bluuebunny/crossref_metadata_2025_split huggingface dataset:
Temperature Sensing, Heat Production, and Conservation
Authors: Guruswamy Jayakar , Epelman Matthew 
Published: May 2024

Abstract
The physiologic changes in response to temperature sensing, heat production, and conservation produced by the body are complex and require an understanding of certain molecular and cellular pathways. Although seemingly immediate reactions are observed, temperature regulatory pathways involve several steps in both the peripheral and central nervous system that indeed have clinical relevance. An awake individual will often produce predictable behaviors in response to temperature fluctuations; however, this is not applicable to the anesthetized patient. It is therefore the responsibility of the anesthesiologist to anticipate temperature derangements and act appropriately to correct them. The hypothalamus maintains temperature within a relatively narrow range, and thus any deviations from normal temperature require prompt intervention. A complex web of receptor modifications, signaling pathways, sensory integration, and behaviors results in finely tuned temperature adaptability in the awake and anesthetized human.
Cerebral Cortex
Authors: Shah Rutvij 
Published: May 2024

Abstract
The cerebral cortex constitutes about 83% of total brain tissue. The cortex has two hemispheres (left and right) and both the hemispheres are connected via corpus callosum. Both the hemispheres have four lobes (frontal, parietal, temporal, and occipital). The cerebral cortex constitutes the highest control areas for memory, attention, vision, language, motor control, and sensory perception. Microscopically, the cerebral cortex has six layers. The cerebral cortex plays an important role in consciousness. Anesthetic agents generate unconsciousness via breaking the communication of the posterior parietal area, posterior cingulate cortex, and precuneus.
Respiratory Centers
Authors: Murguia-Fuentes Ricardo , Kaye Alan D. 
Published: May 2024

Abstract
Respiration, specifically ventilation, is a predominantly involuntary vital function required for energy production and metabolism for survival. The nervous system is able to control and regulate the automatic features of this function through a diffuse group of neurons in the brainstem known as the respiratory center, which is composed of the pneumotaxic center, a dorsal and a ventral respiratory group of neurons. Located in the medulla, the dorsal group mainly stimulates inspiration and the generation of the respiratory rhythm; the ventral group has both inspiratory and expiratory functions, and it contains the pre-Bötzinger complex, which has also been proven to have a role in the respiratory rhythm due to its pacemaker firing pattern; the pneumotaxic center primarily works as an inhibitor of the inspiratory process, shortening its cycle and increasing respiratory rate. The neural mechanisms to achieve this control include the central drive, the afferences of central and peripheral chemoreceptors; the latter sends signaling through branches of the glossopharyngeal and vagal nerves from the carotid and aortic bodies, respectively, to the respiratory center. In terms of chemical stimuli, oxygen and carbon dioxide have direct effect over the chemosensitive area of the brainstem, while oxygen acts indirectly by the stimuli of the peripheral chemoreceptors.
Nociception
Authors: Lennertz Richard 
Published: May 2024

Abstract
Pain can be defined as an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage. Nociception is the process of perceiving pain. Specialized nerve fibers called nociceptors convey noxious stimuli to the spinal cord, where their signals are integrated and passed on to the brain. Injury enhances the perception of pain. Nociceptor sensitization and central sensitization lead to hyperalgesia and allodynia. These changes are discussed in the context of inflammatory pain and neuropathic pain, common types of injury-related pain. Autonomic contributions to pain are also discussed in the context of complex regional pain syndrome.
Lung Functions, Cellular Processes, and Surfactant
Authors: Nathani Harsh , Joseph Antony 
Published: May 2024

Abstract
The lungs are the primary organs of the respiratory system and have multiple physiological functions—gas exchange, immunity, homeostasis, and metabolism. The lungs consist of multiple cell lines, with unique functions, that aid in performing the physiological functions of the respiratory system. Surfactant is an important substance produced by type 2 pneumocytes that helps reduce surface tension within the alveoli.
Oxygen Transport
Authors: Chang Michael , Knox Nigel 
Published: May 2024

