bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical, Fire, and Explosion Hazards
Authors: Frantz Amanda , Giordano Chris
Published: May 2024

Electricity plays a prominent role in everyday life and is required for most modern-day operating room (OR) equipment. It is imperative for every anesthesiologist to be familiar with basic electrical and fire safety in the OR, as they encounter these tools daily. The fire triad is present in almost every surgical case; separating these modifiable risks is important to prevent these disasters and save the lives of patients and personnel. Advances in modern medicine have led to enhanced safety and sophistication of various electrical devices in the OR, but all staff and patients remain susceptible to hazards such as electrical burns, electrical shocks, and fire hazards. By taking the time to understand the basic principles of electronics and fire prevention, the anesthesiologist can create a safer working environment.
Pharmacokinetics of Neuraxial Anesthesia
Authors: Patel Nimesh , Fayed Mohamed
Published: May 2024

Spinal and epidural anesthesia has become an important aspect of perioperative patient care. In order to provide effective neuraxial anesthesia, an understanding of drug pharmacokinetics is required. The nerve fiber size, surface area, and myelination influence the onset of the neuraxial blockade. Baricity, patient positioning, and dose affect drug distribution. The type of local anesthetic used influences the intensity of sensory and motor blockade, duration of action, and toxicity. In addition, adjuvant agents are commonly utilized, which help to optimize anesthesia and analgesia while reducing adverse effects. Vasopressors, opioids, a2-agonists, and sodium bicarbonate are commonly used spinal additives.
Alternative and Herbal Medicines
Authors: Zubair Muhammad Haseeb , De Ranieri Aladino
Published: May 2024

The use of alternative and herbal medications is prevalent in the United States and across the world. All medications have a therapeutic window or dose range which can treat disease and avoid drug toxicity. These medications are not subjected to same rigorous testing and standards; consequently their therapeutic window and side effect profile are not as well defined. Physicians should be cognizant of different types of supplements available in the market and their different biological active forms. Their use history should be part of every anesthesia preoperative history. Lack of substantial evidence against their risks and benefits not only make their effects unpredictable, but also poses a significant challenge for physicians. Careful evaluation and nature of the surgery and the interaction of these agents with anesthetics should govern their perioperative use.
Anesthetic Gases and Vapors
Authors: Reynolds Rhett , Cornett Elyse M.
Published: May 2024

This chapter discusses the inhalation agents commonly used in anesthesia, including nitrous oxide and the volatile agents (desflurane, halothane, isoflurane, sevoflurane). It also reviews the mechanism of action of these agents, although this is not completely understood. In addition, this chapter focuses on the advantages and disadvantages associated with the inhaled gases. The advantages it touches on include bronchodilation, dose-dependent decrease in skeletal and smooth muscle tone, decreased cerebral metabolic rate, and increased cerebral blood flow. Some of the disadvantages considered are as follows: malignant hyperthermia, hepatotoxicity, respiratory depression, myocardial depression, and postoperative nausea. Finally, it discusses the fact that although the volatile anesthetics as a class are similar, each agent is unique.
Minimum Alveolar Concentration (MAC)
Authors: Hua Hao , Cormican Daniel S.
Published: May 2024

Minimum alveolar concentration (MAC) serves as a marker of anesthetic depth while using a volatile anesthetic, and allows for comparison of the potencies between different volatile anesthetic agents. MAC value has a specific definition, and there is clinical significance to varying MAC values, such as MAC-aware and MAC-BAR. Multiple physiological and pharmacological factors affect MAC, which may predispose a patient to inadequate anesthesia or anesthetic overdose. End tidal anesthetic concentration (ETAC) and electroencephalogram-derived bispectral index (BIS) are contemporary means to prevent intraoperative awareness and to target the depth of anesthesia.
Trace Concentrations, Pollution, and Personnel Harzards
Authors: Swanson David E.
Published: May 2024

Operating room personnel hazards include infectious risk from inhalation and contact with bodily fluids, breathing anesthetic gases, toxic fumes from the surgical field, radiation, eye injury from lasers, and psychological stress. Steps need to be taken to minimize these risks. Trace concentrations of anesthetic gas and smoke from the surgical field have raised concerns for over 50 years. Following careful anesthetic technique with a good mask seal and pausing fresh gas flow when the mask is off the patient are steps each anesthesiologist can take to minimize the exposure of personnel to anesthetic gas. The health of the operating room personnel and the environment is impacted by this pollution. Proper preoperative evaluation has been highlighted by the COVID-19 pandemic, as has the availability of adequate supplies of personal protective equipment. The risk of human immunodeficiency virus and hepatitis heightened awareness of the importance of wearing gloves and hand hygiene.
Monoamine Oxidase Inhibitors
Authors: Yates Christopher , Sharma Archit
Published: May 2024

Monoamine oxidase inhibitors (MAOIs) are a separate class from other antidepressants, treating different forms of depression as well as other nervous system disorders such as panic disorder, social phobia, and depression with atypical features. They increase the availability of neurotransmitters such as norepinephrine, serotonin, dopamine, as well as tyramine. The side effect profile of MAOIs can be attributed to alterations in neurotransmitter concentrations as a result of MAO inhibition, the anticholinergic properties of the drugs, and interactions with other medications. The anesthesia provider needs to ensure careful perioperative management of patients on these medications to provide drug-drug interactions and a safe anesthetic.
Anticonvulsants
Authors: Sethi Anish , Trehan Gaurav
Published: May 2024

