in incidence, and with this increase comes additional maternal and fetal risks. Precise diagnosis and timely management of diabetic obstetrical emergencies is critical. In particular, providers must recognize that diabetic ketoacidosis (DKA) may be seen at much lower glucose levels in pregnant patients compared with nonpregnant patients due to physiologic changes of pregnancy. Fluid resuscitation, correction of acidosis and careful electrolyte, glucose, and insulin replacement remain the mainstays of therapy in DKA during pregnancy. Although maternal mortality has decreased over recent decades, fetal mortality remains high, and therefore a multidisciplinary team should guide assessment and treatment of DKA. Decision for early delivery must weigh both the maternal and fetal status and consider adequacy of resuscitative efforts. This chapter provides a brief overview of diabetes in pregnancy with a focus on the diagnosis and management of diabetic emergencies in the obstetrical patient.
Magnesium Toxicity
Authors: Chau Anthony T.
Published: August 2017

Magnesium sulfate is currently the drug of choice for prophylaxis against eclampsia in women with preeclampsia and first-line treatment for eclampsia. In this population, medication administration error is a frequent cause of magnesium toxicity. Symptoms of toxicity are linked to increasing serum concentrations, but routine monitoring is not recommended. Instead, deep tendon reflexes and respiratory rate are the most commonly monitored parameters. However, magnesium serum concentration should be monitored when magnesium toxicity is suspected or in patients at high risk of toxicity. The gastrointestinal and central nervous systems are usually affected first. As the serum concentration becomes extremely high, neuromuscular and cardiovascular effects may occur, leading to respiratory failure and cardiac arrest. In addition to standard advanced life support measures, calcium is the mainstay of treatment and in some cases forced diuresis and dialysis may also be considered.
Local Anesthetic Systemic Toxicity in Pregnancy
Authors: Allen Brian F. S.
Published: August 2017

Local anesthetic systemic toxicity (LAST) is a concern for all practitioners who administer local anesthetics, including neuraxial and regional analgesia and anesthesia for pregnant patients. Toxicity can manifest as neurologic (e.g., seizure) or cardiac (e.g., dysrhythmia) sequelae and even death. Management of LAST differs from advanced cardiovascular life support (ACLS) in several important ways, and the parturient suffering LAST requires even more specific therapy. This chapter reviews the pathophysiology, assessment, and management of LAST in pregnancy, highlighting key differences from ACLS and LAST therapy in the nonpregnant patient. Prevention of this complication is also discussed. Knowledge of this material is essential for timely and appropriate care in order to ensure optional outcome.
Traumatic Brain Injury
Authors: Weaver Sheena M.
Published: August 2017

Traumatic brain injury accounts for over a million emergency room visits each year and frequently results in the need for escalated levels of care, including surgical intervention, at acute care facilities. This chapter reviews the pertinent concepts integral to the perioperative assessment and management of traumatic brain injury, specifically that of acute traumatic subdural and epidural hemorrhages. It discusses that this management hinges on the ability of the clinician to quickly recognize primary injury and its associated pathophysiology, to prevent or reduce secondary injury (including intracranial hypertension), and to adhere to anesthetic principles and evidence-based guidelines linked to improved clinical outcomes. This chapter also reviews the most recent international consensus guidelines, as well as summarizing the decision-making for neurosurgical intervention.
Muscle Weakness
Authors: Easdown L. Jane
Published: August 2017

Muscle weakness in the perioperative period is a common finding and is a risk to patient safety. It can occur as a result of many physiological, pathological, and iatrogenic states. The most common etiology is the use of, misuse of, and failure to reverse neuromuscular blocking drugs (NMBDs). Patients might also present with underlying neuromuscular disorders at baseline or in an exacerbated state after surgery and anesthesia. Muscle weakness can lead to critical events such as respiratory failure and can delay recovery and discharge. The plan for prompt diagnosis and management of a patient with muscle weakness is presented. Knowledge of the pathophysiology, assessment, and treatment of perioperative muscle weakness is essential to ensure optimal patient outcomes.
Nerve Injuries from Positioning and Regional Blocks
Authors: Gupta Rajnish K. , Nickless Alexandria N.
Published: August 2017

Peripheral nerve injury in the perioperative period can have a variety of etiologies, including preexisting patient factors and by surgical and anesthetic complications such as intraoperative positioning and nerve blockade. The actual incidence may be difficult to assess, because most nerve injuries resolve with time and frequently require minimal to no intervention. Injuries often manifest more than 48 hours after surgery and have even been noted in patients who undergo awake procedures and in hospitalized patients who never undergo surgery. This should not negate the fact that close attention to detail when positioning patients and performing regional anesthesia may help decrease the overall incidence of nerve injury and should be considered in every anesthesiologist’s perioperative plan. This chapter reviews proper assessment, treatment, and follow-up for peripheral nerve injuries.
Introduction to Pediatric Crises
Authors: Watkins Scott C.
Published: August 2017

