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Hypercapnia
Hypercapnia (from the Greek ''hyper'' = "above" or "too much" and ''kapnos'' = "smoke"), also known as hypercarbia and CO2 retention, is a condition of abnormally elevated carbon dioxide (CO2) levels in the blood. Carbon dioxide is a gaseous product of the body's metabolism and is normally expelled through the lungs. Carbon dioxide may accumulate in any condition that causes hypoventilation, a reduction of alveolar ventilation (the clearance of air from the small sacs of the lung where gas exchange takes place) as well as resulting from inhalation of CO2. Inability of the lungs to clear carbon dioxide, or inhalation of elevated levels of CO2, leads to respiratory acidosis. Eventually the body compensates for the raised acidity by retaining alkali in the kidneys, a process known as "metabolic compensation". Acute hypercapnia is called acute hypercapnic respiratory failure (AHRF) and is a medical emergency as it generally occurs in the context of acute illness. Chronic hypercapnia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chronic Obstructive Pulmonary Disease
Chronic obstructive pulmonary disease (COPD) is a type of progressive lung disease characterized by long-term respiratory symptoms and airflow limitation. The main symptoms include shortness of breath and a cough, which may or may not produce mucus. COPD progressively worsens, with everyday activities such as walking or dressing becoming difficult. While COPD is incurable, it is preventable and treatable. The two most common conditions of COPD are emphysema and chronic bronchitis and they have been the two classic COPD phenotypes. Emphysema is defined as enlarged airspaces ( alveoli) whose walls have broken down resulting in permanent damage to the lung tissue. Chronic bronchitis is defined as a productive cough that is present for at least three months each year for two years. Both of these conditions can exist without airflow limitation when they are not classed as COPD. Emphysema is just one of the structural abnormalities that can limit airflow and can exist without ai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Respiratory Acidosis
Respiratory acidosis is a state in which decreased ventilation (hypoventilation) increases the concentration of carbon dioxide in the blood and decreases the blood's pH (a condition generally called acidosis). Carbon dioxide is produced continuously as the body's cells respire, and this CO2 will accumulate rapidly if the lungs do not adequately expel it through pulmonary alveolus, alveolar ventilation. Alveolar hypoventilation thus leads to an increased PaCO2, ''Pa''CO2 (a condition called hypercapnia). The increase in ''Pa''CO2 in turn decreases the HCO3−/''Pa''CO2 ratio and decreases pH. Types Respiratory acidosis can be acute or chronic. * In ''acute respiratory acidosis'', the ''Pa''CO2 is elevated above the upper limit of the reference range (over 6.3 kPa or 45 mm Hg) with an accompanying acidemia (pH 30 mEq/L). Causes Acute Acute respiratory acidosis occurs when an abrupt failure of ventilation occurs. This failure in ventilation may be caused by depre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-invasive Ventilation
Non-invasive ventilation (NIV) is the use of breathing support administered through a face mask, nasal mask, or a helmet. Air, usually with added oxygen, is given through the mask under positive pressure; generally the amount of pressure is alternated depending on whether someone is breathing in or out. It is termed "non-invasive" because it is delivered with a mask that is tightly fitted to the face or around the head, but without a need for tracheal intubation (a tube through the mouth into the windpipe). While there are similarities with regard to the interface, NIV is not the same as continuous positive airway pressure (CPAP), which applies a single level of positive airway pressure throughout the whole respiratory cycle; CPAP does not deliver ventilation but is occasionally used in conditions also treated with NIV. Non-invasive ventilation is used in acute respiratory failure caused by a number of medical conditions, most prominently chronic obstructive pulmonary disease (CO ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypoventilation
Hypoventilation (also known as respiratory depression) occurs when ventilation is inadequate (''hypo'' meaning "below") to perform needed respiratory gas exchange. By definition it causes an increased concentration of carbon dioxide (hypercapnia) and respiratory acidosis. Hypoventilation is not synonymous with respiratory arrest, in which breathing ceases entirely and death occurs within minutes due to hypoxia and leads rapidly into complete anoxia, although both are medical emergencies. Hypoventilation can be considered a precursor to hypoxia and its lethality is attributed to hypoxia with carbon dioxide toxicity. Causes Hypoventilation may be caused by: *A medical condition such as stroke affecting the brainstem *Voluntary breath-holding or underbreathing, for example, hypoventilation training or the Buteyko method. *Medication or drugs, typically when taken in accidental or intentional overdose. Opioids and benzodiazepines in particular are known to cause respiratory depress ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Dioxide
Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. It is a trace gas in Earth's atmosphere at 421 parts per million (ppm), or about 0.04% by volume (as of May 2022), having risen from pre-industrial levels of 280 ppm. Burning fossil fuels is the primary cause of these increased CO2 concentrations and also the primary cause of climate change.IPCC (2022Summary for policy makersiClimate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asterixis
