bluuebunny/crossref_metadata_2025 huggingface dataset:
Hypertension
Authors: Sung Kim , Arora Lovkesh L.
Published: March 2023

Hypertension (HTN) is a common medical disorder that an anesthesiologist can face during the perioperative period. The etiology of the disease can be complex, and causes of primary hypertension are not yet fully understood. It is important to understand the many different aspects of hypertension to adequately manage the patient. Although generally managed by primary care providers such as internists, family practitioners, and nurse practitioners, severe perioperative HTN may result in excess surgical bleeding, myocardial ischemia and/or infarction, congestive heart failure (CHF), and acute pulmonary edema (APE). Therefore, it is very vital for the anesthesiology team to have a thorough knowledge and plan to take care of these patients.
Effect of Intracardiac Shunts on Inhalation Induction
Authors: Geara Elie , Alhaddadin Caroline
Published: March 2023

Congenital heart disease (CHD) encompasses a variety of abnormalities that are mostly detected in infancy, early childhood, or less commonly adulthood. With the current surgical and medical treatment, an increasing number of patients with CHD may survive to adulthood and be encountered during non cardiac procedures. Conduct of stable inhalational anesthetic induction in patients with intracardiac shunts requires sound knowledge of the fundamental physiology specific to the underlying shunt lesion; as this can alter the induction time, so if delivery of anesthetic agent is not carefully titrated, it can consequently lead to hemodynamic instability. The inhalational induction of anesthesia is delayed in patients with right-to-left shunt compared to patients with a left-to-right shunt. The anesthesiologist needs to have an in-depth understanding of the physiology and effect of shunt lesions on the uptake, delivery, and equilibration of anesthetic drugs.
Peripheral Arteriosclerotic Disease
Authors: Tadros Racha , Hussain Nasir
Published: March 2023

Peripheral arteriosclerotic disease (PAD) commonly affects the lower extremities. Signs and symptoms of PAD are variable and can present classically with claudication or in an advanced state through chronic limb ischemia. To evaluate a patient with risk factors for PAD, a thorough history, review of systems, and physical examination should be obtained. An ankle-brachial index (ABI) less than 0.9 is sensitive and specific for arterial stenosis and diagnostic for PAD. Management typically involves goal-directed medical therapy (GDMT), such as antiplatelet therapy, statins, exercise rehabilitation, and lifestyle modifications (e.g. smoking cessation). Vascular interventions are typically reserved for patients with severe claudication impairing quality of life.
Advanced Cardiopulmonary Resuscitation
Authors: Laborde Donnie
Published: March 2023

Advanced cardiovascular life support (ACLS) is a set of algorithms created to guide practitioners in treating life-threatening cardiovascular emergencies by implementing and integrating both basic and advanced life support. The majority of victims, in both in-hospital and out-of-hospital settings, do not receive high-quality cardiopulmonary resuscitation (CPR). Successful ACLS outcomes will continue to improve with post–quality assessments, reviewing each link in the chain of survival. Pediatric advanced life support (PALS) certification offers a progressive and organized approach to pediatric assessment. PALS training has been developed for healthcare professionals who respond to emergencies for infants (ages < 1 year) and children (age 1 year to puberty) and assists health service providers with skills and knowledge for treating critically sick infants and children. Professionals acquiring this certification are those who respond to emergency cases, such as pediatric care providers, emergency responders, intensive care unit staff, and emergency room personnel. In 2015, approximately 80% of hospitalized patients with cardiorespiratory arrest had abnormal vital signs documented up to 8 hours before the actual arrest. Early recognition and high-quality CPR are crucial for survival, regardless of the victim’s age. Thanks to the American Heart Association’s commitment and research, the survival rate in hospitals has improved from 23.1% in 2012 to 25.5% in 2015. The American Heart Association’s research has also revealed how organization, coordination, and review of performance is vital for both present and future victim survival.
Pathophysiology of Renal Disease
Authors: Taco Erika , Noguera Edward
Published: March 2023

One of the most feared postoperative complications is acute kidney injury. Postoperative renal failure increases both morbidity and mortality. The blood flow to the kidneys is 20%–25% of the cardiac output, and kidney ultrafiltration is 20% (renal plasma blood flow). About 90% of kidney blood flow is dedicated to cortex. Considering these figures, renal function is very sensitive to hemodynamic changes if kidney autoregulation is exhausted. There are different stages of renal dysfunction; the most severe forms will require renal replacement therapy. Dialysis is a very resource-intensive therapy that increases care costs and is associated with poor quality of life.
Perioperative Electrolyte Abnormalities
Authors: Earls Brent , Sivanesan Eellan
Published: March 2023

Electrolyte imbalance is an important cause of morbidity and mortality in the perioperative patient. These imbalances can lead to dramatic fluid compartment shifts, changes in the electrical conduction of the nervous system, hormone imbalances, and a variety of other pathologies if left untreated. Early recognition and a high index of suspicion is important to reduce complications. Identification of the underlying cause will help avoid overtreatment or undertreatment of electrolyte dyscrasias. Understanding intrinsic regulation of these electrolytes will also assist with identifying potential contributing factors leading to the imbalance. This chapter discusses major causes, clinical signs, and treatments of the major electrolyte disorders.
Fluid Balance During Surgery
Authors: Streetzel Charlotte , Giordano Christopher
Published: March 2023