Anticonvulsants are a broad category of medications that are utilized for the management of epileptic seizures, neuropathic pain syndromes, and psychiatric disorders. Their cellular targets include sodium channels, calcium channels, chloride channels, GABA receptors, and NMDA receptors. Often times, anticonvulsants target multiple receptors to exert their principal effects. When used for epilepsy, these medications are typically continued in the perioperative period. Several drug-drug interactions may occur with anticonvulsant medications due to enzymatic induction, which lead to changes in the metabolism of coadministered drugs. As such, patients on anticonvulsants should be closely monitored for potential adverse effects.
American Society of Anesthesiologists (ASA) Preoperative Testing Guidelines
Authors: Flanagan Timothy F. , Fikry Karim
Published: May 2024

Preoperative assessment is an essential component of safe, adequate and efficient anesthetic care. Preoperative testing guidelines rely on understanding the urgency of the intended procedure and completion of a history and physical exam. Risk stratification can occur after the anesthesiologist reviews the patient’s history with regard to ischemic heart disease, insulin-controlled diabetes, cerebrovascular disease, renal function, congestive heart failure, and the type and/or location of surgery. While testing is commonly not required or available for emergency surgeries, moderate- to high-risk, non-emergency surgeries for patients with poor functional capacity may warrant further testing if such testing would alter decision-making. Subsequent testing is guided by patients’ relevant factors and comorbidities.
Pediatric and Geriatric Doses
Authors: Bess Leah , Chhabada Surendrasingh
Published: May 2024

Pharmacodynamics and pharmacokinetics of drugs are distinctly different in neonates, children, and geriatric patient populations. Differences in the body fluid composition, organ immaturity, and limited reserve, and increased sensitivity to anesthetic agents make them vulnerable to medication-related side effects and toxicity. Thorough understanding of physiology and pharmacologic differences assists with safe dose regimen and optimal perioperative management.
Prophylactic Antibiotics
Authors: Lin Austine , Graber Raymond
Published: May 2024

Perioperative prophylactic antibiotics are administered in order to reduce the risk of surgical site infection (SSI). Multiple studies have demonstrated the efficacy of this practice. However, knowledge about appropriate drug choice, timing, dosing, redosing, and duration has continued to evolve. The practitioner should be aware that there are additional strategies that can be used to reduce the risk of perioperative infections, including maintaining normothermia, preventing hyperglycemia, using appropriate methods to remove hair, reducing the use of bladder catheterization, and using maximal barrier precautions when placing central lines.
Coma and Hyperosmolar Coma
Authors: Gluncic Vicko
Published: May 2024

Loss of consciousness is associated with physiological states (sleeping), anesthesia, and various pathological conditions. There are several terms describing the level to which the consciousness is decreased. Lethargy is the state of slightly reduced alertness and extreme fatigue. The term somnolence describes a drowsy patient who responds to mild stimulus (such as voice), and mumbles incoherently and moves in a disorganized fashion. In contrast, a stuporous patient responds to a vigorous and continuous stimulus only, and upon discontinuation of a stimulus returns to an unresponsive state. Coma is a state of complete unresponsiveness, from which a patient cannot be aroused.
Abdominal Aortic Aneurysm
Authors: Grandhi Ravi K. , Joseph Claire
Published: May 2024

Abdominal aortic aneurysms (AAA) occur due to compromised vascular strength from abnormal elastin activity. The majority of AAA require non-emergent repair via an endovascular approach when they reach over 5.5 cm or begin to grow at a rate of >0.5 cm/year. Patients often have coronary artery disease or respiratory dysfunction associated with smoking. Repair is performed via general or neuraxial anesthesia based on comorbidities and aneurysm morphology. Postoperatively, patients require close monitoring to evaluate renal function and graft-associated complications. If patients don’t receive an early intervention on their AAA, the AAA may rupture, leading to hemodynamic collapse and acute intervention.
Problems of Term and Delivery
Authors: Fayed Mohamed , Younger Joshua
Published: May 2024

Every pregnancy-related death is devastating. About 700 women die each year from complications of pregnancy. About 36% of deaths happened at delivery or in the week after. Heart disease and stroke caused more than 1 in 3 deaths (34%). Other leading causes of death included infections and severe bleeding.1 African American and American Indian were about three times as likely to die from a pregnancy-related cause as white women. Getting regular health care before, during, and after pregnancy can help in identifying these risks and prevent serious health problems. This chapter will summarize several important topics as related to problems of term and delivery.
Enhanced Recovery after Surgery Protocol for Fluid Therapy
Authors: Kassem Hisham , Urits Ivan
Published: May 2024

