bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical, Fire, and Explosion Hazards
Authors: Sheikh Suleman , Watt Stacey
Published: March 2023

The primary initiative of all surgical interactions is patient safety and reducing the occurrence of fires, explosions, and electrical currents as such events increase mortality correlated to burn size, age, and inhalation injury and may result in death and disfigurement. In 2008, the annual incidence of operating room (OR) fires as reported by the Pennsylvania Patient Safety Authority was approximately 650 or 0.63/157,545 operations. In the past years, the diligent research and implementation of new guidelines have decreased the incidence of fires in the operating room to an estimated 0.32/100,000 operations. This chapter discusses the principles, contributing factors, and prevention and management of surgical fires, explosives, and electrical currents.
Controlled Hypotension
Authors: Alexander Anthony , Gloss Feodor J.
Published: March 2023

Controlled or induced hypotension is an anesthetic technique that involves deliberate lowering of the blood pressure to a systolic pressure of 80–90 mm Hg or mean arterial pressure (MAP) to 50–65 mm Hg or 30% less than baseline. The goals of this technique include reducing operative blood loss and improving surgical visibility and thus decreasing operative time. Deep anesthesia with combinations of volatile agent, propofol, or opioid infusions is one approach to providing hypotension. Alternatively, dedicated hypotensive agents such as β-blockers, calcium channel blockers, and vasodilators may be used to achieve these goals. Pharmacological methods may be supplemented by postural (reverse Trendelenburg position) and ventilatory (hyperventilation) interventions. Controlled hypotension carries the theoretical risk of organ hypoperfusion with resultant cerebral, myocardial, hepatic, splanchnic, and renal ischemia. Patients should be carefully selected and attention given to those who are at increased risk of these complications. Decisions regarding the depth and duration of hypotension should be made with these preoperative considerations in mind.
High-Altitude Anesthesia
Authors: Dearden Mark
Published: March 2023

High altitude has direct deleterious effects on human physiology and induces compensatory changes that must be considered when performing anesthesia. And, if not calibrated, anesthetic equipment can malfunction. The body responds to decreased atmospheric oxygen with increased heart rate, blood pressure, minute ventilation, and red blood cell production. Symptoms of high-altitude sickness may include those of hypoxia, pulmonary edema, and central nervous system irritation. Treatment for high-altitude sickness relies on descent. When anesthesia at high altitude is contemplated, there are several important considerations. Medications that reduce respiratory drive should be used only judiciously. Supplemental oxygen should be used liberally. Regional anesthesia and total intravenous anesthesia are good choices because they are relatively unaffected. An inhalational technique should avoid nitrous, and care should be taken to assess gas vaporizers for compensation. Trapped air in the body or medical equipment will expand with rapid ascent and should be planned for in the event of aeromedical evacuation.
Central and Peripheral Nervous Systems
Authors: Nasim Syed Sohaib , Minear Steven
Published: March 2023

The nervous system comprises billions of nerve cells in the body. It is the organization of the nervous system that allows different functions to occur effortlessly. The nervous system is divided into two systems, the central and peripheral nervous systems, based on their location. The central nervous system is organized from the cerebrum to the spinal cord, with layers of communicating inputs throughout. The peripheral nervous system can either respond autonomously to sensory inputs from the body, or relay messages from the central nervous system. Cerebral blood flow and cerebral perfusion pressure are tightly autoregulated to stay consistent across a range of mean arterial pressures. The blood brain barrier is a layer of endothelium with tight junctions, excluding many peripherally circulating molecules. Lipophilic molecules penetrate this barrier better than hydrophilic compounds.
Drug Metabolism
Authors: Jeske Theodore , Knezevic Nebojsa Nick
Published: March 2023

This chapter discusses drug metabolism as being one of the key steps in pharmacokinetics. Every time your patient receives a drug, a complex process occurs. Absorption, distribution, metabolism, and excretion of a particular drug provide vital information for the treatment of your patients. Moreover, the different phases of biotransformation, first- and zero-order metabolism kinetics, bioavailability, relevant drug considerations, and dosing adjustments to keep in mind for different patient comorbidities are considered. Emphasis is also on the effects of single-nucleotide polymorphisms and interindividual drug metabolism patterns. By being familiar with a range of complex pharmacokinetic properties of the drugs used in different anesthetic procedures, patients in pain will warrant optimal plasma drug concentrations, avoidance of adverse effects, and adjustment of therapy for select patient populations.
Intracranial Pressure
Authors: Shin John S. , Bui Timothy T.
Published: March 2023

The four intracranial components that determine intracranial volume and by extension intracranial pressure (ICP) are cells, intracellular and extracellular fluid, cerebrospinal fluid, and blood. The compliance of this system allows for small increases in volume without increasing ICP. Prolonged increases in ICP greater than 15 mm Hg can lead to irreversible ischemia and brain damage. Administration of steroids preoperatively beginning 48–72 hours before surgery can reduce the edema and blood-brain barrier permeability associated with tumors. Intraoperatively, ICP can be decreased by surgical resection of the tumor, medications such as diuretics and steroids, and ventriculostomy or lumbar puncture. Decreasing cerebral blood flow (CBF) can decrease the volume of intracranial blood. This can be achieved by maximizing venous drainage, minimizing elevated intrathoracic pressure, hyperventilating, inducing hypothermia, and administering intravenous anesthetics. Postoperative complications such as seizures increase CBF and cerebral metabolic rate, leading to an increase in ICP.
Evoked Potentials
Authors: Ford Timothy , Abd-Elsayed Alaa
Published: March 2023