The endothelial glycocalyx (EG) is a complex and dynamic structure that lines the innermost surface of all vessels in the human body. Its discovery and implications in the Starling principle led to important realizations about the mechanisms of fluid shifting in the body. Components of the glycocalyx contribute to crucial regulatory functions, including inflammation and recruitment of cells, hemostasis, and homeostasis of intercompartmental fluid shifting. The EG has a remarkable ability to adapt to changes in the local environment to reduce damage to the vasculature; however, it may become damaged when exposed to extreme changes in environment, such as increased shear stress, increased or decreased oxygen availability, and drastic changes in tonicity. Several disease states are associated with degradation of the EG, including heart failure, acute respiratory distress syndrome, nephrotic syndromes, trauma, sepsis, and even cardiopulmonary bypass. Understanding the mechanisms causing damage to the EG and the downstream clinical implications can help physicians avoid and possibly correct these pathologic states.
Esophageal Doppler
Authors: Kim Roy , Abd-Elsayed Alaa
Published: March 2023

Monitoring and assessment of cardiovascular function is often unreliable in critically ill patients. Although pulmonary artery catheterization (PAC) is considered the gold standard for continuous monitoring of cardiac output (CO), it can be difficult to place, and the information provided can be largely misinterpreted or misunderstood. Esophageal Doppler monitoring measures blood flow velocity in the descending thoracic aorta using a flexible ultrasound probe that is much smaller than an ordinary transesophageal echocardiographic probe; it less invasive with a very good safety record. Esophageal Doppler monitoring is an alternative to PAC and can provide important hemodynamic information that can positively affect outcomes.
Anemia
Authors: Shapiro Victoria , Brosnan Heather
Published: March 2023

Anemia is characterized by a decrease in red cell mass and clinically manifests as decrease in circulating red blood cells. Anemia is defined by the World Health Organization (WHO) as a hemoglobin less than 12 g/dL in adult females and less than 13 g/dL in adult males, and it can be classified by morphology and average size of circulating red blood cells or mean corpuscular volume. Preoperative anemia is a significant risk factor for perioperative blood transfusions and is an independent risk factor for perioperative morbidity and mortality. Patients with anemia should be worked up in advance of the elective procedure.
Fibrinolysis
Authors: Tanner Colby B. , Boydston Elaine A.
Published: March 2023

Fibrinolysis is a natural physiologic process that maintains homeostasis by regulating clot formation and degradation. This balance allows for clot remodeling and prevents diffuse thrombosis formation. Fibrinolysis is largely mediated by tissue plasminogen activator (tPA), which cleaves plasminogen into plasmin, ultimately leading to fibrin degradation and clot dissolution. Fibrinolysis can be measured quantitatively via thromboelastography (TEG) and rotational thromboelastometry (ROTEM). Detection of fibrinolysis via these assays and others allows for directed therapy and potential pharmaceutical inhibition of fibrinolysis. This pharmaceutical inhibition, also termed antifibrinolytic therapy, is most commonly performed with medications such as aprotinin, aminocaproic acid, and tranexamic acid. Antifibrinolytic therapy may be indicated in the setting of significant hemorrhage or excessive fibrinolysis (known as hyperfibrinolysis). Because of this, antifibrinolytic therapy has become commonly used in many clinical settings, including trauma, surgery, and cardiopulmonary bypass. When considering initiation of antifibrinolytic therapy, the benefit of decreased hemorrhage and anti-inflammatory effects must be weighed against the theoretical risk of unchecked thrombus formation.
Complications of Transfusion
Authors: Jones Courtney R. , Mechlin Maggie W.
Published: March 2023

Transfusion of blood components is an inextricable part of anesthetic practice when caring for critically ill patients undergoing high-risk surgery. These transfusions can be life-saving in certain patients, but the anesthesiologist must be aware of the most common and highest risk transfusion reactions when analyzing the individual risk-benefit ratio for a particular patient. This chapter reviews the most severe pulmonary reactions with the highest mortality—transfusion associated circulatory overload and transfusion related acute lung injury. The more common complications of febrile, allergic, hypotensive, and hemolytic reactions are also reviewed. If a transfusion reaction occurs, the transfusion should be stopped, and the patient should be given supportive care.
Transfusion Therapy for Massive Hemorrhage
Authors: Tanner Colby B. , Boydston Elaine A.
Published: March 2023

Massive hemorrhage is a major complication of traumatic injury and many surgical operations. Early detection of hemorrhage and appropriate resuscitation is essential to improve outcomes during recovery from the inciting event. Traumatic injury, surgical exposure, and large-volume resuscitation can cause physiologic derangements that result in alterations of the normal coagulation cascade and formation of thrombin clot. Careful balancing of resuscitation using appropriate ratios of packed red blood cells (pRBCs), fresh frozen plasma (FFP), and platelets as well as avoiding crystalloid solutions have been shown to decrease mortality, likely due to improved hemostasis. Additionally, careful evaluation of laboratory values, patient history and pharmacologic exposure can further guide resuscitation efforts and provide information for potential pharmacological intervention.
Parathyroid Disease
Authors: Valenta Karel T. S. , Toth Kenneth S.
Published: March 2023