Enhanced recovery after surgery (ERAS) protocols have emerged to apply to many types of surgeries and provide recommendations to reduce variability and improves patient outcomes. An essential pillar of ERAS protocols is fluid management throughout the entire perioperative period. Preoperatively there is emphasis on limiting prolonged fasting; intraoperatively there is a goal-directed approach to maintain adequate organ perfusion; and postoperatively patients are encouraged to have early oral intake. To provide maximal benefit for the patient there needs to be an understanding among the anesthesiologist, surgeon, and ancillary staff with what directions should be followed. Further investigations are still needed to identify the best goals of fluid management during ERAS surgeries.
Pain Relief
Authors: Cosic Adi , Lawrence Melinda M.
Published: May 2024

Postoperative pain is an unpleasant sequala encountered by patients following almost all surgeries. Although the spectrum for pain is broad, and each patient’s perception of pain different, even mild pain can cause lasting change at the molecular level along pain pathways. Thus, it is imperative for anesthesia providers to have an understanding of the fundamental physiology of pain and its perception, as well as proper treatment.
Other Modalities
Authors: Leonard Ethan R. , Eckmann Maxim S.
Published: May 2024

While opioids and local anesthetics remain the mainstays of perioperative pain management due to their potency and versatility, other pharmacologic and nonpharmacologic treatments are available in the management of postoperative pain. These agents may confer benefits in reducing dependence on opioid therapy through synergism and multimodal pain reduction, thereby possibly improving maintenance of the patient in a more favorable therapeutic window. These agents have unique mechanisms, side effects, and contraindications; therefore patient-centered care requires consideration of how these adjunctive pain treatments can be used appropriately.
Respiratory Consequences of Anesthesia and the Surgical Incision
Authors: Jahromi Behdad , Jani Jai
Published: May 2024

This chapter discusses how anesthesia and surgical incision can impair pulmonary function, leading to hypoxemia. The focus is on the upper airway patency and the patient’s effective respiratory effort, which should be closely monitored. Potential common postoperative pulmonary complications include upper airway obstruction, pulmonary edema, arterial hypoxemia, decreased alveolar ventilation, decreased oxygen pressure, decreased diffusion capacity, ventilation-perfusion mismatch or shunts, and increased venous admixture. Surgical incision is also an important factor in predicting the risk of postoperative respiratory complications. Except in rare cases, all patients receiving general anesthesia should receive supplemental oxygen during postoperative care.
Functional Organization of the Cerebral Cortex
Authors: Latimer Dustin , Kaye Alan D.
Published: May 2024

The central nervous system is composed of neurons within the cerebrum, cerebellum, and brainstem. This review highlights the lobes of the brain and the anatomy of the central nervous system. The cerebral cortex is comprised of four lobes: frontal, parietal, temporal, and occipital. Each of the lobes in the cerebral cortex plays a specific role in function and physiology discussed below. The posterior fossa is discussed as its own region as it houses the most posterior and inferior portions of the cerebral cortex as well as the brainstem and cerebellum. The brainstem functions as the most primitive portion of the human brain. The majority of the cranial nerves are housed within the posterior fossa as well.
Cerebrospinal Fluid
Authors: Nguyen Christina T. , Schulman Nathan
Published: May 2024

This chapter gives an overview of cerebral spinal fluid (CSF) and its implications in anesthetic care. It covers the physiology of CSF formation, including flow through the cerebral ventricular system, electrolyte balance, and mechanisms of absorption. It also briefly discusses abnormalities in CSF pressure caused by imbalances in formation and reabsorption, as well as the effects some anesthetics have on these processes. Included in this chapter is a table comparing the composition of CSF to blood plasma.
Relation to Blood Chemistry and Acid-Base Balance
Authors: DaBreo Evan , Kohan Lynn
Published: May 2024

The physiologic mechanisms of cerebrospinal fluid (CSF) buffering in relation to blood chemistry and acid-base balance are crucial in understanding the ventilatory response to metabolic derangements and induced changes in intracranial pressure (ICP). Hyperventilation is often used in the context of head trauma or neurosurgical procedures to reduce ICP; however, careful use of this technique is critical. Because non-ionized CO2 molecules, and not ionized molecules such as H+, are able to cross the blood-brain barrier, induced changes in cerebrovascular blood flow (CBF) are largely independent of systemic arterial pH. Due to compensatory mechanisms, CBF will return to baseline as both blood and CSF pH return to normal over 6–24 hours, regardless of continued hyperventilation. Preoperative communication with the neurosurgical team prior to procedure is key for planning any potential need for reduction in ICP to improve operative conditions. Postoperatively this return to baseline must be kept in mind as prolonged hyperventilation also results in increased “CO2 reactivity,” making the patient more susceptible to acute rises in ICP.
General Organization of the Spinal Cord
Authors: Ozcan Asli , Conermann Till
Published: May 2024

This chapter on spinal cord general organization serves as a basic overview of the organization of the spinal cord, emphasizing high-yield points for anesthesiology board examination purposes. Gross anatomy of the vertebral column and the spinal cord are discussed. Important details about spinal nerves, gray matter, and white matter are reviewed, including critical portions such as the laminae of Rexed. An illustration of a cross-section of the spinal cord is shown to highlight critical structures of the gray and white matter. The arterial blood supply to the spinal cord is also reviewed.
The Sympathetic Nervous System
Authors: Cosic Adi , Lawrence Melinda M.
Published: May 2024