Abstract
Oxygen is an essential component of life, contributing to aerobic respiration by acting as the terminal electron acceptor in the ATP-generating electron transport chain in the mitochondria at the cellular level. As such, it is easily overlooked as the most common drug administered during anesthesia and critical care medicine. Oxygen transport can be described as convective or diffusive, the latter distinguished from the former as a passive process. The main carrier of oxygen during transport in the systemic circulation is hemoglobin, to which 98% of oxygen is bound. The affinity of oxygen to these hemoglobin carriers is crucial to its delivery to the tissue beds. This chapter focuses on the transport and delivery of oxygen, and physiological effects on this process.
Systemic Effects of Hypocarbia and Hypercarbia
Authors: Smith Sarah C. 
Published: May 2024

Abstract
The normal PaCO2 level in an adult is 38–42 mmHg, but physiologic adaptations to certain stimuli, pathologic processes, or even iatrogenic interventions may result in deviations from this normal range. The resulting hypo- or hypercarbia may have a variety of effects on different organ systems, and the nature and magnitude of these effects is dictated by whether the change in PaCO2 is acute or chronic. The perioperative period is often accompanied by alterations in PaCO2 due to the respiratory effects of anesthetics and analgesics or the deliberate or inadvertent induction of hyper- or hypocarbia by the anesthesiologist. Alternatively, patients may present for surgery in disease states resulting in perturbations in PaCO2, or may develop hypercarbia as a result of the insufflation of CO2 for facilitation of a procedure, such as laparoscopic surgery or endoscopy. The anesthesiologist must be aware of the systemic effects of hyper- and hypocarbia so that these alterations in physiology can either be managed or deliberately exploited for therapeutic effect.
Basic Interpretation of Arterial Blood Gas and Temperature Correction
Authors: Zanath Erica , Helou Mada 
Published: May 2024

Abstract
Acid-base balance is important physiologically as biochemical reactions are dependent upon normal pH. Normal physiologic pH is 7.4. A blood pH &lt;7.35 is acidemia, whereas a blood pH &gt;7.45 is alkalemia. According to the Henderson-Hasselbalch equation, pH is directly proportional to changes in bicarbonate ion concentration and indirectly proportional to changes in PaCO2. A primary disturbance in PaCO2 is respiratory disorder, whereas a primary disturbance in bicarbonate ion concentration is a metabolic disorder. Buffers and both respiratory and renal alterations compensate for changes in acid-base balance. Blood gas analysis should proceed in a systematic manner: (1) evaluate pH—acidemia vs. alkalemia; (2) determine if the primary disturbance is respiratory or metabolic; (3) determine if compensation is present; (4) evaluate chronicity.
Respiratory Centers
Authors: Cornwell Drew , Kohan Lynn 
Published: May 2024

Abstract
Discussion in this chapter reviews high-yield details of neural control of ventilation as generated by the respiratory center. Primary control is generated in the brainstem, specifically the medulla and pons. Within the medulla exist two groups referred to by their positioning: the dorsal respiratory group (DRG) and ventral respiratory group (VRG). The DRG is associated with control of inspiration, while the VRG is associated with expiration. Pontine control of respiratory rhythm is well demonstrated in animal studies, but less effectively demonstrated in humans. Cortical input and control play a lesser role, but is obvious as demonstrated by the ability to intentionally hyper/hypoventilate oneself, as well as the limbic and hypothalamic response during emotional states.
Central and Peripheral Chemoreceptors
Authors: Cornwell Drew , Kohan Lynn 
Published: May 2024

Abstract
This chapter will present a brief overview of the central and peripheral chemoreceptors discusses their important role in afferent signaling for the control of ventilation. Chemoreceptors respond to changes in carbon dioxide, pH, and oxygen to augment ventilation in order to maintain homeostasis. Central receptors of the brain within the CSF respond primarily to changes in arterial carbon dioxide levels. A number of peripheral receptors exist in various locations (carotid body, aortic arch, and parenchyma of the lungs) and react to altered arterial oxygen and hydrogen concentrations. The chapter also discusses the anesthetic considerations of chemoreceptors in relation to preoperative and intraoperative periods.
Respiratory and Congenital Pediatric Airway Problems
Authors: Al-Haddadin Caroline , Harb Alain 
Published: May 2024

