Obstructive Sleep Apnea

Epidemiology and Classification

Epidemiology

• Most common sleep-related breathing disorder
• Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency of approximately 20%–30% in men and 10%–15% in women (note that rates are similar between men and postmenopausal women)
• Prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency increases with age with a plateau Plateau Cardiac Physiology after the seventh decade.
• Obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity ( body mass index Body mass index An indicator of body density as determined by the relationship of body weight to body height. Bmi=weight (kg)/height squared (m2). Bmi correlates with body fat (adipose tissue). Their relationship varies with age and gender. For adults, bmi falls into these categories: below 18. 5 (underweight); 18. 5-24. 9 (normal); 25. 0-29. 9 (overweight); 30. 0 and above (obese). Obesity [ BMI BMI An indicator of body density as determined by the relationship of body weight to body height. Bmi=weight (kg)/height squared (m2). Bmi correlates with body fat (adipose tissue). Their relationship varies with age and gender. For adults, bmi falls into these categories: below 18. 5 (underweight); 18. 5-24. 9 (normal); 25. 0-29. 9 (overweight); 30. 0 and above (obese). Obesity] ≥ 30 kg/m²) correlates strongly with obstructive sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep apnea (OSA).
• African Americans are more likely to develop OSA independent of age and BMI BMI An indicator of body density as determined by the relationship of body weight to body height. Bmi=weight (kg)/height squared (m2). Bmi correlates with body fat (adipose tissue). Their relationship varies with age and gender. For adults, bmi falls into these categories: below 18. 5 (underweight); 18. 5-24. 9 (normal); 25. 0-29. 9 (overweight); 30. 0 and above (obese). Obesity.
• Global prevalence Prevalence The total number of cases of a given disease in a specified population at a designated time. It is differentiated from incidence, which refers to the number of new cases in the population at a given time. Measures of Disease Frequency more than doubled from 1990 to 2010 (may relate to increased detection and/or increased rates of obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity)

Classification

• Sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep apnea:
  • Repeated cessation of breathing for > 10 seconds during sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep
  • Results in sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep interruption, fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia, and daytime sleepiness Daytime sleepiness Narcolepsy 
• Obstructive sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep apnea:
  • Flaccid soft tissues obstruct airway Airway ABCDE Assessment, leading to hypoventilation during sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep
• Central sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep apnea (CSA):
  • Airflow limitation and/or ventilation Ventilation The total volume of gas inspired or expired per unit of time, usually measured in liters per minute. Ventilation: Mechanics of Breathing problem mediated by aberrant central nervous system Central nervous system The main information-processing organs of the nervous system, consisting of the brain, spinal cord, and meninges. Nervous System: Anatomy, Structure, and Classification
  • May be hyper- or hypoventilation 
• Mixed sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep apnea:
  • Combination of both OSA and CSA
• Obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity hypoventilation syndrome (OHS):
  • Extra adipose tissue Adipose tissue Adipose tissue is a specialized type of connective tissue that has both structural and highly complex metabolic functions, including energy storage, glucose homeostasis, and a multitude of endocrine capabilities. There are three types of adipose tissue, white adipose tissue, brown adipose tissue, and beige or “brite” adipose tissue, which is a transitional form. Adipose Tissue: Histology in obese individuals leads to hypoventilation while awake.
  • Also known as Pickwickian syndrome