The autonomic nervous system is an integral part of the body’s hemostasis, maintaining mechanisms through two opposing forces. The autonomic nervous system is split into two subtypes, the sympathetic nervous system (SNS) and parasympathetic nervous system (PSNS). The SNS and PSNS act in response to stimuli, and regulate body functions such as digestion, response to stress, heart and respiratory rate, and many others. The SNS possesses an ability to release large amounts of catecholamines in response to stressful stimuli, earning it the common description of “fight or flight.” In the context of the far-reaching effects of the SNS and its importance in anesthesia, it is crucial for anesthesia providers to have a thorough understanding of its mechanisms.
Afferent and Efferent Pathways
Authors: Singh Simranjit , Waghray-Penmetcha Taruna
Published: May 2024

The autonomic nervous system (ANS) is divided into not only sympathetic and parasympathetic divisions, but afferent and efferent pathways as well. Afferent fibers transmit sensory information from the periphery to higher centers, while efferent fibers transmit modulate responses from the central nervous system back to the periphery in order to maintain homeostasis. Efferent pathways are divided into sympathetic and parasympathetic branches, whereas a single afferent sensory system conducts information for the ANS. Both pathways typically share the same postganglionic nerve fibers. A majority of afferent signals converge at the solitary nucleus in the medulla, before being sent to other areas of the brain. Preganglionic parasympathetic efferent pathways are controlled by cranial nerves III, VII, IX, X, and sacral fibers S2–S4. Postganglionic nerves are located near the effector organ. Meanwhile, preganglionic sympathetic efferents originate from spinal cord levels T1–L2 and synapse with the paraspinal postganglionic sympathetic chain, before axons are sent to the periphery.
Meninges
Authors: Abdallah Rany T. , Villatoro-Lopez Jasmin
Published: May 2024

The meninges are membranous layers surrounding the central nervous system (CNS). The meninges provide protection of the soft neural tissue of the brain and the spinal cord. They are composed of three distinct layers: the outermost dura mater, the middle arachnoid mater, and the innermost pia mater. The meninges contain space via which cerebrospinal fluid (CSF) travels through the CNS. Defects in the meninges are believed to cause two neurodevelopmental disorders in humans: Dandy-Walker malformation, and cobblestone lissencephaly. Both conditions can impair the function of the brain. Both Dandy-Walker malformation and Walker-Warburg syndrome symptoms occur at birth or early infancy.
Carotid and Aortic Bodies and Carotid Sinus
Authors: Vasant Kris , Ahmed Muhammad Fayyaz
Published: May 2024

In this chapter the authors discuss the different types of chemoreceptors, with particular focus on structure, function, and physiologic effects on maintaining homeostasis. The main peripheral chemoreceptors in the body, which include the carotid and aortic bodies, are discussed. The chapter also outlines the structure and function of the carotid sinus. Clinically relevant anesthetic considerations have been mentioned for clinically managing patients.
Ganglia, Rami Communicantes and Sympathetic Chain
Authors: Friedman Eric D. , Subieta-Benito Gunar G.
Published: May 2024

Ganglia, autonomic fibers and plexuses of both the sympathetic and parasympathetic nervous system network with one another to maintain a homeostatic balance in nearly every organ system in the human body. Although its anatomy is well understood, the intrinsic functions of this system remain a challenge for most physicians due to its involvement in life-sustaining functions and pain control. In the latter, dysfunctional sympathetic ganglia could contribute to pain syndromes that are currently beyond the ability to cure. Given the overlap, but also independence from somatic nerves, it is important to understand the sympathetic anatomic relationships in order to maximize therapeutic yield.
Work of Breathing
Authors: Pham Ba Hoang Nguyen , Bang Jason
Published: May 2024

Work of breathing is defined as the energy spent to move air in and out of the lung during inspiration and expiration, respectively. It comprises the elastic work and the resistive work; their relationship can be demonstrated through the Campbell diagram. The increase in work of breathing can be seen in various comorbidities such as obesity, congestive heart failure, and lung diseases. It can be minimized by altering factors that affect the elastic and resistive work. The practical importance of understanding and calculating the work of breathing in the operating room and more so in the field of intensive care is to optimize the ventilator settings according to the needs of the patient.
Distribution of Perfusion
Authors: Rodriguez Gloria , Jamroz Tatiana
Published: May 2024

The pulmonary circulation is a low-pressure system and is characterized by a low vascular resistance compared to the systemic circulation. This lower vascular resistance allows the existence of thinner capillaries and alveolar walls that facilitate diffusion of oxygen and CO2 for gas exchange. The distribution of blood received by the lungs is not uniform, and based on the interactions between alveolar pressure, pulmonary capillary arterial, and venous pressures, as well as interstitial pressures, the lungs have been divided into four different zones called the West lung zones. Several factors regulate blood supply to different areas of the lungs. One of the most important is the phenomenon known as hypoxic pulmonary vasoconstriction, in which blood is diverted away from poorly ventilated alveoli and redirected toward better ventilated ones.
Blood Gas
Authors: Knox Nigel , Chang Michael
Published: May 2024