Abstract
Pediatric airway disorders may be congenital (anatomical) or acquired (infectious), with obstruction being a common feature. These congenital syndromes are very challenging, and some are common: Hurler, Pierre Robin, Treacher Collins, Goldenhar, and Crouzon syndromes, and cleft lip and palate. Clinical presentation and consequences of airway obstruction vary by age. The perioperative care of these patients involves input from many specialists. The benefit of the surgical procedure should be balanced against the risk of exposing the child to general anesthesia. Anesthesia should ideally be given by experienced anesthesiologists in handling pediatric airway problems and resuscitation, and in a center in which pediatric intensive care facilities are available. Some patients may present with an isolated airway abnormality, while others present with associated anomalies or syndromes. A comprehensive preoperative assessment is crucial for the preparation and management of anesthesia. Patients with mild airway obstruction can usually be managed conservatively with nasopharyngeal airways or prone positioning. Moderate or severe obstruction requires more invasive interventions such as laryngeal mask airway (LMA), video laryngoscopy, fiberoptic intubation, or tracheostomy. Awake intubation often cannot be used in children because of inadequate cooperation. In addition, children have higher rates of oxygen consumption, significantly shortening the period of apnea that can be safely tolerated. Patients should be extubated when fully awake, with close observation for signs of airway obstruction. Adequate analgesia is an important part of the balanced anesthetic technique.
Vocal Cords
Authors: Moore Warner , Kaye Alan D. 
Published: May 2024

Abstract
The vocal cords, located in the larynx, serve three vital purposes: protection from choking, vibration in order to produce sound, and regulation of airflow into the lungs. Depending on age and gender, approaches to treating the underlying problem in the vocal cords may vary. Some of the most common clinical diagnoses involving the vocal cords include laryngitis (usually bacterial or viral infection), laryngeal papillomatosis, and vocal cord paralysis. Many specialized techniques may be used to assess the severity of damage to the vocal cords, including videostroboscopy and laryngeal electromyography. For anesthetic management, pre- and postoperative risk factors should always be evaluated and minimized. Depending on the severity of the surgery, local anesthesia, light sedation, and general anesthesia are all options indicated for use. After surgery, continuous positive airway pressure (CPAP) and heliox can improve complications of stridor until the patient fully recovers from anesthesia.
Steroids
Authors: Maheshwari Neeraj , Manders Larry 
Published: May 2024

Abstract
Corticosteroids are well known for their anti-inflammatory and immunosuppressive effects. It is no surprise that the diverse functions of steroids have allowed them to be used in equally diverse disease states, including autoimmune, rheumatologic, infectious, inflammatory, and neoplastic processes. The regimented use of corticosteroids have been well established in pathologies involving reactive airway disease; however, there are no clear guidelines regarding the use of this class of medications in the perioperative and critical care settings. This outlines the anti-inflammatory properties of systemic and inhaled corticosteroids used to treat and manage various pulmonary diseases, including bronchial asthma and chronic obstructive pulmonary disease (COPD).
Ventricular Function
Authors: Yousef John , Manders Larry 
Published: May 2024

Abstract
The heart consists of four chambers: two atrias and two ventricles. The right ventricle is a low-pressure system which pumps the blood incoming from the body and into the lungs. The left ventricle is a high-pressure system that pumps oxygenated blood from the lungs and into the body. Each side of the heart has its own pressure gradients, muscle composition, blood supply, and anatomical differences. This chapter briefly discusses the anatomical composition of the heart with preference paid toward the ventricles, which are the drivers of output for each respective side of the heart.
Force, Velocity, Length, Rate of Shortening
Authors: Daklallah Youssef , Manders Larry 
Published: May 2024

Abstract
Understanding cardiac performance is dependent on understanding myocardial contractility and inotropy. The concept of inotropy is multifaceted. It is defined as the force of a cardiac muscle’s contraction. Inotropy can be affected by multiple variables and disease processes that are relevant to any patient receiving an anesthetic. In this chapter, the authors define and discuss the relationships between the force of contraction, sarcomere length, velocity, and the rate of shortening.
Myocardial Oxygen Utilization/Consumption
Authors: Tobes Daniel , Manders Larry 
Published: May 2024