Risk Factors and Pathophysiology

Risk factors

• Obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity:
  • Condition of metabolic or nutritional nature
  • Characterized by accumulation of excess body fat
  • Assessed by BMI BMI An indicator of body density as determined by the relationship of body weight to body height. Bmi=weight (kg)/height squared (m2). Bmi correlates with body fat (adipose tissue). Their relationship varies with age and gender. For adults, bmi falls into these categories: below 18. 5 (underweight); 18. 5-24. 9 (normal); 25. 0-29. 9 (overweight); 30. 0 and above (obese). Obesity, ≥ 30 kg/m² is considered obese
• Congenital Congenital Chorioretinitis or acquired craniofacial abnormalities: 
  • Abnormalities of the jaw Jaw The jaw is made up of the mandible, which comprises the lower jaw, and the maxilla, which comprises the upper jaw. The mandible articulates with the temporal bone via the temporomandibular joint (TMJ). The 4 muscles of mastication produce the movements of the TMJ to ensure the efficient chewing of food. Jaw and Temporomandibular Joint: Anatomy ( micrognathia Micrognathia Abnormally small jaw. Pierre Robin Sequence or retrognathia Retrognathia A physical misalignment of the upper (maxilla) and lower (mandibular) jaw bones in which either or both recede relative to the frontal plane of the forehead. Marfan Syndrome)
  • Tonsillar hyperplasia Hyperplasia An increase in the number of cells in a tissue or organ without tumor formation. It differs from hypertrophy, which is an increase in bulk without an increase in the number of cells. Cellular Adaptation
  • Macroglossia Macroglossia The presence of an excessively large tongue, which may be congenital or may develop as a result of a tumor or edema due to obstruction of lymphatic vessels, or it may occur in association with hyperpituitarism or acromegaly. It also may be associated with malocclusion because of pressure of the tongue on the teeth. Wilms Tumor
  • Neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess circumference > 43 cm (17 in.)
  • Previous airway Airway ABCDE Assessment surgery
  • Nasal polyps ( benign Benign Fibroadenoma lesions of the nasal mucosa Nasal mucosa The mucous lining of the nasal cavity, including lining of the nostril (vestibule) and the olfactory mucosa. Nasal mucosa consists of ciliated cells, goblet cells, brush cells, small granule cells, basal cells (stem cells) and glands containing both mucous and serous cells. Nose Anatomy (External & Internal) that typically present with postnasal drip and nasal obstruction; usually due to chronic inflammation Chronic Inflammation Inflammation) or septal deviation
  • Hypertrophied pharyngeal muscles Pharyngeal Muscles The muscles of the pharynx are voluntary muscles arranged in two layers. The external circular layer consists of three constrictors (superior, middle, and inferior). The internal longitudinal layer consists of the palatopharyngeus, the salpingopharyngeus, and the stylopharyngeus. During swallowing, the outer layer constricts the pharyngeal wall and the inner layer elevates pharynx and larynx. Pharynx: Anatomy
• Advanced age: increased incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency > 65 years
• Alcohol consumption before sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep
• Use of sedatives
• Acromegaly Acromegaly A condition caused by prolonged exposure to excessive human growth hormone in adults. It is characterized by bony enlargement of the face; lower jaw (prognathism); hands; feet; head; and thorax. The most common etiology is a growth hormone-secreting pituitary adenoma. Acromegaly and Gigantism: excess production of growth hormone by the pituitary Pituitary A small, unpaired gland situated in the sella turcica. It is connected to the hypothalamus by a short stalk which is called the infundibulum. Hormones: Overview and Types gland
• Hypothyroidism Hypothyroidism Hypothyroidism is a condition characterized by a deficiency of thyroid hormones. Iodine deficiency is the most common cause worldwide, but Hashimoto’s disease (autoimmune thyroiditis) is the leading cause in non-iodine-deficient regions. Hypothyroidism:
  • Deficiency of T3 T3 A T3 thyroid hormone normally synthesized and secreted by the thyroid gland in much smaller quantities than thyroxine (T4). Most T3 is derived from peripheral monodeiodination of T4 at the 5′ position of the outer ring of the iodothyronine nucleus. The hormone finally delivered and used by the tissues is mainly t3. Thyroid Hormones and T4 T4 The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (monoiodotyrosine) and the coupling of iodotyrosines (diiodotyrosine) in the thyroglobulin. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form triiodothyronine which exerts a broad spectrum of stimulatory effects on cell metabolism. Thyroid Hormones hormones Hormones Hormones are messenger molecules that are synthesized in one part of the body and move through the bloodstream to exert specific regulatory effects on another part of the body. Hormones play critical roles in coordinating cellular activities throughout the body in response to the constant changes in both the internal and external environments. Hormones: Overview and Types
  • Clinical features of hypothyroidism Hypothyroidism Hypothyroidism is a condition characterized by a deficiency of thyroid hormones. Iodine deficiency is the most common cause worldwide, but Hashimoto’s disease (autoimmune thyroiditis) is the leading cause in non-iodine-deficient regions. Hypothyroidism are primarily due to the accumulation of matrix substances and a decreased metabolic rate.
• Poor muscle tone Muscle tone The state of activity or tension of a muscle beyond that related to its physical properties, that is, its active resistance to stretch. In skeletal muscle, tonus is dependent upon efferent innervation. Skeletal Muscle Contraction due to brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification injury or neuromuscular disease