This chapter discusses the analysis and utilization of the information acquired with a blood gas. A focus is placed on ABG interpretation, allowing for an improvement in the anesthesiologist’s assessment. In turn, it also identifies some of the more common systemic effects associated with abnormalities in both oxygen and carbon dioxide levels.
Special Considerations in Pediatric Otolaryngology Surgery
Authors: McDaniel Eric , Fromer Ilana R.
Published: May 2024

Pediatric otolaryngology procedures are the most frequently performed surgeries in children. They are often booked as same-day procedures despite their disproportionately high risk of complications which require a close working partnership between surgeon and anesthesiologist to formulate a clear plan of management to ensure safe patient care and good outcomes. The most common pediatric otolaryngology surgeries include but are not limited to: cleft lip and palate, tonsillectomy and adenoidectomy, common ear procedures, peritonsillar abscess, rigid bronchoscopy and laryngoscopy techniques including jet ventilation and laser surgery, and foreign body aspiration. This chapter will deal with the high-yield preoperative, intraoperative, and postoperative considerations in managing the anesthesia for these surgeries.
Nasal Anatomy and Pathology
Authors: Falgoust Evan , Kaye Alan D.
Published: May 2024

Respiratory anatomy, specifically the nose, is an important anatomical landmark, as well as common source of pathological abnormalities. The cell type, blood supply, and nerve supply all play various roles in the function of the nose, and these critical factors are described regarding individual significance in numerous pathological. Therapeutic considerations are described in the treatment of epistaxis, rhinitis, and nasal polyps, including pharmacological management strategy as well as surgical treatments.
Pharynx
Authors: Penny Kayla , Cornett Elyse M.
Published: May 2024

The pharynx extends from the base of the skull to the inferior border of the cricoid cartilage. It serves as a common channel for both swallowing and respiration. The internal pharynx consists of the nasopharynx, oropharynx, and laryngopharynx, and is innervated by various branches of the external carotid artery. Pharyngeal function is decreased in anesthetized patients. The anesthesiologist should evaluate the anatomy of the airway, including the pharynx, to determine whether the patient is at risk for a difficult intubation.
Larynx
Authors: Iqbal Fatima , Cornett Elyse M.
Published: May 2024

The larynx is a segment of the respiratory tract that connects the pharynx to the trachea and serves to maintain a patent airway, prevent aspiration of food into the trachea, and provide vocalization. These functions are achieved by its cartilaginous framework, interconnected with ligaments and joints, that support its various muscles innervated by branches of the vagus nerve (CN X). An appreciation of its anatomy is necessary for anesthesiologists to provide proper airway management and for appropriate care to the pediatric population, who possess significant anatomical differences in their larynx from the adult population.
Innervation
Authors: Lauve Sarah , Cornett Elyse M.
Published: May 2024

Efferent innervation of the respiratory tract and respiratory muscles originates in the medulla and pons and is supplied through the phrenic, vagus (X), and glossopharyngeal nerves (IX). Sensory afferent information is provided to the respiratory control centers in the medulla and pons via efferent neurons from the lungs and chemoreceptors, regulated by pH, partial pressure of oxygen (PaO2), partial pressure of carbon dioxide (PaCO2), and arterial perfusion pressure.
Differences between Infant and Adult Airway
Authors: Jeffers Susan , Kaye Alan D.
Published: May 2024

Neonates and infants differ from adults in many ways, and it is imperative that the anesthesiologist be familiar with these differences in order to provide safe airway management and carry out appropriate treatment plans. Infants vary from adults in both anatomical and physiological characteristics. The unique anatomy of neonates and infants influences the approach the provider should take during airway and ventilator management. Important anatomical considerations include the larger head and tongue of infants, their shorter and more compliant airway, as well as the differences in position of the glottis between infants and adults.
Structures and Relationships in the Neck and Chest
Authors: Saunders Alpaugh E. , Kaye Alan D.
Published: May 2024

The anesthesiologist’s role during surgical and procedural interventions requires expertise in the anatomy, physiology, and management of the structures in the neck and chest. The anesthesiologist can perform a variety of procedures to obtain physiologic measurements and maintain respiratory and cardiovascular homeostasis, along with providing pain control. It is vital to have a thorough understanding of the relevant anatomy and landmarks in order to perform these procedures safely. This chapter outlines the anatomic structures and their relationships in the neck and chest and includes pertinent considerations for the anesthesiologist.
Leukotriene Modifier Drugs
Authors: Cruz Adam , Manders Larry
Published: May 2024

The leukotriene modifiers include montelukast, zafirlukast, and zileuton. These medications mitigate the effects and production of leukotrienes, proinflammatory mediators produced during inflammatory responses via arachidonic acid breakdown. As anti-inflammatory agents, the leukotriene modifiers are indicated for use in prophylaxis of asthma exacerbations and chronic asthma treatment. This chapter highlights leukotriene synthesis and their effects on the pulmonary system. Furthermore, the current pharmacological agents are highlighted, as well as their anesthetic considerations.
Pre- and Post-Capillary Sphincter Control in Shock
Authors: Cook Rollin , Sharma Archit
Published: May 2024