Evoked potentials are electrophysiologic responses of the nervous system to electrical stimuli. They involve applying a current to a sensory nerve and measuring the response on the sensory cortex with a scalp electrode. They serve as a surrogate measure for neurologic functional integrity for patients under general anesthesia during a variety of neurosurgical procedures and occasionally nonneurosurgical procedures, including cardiopulmonary bypass and deep circulatory arrest. Evoked potentials commonly monitored in the operating room include motor, sensory, visual, and auditory potentials. Changes in evoked potentials can serve as indicators for risk of neural injury and guide interventions to prevent permanent damage undertaken by both the surgeon and anesthesiologist.
Peripheral Nerve Blocks (Head)
Authors: Pride Keth , Blaine Scott
Published: March 2023

Regional anesthesia for procedures involving the head can be easily achieved through the careful application of peripheral nerve blockade. Because the head has predictable surface and bony landmarks, the blocks can easily be placed pre- and intraoperatively to provide both regional anesthesia and postoperative analgesia with minimal complications. The peripheral blockade of nerves involving the head can provide perioperative anesthesia as well as management of both perioperative pain and chronic pain. The purpose of this chapter is to provide information and recommendations on how to best perform these blocks as well as describe their indications, complications, and relevant surrounding anatomy.
Intravenous Lipid Emulsion Therapy and the American Society of Regional Anesthesia Checklist for Local Anesthetic Toxicity
Authors: Schroeder Kristopher M. , Pfaff Andrew
Published: March 2023

With the increased utilization of regional anesthesia as part of a multimodal analgesic regimen in enhanced recovery after surgery protocols, the pain practitioner must be aware of the diagnosis and management of local anesthetic systemic toxicity (LAST). The mainstay of treatment for LAST is the administration of intravenous lipid emulsion (ILE) therapy, which is provided as an initial bolus followed by an infusion. ILE works by several mechanisms, which include both a redistribution of local anesthetic from areas of toxicity to areas of metabolism and direct cardiotonic and vasoactive effects. LAST differs from other advanced cardiac life support (ACLS) scenarios as resuscitation is often prolonged, and several common code medications such as epinephrine and vasopressin should have dose reductions or be omitted entirely. The American Society of Regional Anesthesia and Pain Medicine (ASRA) maintains a checklist for the treatment of LAST, last updated in 2017. The checklist describes the diagnosis and management of suspected LAST, several risk-reducing measures to prevent LAST, and a proposed LAST rescue kit that should be readily available whenever local anesthetic is used.
Role of Regional Anesthesia in Enhanced Recovery Protocols
Authors: Schroeder Kristopher M. , Pfaff Andrew
Published: March 2023

Enhanced recovery protocols offer the promise of improved patient care while simultaneously reducing costs and hospital resource utilization. Core to the development of any successful enhanced recovery protocol is effective pain management. Opioid administration in the postoperative period may be associated with a number of adverse events (nausea, urinary retention, respiratory depression, etc.) that may hinder efforts to improve the postoperative experience and expedite hospital discharge. In contrast, the thoughtful application of regional anesthesia/analgesia techniques may benefit patients via improved pain control and reduced opioid requirements. Improvements in ultrasound imaging techniques and the proliferation of available fascial plane blocks have increased the number of patients and surgical procedures that may benefit from perioperative regional anesthesia.
Prolonged QT Syndrome
Authors: Ferguson Kris , Papapetrou Peter
Published: March 2023

Long QT syndrome is an uncommon condition and, if left untreated, can be a life-threatening condition. Patient presentation can range from asymptomatic to sudden death. The typical presentation is in younger patients, with symptoms ranging from asymptomatic to mild palpitations to cardiac arrest. Treatment is proportional to symptomatology. Outpatient medication management is directed toward minimizing factors that increase sympathetic output and β-blockade. More invasive management such as with defibrillators are life-saving for severe symptomatic disease. Anesthesia management is directed toward avoiding agents that prolong the QT interval, keeping the patient comfortable by avoiding loud noises, and minimizing pain and anxiety.
CNS Drugs for Nonanesthetic Use
Authors: Sekhri Nitin , Hui Kevin
Published: March 2023

Anesthesiologists use several classes of medications that target the central nervous system (CNS) for nonanesthetic use to treat side effects, mitigate risk of complications and treat postoperative pain. In addition, many patients will be on chronic medications that are CNS active, and understanding anesthetic implications is of the utmost importance for the practicing anesthesiologist. Of particular importance are medications used to treat patients with chronic opioid use disorder, such as methadone, naltrexone, and buprenorphine. This chapter is an overview of CNS-active medications that are commonly used outside of the operating room that are imperative to know for the physician anesthesiologist.
α2-Agonists
Authors: Shah Nimit K. , Al-Jindi Piotr
Published: March 2023