Clinicians caring for pediatric patients must be prepared to manage the wide range of physiological norms and diverse pathological states that children may pose when presenting for anesthesia and surgery. Anesthesiologists caring for children should be familiar with syndromes and diseases that pose increased risk for difficult airway (e.g., Treacher-Collins, Pierre-Robin), malignant hyperthermia (e.g., King Denborough, central core disease), hyperkalemia (e.g., muscular dystrophies, periodic hyperkalemic paralysis), and sudden cardiac arrest (e.g., William’s, Pompe, myocarditis/cardiomyopathy). However, these diseases and syndromes are relatively rare, and the majority of challenging pediatric patients will not carry a named syndrome. Some of the more challenging cases an anesthesiologist may face include the child presenting emergently for surgery, neonates needing surgical intervention, and children with severe comorbidities including cardiac and pulmonary diseases. This section is dedicated to the pediatric patient and the unique challenges these patients pose to those tasked with caring for them.
Coagulation System
Authors: Burger Christina F. , Bellomy Melissa L. , Schlesinger Joseph J.
Published: August 2017

Anticoagulation is increasingly prevalent in the general population and poses a significant risk of increased bleeding in patients needing urgent or emergent surgical procedures. There are two main classes of direct or anticoagulants: direct thrombin inhibitors and factor Xa inhibitors. Management of these patients requires assessment of bleeding risk, possible reversal of anticoagulation, and subsequent management after surgery to prevent postoperative complications associated with either bleeding or clot formation (due to cessation of anticoagulants). This chapter covers the proper assessment and management of patients on oral direct thrombin inhibitor or oral Factor Xa inhibitor therapies.
Alcohol Withdrawal
Authors: McGrane Tracy
Published: August 2017

This chapter, “Alcohol Withdrawal,” reviews the prevalence, presentation, pathophysiology, and anesthetic considerations for patients encountered at risk of alcohol withdrawal, as well as current intensive care unit practices caring for patients at risk of alcohol withdrawal to allow for improved perioperative crisis management. It reviews physiologic derangements in both acute and chronic alcoholism, and reviews the current evidence for prevention and treatment of alcohol withdrawal in the intensive care unit, including fixed-dose versus loading-dose versus symptom-based treatment using benzodiazepines, and the use of alcohol, barbiturates, propofol, beta blockers, and alpha-2 agonists as treatment choices. Also discussed are complications of alcohol withdrawal syndrome to recognize and considerations for treatment of pregnant women and elderly patients in alcohol withdrawal.
Hypovolemic Shock
Authors: Weyker Paul David , Webb Christopher Allen-John , Brentjens Tricia E.
Published: August 2017

Broadly defined, hypovolemia represents inadequate circulating plasma volume leading to decreased cardiac preload and thus decreased cardiac output and blood pressure. Many classification schemes have been proposed to categorize hypovolemia based on relative levels of decreased plasma volume. Common causes of hypovolemic shock during the perioperative period include hemorrhage and diuretic use. In general, studies support a conservative hemoglobin goal of about 7 g/dL as compared with a liberal goal of 10 g/dL in hemodynamically stable patients without active cardiac ischemia or risk factors. In patients with large volume blood loss, institutionally approved massive transfusion protocols can help provide blood products quickly. The trauma literature supports a balanced massive transfusion protocol using a 1:1:1 (plasma:platelet:red blood cell) strategy of transfusion.
Cardiac catheterization
Authors: Thorne Sara , Bowater Sarah
Published: August 2017

The purpose of cardiac catheterization in patients with congenital heart disease is to gain information about complex anatomy and haemodynamics, especially with respect to pulmonary artery pressure and vascular resistance. This chapter outlines indications for cardiac catheterization, precatheterization care, normal values and calculations, and catheter interventions in ACHD.
Cyanosis
Authors: Thorne Sara , Bowater Sarah
Published: August 2017

This chapter explores cyanosis in ACHD, including examples of cyanotic congenital defects, non-cardiac manifestations of cyanosis, and management of common emergencies in cyanotic heart disease. It also presents a checklist for inpatients with cyanotic heart disease.
Eisenmenger syndrome
Authors: Thorne Sara , Bowater Sarah
Published: August 2017

This chapter describes Eisenmenger syndrome, which can occur when there is a large, nonrestrictive communication between the systemic and pulmonary circulations. This shunt can be at atrial, ventricular, or arterial levels. The chapter discusses the natural history of Eisenmenger syndrome as well as complications, extracardiac manifestations, physical signs, investigations, and management.
Pulmonary hypertension in ACHD
Authors: Thorne Sara , Bowater Sarah
Published: August 2017