The microcirculation is a complex and integrated system that supplies and distributes oxygen throughout the tissues. In normal states, the delivery of oxygen and electrolytes to peripheral organs is controlled by neurohumoral mechanisms which act through specific control mechanisms in the circulatory system, such as the pre-capillary sphincters. Shock states causes abnormal microvascular oxygen transport as significant numbers of capillaries stop flowing and the microcirculation fails to compensate for decreased functional capillary density. This chapter discusses both the normal functioning of the microvasculature, as well as the changes that are introduced in a shock state, as the body tries to maintain homeostasis.
Regulation of Circulation and Blood Volume
Authors: Dressen Kirk , Sharma Archit
Published: May 2024

Circulation is regulated by neural, endocrine, and autoregulatory systems via control of systemic arterial pressure and heart function. Vasomotor fibers reach small arteries, arterioles, venules, and veins from sympathetic nerve origins in the medulla and pons known as the vasomotor center. Both increased and decreased blood volumes can have clinical complications and hence the maintenance of blood volume is crucial to normal perfusion of body tissues. Blood volume, normally proportioned with extracellular fluid in the body, is closely controlled through a combination of factors. This chapter reviews how these mechanisms work in conjunction to protect the body during periods of instability.
Digoxin
Authors: Perez-Ruiz Carlos M. , Abdullah Ali
Published: May 2024

Cardiac glycosides have important effects on cardiac contractility and conduction activity. The main clinical importance is its use in two situations: heart failure due to systolic dysfunction, and in certain supraventricular tachyarrhythmias (e.g., atrial fibrillation or flutter). The drug originates from the foxglove plant, also known as the Digitalis plant, and has been studied since the 1780s. The term “digitalis” has also been used to describe the whole group of cardiac glycosides (digoxin and digitoxin). Digitoxin has not been widely available since the 1980s. Consequently, digoxin has become the only cardiac glycoside available in most countries.
Phosphodiesterase III Inhibitors (Inotropic Dilators)
Authors: Haswah Muin , Kolesnikov Igor
Published: May 2024

Phosphodiesterase (PDE) III inhibitors are pharmacologic agents that have been used in a variety of cardiovascular settings. They are known for their inotropic, vasodilator, afterload-reducing properties. PDE inhibitors are most commonly used in patients with congestive heart failure. Milrinone (the most common drug from the class) is a bipyridine derivative of amrinone (an older drug), inhibiting the enzyme phosphodiesterase III ordinarily found in cardiac myocytes. PDEs are responsible for the breakdown of c-AMP. Therefore, PDE inhibitors lead to increased c-AMP which in turn creates improved uptake, storage and uptake of calcium from sarcoplasmic reticulum during excitation-contraction coupling. These drugs also have separate direct vasodilatory properties (milrinone ˃ amrinone). Despite milrinone’s clear vasodilatory clinical benefit, its significance to treat congestive heart failure as a single agent remains controversial in comparison to conventional therapy. Milrinone is currently only available in intravenous form. Arrhythmias and hypotension are among its most frequent adverse side effects. Milrinone dosing should be reduced or avoided in patients with renal disease, as the medication is renally excreted.
Electrolytes
Authors: Cieslinski Lindsey
Published: May 2024

Physiologic responses to surgical stress have significant implications for perioperative fluids. Electrolyte homeostasis is essential to proper organ function. Potassium (K+) and sodium (Na+) are the predominant cations in the intracellular fluid (ICF) and extracellular fluid (ECF). While chloride is the main anion in the ECF, changes in Cl– are mainly secondary to changes in Na+. Sodium balance is related to ECF volume and water balance. The charged lipid nature of the cell membrane does not allow cations to cross; this makes the composition of ions on either side of the membrane different. Na+, K, Cl– ions have an ATP-dependent process to maintain a gradient across the membrane, while calcium (Ca2+) and magnesium (Mg2+) are important for vascular tone; Ca2+ is needed for inotropy and peripheral vasoconstriction. Mg2+ antagonizes the effect of Ca2+ on the vasculature, and plays a vital role in ATP production and as a cofactor for DNA production. This chapter discusses the fundamental electrolytes Na+, K+, Ca2+, and Cl– and Mg2+ with a focus on basic science content with perspective of clinical practice and application.
Diuretics
Authors: Brown J. , Ramirez Maria F.
Published: May 2024

Diuretics are commonly prescribed medications that are designed to increase urine output by decreasing the reabsorption of water and sodium. They are categorized by their primary site of action along the renal nephron. Diuretics are commonly used to treat condition associated with volume overload such as heart failure, pulmonary edema and cerebral edema. Side effects of diuretics such as electrolyte imbalances and hypovolemia vary by class and are important to consider, as they can lead to increased perioperative morbidity and mortality. Proper preoperative evaluation and perioperative management, as well as a thorough understanding of each class of diuretics, are required when patients utilizing these medications undergo anesthesia. This abstract will highlights the mechanism of action, clinical indications, adverse effects and other key factors relevant to the anesthesia management.
Blood Transfusions
Authors: Boydston Elaine A.
Published: May 2024