The α2-receptors bind with norepinephrine (NE) and epinephrine (E) and inhibit the release of further NE and subsequent neural firing. The two potent α2-agonists used in practice are dexmedetomidine and clonidine. Dexmedetomidine is a specific α2-adrenoceptor agonist with sedative, anxiolytic, analgesic, and sympatholytic properties. It has minimal effect on respiratory drive, which is a key advantage. It has a quick onset and short duration of action. Currently, it has only been licensed for use in intravenous infusions in the intensive care unit (ICU) for 24 hours. If used more than 24 hours, rebound hypertension is common. Following a rapid intravenous bolus (especially a high dose), it shows biphasic blood pressure response of the initial short phase of hypertension (HTN) and subsequent hypotension. Usually, the bradycardia produced by dexmedetomidine is clinically insignificant but may be significant in elderly patients, patients with heart blocks or severe cardiac diseases, and patients using heart rate–slowing medications. It is useful as a premedication, adjunct in general anesthesia (GA) and regional anesthesia (RA), ICU and procedural sedation, monitored anesthesia care (MAC) sedation, treatment and prevention of emergence delirium and postoperative shivering, and chronic pain. Clonidine has been traditionally used as an antihypertensive agent but has been found useful as an adjunct in GA and RA because of its similar properties of sedation, anxiolysis, analgesia, and sympatholysis. Other uses include treatment of opioid-induced hyperalgesia; ethyl alcohol, opioid, and nicotine withdrawal, treatment, and prevention of emergence delirium; and postanesthetic shivering. Rebound HTN and biphasic responses are seen with clonidine as well.
Antidepressants, Antiparkinson Drugs
Authors: Latimer Dustin , Cornett Elyse M.
Published: March 2023

Antidepressants are often used for a variety of conditions, including depression, anxiety, chronic pain, poor energy, and various off-label applications, among others. Serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants, and monoamine oxidase inhibitors are all types of antidepressants that are available (MAOIs). In certain cases, MAOIs are used to treat Parkinson disease, which is a clinically recognized neurodegenerative disorder that affects mostly the elderly population. L-DOPA, another Parkinson medication, is a prodrug that converts to dopamine in the brain and enhances dopaminergic action by boosting dopamine levels in the brain. It is used to treat Parkinsonism and other neurodegenerative diseases.
Antiaspiration Medications
Authors: Shah Nimit K. , Rahman Abed
Published: March 2023

Pulmonary aspiration is a rare but serious complication of anesthesia that can be benign or lead to significant mortality and morbidity in the perioperative period; thus it requires careful consideration regarding prophylactic measures. Pulmonary aspiration is defined as inhalation of oropharyngeal or gastric contents into the respiratory tract. Inhalation of solid material can lead to physical obstruction, whereas the acidity of the fluid will lead to a pneumonitis. This chapter reviews patient, surgical, and anesthetic factors that need to be taken into consideration to assess the risk of aspiration. It also reviews the optimal timing and dosing of antiaspiration medications.
Parasympathetic Nervous System
Authors: Munoz-Allen Maria E.
Published: March 2023

The parasympathetic nervous system (PSNS) is the counterpart and complement to the sympathetic nervous system (SNS) in maintaining cardiovascular, gastrointestinal, and thermal homeostasis. While activation of the SNS elicits the “fight-or-flight” response, the PSNS is more closely associated with the maintenance of organ function by modulating and/or down regulating the responses of the organism to internal and external stimuli. By utilizing our knowledge and understanding of the pharmacology of the autonomic nervous system, as it relates to the interactions of various medications that are administered during the delivery of anesthesia, we can promote and maintain safety for patients in the peri-operative period.
Anatomy of the Nervous System
Authors: Cutler Timothy , Zaky Sherif
Published: March 2023

Nociception, from the Latin noci (harm or injury), is the neural response to a noxious stimulus. It involves a four-part physiologic progression: transduction, transmission, modulation, and perception. This process results in the interpretation of pain, or “an unpleasant sensory and emotional experience associated with actual or potential tissue damage,” as defined by the International Association for the Study of Pain. Nociception occurs via a series of neurons, termed first, second, and third order, to signal an encounter with a painful stimulus from the periphery to the cerebral cortex. Neurotransmitters are released at synapses to relay both excitatory and inhibitory signals between neurons. First-order neurons are located in the dorsal root ganglion and synapse, with second-order neurons in the ipsilateral dorsal horn. Second-order neurons ascend the spinal cord, usually via the contralateral spinothalamic tract, then synapse with the third-order neurons in the thalamus. Third-order neurons finally transmit the signal to somatosensory areas I and II in the post–central gyrus of the parietal cortex or to the superior sylvian fissure.
Musculoskeletal System
Authors: Money Sarah , Aiyer Rohit
Published: March 2023

The musculoskeletal system facilitates voluntary and involuntary movement and is a core component of functional capacity, strength, and endurance. Signals for motor function descend from the cortex through the spinal cord to the motor nerve and skeletal muscle, resulting in muscle cell depolarization and contraction. The neuromuscular junction is arguably the most important point in this communication circuit, as it is the site of many paralytics necessary in anesthesia, but interference with any part of the motor signal will result in akinesia. This chapter discusses the anatomy and organization of the nervous system as it relates to musculoskeletal function.
Drug Intoxication
Authors: Smith Sarah C.
Published: March 2023