Parathyroid disease is due to overproduction or underproduction of parathyroid hormone by the chief cells of the parathyroid gland. Parathyroid hormone plays an important part in control of calcium levels. Hyperparathyroidism, or elevated parathyroid hormone levels, can have signs and symptoms of hypercalcemia, such as hypertension, arrhythmias, and altered mental status. Hypoparathyroidism, or low parathyroid hormone, can present with signs and symptoms of hypocalcemia, such as perioral numbness and hypotension. Primary hyperparathyroidism is often treated surgically and can result in hypoparathyroidism postoperatively, leading to hypocalcemia and its sequelae. Perioperative recurrent laryngeal nerve injury is another concern, which if bilateral will require emergent reintubation.
Adrenal Disease
Authors: Dalton Allison K.
Published: March 2023

The adrenal gland is composed of the medulla and cortex. The adrenal medulla secretes catecholamines. Pheochromocytomas are the result of excess secretion of norepinephrine, epinephrine, or dopamine, leading to hypertension, tachycardia, headaches, and diaphoresis. Patients with pheochromocytoma are at high risk of malignant hypertension, arrhythmias, myocardial ischemia, and stroke during surgery unless adequate alpha antagonism is provided preoperatively. The adrenal cortex secretes androgens, mineralocorticoids, and glucocorticoids. Conditions associated with excess or insufficient hormone secretion may lead to alterations in blood pressure, changes in electrolytes, and hyper- or hypoglycemia. Careful assessment of these conditions preoperatively leads to optimization for intraoperative care and postoperative monitoring of patients with adrenal disease.
Charcot-Marie-Tooth Disease
Authors: Fritzler Anthony
Published: March 2023

Charcot-Marie-Tooth (CMT) disease is the most common inherited neuromuscular disease and presents many potential considerations for the administration of anesthesia. Type 1 CMT (CMT1) is the most common, of which 70% of cases are CMT1A. Key characteristics of all types are genetic heterogeneity, age-dependent penetrance, and variable expressivity. The most common type, CMT1A, is inherited in an autosomal dominant (AD) pattern and results from a duplication of chromosome 17, resulting in excess gene expression and overproduction of peripheral myelin protein 22 (PMP22). Diagnosis largely depends on a thorough history and physical examination, nerve conduction studies, and genetic analysis. CMT is a lifelong disease, and treatment is mainly supportive, focusing on symptom management. Anesthetic considerations include the possibility for cardiac conduction anomalies, cardiomyopathy, and impaired pulmonary function. CMT disease is a condition of chronic denervation, which prompts concerns for the use of succinylcholine and triggering agents for malignant hyperthermia (MH). All types of anesthesia have been performed successfully and safely in patients with CMT disease, and the anesthetic should be tailored to the individual needs of the patient.
Muscular Dystrophies
Authors: Berkelhamer Maura C.
Published: March 2023

This chapter outlines the distinctions in muscle dystrophy disorders and their common manifestation of muscle membrane anomalies causing respiratory embarrassment, arrhythmias, and cardiomyopathy. Rhabdomyolysis leading to hyperkalemic arrest is a risk for patients with all types of muscular dystrophies. Severe muscle contraction with triggering anesthetic agents is seen in patients with myotonic dystrophy. However, patients with muscular dystrophies do not have a risk of malignant hyperthermia greater than the general population. Patients with muscular dystrophies are at risk of cardiorespiratory decompensation from the effects of anesthetic well into the postoperative period. Perioperative multidisciplinary care initiated well before the date of surgery is indicated for patients with muscular dystrophies. A strategy to approach anesthetizing patients with undiagnosed hypotonia is presented.
Mitochondrial Myopathies
Authors: Berkelhamer Maura C.
Published: March 2023

This chapter explores how mitochondrial disorders underlie a spectrum of diseases. Mitochondria are involved in cellular energy production and the synthesis of essential molecules for cellular function as well as apoptosis and cell death. Mitochondria membranes host the electron transport chain of protein/enzyme complexes responsible for cellular energy production. Defects in these complexes reduce the cellular energy necessary for normal organ function. The clinical presentations of mitochondrial disorders are numerous. They include mitochondrial myopathies and mitochondrial encephalopathies. Nerve cells in the brain and muscles require a great deal of energy and thus appear to be particularly affected. Because mitochondria are in every cell of the body, mitochondrial disorders can affect every organ system. It is important to recognize the clinical manifestations of these disorders and understand the effects of anesthetic drugs on mitochondrial function to prevent acidosis and metabolic crisis.
Lambert-Eaton Myasthenic Syndrome
Authors: Sam Sabrina S. , Sarrafpour Syena
Published: March 2023