Anesthesiologists are major users of blood products due to the large number of transfusions that occur in the operating room and perioperative setting; thus it is important to be well versed in the practice of blood transfusion, including the indications, risks, and complications. Treatment of symptomatic anemia and bleeding frequently includes transfusion of packed red blood cells (PRBCs) in order to replace lost intravascular volume and maintain cardiac output, and to maintain hemoglobin levels adequate to preserve oxygen delivery to vital organs and other tissues. Transfusion of plasma containing blood products and platelets is performed in order to avoid or correct coagulopathies due to either qualitative or quantitative defects in coagulation enzymes or platelets. The risks and complications of blood transfusion include the possibility of transmission of blood-borne pathogens, immunologic reactions including hemolytic and febrile (non-hemolytic) transfusion reactions, pulmonary edema and respiratory failure due to either transfusion-related acute lung injury (TRALI) or transfusion-associated circulatory overload (TACO), and other derangements due to the transfusion of a large number of blood products such as hypothermia, hyperkalemia, citrate toxicity and acidosis. In the setting of massive hemorrhage or trauma, fixed ratios of blood products are typically administered as part of a “massive transfusion protocol” in order to reduce blood loss, decrease transfusion requirements, and improve mortality. In the absence of suitable donor blood product availability or patient consent to transfusion, several alternatives exist, including pre-deposit autologous blood donation (PABT), cell salvage, and acute normovolemic hemodilution (ANH).
Immunosuppressive and Anti-Rejection Drugs
Authors: Syed Madiha , Palm Nicole
Published: May 2024

Rates of organ transplantation have increased every year in the United States; in 2019, 39 718 organs were transplanted. Patients who receive organs from a genetically different donor require immunosuppressive medications to prevent and treat rejection of the transplanted organ. Due to the increased number of organs being transplanted, these patients will frequently present to the operating room for non-transplant or emergency surgery. Anesthesiologists involved in the perioperative care of these patients need to understand the immunosuppressive regimens that patients are prescribed, possible side effects, and drug interaction with medications used in the perioperative period. This chapter provides a concise review of current immunosuppressive regimens, drug interactions in the perioperative period, preoperative evaluation, and management of transplant recipients.
Massive Transfusion Protocol
Authors: Genis Alina
Published: May 2024

Massive transfusion protocols (MTP) are incorporated at various institutions to facilitate the replacement of large blood volume in a short period of time in responsive to uncontrolled hemorrhage. The presence of an MTP has been shown to decrease the amount of each blood component transfused, turnaround times, and hospital expenses. Traumatic injury and massive acute blood loss often are associated with trauma-induced coagulopathy. Trauma-induced coagulopathy can be attenuated by the avoidance of hypothermia, acidosis, and dilution by administration of a large amount of crystalloid fluids. Significant data support the replacement of blood products in equal ratios. Recent studies have also explored the potential benefits of incorporating adjunct therapies as part of an MTP. Antifibrinolytics, finrinogen concentrate, cryoprecipitate, and factor VIIa are occasionally utilized as part of the transfusion protocol. Although transfusing large amounts of blood products to an exsanguinating patient can be life-saving, risks such as hypocalemia, hyperkalemia, citrate toxicity, and hypothermia should be anticipated and addressed if necessary.
Pituitary Gland
Authors: Jenkins Thomas Keith , Giordano Chris
Published: May 2024

The pituitary gland is an endocrine gland resting in a small cavity of the ethmoid bone at the base of the brain. It produces eight major systemically acting hormones. Hyper- or hyposecretion of these hormones can result in disease processes, which may have a significant impact on anesthetic management. Acromegaly, caused by overproduction of growth hormone, can lead to difficult airways due to macroglossia and obstructive sleep apnea. Diabetes insipidus ensues from a low antidiuretic hormone level, leading to increased urine output and electrolyte derangements that may require fluid or hormone replacement. The syndrome of inappropriate antidiuretic hormone secretion is caused by antidiuretic hormone-secreting tumors and results in a hypo-osmotic state that often requires gentle electrolyte replacement. Finally, the removal of the pituitary gland (hypophysectomy) is a treatment for pituitary adenoma and causes iatrogenic panhypopituitarism. These patients require lifelong hormone replacement and stress-dose steroids because the hypothalamic-pituitary-adrenal axis does not function.
Relationship to Hormones
Authors: Costa Santos Lucas , Rossi Raquel Montagner
Published: May 2024

Metabolic adjustments are necessary for adaptation to ever changing environmental and biological conditions. The main agents responsible for this process are hormones, which act to maintain a balance between anabolic and catabolic states. Insulin and growth hormone are major anabolic hormones and act in one side of this interaction promoting molecular synthesis. Insulin also promotes glycogenesis, glucose uptake, and fatty acid uptake. On the other hand, cortisol, catecholamines, and glucagon exert catabolic effects and are responsible for maintaining available energy sources in situations where a higher demand is presented, mainly by inducing opposing processes such as glycogenolysis, gluconeogenesis, and lipolysis.
Prejunctional Components and Events
Authors: Roche Shaun , Moncayo Ruth E.
Published: May 2024