Drug intoxication presenting as a change in mental status may occur following intentional use of a recreational substance, attempt of suicide, accidental or occupational exposure, or even as a result of terrorism or deliberate poisoning by a criminal actor. The anesthesiologist must be prepared to identify and manage many forms of toxicity, particularly in the emergent setting, when victims of toxicity require airway management and other invasive procedures. History, physical examination, and laboratory studies can often identify the substance to which the patient was exposed, such that an appropriate anesthetic plan can be implemented. Depending on the source of toxicity, ongoing intensive care management in the postanesthesia period may be necessary until symptoms are adequately controlled and neurological functioning has recovered. Intoxication secondary to drugs of abuse can significantly alter the response to anesthetics and analgesics, while pain management in these patients can be particularly challenging.
Air Embolism
Authors: Linares Samuel , Nasr Ned F.
Published: March 2023

A vascular air embolism (VAE) is the entrainment of gas or exogenous air from the operative field in the arterial or venous vasculature. The incidence of VAE varies from 10% to 97% depending on the surgical procedure, being more common in neurosurgery, orthopedic shoulder surgery, and gynecological procedures. The two most important factors determining the morbidity and mortality are the volume of air and the rate of accumulation. Small amounts of air have subclinical presentation, as most is absorbed in the circulation; moderate amounts can cause pulmonary hypertension; large amounts can cause right-side heart obstruction, ventricular collapse, and death. The clinical manifestations include arrhythmias, hypotension, cardiogenic shock, dyspnea, decreased end-tidal CO2, increased end-tidal nitrogen, seizures, and altered mental status. The main goals of treatment consist of preventing further air entry, reduction of air entrained, and hemodynamic support. The anesthetic considerations consist of proper assessment in the preoperative period, as well as optimization of patient positioning. In the operating room, a precordial Doppler is the most sensitive and least invasive monitor; other diagnostic methods include end-tidal nitrogen and drop of end-tidal CO2. During the postoperative period, the patient should continue to be monitored in an intensive care unit.
Fluid Management in Neurosurgery
Authors: Naftalovich Rotem , Denis Daniel
Published: March 2023

Fluid movement within capillaries can be conceptualized by the oncotic gradient model as per the Starling law. The blood-brain barrier in the central nervous system begets the osmotic gradient as the primary driving force. The goal of fluid management during neurosurgery should be euvolemia to maintain cerebral perfusion pressure and intravascular volume using iso-osmolar crystalloids. Hypo-osmolar solutions should generally be avoided to prevent worsening cerebral edema. Hyperosmolar solutions such as mannitol and hypertonic saline can be used to preferentially draw free water from the interstitial space into the vasculature, decreasing cerebral edema and improving surgical exposure. Glucose-containing solutions should be avoided as hyperglycemia is associated with worse neurological outcomes. Prevention of vasospasm in subarachnoid hemorrhage can be managed medically with nimodipine and fluid management, with hemodynamic goals favoring perfusion. This can be achieved by the traditional “triple H” therapy of hypervolemia, hypertension, and hemodilution, but care must be taken to avoid hypervolemia-related side effects: pulmonary edema, myocardial ischemia (from increased afterload), and hyponatremia. Traumatic brain injury patients can present with significant hemodynamic instability, which further complicates their resuscitation.
Stereotactic and Gamma-Knife Techniques, Deep Brain Stimulator Placement, Intraoperative Wake-Up Techniques
Authors: Kim Roy , Abd-Elsayed Alaa
Published: March 2023

Neurosurgical procedures can often involve unique challenges for the anesthesiologist as the surgeries can often involve new technologies and take place in non–operating room settings. Gamma-knife radiosurgery is a stereotactic procedure that often takes place in a remote location and can take anywhere from six to ten hours to complete. It has the advantage of avoiding nearby healthy tissue to a greater extent than traditional methods. Deep brain stimulators are also being utilized for more than simply Parkinson’s disease. These procedures, along with extensive spine surgeries, can sometimes require an intraoperative wake-up test. Understanding the unique challenges for these procedures can help facilitate prevention of complications and ensure optimal outcomes for patients.
Bronchial and Pulmonary Circulations
Authors: Brewer Jordan , Giordano Christopher
Published: March 2023

Deoxygenated blood flows to the lungs via the pulmonary circulatory system to offload carbon dioxide in exchange for oxygen at the alveolar surfaces. This refreshed blood is returned to systemic circulation to meet the body’s metabolic demands. The lungs also require a system of perfusion, called bronchial circulation. This complex web of dual circuits depends largely on pressure gradients between atmospheric and arterial systems to drive blood flow. Ventilation strategies and hemodynamic control can affect the regional blood flow and autoregulatory functions of the pulmonary vasculature. Anesthesiologists should understand its organization and implications on physiology as they can interact with and augment its function in the operating theater.
Effects of Imbalance on Electrolytes and Organ Perfusion
Authors: Maben Sarah
Published: March 2023