Pathophysiology

• Sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep results in loss of the wakefulness drive to breathe, decreased motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology output to respiratory muscles, decreased upper airway Airway ABCDE Assessment (UA) size, increased UA resistance Resistance Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow. Ventilation: Mechanics of Breathing.
  • Leads to apneic and hypopneic episodes in susceptible individuals
• Apneic and hypopneic episodes → increased arterial carbon dioxide (CO₂) levels ( hypercapnia Hypercapnia A clinical manifestation of abnormal increase in the amount of carbon dioxide in arterial blood. Neonatal Respiratory Distress Syndrome) → stimulates respiratory efforts against the narrowed upper airway Airway ABCDE Assessment until the individual is awakened
  • Hypercapnia Hypercapnia A clinical manifestation of abnormal increase in the amount of carbon dioxide in arterial blood. Neonatal Respiratory Distress Syndrome → respiratory acidosis Acidosis A pathologic condition of acid accumulation or depletion of base in the body. The two main types are respiratory acidosis and metabolic acidosis, due to metabolic acid build up. Respiratory Acidosis
  • Increased respiratory efforts are achieved by sympathetic effects → secondary tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children and hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension
  • Reduced airflow results in pulmonary hypoxia Hypoxia Sub-optimal oxygen levels in the ambient air of living organisms. Ischemic Cell Damage which triggers pulmonary vasoconstriction Vasoconstriction The physiological narrowing of blood vessels by contraction of the vascular smooth muscle. Vascular Resistance, Flow, and Mean Arterial Pressure (Euler-Liljestrand mechanism) → pulmonary hypertension Pulmonary Hypertension Pulmonary hypertension (PH) or pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary arterial pressure, which can lead to chronic progressive right heart failure. Pulmonary hypertension is grouped into 5 categories based on etiology, which include primary PAH, and PH due to cardiac disease, lung or hypoxic disease, chronic thromboembolic disease, and multifactorial or unclear etiologies. Pulmonary Hypertension → cor pulmonale Cor Pulmonale Cor pulmonale is right ventricular (RV) dysfunction caused by lung disease that results in pulmonary artery hypertension. The most common cause of cor pulmonale is chronic obstructive pulmonary disease. Dyspnea is the usual presenting symptom. Cor Pulmonale

Clinical Presentation

• Often, the patient is unaware of their symptoms and is brought in by their spouse or sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep partner.
• Symptoms may include:
  • Nocturnal restlessness 
  • Vivid, strange, or threatening dreams 
  • Interrupted sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep, frequent awakenings
  • Snoring, choking, or gasping while asleep
  • Nocturia Nocturia Frequent urination at night that interrupts sleep. It is often associated with outflow obstruction, diabetes mellitus, or bladder inflammation (cystitis). Arginine Vasopressin Disorders (Diabetes Insipidus)
  • Diminished ability to concentrate
  • Cognitive deficits
  • Irritability and other changes in mood
  • Morning headaches
  • Daytime sleepiness Daytime sleepiness Narcolepsy