Lambert-Eaton myasthenic syndrome (LEMS) is an autoimmune disorder that results in decreased release of acetylcholine at the neuromuscular junction secondary to autoantibodies against calcium channels at the presynaptic nerve terminal. Patients with LEMS generally have proximal limb muscle weakness that is worse in the lower extremities and improves with activity. LEMS is diagnosed via detailed history and physical examination along with electrophysiology. Imaging of the chest should be performed to rule out small cell lung cancer. There is no cure for LEMS not associated with malignancy; therefore, therapy is targeted at symptom relief. Firdapse and Ruzurgi were recently approved for treatment. Individuals with LEMS are sensitive to both depolarizing and nondepolarizing neuromuscular blocking drugs.
Ion Channel Myotonias, Myotonia Congenita, and Acquired Neuromyotonia
Authors: Hughes Meghan C. , Abd-Elsayed Alaa
Published: March 2023

Myotonia congenita (MG) and various ion channel myotonias all fall under the umbrella of nondystrophic myotonias (NDMs) and are distinct from myotonic dystrophy because they are caused by dysfunction of key skeletal muscle ion channels alone without any other systemic effects. NDMs are characterized by electrical myotonia, “defined as the prolongation of skeletal muscle relaxation time following sudden voluntary contraction or external mechanical stimulation.” Hyperexcitability of muscles is central to all of these disease states. The NDMs are divided into two groups: the chloride channelopathies (myotonia congenita) and the sodium channelopathies (paramyotonia congenita [PMC] and the potassium-aggravated myotonias [PAMs]). In contrast, acquired neuromyotonia is an autoimmune disease where approximately 40% of affected individuals have antibodies to voltage-gated potassium channels (VGKCs) that directly affect the neuromuscular junction.
Neuropathic Pain States
Authors: Jenkinson Robert H. , Abd-Elsayed Alaa
Published: March 2023

Neuropathic pain is defined by the International Association for the Study of Pain as “pain caused by a lesion or disease of the somatosensory nervous system.” Due to this wide neuroanatomic territory, a variety of distinct neuropathic pain diagnoses exist that have unique presentations, including painful diabetic peripheral neuropathy, complex regional pain syndrome, phantom limb pain, lumbar radiculopathy, chronic postsurgical pain, postherpetic neuralgia, and trigeminal neuralgia. Neuropathic pain is not on its own a diagnosis but rather a classification of diagnostic entities. While some neuropathic pain states have distinct imaging or laboratory findings, many are entirely clinically diagnosed based on a neuroanatomically plausible distribution as well as specific qualities and characteristics of the discomfort. As a category, neuropathic pain presents a challenge for clinicians in both diagnosis and treatment. It contributes significantly to the global health burden, and roughly 10% of the general population suffers from some form of chronic neuropathic pain.
Phantom Limb Pain
Authors: Mauer Kim , Abd-Elsayed Alaa
Published: March 2023

This chapter on phantom limb pain and its pathophysiology describes the pathophysiology that is known about phantom limb syndrome. Phantom limb syndrome is defined as the ability to feel sensations and even pain in a limb or limbs that no longer exist. Neuroplasticity, the ability of our neuronal pathways to modify and adjust, is likely responsible for some of the characteristics of phantom limb syndrome. Overall, the etiology and pathophysiologic mechanisms of phantom pain are not clearly defined. Some common treatments for the condition are described as well as a more in-depth description of neuroplasticity and mirror box therapy.
Postoperative Epidural Analgesia
Authors: Rushmer Timothy , Abd-Elsayed Alaa
Published: March 2023

This chapter covers the use of epidurals for postoperative analgesia: indications, contraindications, American Society of Regional Anesthesia and Pain Medicine guidelines for patients on anticoagulants, relevant anatomy and physiology, factors affecting spread, additives, and complications. Epidural analgesia is often used in postoperative patients as part of a multimodal analgesic plan. Epidurals are usually placed prior to surgery in patients undergoing large incisions and/or patients expected to have issues with pain control postoperatively. Occasionally, epidurals are placed after surgery in patients without contraindications or recent anticoagulation. One common situation is patients who develop postoperative ileus and have high opioid requirements, as epidurals can facilitate reduced opioid requirements and improvement of the ileus.
Patient-Controlled Analgesia
Authors: Jenkinson Robert H. , Abd-Elsayed Alaa
Published: March 2023

Patient-controlled analgesia (PCA) is one of the most common methods used to provide postoperative pain control to patients. The most common form of PCA utilizes a programmable infusion pump to deliver a standard dose of intravenous opioid on demand by the patient. Although intravenous PCA administration is the most commonly utilized route for acute pain, epidural and intrathecal PCA use has become increasingly popular. PCA provides better pain control and a higher rate of patient satisfaction than traditional intermittent analgesic administration by medical staff. It can be a safe and effective method of providing patients with pain relief but still requires regular monitoring and should be individualized to each patient.
Systemic Multimodal Analgesia
Authors: Lennertz Richard , Bevil Kristin
Published: March 2023

Multimodal analgesia refers to the use of medications with different mechanisms of action to provide analgesia. The combination of medications should promote analgesia while limiting unwanted side effects. While there has been widespread adoption of multimodal analgesia, evidence of its efficacy is conflicting. Opioids provide potent analgesia and continue to play an important role in pain management. In addition, several systemic medications may be used to provide multimodal analgesia. Acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) are the most broadly supported medications used in these regimens. Some evidence supports the use of ketamine and dexmedetomidine. Lidocaine infusions may be effective in colorectal and abdominal surgeries but have not been compared against common regional techniques.
Continuous Spinal and Epidural Anesthesia
Authors: Girma Brook , Kaye Alan D.
Published: March 2023