Acid-base regulation is primarily controlled by the lungs via alveolar ventilation and the kidneys via bicarbonate (HCO3−) resorption or excretion. The net acid excretion in the kidney equals the bicarbonate production. Other electrolytes are affected by the systemic pH and move intra- or extracellularly to compensate. At the cellular level, potassium (K+) is the predominant intracellular cation, with an intracellular concentration of 140–150 mEq/L and a serum concentration of 3.5–5 mEq/L. Normal serum sodium (Na+) concentration is 140 mEq/L and serum chloride (Cl−) concentration is 100 mEq/L. Disproportionate changes in serum chloride concentration relative to sodium concentration indicates an acid-base disorder. Changes to serum pH affect cellular metabolism, leading to ischemia, cell death, and decreased organ perfusion.
The Anion Gap and Metabolic Acidosis
Authors: Stayner Scott , Ferguson Kris
Published: March 2023

Acidosis generally is defined as an arterial blood pH (pHa) of less than 7.35. Metabolic acidosis is due to a decrease in bicarbonate [HCO3−]. The decrease in HCO3− usually occurs secondary to one or a combination of three processes: consumption to neutralize the pHa, wasting of bicarbonate through the kidneys or gastrointestinal tract, and dilution of the extracellular compartment. The typical response to metabolic acidosis in awake and healthy patients is an increase in respiration to eliminate CO2. However, under general anesthesia, the patient will not be able to mount a respiratory response. Calculating the anion gap will help in determine the underlying cause of the metabolic acidosis so that the appropriate corrective interventions can be performed.
Lung Function and Cell Processes
Authors: Prabhakar Amit , Warth Matt
Published: March 2023

Clinicians who work in the perioperative space need to have a solid fundamental understanding of pulmonary anatomy and physiology and the unique cellular processes that allow for gas exchange and enzymatic metabolism. Pulmonary anatomy can be divided into portions that either participate in gas exchange or those that do not participate in gas exchange, also known as dead space. The respiratory epithelium is composed of a unique group of cells called pneumocytes that help to facilitate gas exchange and maintain the integrity of the pulmonary architecture. Alveolar macrophages and dendritic cells also work to provide immunologic protection.
Restrictive Lung Disease
Authors: Samuel Binoy , Merkow Justin
Published: March 2023

Restrictive lung diseases range from intrinsic to extrinsic causes and are broadly defined as decreased lung volumes manifesting as a decrease in total lung capacity (TLC), forced expiratory volume in 1 second (FEV1), and forced vital capacity (FVC). Intrinsic causes are typically a result of increased scarring, inflammation, and stiffening of the lung as compared to extrinsic causes, which are a result of forces external to the lung limiting the ability of the lungs to fully expand. Preoperative consideration for these patients includes adequate workup and optimization and treatment of the underlying etiology prior to elective surgery. Intraoperative treatment includes lung-protective ventilation strategies, avoiding high lung volumes, limiting excessive FiO2, and mitigating extrinsic factors that are contributing or playing a role in restrictive physiology. These patients are at higher risk for postoperative pulmonary complications and should be managed with care in the postoperative setting.
Respiratory Adjuncts
Authors: McMaster Michelle
Published: March 2023

Respiratory adjuvants such as heliox, nitric oxide, epoprostenol, and perioperative steroids can be used to improve ventilation/perfusion mismatching in the perioperative setting. Heliox improves ventilation by affecting air density. Nitric oxide and epoprostenol are potent vasodilators that preferentially affect ventilated pulmonary vasculature when administered via inhalation. Intraoperative steroids reduce inflammation and edema in patients with traumatic intubations and bronchospasm and can also be used in patients with chronic obstructive pulmonary disease who take chronic oral steroids.
Choice of Anesthesia/Anesthetic Techniques in Thoracic Surgery
Authors: Bialorucki Callan
Published: March 2023

The thoracic surgery patient population and surgical techniques introduce unique physiologic considerations when devising an anesthetic plan. Premedication prior to induction of anesthesia can be utilized to mitigate the risk of perioperative bronchospasm. Induction agents should be chosen on a case-by-case basis, with considerations given to propensity for reactive airway complications and concomitant cardiopulmonary disease. Thoracic surgery often utilizes one-lung ventilation techniques, which can be accomplished with a double-lumen endotracheal tube or an endobronchial blocker. One-lung ventilation, hypoxic pulmonary vasoconstriction, avoidance of acute lung injury, and postoperative pain control all complicate devising an anesthetic plan for thoracic surgical patients and can be addressed in several ways.
Advanced Anesthesia Review
Authors: Mahboobi Sohail K. , Coplai Dillon B.
Published: March 2023