Abstract
Myocardial O2 supply and demand exist at all times in a fragile balance. Situations where demand exceeds supply lead to myocardial ischemia. The heart has a relatively high O2 consumption (MVO2) compared with other organs due to its workload. MVO2 can vary greatly based on the current workload of the heart; MVO2 during heavy exercise exceeds that of any other organ in the body. This chapter will summarize myocardial oxygen utilization and consumptions as it relates to ability pump blood and transport oxygen to the rest of our body.
Cardiac Output
Authors: Sohn Jacqueline , Pesa Nicholas 
Published: May 2024

Abstract
Cardiac output (CO) is defined as a volume of blood ejected by the heart per unit of time. This chapter discusses the four factors that affect cardiac output: heart rate, myocardial contractility, preload, and afterload. Furthermore, it also discusses the physiological background of Fick’s principle and its use to calculate the cardiac output using physiological markers such as oxygen content and oxygen consumption.
Blood Volume and Distribution
Authors: Al-Attar Neal , Manders Larry 
Published: May 2024

Abstract
Approximately 60% of a person’s body weight is water. This can be further categorized and stated as 40% of one’s body weight is intracellular fluid, 15% is interstitial fluid, and 5% is intravascular fluid. Maintenance of the intravascular volume is critical for adequate organ perfusion and function. This chapter briefly discusses the blood volume and distribution. The chapter highlights changes with age and sex, as well as predicting allowable changes and organ distribution during homeostasis.
Systolic, Diastolic, Mean, and Perfusion Pressures
Authors: Zanath Erica , Helou Mada 
Published: May 2024

Abstract
Blood pressure is generally reported as three components: a systolic pressure, diastolic pressure, and mean pressure. The systolic blood pressure is the highest pressure within the arterial vasculature. The diastolic blood pressure is the lowest pressure within the arterial vasculature reflective of the resting vessel tone. Mean arterial blood pressure is the average pressure in the vasculature. In addition to these aforementioned components, there are other important terms to understand with response to blood pressure and its effect on organ perfusion. Pulse pressure is the difference between systolic and diastolic pressure. Perfusion pressure represents the blood pressure driving blood flow to a specified organ.
Viscosity and Rheology
Authors: Padilla David , Sharma Archit 
Published: May 2024

Abstract
Blood viscosity and its behaviors under various degrees of shear stress (rheology) plays an important role in clinical situations of importance to the anesthesiologist. This chapter discusses examples of these various phenomenon, such as the overall transport of oxygen in the circulatory system, the determination of total peripheral resistance, the pathogenesis of deep-vein thrombosis, and tissue perfusion during open-heart surgery. A sound knowledge of rheological principles is thus an important requirement for optimal patient care, and the anesthesia provider can manipulate these to provide the best care to the patient.
Basics of Cardiopulmonary Resuscitation
Authors: Laborde Donnie 
Published: May 2024

Abstract
Cardiac arrest remains one of the leading causes of death. Thanks to the work and research of the American Heart Association, the survival rate has continued to improve over the last several years. Early recognition of cardiac arrest and high-quality basic life support (BLS) is vital for the return of spontaneous circulation (ROSC). BLS encompasses the following elements: assessment, airway conservation, ventilation (i.e., rescue breathing), and chest compression. The overarching goal of BLS is to provide oxygen, ventilation, and blood circulation. This is necessary to sustain cellular life until ROSC, or a secondary assessment, can be obtained to determine the problem, or reverse the underlying cause of cardiac arrest. If a patient appears unconscious, and the scene is safe to enter, the BLS assessment should begin immediately. The chapter includes a few of the American Heart Association Guideline Updates necessary for high quality cardiopulmonary resuscitation.
Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers
Authors: Ohia Laurence , Guzman Jacob 
Published: May 2024