Neuroaxial anesthesia was first conceived in the 19th century and became an integral part of anesthesia in the 20th century, providing an alternative for general anesthesia. Local anesthetic and opioids are generally administered in the epidural space (epidural anesthesia) or intrathecal space (spinal anesthesia). Some studies have shown that neuroaxial anesthesia was associated with lower postoperative morbidity, diminished surgical stress response demonstrated by decreased hyperglycemia, lower cortisol levels, and some lower pro-inflammatory cytokines. In this regard, it is important to know the anatomy, risks, and indications for neuroaxial blockade and the differences between epidural and spinal anesthesia, which are discussed in detail.
Neurolytic and Nonneurolytic Blocks in Pain Management
Authors: Rushmer Timothy , Abd-Elsayed Alaa
Published: March 2023

As this chapter discusses, neurolytic blocks involve the destruction of afferent somatic or sympathetic nerves. This can be accomplished with a variety of methods, including radio-frequency ablation, cryoablation, and injection of alcohol, glycerol, or phenol. Choice of technique depends on the target and indications for the procedure. Diagnostic nerve blocks should precede most neurolytic blocks to ensure the correct target (and adequate relief of the patient’s pain) prior to neurolysis. Common neurolytic blocks include celiac plexus block, superior hypogastric plexus block, ganglion impar block, lumbar sympathetic block, and stellate ganglion block. Nonneurolytic blocks with local anesthetics can be performed not only for perioperative pain, but also in the setting of chronic or cancer pain. Generally, nonneurolytic blocks provide short-term relief, but can provide pain relief beyond the duration of the local anesthetic in chronic pain patients. Nonneurolytic blocks also allow for opportunities for physical therapy and strengthening and can help reduce opioid use in acute and chronic pain.
Neuromuscular Blockers
Authors: Nathani Harsh , Gwam Chike
Published: March 2023

Neuromuscular blocking agents are used to facilitate tracheal intubation, relax abdominal muscles, maintain immobility during surgery and facilitate mechanical ventilation. Neuromuscular blockers are advantageous for airway management in the pediatric population; however, clinicians must be cautious of the age-dependent changes in the sensitivity to, metabolism of, and adverse reactions of these agents. Clinicians should consider the physiological and pharmacological differences between children and adults when using these agents in the pediatric populations to better titrate neuromuscular blockade when indicated. Commonly used agents are divided into two subcategories: depolarizing agents and nondepolarizing agents; each has their advantages and disadvantages. The reversal of nondepolarizing agents with acetylcholinesterase inhibitors has also been well studied, as has that of sugammadex.
Problems in Intubation and Extubation
Authors: Horvath Balazs , Kloesel Benjamin
Published: March 2023

Endotracheal intubation and extubation in neonates, infants, and children are frequently challenging due to the developing anatomy and physiology. Congenital malformations, syndromes, and coexisting pathology of other organ systems may present additional unique difficulty during securing the airway and ensuring adequate ventilation and oxygenation. Meticulous attention to the steps and anticipating potential pitfalls of airway management from the first moment of encountering the patient until discharge from the recovery room are keys to safe patient care. This chapter reviews the most common problems during endotracheal intubation and extubation that are related to both the normal development and pathological conditions of pediatric patients.
Metabolism, Fluid Distribution, and Renal Function
Authors: Kremen Elizabeth , Keshavarzi Sahel
Published: March 2023

Pediatric physiology differs keenly from adult physiology in a number of ways. This chapter looks at differences in metabolism, fluid distribution, and renal function. Neonates and acutely ill children are more vulnerable to depletion of glycogen stores. Metabolism of medications is often prolonged in neonates due to fewer active enzymes; is more rapid in children; and reaches adult values in adolescence. Infants have a higher body water percentage by weight than adults do. Infants also have more fluid in the extracellular compartment, including the intravascular space, compared to adults. Renal filtration function and urine-concentrating ability in neonates are much less developed than in adults, leading to prolonged clearance rates of renally excreted drugs. Similarly, neonates are also more vulnerable to fluid perturbations and electrolyte imbalances until their homeostatic autoregulatory mechanisms more fully develop.
Congenital Heart and Major Vascular Disease
Authors: Sinton Jamie W.
Published: March 2023

Approximately 6 per 1000 live births are affected by congenital heart disease (CHD). While there is no mechanism for decreasing the prevalence of infants born with CHD, mortality from CHD has declined in countries with a higher sociodemographic index. Anesthetic and perioperative care during corrective or palliative cardiac surgery contribute to successful outcomes. Just as the physiology of pediatric patients differs from adults, so does their anesthetic management. This chapter describes and classifies CHD into acyanotic, cyanotic, major vascular disease, and pulmonary hypertension. Discussion of anatomy, physiology, natural history, palliative or treatment course, and anesthetic management is provided in other chapters.
Congenital Diaphragmatic Hernia
Authors: Wasson Cassandra , Diaz Christina D.
Published: March 2023

