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Negative Pressure Pulmonary Edema
Negative-pressure pulmonary edema (NPPE), also known as Postobstructive Pulmonary Edema, is a clinical phenomenon that results from the generation of large negative pressures in the airways during attempted inspiration against some form of obstruction of the upper airways. The most common reported cause of NPPE reported in adults is laryngospasm, while the most implicated causes in children are infectious croup and epiglottitis. The large negative pressures created in the airways by inhalation against an upper airway obstruction can lead to fluid being drawn from blood vessels supplying the lungs into the alveoli, causing pulmonary edema and impaired ability for oxygen exchange (hypoxemia). The main treatment for NPPE is supportive care in an intensive care unit and can be fatal without intervention. Physiology NPPE develops as a result of significant negative pressure generated in the chest cavity by inspiration against an upper airway obstruction. These negative pressures in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laryngospasm
Laryngospasm is an uncontrolled or involuntary muscular contraction (spasm) of the vocal folds. The condition typically lasts less than 60 seconds, but in cases partial blocking it may last 20 to 30 minutes and hinder inspiration, while exhalation remains easier. It may be triggered when the vocal cords or the area of the trachea below the vocal folds detects the entry of water, mucus, blood, or other substance. It is characterized by stridor or retractions. Some people have frequent laryngospasms, whether awake or asleep. In an ear, nose, and throat practice, it is typically seen in people who have silent reflux disease. It is also a well known, infrequent, but serious perioperative complication. It is likely that more than 10% of drownings involve laryngospasm, but the evidence suggests that it is not usually effective at preventing water from entering the trachea. Signs and symptoms Laryngospasm is characterized by involuntary spasms of the laryngeal muscles. It is ass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lymphatic System
The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphatic or lymphoid organs, and lymphoid tissues. The vessels carry a clear fluid called lymph (the Latin word ''lympha'' refers to the deity of fresh water, "Lympha") back towards the heart, for re-circulation. Unlike the circulatory system that is a closed system, the lymphatic system is open. The human circulatory system processes an average of 20 litres of blood per day through capillary filtration, which removes plasma from the blood. Roughly 17 litres of the filtered blood is reabsorbed directly into the blood vessels, while the remaining three litres are left in the interstitial fluid. One of the main functions of the lymphatic system is to provide an accessory return route to the blood for the surplus three litres. The other main function is that of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suxamethonium Chloride
Suxamethonium chloride, also known as suxamethonium or succinylcholine, or simply sux by medical abbreviation, is a medication used to cause short-term paralysis as part of general anesthesia. This is done to help with tracheal intubation or electroconvulsive therapy. It is administered by injection, either into a vein or into a muscle. When used in a vein, onset of action is generally within one minute and effects last for up to 10 minutes. Common side effects include low blood pressure, increased saliva production, muscle pain, and rash. Serious side effects include malignant hyperthermia and allergic reactions. It is not recommended in people who are at risk of high blood potassium or a history of myopathy. Use during pregnancy appears to be safe for the baby. Suxamethonium is in the neuromuscular blocker family of medications and is of the depolarizing type. It works by blocking the action of acetylcholine on skeletal muscles. Side effects of succinylcholine chloride ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surgical Airway Management
Surgical airway management (bronchotomy or laryngotomy) is the medical procedure ensuring an open airway between a patient’s lungs and the outside world. Surgical methods for airway management rely on making a surgical incision below the glottis in order to achieve direct access to the lower respiratory tract, bypassing the upper respiratory tract. Surgical airway management is often performed as a last resort in cases where orotracheal and nasotracheal intubation are impossible or contraindicated. Surgical airway management is also used when a person will need a mechanical ventilator for a longer period. The surgical creation of a permanent opening in the larynx is referred to as laryngostomy. Surgical airway management is a primary consideration in anaesthesia, emergency medicine and intensive care medicine. Surgical methods for airway management include cricothyrotomy and tracheostomy History Asclepiades of Bithynia is credited with being the first person who proposed bronch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stridor
Stridor (Latin for "creaking or grating noise") is a high-pitched extra-thoracic breath sound resulting from turbulent air flow in the larynx or lower in the bronchial tree. It is different from a stertor which is a noise originating in the pharynx. Stridor is a physical sign which is caused by a narrowed or obstructed airway. It can be inspiratory, expiratory or biphasic, although it is usually heard during inspiration. Inspiratory stridor often occurs in children with croup. It may be indicative of serious airway obstruction from severe conditions such as epiglottitis, a foreign body lodged in the airway, or a laryngeal tumor. Stridor should always command attention to establish its cause. Visualization of the airway by medical experts equipped to control the airway may be needed. Causes Stridor may occur as a result of: * foreign bodies (e.g., aspirated foreign body, aspirated food bolus); * infections (e.g., epiglottitis, retropharyngeal abscess, croup); * subglottic stenos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anaphylaxis
Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the following: an itchy rash, throat closing due to swelling which can obstruct or stop breathing; severe tongue swelling which can also interfere with or stop breathing; shortness of breath, vomiting, lightheadedness, loss of consciousness, low blood pressure, and medical shock. These symptoms typically start in minutes to hours and then increase very rapidly to life-threatening levels. Urgent medical treatment is required to prevent serious harm or death, even if the patient has used an epipen or has taken other medications in response, and even if symptoms appear to be improving. Common causes include allergies to insect bites and stings, allergies to foods – including nuts, milk, fish, shellfish, eggs and some fresh fruits or dried fruits; a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuromuscular-blocking Drug