Abstract
The renin-angiotensin-aldosterone system inhibitors such as the ACEIs and ARBs are well established as therapies for managing as well as reducing morbidity due to hypertension, congestive heart failure, coronary artery disease, and diabetic retinopathy. This chapter aims to present and review the pharmacokinetics, discuss the clinical indications of ACEIs and ARBs with some literature review, explore the various adverse effects and medications that can be used to treat some of the adverse effects, and indicate contraindications to using these medications. Anesthetic considerations with regard to continuing ACEIs in the perioperative period and frequency of intraoperative hypotension, as well as recommendations regarding withholding ACEIs and ARBs in the preoperative period, also are presented.
Hepatic Function and Metabolism
Authors: Mahmood Faraz , Hackl Florian 
Published: May 2024

Abstract
The liver plays a vital role in human metabolism. Synthetic functions of the liver include synthesis of heme, albumin, and coagulation factors. Albumin significantly contributes to plasma oncotic pressure, as well as binding to exogenous drugs, providing immunomodulation, and antioxidant effects. The coagulation system is maintained with a balance between anti-thrombotic and pro-thrombotic processes. The liver is involved in synthesis of most pro- and anti-coagulant factors and liver injury can severely impair these processes and result in impaired coagulation, qualitatively or quantitatively altered platelets, or even disseminated intravascular coagulation (DIC). Moreover, the liver is essential for the metabolism of protein, carbohydrates, fat, and drugs. Hepatocellular insult or injury can result in altered drug metabolism or their availability in the body.
Anatomy of the Gastrointestinal and Hepatic Systems
Authors: Flanagan Timothy F. , Hackl Florian 
Published: May 2024

Abstract
The GI tract transports and absorbs water, electrolytes, and nutrients. Passage of materials is facilitated by peristaltic contractions of a smooth muscle layer and regulated by muscle sphincters. Liver anatomy, physiology, and pathophysiology are closely linked to the GI tract. Besides metabolic and synthetic functions, the liver is responsible for the production and secretion of bile into the duodenum via the common bile duct, facilitating fat absorption. The normal physiology, motility, and secretory activity of the GI tract can be altered by anesthetic drugs, and sympathetic and parasympathetic stimulation. Cirrhosis and end-stage liver disease are associated with portal hypertension, resulting in formation of varices along the GI tract. Anesthetic management in patients with diseases of the GI tract and end-stage liver disease is challenging and requires an understanding of the normal liver and GI anatomy. This chapter describes the basics of liver and GI anatomy, histology, and important pathophysiological processes.
Renal and Urinary Systems/Electrolyte Balance
Authors: Cieslinski Lindsey 
Published: May 2024

Abstract
The kidneys are essential organs for maintenance of homeostasis within the body. The functional unit of the kidney is the nephron. It is responsible for glomerular filtration, tubular reabsorption, and tubular secretion resulting in urine formation. Renal blood flow (RBF) is regulated via intrinsic and extrinsic autoregulatory mechanisms when the mean arterial pressure is normally maintained. The kidney is a major regulator of body water, and inorganic ions necessary to maintain electrolyte balance. It regulates body fluid osmolality and intravascular volume, eliminates metabolic waste products, and aids in regulation of pH via acid-base balance. Hormones essential to metabolic function are secreted by the kidneys. The chapter also highlights some perioperative considerations when the renal physiology is disrupted.
Alternatives to Blood Transfusion
Authors: Watt Stacey , Lamb Jennifer 
Published: May 2024

Abstract
This chapter will focus on alternatives to blood transfusion as a means to maintain patient hemodynamic stability in the field of anesthesiology. Topics will include a brief description of optimal transfusion practice and potential situations where avoiding blood transfusion may be appropriate or desirable. Preoperative patient optimization will be discussed, with a focus on correction of preexisting anemia, augmentation of innate hematopoiesis, and potential autologous blood donation prior to going to the operating room. Intraoperative strategies to be considered include methods for minimizing procedural blood loss, as well as accepted practices for managing intravascular volume derangements. Normovolemic hemodilution and autotransfusion after surgical blood salvage will be examined as intraoperative alternatives to allogenic blood transfusion.