Congenital diaphragmatic hernias (CDHs) are characterized by herniation of abdominal contents into the chest cavity due to a developmental defect of the diaphragm. This inhibits growth of the lungs and leads to pulmonary hypertension. The most common hernia is posterolateral, or Bochdalek. CDH is usually an isolated finding but can be associated with structural abnormalities, chromosomal defects, or single-gene disorders. The majority of CDH are diagnosed prenatally with routine ultrasound. Herniation of the liver into the chest is a poor prognostic factor. The ratio of observed-to-expected lung area to head circumference helps predict survival outcomes. For severe cases diagnosed prenatally, fetoscopic endoluminal tracheal occlusion is an experimental option. Less severe cases are delivered at a tertiary center and intubated immediately after delivery to avoid insufflation of the stomach, and an orogastric tube is used to decompress the stomach. Permissive hypercapnic ventilation with low inspiratory pressures is utilized as aggressive ventilation may cause a contralateral pneumothorax. CDH is a physiologic emergency, not a surgical emergency, unless herniated bowel is ischemic. Increased abdominal pressure, cephalad displacement of the diaphragm, decreased functional residual capacity, and compression of the inferior vena cava should be anticipated intraoperatively after hernia reduction. Overall survival rate is 70%–90% neonates without extracorporeal membrane oxygenation, but they have long-term morbidity.
Necrotizing Enterocolitis
Authors: Wasson Cassandra , Diaz Christina D.
Published: March 2023

Necrotizing enterocolitis (NEC) is one of the most common diseases in neonates, affecting primarily preterm infants less than 32 weeks’ gestational age. It has a mortality rate of up to 30%. Those patients that survive frequently have a number of morbidities, including short-bowel syndrome and neurodevelopmental delays. The initial signs and symptoms include feeding intolerance, abdominal distention, and bloody stools. Abdominal x-ray findings of portal venous gas and pneumatosis intestinalis (gas within the bowel wall) are pathognomonic for NEC. It is managed either medically or surgically based on the clinical presentation and severity of the illness. Intraoperative anesthetic management requires considerations for premature neonates and special considerations for the disease process itself. Postoperatively, these patients require continued monitoring and management in a neonatal intensive care unit.
Hydrocephalus
Authors: Sinton Jamie W.
Published: March 2023

Hydrocephalus and cerebrospinal fluid (CSF) diversion operations are the most common pediatric neurosurgical procedures. Hydrocephalus may be congenital, associated with a syndrome, or occur as a result of trauma, infection, or tumor. Additionally, some syndromes associated with hydrocephalus include Arnold-Chiari and myelomeningocele. Hydrocephalus may be noncommunicating or communicating. Noncommunicating hydrocephalus is obstructive, and communicating hydrocephalus occurs when CSF absorption is inadequate. Symptoms may be insidious and subtle. Routine surveillance with head circumference measurements during well-child checks at the pediatrician may raise the first suspicion of hydrocephalus. Open fontanelles afford infants additional protection against dangerous increases in intracranial pressure and herniation. This chapter covers etiologies, pathophysiology, and surgical management of hydrocephalus.
Juvenile Idiopathic Arthritis
Authors: Fritzler Anthony
Published: March 2023

Juvenile idiopathic arthritis (JIA) is a wide-ranging term and includes all forms of arthritis that begin before 16 years of age, persist for more than 6 weeks, and are of unknown origin. The systemic form of JIA is associated with the most anesthesia-related concerns. Most forms of JIA are thought to have an autoimmune etiology. Systemic JIA is unique in that there is an absence of autoantibodies. It is considered to be a polygenic autoinflammatory syndrome. Diagnosis of JIA is based on history, symptoms, multiple laboratory studies, and imaging studies. Treatment of all forms typically consists of nonsteroidal anti-inflammatory drugs (NSAIDs) and disease-modifying antirheumatic drugs (DMARDs). Methotrexate is the standard first-line agent. Elective procedures should only be performed when the patient is in stable remission. Potential anesthetic concerns are considerable and multisystemic in nature, including the cardiovascular and pulmonary systems. Airway management can present a challenge, as cervical spine abnormalities such as ankylosis and subluxation are common. In the perioperative period, it is essential to be cognizant of the constant potential for an exacerbation of systemic JIA or the development of macrophage activation syndrome (MAS), which can be life threatening.
Pediatric Management of Postoperative Nausea and Vomiting
Authors: Santana Lisgelia
Published: March 2023

Postoperative nausea and vomiting (PONV) are frequent but often missed complications and a source of significant morbidity. Various independent risk factors have been implicated in the development of pediatric PONV, including the use of opioids and volatile anesthetics and higher pain scores. The use of multimodal anesthesia, including nonopioid analgesics and total intravenous drugs, in favor of volatile anesthetics and an appropriate regimen of prophylactic pharmacotherapy could potentially mitigate the risk of PONV. Frequently administered drug classes for the prevention of PONV include 5-HT3 (5-hydroxytryptamine, serotonin) antagonists, corticosteroids, and anticholinergics. This chapter provides comprehensive information on the risk factors contributing to the occurrence of PONV in children, outlines the current opinion on the drugs that are commonly used, and provides an overview of the guidelines that are used to help establish the prophylaxis and treatment of pediatric PONV.
Mechanisms of Placental Transfer and Placental Transfer of Specific Drugs
Authors: Ahmed Muhammad Fayyaz , Kamel Ihab
Published: March 2023