Diagnosis

• Suspicion is raised based on a thorough history, including information from bed partner/spouse. A common questionnaire to estimate pretest probability Probability Probability is a mathematical tool used to study randomness and provide predictions about the likelihood of something happening. There are several basic rules of probability that can be used to help determine the probability of multiple events happening together, separately, or sequentially. Basics of Probability of OSA is:
  • STOP-BANG
    • Do you Snore loud enough to be heard through closed doors, or your bed partner elbows you for snoring at night?
    • Do you often feel Tired, fatigued, or sleepy during the day?
    • Has anyone Observed you stop breathing, or choking/gasping during your sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep?
    • Do you have or are you being treated for high blood Pressure?
    • B MI MI MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction > 35 kg/m²
    • Age older than 50 years?
    • Neck size large: male > 17-inch shirt collar and female > 16-inch shirt collar
    • Gender: male?
  • Low risk of OSA: Yes to 0–2 questions
  • Intermediate risk of OSA: Yes to 3–4 questions
  • High risk of OSA: Yes to 5–8 questions
• Polysomnography Polysomnography Simultaneous and continuous monitoring of several parameters during sleep to study normal and abnormal sleep. The study includes monitoring of brain waves, to assess sleep stages, and other physiological variables such as breathing, eye movements, and blood oxygen levels which exhibit a disrupted pattern with sleep disturbances. Physiology of Sleep (PSG): gold-standard diagnostic test for OSA
  • Patient is monitored on video overnight while hooked up to electrocardiogram Electrocardiogram An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG) ( ECG ECG An electrocardiogram (ECG) is a graphic representation of the electrical activity of the heart plotted against time. Adhesive electrodes are affixed to the skin surface allowing measurement of cardiac impulses from many angles. The ECG provides 3-dimensional information about the conduction system of the heart, the myocardium, and other cardiac structures. Electrocardiogram (ECG)), electroencephalogram ( EEG EEG Seizures), pulse oximetry, and nasal prongs to assess snoring, sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep architecture, and physiologic changes during sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep. 
  • The severity of OSA can be determined from the Apnea/Hypopnea index (AHI), which is calculated as the number of apneic episodes per hour of sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep during a sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep study.
    • AHI ≥ 5 = mild OSA
    • AHI ≥ 15 = moderate OSA
    • AHI > 30 = severe OSA
  • If EEG EEG Seizures monitoring is used, then the arousal index ( AI AI Conditions in which the production of adrenal corticosteroids falls below the requirement of the body. Adrenal insufficiency can be caused by defects in the adrenal glands, the pituitary gland, or the hypothalamus. Adrenal Insufficiency and Addison Disease) can be calculated as the number of arousals per hour of sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep.

Management

Conservative management

Improving modifiable risk factors:

• Weight loss Weight loss Decrease in existing body weight. Bariatric Surgery 
• Cessation of consumption of sedatives/alcohol
• Oral appliances or splints during sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep to prevent airway Airway ABCDE Assessment collapse/obstruction

Positive airway Airway ABCDE Assessment pressure devices

• Continuous positive airway Airway ABCDE Assessment pressure ( CPAP CPAP A technique of respiratory therapy, in either spontaneously breathing or mechanically ventilated patients, in which airway pressure is maintained above atmospheric pressure throughout the respiratory cycle by pressurization of the ventilatory circuit. Noninvasive Ventilation): most effective treatment method
  • Noninvasive ventilation Ventilation The total volume of gas inspired or expired per unit of time, usually measured in liters per minute. Ventilation: Mechanics of Breathing that uses positive air pressure to keep airways open
  • Improves restlessness, snoring, cognition, daytime somnolence and quality Quality Activities and programs intended to assure or improve the quality of care in either a defined medical setting or a program. The concept includes the assessment or evaluation of the quality of care; identification of problems or shortcomings in the delivery of care; designing activities to overcome these deficiencies; and follow-up monitoring to ensure effectiveness of corrective steps. Quality Measurement and Improvement of life
  • Low adherence rate
• Bilevel positive airway Airway ABCDE Assessment pressure ( BiPAP BiPAP Noninvasive Ventilation): provides a higher pressure during inhalation and a lower one during exhalation

Surgery

• Resection of nasal polyps 
• Nasal septal deviation correction
• Reduction of enlarged tonsils Tonsils Tonsillitis or hypertrophied inferior turbinates Turbinates The scroll-like bony plates with curved margins on the lateral wall of the nasal cavity. Turbinates, also called nasal concha, increase the surface area of nasal cavity thus providing a mechanism for rapid warming and humidification of air as it passes to the lung. Nose Anatomy (External & Internal)
• Uvulopalatopharyngoplasty: resection of uvula Uvula A fleshy extension at the back of the soft palate that hangs above the opening of the throat. Peritonsillar Abscess, soft palate Soft palate A movable fold suspended from the posterior border of the hard palate. The uvula hangs from the middle of the lower border. Palate: Anatomy, tonsils Tonsils Tonsillitis, and excess oropharyngeal tissue
• Maxillomandibular advancement for patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with retrognathia Retrognathia A physical misalignment of the upper (maxilla) and lower (mandibular) jaw bones in which either or both recede relative to the frontal plane of the forehead. Marfan Syndrome or micrognathia Micrognathia Abnormally small jaw. Pierre Robin Sequence
• Tracheotomy Tracheotomy Surgical incision of the trachea. Basic Procedures: only used in severe refractory life-threatening OSA
• Bariatric surgery Bariatric surgery Bariatric surgery refers to a group of invasive procedures used to surgically reduce the size of the stomach to produce early satiety, decrease food intake (restrictive type) and/or alter digestion, and artificially induce malabsorption of nutrients (malabsorptive type). The ultimate goal of bariatric surgery is drastic weight loss. Bariatric Surgery