One-lung ventilation (OLV) is the technique of ventilating one lung while letting the other collapse, and the list of procedures it is used for continues to grow. Techniques include bronchial blockers, mainstemming single-lumen tubes (SLTs), and—most prominently—double-lumen tubes (DLTs). To choose a DLT size, the ideal technique involves measuring the left mainstem bronchus on chest x-ray or computed tomographic scan and using a table to select the appropriate size. OLV preoperative evaluations emphasize reviewing the patient’s airway and pulmonary function, including taking special note of relevant/pulmonary imaging as well as any available pulmonary function tests. Barring patient-specific requirements, OLV is typically performed with a balanced anesthetic technique. Placement technique (direct or indirect laryngoscopy or fiber-optic) depends on the patient’s anatomy, though a fiber-optic scope is always used to confirm appropriate placement. During OLV, the deflated lung is perfused but not ventilated, causing a shunt and ventilation/perfusion (V/Q) mismatch and a fall in arterial oxygenation. Hypoxic pulmonary vasoconstriction (HPV) is the body’s physiological response to divert pulmonary blood from hypoxic to ventilated alveoli. Hypoxia during OLV is common, and the anesthesia provider should be well versed in the techniques and interventions that can be used to treat it. At the end of the procedure, the patient should be evaluated according to extubation criteria. If postoperative ventilation is required, a DLT can be replaced with a SLT for postoperative ventilation.
Thoracoscopy
Authors: Dabaliz Al-Awwab Mohammad , Stachur Christina
Published: March 2023

Video-assisted thoracoscopic surgery (VATS) techniques are used for both diagnostic and therapeutic purposes across a variety of pleural diseases, pulmonary resections, and peripheral biopsies. Other nonpulmonary indications for VATS include cardiac and esophageal surgeries. This chapter describes the indications and anesthetics management for patients undergoing thoracoscopy. Included are the preoperative, intraoperative, and postoperative considerations that will help the anesthesia provider plan a safe anesthetic and avoid common complications. We also describe important aspects of lung isolation and one lung ventilation (OLV) which are both necessary for appropriate surgical exposure, including differences with open thoracotomies, and the stepwise management of hypoxia in OLV.
Postoperative Pain
Authors: Hussain Nasir , Weaver Tristan E.
Published: March 2023

Postoperative pain, if not treated sufficiently, may progress to a pathological chronic pain syndrome, leading to significant disability and suffering. Preemptive and early treatment has been shown to decrease the incidence of chronic pain down the road. Various medication classes, including opioids, serotonin norepinephrine reuptake inhibitor (SNRIs), tricyclic antidepressant, local anesthetics, α2-agonists, nonsteroidal anti-inflammatory drugs, N-methyl-d-aspartate receptor antagonists, and agonists-antagonists, are at the perioperative consultant’s disposal when treating pain. While most medications in the immediate postoperative period will be given intravenously, other routes of administration, such as oral, epidural, intrathecal, subcutaneous, transcutaneous, transmucosal, intramuscular, and interpleural, may be appropriate under certain circumstances. Adjunctive techniques and therapies, including transcutaneous electrical nerve stimulation (TENS), cryotherapy, acupuncture, and hypnosis, may also be used in order to relieve pain and minimize opioid dosing and side effects.
Ventilator Support and Extubation Criteria
Authors: Mori Benjamin B. G. , Akintorin Abayomi
Published: March 2023

Mechanical ventilation (MV) is a vital life support measure, but prolonged use is associated with morbidity. Indications include apnea, respiratory distress, hypoxemia, and hypercapnia. MV unloads the increased work of breathing and stops the development of acidosis with respiratory depression. There are no absolute contraindications, but tension pneumothorax, bronchopleural fistula, right ventricular failure, and hypovolemic shock are relative contraindications. A thorough understanding of the different modes of MV is essential for successful application. The common terms used with MV should be known, and efforts should be focused on MV liberation as soon as the patient meets criteria for safe extubation.
Sleep Apnea
Authors: Mahboobi Sohail K.
Published: March 2023

Obstructive sleep apnea (OSA) is the most common type of sleep apnea that occurs predominantly in overweight males, but nonobese patients, females, and children can also develop this condition, particularly in the presence of certain anatomical conditions (e.g., tonsillar hypertrophy and craniofacial abnormalities). OSA is characterized by episodes of obstruction, leading to apnea and hypoxemia during sleep that can ultimately result in cardiac arrhythmias, pulmonary hypertension, and heart failure. Preoperative assessment for the presence of OSA is important and requires a detailed history, physical examination for assessment of airway, and the signs of heart failure. Optimization is required to plan and execute safe anesthesia for these patients. The STOP-BANG questionnaire provides early screening to evaluate further for the presence of OSA. These patients are prone to develop early hypoxia, can have a difficult airway, and are at high risk for postoperative respiratory complications. Regional and subarachnoid anesthesia should be considered if possible, and multimodal analgesia should be planned for general anesthesia to reduce opioid requirements and to avoid respiratory depression. Continuous positive airway pressure (CPAP) device should be used in the postoperative period. The patient should be treated with supplemental oxygen therapy with monitoring, and discharge planning should include evidence of complete recovery to baseline.
Volutrauma, Barotrauma, and Biotrauma
Authors: Mahboobi Sohail K. , Bolanos Joshua F.
Published: March 2023