Pulmonary arterial hypertension (PAH) is a common complication in ACHD patients, with a prevalence of around 10% in developed countries. It is most commonly due to large, uncorrected left-to-right shunts, although a permissive genotype might explain its development in other, seemingly lower-risk, patients. Histologically, PAH in ACHD is the same as PAH due to other aetiologies, such as idiopathic and connective tissue disease.
Rare conditions presenting in adulthood
Authors: Thorne Sara , Bowater Sarah
Published: August 2017

This chapter discusses rare conditions presenting in adulthood, including coronary anomalies (left coronary artery from pulmonary artery [LCAPA], congenital coronary arteriovenous fistulae) and sinus of Valsalva aneurysm.
Emergencies
Authors: Thorne Sara , Bowater Sarah
Published: August 2017

There are a number of ACHD emergencies in which quick and simple management can prevent unnecessary morbidity or mortality. Senior in-house help must always be requested and urgent advice sought from the specialist ACHD unit. This chapter discusses haemoptysis in a cyanotic patient, emergencies and pitfalls to avoid in cyanotic heart disease, haemoptysis or haematemesis in patients with repaired coarctation, and tachyarrhythmias.
Contraception and pregnancy
Authors: Thorne Sara , Bowater Sarah
Published: August 2017

Heart disease is the largest single cause of maternal death in the UK. The number and complexity of survivors of congenital heart disease well enough to consider pregnancy are growing. The maternal risk amongst this population varies from being no different to that of the general population, to carrying a high risk of long-term morbidity and >40% risk of death. This chapter discusses contraception, preconception, pregnancy and delivery, and post-partum care.
Endocarditis
Authors: Thorne Sara , Bowater Sarah
Published: August 2017

Nearly all patients with congenital heart disease have a lifelong risk of bacterial endocarditis. This chapter discusses antibiotic prophylaxis, as well as UK and European guidelines.
Univentricular heart (tricuspid atresia/single ventricle)
Authors: Katritsis Demosthenes G. , Gersh Bernard J. , Camm A. John
Published: August 2017

Conditions denoted by the term univentricular heart are described, and the clinical problems encountered in these malformations are discussed.
The Fontan patient
Authors: Katritsis Demosthenes G. , Gersh Bernard J. , Camm A. John
Published: August 2017

Description of the Fontan operation is provided; conditions that are treated with this operation are presented, and the clinical problems encountered by patients who have been subjected to a Fontan operation are discussed.
Stable coronary artery disease
Authors: Katritsis Demosthenes G. , Gersh Bernard J. , Camm A. John
Published: August 2017

Diagnosis and current therapy of stable coronary artery disease are discussed. Recent recommendations by the ACC/AHA and ESC have been summarized and tabulated.
Classification, epidemiology, and pathophysiology of heart failure
Authors: Katritsis Demosthenes G. , Gersh Bernard J. , Camm A. John
Published: August 2017

Definitions of heart failure are presented, and the epidemiology, aetiology, and pathophysiology of the disease are discussed.
Heart failure with preserved left ventricular ejection fraction
Authors: Katritsis Demosthenes G. , Gersh Bernard J. , Camm A. John
Published: August 2017

Definition, aetiology, and management of heart failure in the context of a preserved left ventricular function are discussed.
Acute heart failure and cardiogenic shock
Authors: Katritsis Demosthenes G. , Gersh Bernard J. , Camm A. John
Published: August 2017

The current management of acute heart failure and cardiogenic shock are discussed.
Left ventricular non-compaction
Authors: Katritsis Demosthenes G. , Gersh Bernard J. , Camm A. John
Published: August 2017

This chapter describes the recognition and management of left ventricular non-compaction and the resultant cardiomyopathy.
Acute myocarditis
Authors: Katritsis Demosthenes G. , Gersh Bernard J. , Camm A. John
Published: August 2017

Classification, diagnosis, and current evidence-based treatment of myocarditis are presented.
Pericardial anatomy and congenital pericardial defects
Authors: Katritsis Demosthenes G. , Gersh Bernard J. , Camm A. John
Published: August 2017

Pericardial anatomy and congenital pericardial defects are described.
Acute and relapsing pericarditis
Authors: Katritsis Demosthenes G. , Gersh Bernard J. , Camm A. John
Published: August 2017

Acute and relapsing pericarditis and their therapy are discussed.
Atrial fibrillation
Authors: Katritsis Demosthenes G. , Gersh Bernard J. , Camm A. John
Published: August 2017

Classification, epidemiology, aetiology, and the pathophysiological consequences of atrial fibrillation are discussed. Rate and rhythm control therapy, anticoagulation with warfarin and new drugs, and current indications of catheter ablation are presented. ACC/AHA and ESC recommendations have been summarized and tabulated.