The prejunctional portion of the neuromuscular junction is responsible for the synthesis, storage, and release of the neurotransmitter acetylcholine (ACh) across the synaptic cleft, as well as the reuptake of choline after hydrolysis. This process is facilitated by voltage-gated channels that control the flow of ions across the nerve terminal membrane. Basic understanding of the anatomy and physiology of the prejunctional component of the neuromuscular junction will guide an understanding of the mechanism of action of neuromuscular blocking agents and their side effects, as well as providing anesthetic clinical correlation to prejunctional membrane disorders such as in Eaton-Lambert syndrome. This chapter covers the prejunctional events and components of the neuromuscular junction, the synthesis and release of ACh, prejunctional nicotinic and muscarinic receptors, and anesthetic clinical considerations associated with presynaptic neuromuscular junction abnormalities.
Depression
Authors: Goldstein Mark A. , Goldstein Myrna Chandler
Published: May 2024

Prior to the COVID-19 pandemic, there had been a growing mental health crisis for adolescents. In 2019, the prevalence of depression in the adolescent age groups ran from 10 to 20 percent. After the pandemic, the rates are even higher. Factors that may predispose adolescents to depression include early life stressors, genetic makeup, and being a child of a depressed parent. Depression can lead some adolescents to use substances, and substance use may induce depression. And, of course, depression is a major factor in the cause of suicidal behavior in adolescents. But the problematic use of social media may also be linked to depression in the adolescent age group. Racism is associated with poorer mental health outcomes including depression; this is more likely to occur in female adolescents. Adolescents should be screened periodically for depression since there are effective treatments that include therapies and medications.
Cyberbullying
Authors: Goldstein Mark A. , Goldstein Myrna Chandler
Published: May 2024

Adolescents have a significant risk of being harmed by cyberbullying since their brains are still developing emotion control, judgment, and executive functions. Social media sites are known settings for cyberbullying behaviors. The symptoms of cyberbullying may be nonspecific, including changes in sleep and eating patterns, increased anxiety and school absenteeism, and increasing self-harm behaviors. Victims of cyberbullying may experience negative physical and mental outcomes including an increased risk to abuse substances as well as an increased likelihood to have suicidal behaviors. Cyberbully perpetration is associated with problematic internet use as well substance use, depression, and low self-esteem. Cyberbullying prevention efforts should include families, schools, health care providers, and governments.
Divorce
Authors: Goldstein Mark A. , Goldstein Myrna Chandler
Published: May 2024

Parental divorce may affect adolescents in their biological, psychological, and social domains with problems continuing into adulthood. A parental divorce is considered an adverse childhood experience that could have an impact on an early adolescent’s brain circuitry, leading to lifelong issues. Understandably, parental divorce is a very stressful event. Children of divorced parents have a higher risk for depression and suicidality compared to those with married parents. Adolescents in divorced families may use substances earlier than those in intact families, and there are some studies that suggest an association between parental divorce and anger, aggression, and hostility in adolescents. Early referral to individual or group therapy for those adolescents experiencing divorce may be helpful.
Model of Pain in Vulnerable Populations and the Role of Social Determinants of Health
Authors: Meghani Salimah H. , Janevic Mary R.
Published: May 2024

This chapter explores the mechanisms behind inequities in pain prevalence, experience, and outcomes among subgroups, including minoritized and racialized populations. The chapter emphasizes the need for an anti-racist framework to confront racism in pain care and support cultural humility and critical self-reflection in clinical practice and research. Policy interventions, such as improving access to non-opioid and nonpharmacological pain interventions, expanding insurance access, and promoting patient-centered outcomes in pain research, are also highlighted as potential avenues for reducing pain care disparities. The chapter cautions against making biological or behavioral attributions and invoking easy misconceptions about the mechanisms behind disparities, instead urging readers to carefully examine these disparities and address the social risks and epigenetic risks underlying them. Ultimately, the chapter calls for continued efforts to create equitable models of pain care to reduce the burden of pain and improve the well-being of all individuals and communities.
Insight and Responsibility
Authors: Gallagher Rollin M.
Published: May 2024

Millennia-old philosophical considerations of morality and values in the practice of medicine have led to the development of the field of bioethics encompassing the domains of clinical care, education and training, clinical and basic research, health administration, and public policy. As “keyholders” to solutions to the universal human problem of pain, the pain field must not only provide good care to patients but also steward needed progress in education, science, and health system policy that will improve pain care across populations. This challenge requires both insight and responsibility. Practitioners must understand human nature—humans’ vulnerabilities and strengths—and how these attributes interact with management of the complexity of pain throughout the continuum of care. Core ethical principles (beneficence, nonmaleficence, respect for autonomy, justice, and double effect) help guide daily clinical work, but practice conditions dictated by a commercialized health care system challenge these principles. Data science algorithms based on medical variables help standardize care in clinical practice guidelines, but they must include psychosocial variables to remediate care disparities in providing effective biopsychosocial stepped care. Sociocultural factors, such as mental illness, racism, and poverty, interact with institutionalized barriers such as inadequate training, interspecialty economic disparities, and specialty tribalism to perpetuate poor care. Stewardship teamwork, involving all sectors of the health system and policymakers, is needed to improve pain care for vulnerable populations.