Mechanical ventilation may lead to harmful effects on lungs, also known as ventilator-induced lung injury (VILI). Three types of VILI are barotrauma, volutrauma, and biotrauma. In barotrauma, there is an increase in pressure in the alveoli compared to extra-alveolar tissues, which leads to their rupture. In volutrauma, alveolar overdistension due to excessive volume creates a disruption of the alveolar basement membrane and intracellular junctions, which can result in increased capillary permeability and alveolar edema. In addition, alveoli experience trauma from shear forces due to “cyclical atelectasis” or the repetitive opening and closing of alveoli. Finally biotrauma is the release of inflammatory mediators following lung damage. Adopting lung-protective techniques such as maintaining low tidal volumes of 6–8 mL/kg of ideal body weight, plateau pressures less than 30 cm H2O and peak inspiratory pressures less than 40 cm H2O can reduce the risk of developing VILI. Muscle relaxants, extracorporeal membrane oxygenation, and ventilation in prone position are also used with some success.
Normal Anatomy of Heart and Major Vessels
Authors: Rodrigue Marc , Bandi Subramanya
Published: March 2023

Cardiac anatomy plays a vital role in its function. Basic anatomy is well described and illustrated in a numerous texts. Often, this is demonstrated as a self-activating, 4-chambered organ that circulates blood in series to the pulmonary and systemic vasculature. An intricate system of one way valves, complex blood supply system, and an automatic electrical conduction system regulates the performance of this organ with each heartbeat. An in-depth knowledge of cardiac anatomy, and the clinical implications, cannot be undervalued in the practice of anesthesiology.
Cardiac Catheterization
Authors: de Gala Virgilio , Sofjan Iwan
Published: March 2023

The growing number of types and complexity of procedures performed in the cardiac catheterization laboratories has led to an increased involvement of the anesthesiologist. Such procedures include left and right heart catheterization, coronary angiography, electrophysiological studies, implantation of pacemakers and defibrillators, and various percutaneous structural heart interventions. In addition to the anesthetic concerns related to the particular procedure and the patient’s cardiac disease, catheterization laboratories are often located outside the main operating room areas, which presents a unique set of challenges, especially in case of emergencies. This section focuses on right and left heart catheterizations, coronary angiography, and anesthesia concerns with delivering care in the catheterization laboratories.
Conduction Abnormalities and Rhythm Defects
Authors: Gray Ellyn , Sharma Archit
Published: March 2023

Cardiac arrhythmias are commonly encountered perioperatively, and these can be associated with increased perioperative risk. The causes of the conduction abnormalities and rhythm abnormalities can be reversible. Their etiologies can be classified into several broad categories, including bradyarrhythmias, supraventricular arrhythmias, ventricular arrhythmias, and inherited disorders. Inherited disorders include prolonged QT syndrome and Brugada syndrome. This chapter discusses the details of these conduction abnormalities, including perioperative considerations, medical and surgical management, and management with pacemakers and automated implanted cardioverter/defibrillators (AICDs). Diagnosis includes an electrocardiogram at minimum. Also, the management of pacemakers and AICDs are reviewed, including their indications, types and possible settings, and reprogramming perioperatively.
Ablations, Cryotherapy, and Maze Procedure
Authors: Moskal Anna
Published: March 2023

Cardiac arrhythmias are common and an important source of mortality and morbidity. Current management options include surgical and catheter ablative techniques using surgical incisions, cryotherapy, or radio-frequency (RF) energy. General indications include drug-resistant arrhythmias, drug intolerance, severe symptoms, or a desire to avoid lifelong symptoms. Ablative procedures can abolish the origins of arrhythmias by interposition of scar tissue along a reentry pathway or by isolating an ectopic area. Paroxysmal atrial fibrillation (PAF) often results from ectopic beats originating in the pulmonary veins, and ablative strategy involves pulmonary vein isolation (PVI). Catheter ablation for persistent atrial fibrillation (AF) is less effective and requires an additional ablation of sites identified during a stepwise mapping process. Surgical ablation for atrial fibrillation (i.e., Maze procedure) can be performed without an additional risk of operative mortality or major morbidity and is recommended at the time of concomitant open heart surgery to restore sinus rhythm. The Cox maze III procedure achieved high cure rates and became the surgical gold standard for the treatment of atrial fibrillation. Different ablation techniques have unique complications and requirements for anesthesia. Monitored anesthesia care (MAC) is most commonly utilized to prevent arrhythmia suppression. However, patients who are unable to lie still, flat, or tolerate the procedure under sedation may require general anesthesia. Protracted procedures involving left atrial ablation and transseptal puncture may be better performed under general anesthesia. Major complications of ablation procedures include cardiac tamponade and esophageal injury.
Heart Failure and Cardiomyopathy
Authors: Arora Lovkesh L. , Sharma Surangama
Published: March 2023

Heart failure (HF) is one of the most prevalent diseases of the elderly patient. Heart failure is defined as a clinical condition arising from impaired ventricular relaxation or systolic ejection of the cardiac ventricles. The underlying pathophysiology varies considerably, and approximately 50% of the patients suffer from HF with reduced left ventricular ejection fraction. Mortality in the perioperative period is increased in patients with HF and therefore needs careful planning and management. The role of adequate preoperative evaluation and preparation of patients with HF is vital to overall a patient’s survival. It becomes clear that the New York Heart Association classification and parameters like brain natriuretic peptide play a crucial role in risk stratification and prediction of outcome.
Systolic Versus Diastolic Dysfunction
Authors: Ahmed Andaleeb A. , Mahboobi Sohail K.
Published: March 2023