The placenta is closely involved in exchange of fetal and maternal blood for transfer of waste, nutrients, gases, and drugs. The placenta allows bidirectional transfer of various substances through an imperfect barrier involving complex transport mechanism. The permeability of the membrane and availability of certain processes limits movement freely. Modes of placental transfer include simple diffusion, facilitated diffusion, active transport, and pinocytosis. Multiple factors impact the placental transfer for nutrients, drugs, and waste substances, such as degree of ionization and molecular size. Knowledge of the drugs that cross the placenta is critical for ensuring fetal safety during pregnancy and delivery.
Other Blocks
Authors: Stram Mark L.
Published: March 2023

Although typically epidural (and intrathecal) anesthesia are considered “first-line” modalities for management of labor pain, there are times when these neuraxial blocks are not possible. This may be due to lack of an experienced provider, as is common in rural areas and undeveloped countries, or there may be contraindications for providing such blocks (e.g., previous spine surgery or a coagulation disorder). The parturient may be unwilling to consider a neuraxial block. An obstetrician typically performs paracervical and pudendal blocks during the first and second stages of labor, respectively. The lumbar sympathetic block is an advanced regional analgesia technique performed by an experienced anesthesia provider during the first stage of labor. These three techniques and important complications are described in this chapter on alternatives to neuraxial labor analgesia.
Physiology of Labor
Authors: Ejiogu Nwadiogo , Orlando Barbara
Published: March 2023

The main changes observed during labor are essentially a considerable increase in cardiac output, even more than during pregnancy, associated with a worsening of the increase in minute ventilation seen during pregnancy. Major airway edema is common and can affect intubating conditions in the case of general anesthesia, which can be worsened by a severe increase in the risk of gastric aspiration during labor, despite the strict fasting (nil per os, NPO) guidelines with clear liquid diet. Last, increased intracranial pressure (ICP) during the pushing period with the Valsalva maneuver can jeopardize the parturient’s health in case of preexisting neurologic conditions.
Influence of Anesthetic Technique on Labor
Authors: Im Mary J. , Kamel Ihab
Published: March 2023

Epidural analgesia is the gold standard modality to alleviate pain associated with labor. Over the past decades, an association between epidural analgesia and undesirable obstetric effects has been reported. Reported undesirable obstetric effects include prolonged labor, increased incidence of assisted vaginal delivery, and increased rate of cesarean delivery. Currently, evidence indicates that the only undesirable effect of labor epidural analgesia is a prolongation of the second stage of labor, with concerns about maternal and neonatal outcomes associated with the duration of the second stage of labor or active pushing. The risks of postpartum hemorrhage, advanced degree of perineal lacerations, chorioamnionitis, as well as neonatal complications, have been observed to be higher with the prolongation of second stage. Prolongation of the second stage of labor can be minimized by using a low-concentration local anesthetic solution for epidural analgesia.
Ectopic Pregnancy
Authors: Noguera Edward
Published: March 2023

Obstetric hemorrhage is leading cause of maternal death. Ectopic pregnancy is the leading cause of maternal deaths due to hemorrhagic complications (10%–15%). A fertilized egg that grows outside of the uterus, an ectopic pregnancy, can lead to rupture of the structure in which the egg is developing, leading to hemorrhage. The prevalence of ectopic pregnancy is 6%–16%. The implantation sites are the fallopian tubes (95%), ovary (3%), and abdomen (2%). A ruptured ectopic pregnancy is a surgical emergency that can cause hemorrhagic shock. Anesthesiologists should be prepared for the management of shock intraoperatively when caring for patients with an ectopic pregnancy.
Heart Disease
Authors: Ahmed Muhammad Fayyaz , Kamel Ihab
Published: March 2023

Cardiovascular disease during pregnancy can lead to significant maternal-fetal morbidity and mortality. Cardiovascular disease affects 1%–4% of pregnancies in United Stated annually. Congenital heart disease, pulmonary hypertension, valvular heart disease, and cardiomyopathy are among the common ailments that can affect patient outcomes. Understanding of the pathophysiology of various cardiac diseases is the quintessential foundation for proper and safe management during and after delivery. The interplay between the physiologic changes of pregnancy, individual patient disease severity, and the pathophysiology of each disease dictates an individualized multidisciplinary care geared toward optimizing hemodynamics and cardiac function during all phases of anesthesia administration.
Hematologic Disorders
Authors: Hyers Benjamin M. , Chung Kevin W.
Published: March 2023

Sickle cell anemia, idiopathic thrombocytopenic purpura, von Willebrand disease, disseminated intravascular coagulation, patients on anticoagulant therapy, and Rh and ABO incompatibility are common hematologic disorders and states seen during a pregnancy. Anesthesiologists caring for these patients need to consider the risk for epidural hematoma formation after placement of neuraxial anesthesia. The perioperative care for these patients involves a multidisciplinary team to ensure the safety of the patient and her fetus. Preoperative assessment and anesthetic considerations are individualized for each patient and are specific to each disease process. Therefore, it is important to understand the pathophysiology and treatment of these diseases.
Neurologic Disorders
Authors: Brakoniecki Katrina , Chung Kevin W.
Published: March 2023