Neuromuscular-blocking drugs block neuromuscular transmission at the neuromuscular junction, causing paralysis of the affected skeletal muscles. This is accomplished via their action on the post-synaptic acetylcholine (Nm) receptors. In clinical use, neuromuscular block is used adjunctively to anesthesia to produce paralysis, firstly to paralyze the vocal cords, and permit intubation of the trachea, and secondly to optimize the surgical field by inhibiting spontaneous ventilation, and causing relaxation of skeletal muscles. Because the appropriate dose of neuromuscular-blocking drug may paralyze muscles required for breathing (i.e., the diaphragm), mechanical ventilation should be available to maintain adequate respiration. Patients are still aware of pain even after full conduction block has occurred; hence, general anesthetics and/or analgesics must also be given to prevent anesthesia awareness. Nomenclature Neuromuscular blocking drugs are often classified into two br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sugammadex
Sugammadex, sold under the brand name Bridion, is a medication for the reversal of neuromuscular blockade induced by rocuronium and vecuronium in general anaesthesia. It is the first selective relaxant binding agent (SRBA). It is marketed by Merck. The most common side effects include cough, airway problems due to the anaesthesia wearing off, reduced blood pressure and other complications such as changes in heart rate. Text was copied from this source which is © European Medicines Agency. Reproduction is authorized provided the source is acknowledged. Medical uses Sugammadex is indicated for the reversal of neuromuscular blockade induced by rocuronium or vecuronium. Pharmacology Pharmacodynamics Sugammadex is a modified γ-cyclodextrin, with a lipophilic core and a hydrophilic periphery. This gamma cyclodextrin has been modified from its natural state by placing eight carboxyl thio ether groups at the sixth carbon positions. These extensions extend the cavity size allowing gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrostatics
Fluid statics or hydrostatics is the branch of fluid mechanics that studies the condition of the equilibrium of a floating body and submerged body " fluids at hydrostatic equilibrium and the pressure in a fluid, or exerted by a fluid, on an immersed body". It encompasses the study of the conditions under which fluids are at rest in stable equilibrium as opposed to fluid dynamics, the study of fluids in motion. Hydrostatics is a subcategory of fluid statics, which is the study of all fluids, both compressible or incompressible, at rest. Hydrostatics is fundamental to hydraulics, the engineering of equipment for storing, transporting and using fluids. It is also relevant to geophysics and astrophysics (for example, in understanding plate tectonics and the anomalies of the Earth's gravitational field), to meteorology, to medicine (in the context of blood pressure), and many other fields. Hydrostatics offers physical explanations for many phenomena of everyday life, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Croup
Croup, also known as laryngotracheobronchitis, is a type of respiratory infection that is usually caused by a virus. The infection leads to swelling inside the trachea, which interferes with normal breathing and produces the classic symptoms of "barking/brassy" cough, inspiratory stridor and a hoarse voice. Fever and runny nose may also be present. These symptoms may be mild, moderate, or severe. Often it starts or is worse at night and normally lasts one to two days. Croup can be caused by a number of viruses including parainfluenza and influenza virus. Rarely is it due to a bacterial infection. Croup is typically diagnosed based on signs and symptoms after potentially more severe causes, such as epiglottitis or an airway foreign body, have been ruled out. Further investigations, such as blood tests, X-rays and cultures, are usually not needed. Many cases of croup are preventable by immunization for influenza and diphtheria. Most cases of croup are mild and the child can b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Afterload
Afterload is the pressure that the heart must work against to eject blood during systole (ventricular contraction). Afterload is proportional to the average arterial pressure. As aortic and pulmonary pressures increase, the afterload increases on the left and right ventricles respectively. Afterload changes to adapt to the continually changing demands on an animal's cardiovascular system. Afterload is proportional to mean systolic blood pressure and is measured in millimeters of mercury (mm Hg). Hemodynamics Afterload is a determinant of cardiac output. Cardiac output is the product of stroke volume and heart rate. Afterload is a determinant of stroke volume (in addition to preload, and strength of myocardial contraction). Following Laplace's law, the tension upon the muscle fibers in the heart wall is the pressure within the ventricle multiplied by the volume within the ventricle divided by the wall thickness (this ratio is the other factor in setting the afterload). The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Preload (cardiology)
In cardiac physiology, preload is the amount of sarcomere stretch experienced by cardiac muscle cells, called cardiomyocytes, at the end of ventricular filling during diastole. Preload is directly related to ventricular filling. As the relaxed ventricle fills during diastole, the walls are stretched and the length of sarcomeres increases. Sarcomere length can be approximated by the volume of the ventricle because each shape has a conserved surface-area-to-volume ratio. This is useful clinically because measuring the sarcomere length is destructive to heart tissue. It requires cutting out a piece of cardiac muscle to look at the sarcomeres under a microscope. It is currently not possible to directly measure preload in the beating heart of a living animal. Preload is estimated from end-diastolic ventricular pressure and is measured in millimeters of mercury (mmHg). Estimating preload Though not exactly equivalent to the strict definition of ''preload,'' end-diastolic volume is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