Clinical Relevance

Possible complications of obstructive sleep Sleep A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility. Physiology of Sleep apnea:

• Hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension: condition defined as a systolic blood pressure ≥ 130 mm MM Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies. Multiple Myeloma Hg and/or a diastolic blood pressure ≥ 80 mm MM Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies. Multiple Myeloma Hg
• Stroke: acute neurological condition characterized by an impairment in the arterial blood supply to brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification tissue. Usually due to a focal vascular cause, such as an embolism or the rupture of an aneurysm Aneurysm An aneurysm is a bulging, weakened area of a blood vessel that causes an abnormal widening of its diameter > 1.5 times the size of the native vessel. Aneurysms occur more often in arteries than in veins and are at risk of dissection and rupture, which can be life-threatening. Thoracic Aortic Aneurysms 
• Dementia Dementia Major neurocognitive disorders (NCD), also known as dementia, are a group of diseases characterized by decline in a person’s memory and executive function. These disorders are progressive and persistent diseases that are the leading cause of disability among elderly people worldwide. Major Neurocognitive Disorders: term used to group diseases and conditions characterized by a decline in memory Memory Complex mental function having four distinct phases: (1) memorizing or learning, (2) retention, (3) recall, and (4) recognition. Clinically, it is usually subdivided into immediate, recent, and remote memory. Psychiatric Assessment, language, problem-solving, and other executive functioning skills
• Pulmonary hypertension Pulmonary Hypertension Pulmonary hypertension (PH) or pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary arterial pressure, which can lead to chronic progressive right heart failure. Pulmonary hypertension is grouped into 5 categories based on etiology, which include primary PAH, and PH due to cardiac disease, lung or hypoxic disease, chronic thromboembolic disease, and multifactorial or unclear etiologies. Pulmonary Hypertension: condition of chronically elevated mean pulmonary arterial pressure Pulmonary Arterial Pressure Pulmonary Hypertension Drugs ≥ 20 mm MM Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies. Multiple Myeloma Hg
• Cor pulmonale Cor Pulmonale Cor pulmonale is right ventricular (RV) dysfunction caused by lung disease that results in pulmonary artery hypertension. The most common cause of cor pulmonale is chronic obstructive pulmonary disease. Dyspnea is the usual presenting symptom. Cor Pulmonale: also known as right-sided heart failure Right-Sided Heart Failure Ebstein’s Anomaly, a condition characterized by an alteration in the structure and function of the right ventricle of the heart due to a primary disorder of the respiratory system
• Respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure: insufficient levels of oxygen in the systemic bloodstream, due to inadequate oxygenation of blood or inadequate ventilation Ventilation The total volume of gas inspired or expired per unit of time, usually measured in liters per minute. Ventilation: Mechanics of Breathing or both
• Cardiac disorders:
  • Arrhythmia: abnormality in the rate or rhythm of the heartbeat
  • Myocardial infarction Myocardial infarction MI is ischemia and death of an area of myocardial tissue due to insufficient blood flow and oxygenation, usually from thrombus formation on a ruptured atherosclerotic plaque in the epicardial arteries. Clinical presentation is most commonly with chest pain, but women and patients with diabetes may have atypical symptoms. Myocardial Infarction: ischemic damage to the myocardium Myocardium The muscle tissue of the heart. It is composed of striated, involuntary muscle cells connected to form the contractile pump to generate blood flow. Heart: Anatomy, which occurs when blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure is reduced or completely obstructed to a part of the heart
  • Sudden cardiac death Sudden cardiac death Cardiac arrest is the sudden, complete cessation of cardiac output with hemodynamic collapse. Patients present as pulseless, unresponsive, and apneic. Rhythms associated with cardiac arrest are ventricular fibrillation/tachycardia, asystole, or pulseless electrical activity. Cardiac Arrest: sudden, unexpected death as a result of cardiac arrest Cardiac arrest Cardiac arrest is the sudden, complete cessation of cardiac output with hemodynamic collapse. Patients present as pulseless, unresponsive, and apneic. Rhythms associated with cardiac arrest are ventricular fibrillation/tachycardia, asystole, or pulseless electrical activity. Cardiac Arrest. This occurs within 1 hour of symptom onset. Usually caused by acute coronary syndrome