As the medical management of women with underlying neurologic diseases advances, many of these women are carrying healthy babies to term with the aid of maternal fetal medicine colleagues. These patients are particularly complex to manage in both the peripartum and perioperative periods. The physiologic changes of pregnancy can greatly affect these individuals’ anesthetic management. Whether on the labor and delivery floor or in the operative suite, it is important to consider these patients’ respective disease processes and their relationship to neuraxial techniques, pharmacological agents, and general hemodynamics. This chapter discusses those disease processes.
Antepartum Hemorrhage
Authors: Im Mary J. , Kamel Ihab
Published: March 2023

Antepartum bleeding can lead to adverse fetal and maternal consequences if not identified and treated promptly. Antepartum vaginal bleeding may occur in as many as 25% of pregnant women. Maintaining a high index of suspicion in high-risk patients is key to early identification. Proper management will vary according to the etiology of antepartum hemorrhage. The most common etiologies of antepartum hemorrhage are placenta previa, placenta abruption, vasa previa, and uterine rupture. Women presenting with active, ongoing obstetric hemorrhage require stabilization and preparation for delivery by cesarean section. Proper obstetric management and special anesthetic considerations are essential for maternal and fetal well-being.
Preterm Labor
Authors: Taco Erika , Spencer Kevin
Published: March 2023

Prematurity is the leading cause of neonate morbidity and mortality. In the United States, the preterm rate varies widely, from 7.5% to 13.6%, with an average of 11%. Modifiable risk factors should be controlled to avoid preterm labor. Preterm labor is defined as regular uterine contractions accompanied by a change in cervical dilation, effacement, or both occurring at less than 37 and more than 20 weeks’ gestational age. Tocolytic therapy should be used judiciously based on obstetric goals. Anesthesiologists and obstetricians should maintain close communication to improve the fetal outcomes and decrease long-term complications in neonates. Anesthetic management entails similar goals to that of a full-term labor and delivery by favoring neuraxial techniques in the absence of its contraindications.
Multiple Gestation
Authors: Knoblock Steven , Younger Joshua D.
Published: March 2023

Three percent of all births are now a result of twin pregnancies, and 0.2% of pregnancies are higher multiples. It is important to become familiar with the needs and challenges a multiple-gestation pregnancy may present. An anesthesia provider in the obstetric environment is tasked with not only caring for the laboring patient but also tailoring an anesthetic for the most desirable outcomes for the expectant multiples. This necessitates familiarity with how a multiple-gestation pregnancy physiologically differs from a single gestation. It is also essential to acknowledge the fetal effects of a multiple-gestation pregnancy. Last, anesthesia optimization in the setting of multiple gestation is critical to the success during the labor and delivery course.
Nerve Injury Monitoring During ENT Surgery
Authors: Burnett Garrett W.
Published: March 2023

Intraoperative nerve monitoring during otolaryngologic surgery allows for identification of nerves susceptible to injury during surgery using electromyography. Commonly monitored nerves include the facial nerve (VII), recurrent laryngeal nerve (X), and spinal accessory nerve (XI). Specialized equipment is necessary for electromyographic (EMG) monitoring of these nerves, and collaboration between the otolaryngologist and anesthesiologist is required. Medications such as neuromuscular blockade should be avoided in order not to disrupt EMG signals. Careful electrode placement and vigilant monitoring are important components of intraoperative neuromonitoring. Early recognition of postoperative nerve injury is crucial, particularly in recurrent laryngeal nerve injury, which may result in stridor, airway obstruction, or aspiration.
Ophthalmologic Anesthesia
Authors: Teixeira Camila , Minear Steven
Published: March 2023

The goals of ophthalmologic anesthesia include the maintenance of a stable intraocular pressure (IOP) and avoidance of oculocardiac reflex (OCR) in a comfortable, motionless patient. Regional anesthesia in ophthalmologic surgery has several advantages over general anesthesia, such as postoperative analgesia enhancement and nausea and vomiting reduction. Due to its akinetic feature, it also has some advantages over topical anesthesia. To reduce the risk of injury to the major structures in the intraconal space, recently the peribulbar block has been replacing retrobulbar anesthesia. However, even with remarkable widespread use, regional anesthesia can elevate the IOP, and eye blocks often represent a threat for patients at risk of expulsive hemorrhage, especially those with open globe injury. In conclusion, the anesthesia technique choice can be a challenging decision that should be made individually depending on patient cooperation, surgeon skills, type of procedure, and resource availability at the assigned facility.
Anesthesia for MRI
Authors: Cosic Adi , Abouhassan Soozan S.
Published: March 2023

Magnetic resonance imaging (MRI) is an imaging modality that has revolutionized body imaging and has been present for over 40 years. It continues to undergo advancements. Making use of powerful magnetic fields, it is a useful tool in the diagnosis of soft tissue ailments and abnormalities that might otherwise not be seen with other imaging. However, its qualities pose a unique challenge to the anesthesiologist providing care in the radiology suite, which is an unfamiliar setting with inherent risk. Additionally, MRI-created magnetic fields are often many times the strength of Earth’s and require thoughtfulness in regard to how the anesthetics will be provided, the monitors and their position, and potential patient implants.