The intricate interplay between systolic and diastolic function is required for maintaining adequate cardiac output. Any impairment in systolic and diastolic function can lead to the clinical syndrome of heart failure. Isolated systolic and diastolic dysfunction are independent risk factors for adverse cardiovascular outcomes. The hallmark of systolic dysfunction is reduced ejection fraction. Diastolic dysfunction is characterized by impaired relaxation and/or increased chamber stiffness. The clinical syndrome of heart failure secondary to systolic dysfunction is termed as heart failure with reduced Ejection fraction (HFrEF), and heart failure in the presence of diastolic dysfunction with normal or near-normal ejection fraction (>50%) is termed as heart failure with preserved ejection fraction (HFpEF). Diagnosis of systolic and diastolic dysfunction is made with echocardiography.
Heart Transplantation
Authors: Leonardi James , Cormican Daniel
Published: March 2023

Cardiac transplantation is indicated in patients with end-stage heart failure; medical management alone of end-stage heart failure has an abysmal long-term prognosis. Many patients may be on mechanical circulatory support, such as a ventricular assist device (VAD), as A means to bridge the patient to transplant. Anesthetic management of patients undergoing orthotopic heart transplantation (OHT) requires great care in induction of general anesthesia of the graft recipient, specific knowledge of the surgical conduct of the transplantation procedure, and understanding of potential issues uniquely related to the immediate posttransplant period. Prognosis for cardiac transplant recipients is improving with immunosuppressive regimens to reduce the risk of allograft rejection.
Constrictive Pericarditis
Authors: Grandhi Ravi K. , Abd-Elsayed Alaa
Published: March 2023

Constrictive pericarditis (CP) is a condition caused by different etiologies, such as pericardial disease and cardiac surgery. CP is caused by a fibrotic pericardium. CP can be symmetric or asymmetric, affecting the right or left side predominantly, which affects ventricular interdependence. CP most commonly occurs after pericardial disease or cardiac surgery or for idiopathic reasons. In the developing world and immunocompromised patients, tuberculosis has to be considered. CP causes pressure on the different cardiac chambers, impairing cardiac function to different degrees depending on the severity of the condition. CP, if mild, can be treated conservatively; severe disease will require pericardiectomy.
Cardiopulmonary Bypass
Authors: Sung Kim , Arora Lovkesh L.
Published: March 2023

Cardiopulmonary bypass (CPB) is a technique that is often used in surgical procedures that involve the heart and major vessels. It is an essential method to provide a bloodless field for cardiac surgeries. This technique can support or take over the cardiac output of the patient, which allows surgeons to operate on the heart and major vessels without compromising adequate perfusion to vital organs. It is important to understand the CPB system and components to safely manage the patient as the patient goes on CPB and comes off CPB. Anesthesiologists have a critical role in managing patients’ hemodynamics, coagulation, anesthetic, and electrolyte balance while on CPB.
Ventricular Assist Devices
Authors: Patel Priyanka H. , McConnell Matthew
Published: March 2023

Ventricular assist devices (VADs) are utilized in patients with heart failure for whom medical therapy is no longer effective. The utilization of VADs in management of heart failure has been shown to be superior to medical treatment alone. The classification of VADs is broad and includes any device that assists a ventricle’s function. Common complications of VADs include right heart failure, infection, and thrombosis. Previously, cardiopulmonary resuscitation (CPR) during cardiac arrest was contraindicated in patients with VADs, but recent guidelines suggest in patients with low-flow states, CPR may be indicated. Proper evaluation of patients is essential prior to proceeding with surgical interventions.
Pulmonary Embolism
Authors: Arora Lovkesh L. , Sharma Surangama
Published: March 2023

Surgery predisposes patients to pulmonary thromboembolism even as late as 1 month postoperatively. Acute pulmonary embolism is a life-threatening condition that can lead to both acute and long-term morbidity and mortality. Despite significant advances in the prophylaxis and diagnosis of deep venous thrombosis, the mortality and recurrence rate of pulmonary embolism remain high. The clinical presentation of acute pulmonary thromboembolism ranges from shock or sustained hypotension to mild dyspnea. Pulmonary embolism may even be asymptomatic and diagnosed by imaging procedures performed for other purposes. Depending on the clinical presentation, the case fatality rate for acute pulmonary embolism ranges from 1% to 60%. Anticoagulation is the mainstay of therapy for pulmonary embolism.
Pulmonary Edema
Authors: Punia Sangini , Arora Lovkesh L.
Published: March 2023

Pulmonary edema refers broadly to the abnormal accumulation of fluid within the extravascular lung tissue, adversely affecting gas exchange across the capillary membrane. Pulmonary edema can cause acute respiratory insufficiency, resulting in a life-threatening emergency event. Although diagnostic classification differentiates between cardiogenic and noncardiogenic pulmonary edema, the pathobiology is more complex than the hydrostatic versus permeability dichotomy alone. Patients need early stabilization of oxygenation and ventilation, preferably with high-flow nasal cannula oxygen or noninvasive ventilation while the diagnostic cause is investigated with echocardiography and other testing. For the best possible patient outcomes, it is essential that physicians in all clinical areas are equipped to accurately recognize, assess, and manage patients with acute pulmonary edema.