Asterixis, more colloquially referred to as flapping tremor, is a tremor of the hand when the wrist is extended, sometimes said to resemble a bird flapping its wings. This motor disorder is characterized by an inability to maintain a position, which is demonstrated by jerking movements of the outstretched hands when bent upward at the wrist. The tremor is caused by abnormal function of the diencephalic motor centers in the brain, which regulate the muscles involved in maintaining position. Asterixis is associated with various encephalopathies due especially to faulty metabolism. The term derives from the Greek ''a'', "not" and ''stērixis'', "fixed position". Asterixis is the inability to maintain posture due to a metabolic encephalopathy. This can be elicited on physical exam by having the patient extend their arms and bend their hands back. With a metabolic encephalopathy, the patient is unable to hold their hands back resulting in a “flapping” motion consistent with aste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rebreather
A rebreather is a breathing apparatus that absorbs the carbon dioxide of a user's breathing, exhaled breath to permit the rebreathing (recycling) of the substantially unused oxygen content, and unused inert content when present, of each breath. Oxygen is added to replenish the amount metabolised by the user. This differs from open-circuit breathing apparatus, where the exhaled gas is discharged directly into the environment. The purpose is to extend the breathing endurance of a limited gas supply, and, for covert military use by frogmen or observation of underwater life, eliminating the bubbles produced by an open circuit system and in turn not scaring wildlife being filmed. A rebreather is generally understood to be a portable unit carried by the user. The same technology on a vehicle or non-mobile installation is more likely to be referred to as a life-support system. Rebreather technology may be used where breathing gas supply is limited, such as underwater or in space, where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dyspnea
Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathing, breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity", and recommends evaluating dyspnea by assessing the intensity of its distinct sensations, the degree of distress and discomfort involved, and its burden or impact on the patient's activities of daily living. Distinct sensations include effort/work to breathe, chest tightness or pain, and "air hunger" (the feeling of not enough oxygen). The tripod position is often assumed to be a sign. Dyspnea is a normal symptom of heavy physical exertion but becomes disease, pathological if it occurs in unexpected situations, when resting or during light exertion. In 85% of cases it is due to asthma, pneumonia, cardiac ischemia, interstitial lung disease, congesti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Respiratory Disease
Respiratory diseases, or lung diseases, are pathology, pathological conditions affecting the organs and tissues that make gas exchange difficult in Breathing, air-breathing animals. They include conditions of the respiratory tract including the trachea, bronchi, bronchioles, Pulmonary alveolus, alveoli, pulmonary pleurae, pleurae, pleural cavity, the nerves and muscles of respiration. Respiratory diseases range from mild and self-limiting, such as the common cold, influenza, and pharyngitis to life-threatening diseases such as bacterial pneumonia, pulmonary embolism, tuberculosis, Asthma, acute asthma, lung cancer, and severe acute respiratory syndromes, such as Coronavirus disease 2019, COVID-19. Respiratory diseases can be classified in many different ways, including by the organ or tissue involved, by the type and pattern of associated signs and symptoms, or by the cause of the disease. The study of respiratory disease is known as pulmonology. A physician who specializes in res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Death
Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain death is sometimes used as a legal definition of death. The remains of a former organism normally begin to decompose shortly after death. Death is an inevitable process that eventually occurs in almost all organisms. Death is generally applied to whole organisms; the similar process seen in individual components of an organism, such as cells or tissues, is necrosis. Something that is not considered an organism, such as a virus, can be physically destroyed but is not said to die. As of the early 21st century, over 150,000 humans die each day, with ageing being by far the most common cause of death. Many cultures and religions have the idea of an afterlife, and also may hold the idea of judgement of good and bad deeds in one's life ( h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unconsciousness
Unconsciousness is a state in which a living individual exhibits a complete, or near-complete, inability to maintain an consciousness, awareness of self and environment or to respond to any human or environmental Stimulus (physiology), stimulus. Unconsciousness may occur as the result of traumatic brain injury, Cerebral hypoxia, brain hypoxia (inadequate oxygen, possibly due to a brain infarction or cardiac arrest), severe intoxication with drugs that Depressant, depress the activity of the central nervous system (e.g., Alcohol (drug), alcohol and other hypnotic or sedative drugs), severe fatigue, pain, Anesthesia, anaesthesia, and other causes. Loss of consciousness should not be confused with the notion of the Unconscious mind, psychoanalytic unconscious, cognitive processes that take place outside awareness (e.g., implicit cognition), and with altered states of consciousness such as sleep, delirium, hypnosis, and other altered states in which the person responds to stimuli, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convulsions
A convulsion is a medical condition where the body muscles contract and relax rapidly and repeatedly, resulting in uncontrolled shaking. Because epileptic seizures typically include convulsions, the term ''convulsion'' is sometimes used as a synonym for ''seizure''. However, not all epileptic seizures lead to convulsions, and not all convulsions are caused by epileptic seizures. Convulsions are also consistent with an electric shock and improper enriched air scuba diving. Non-epileptic convulsions have no relation with epilepsy, and are caused by non-epileptic seizures. Convulsion is a common term generally describing uncontrollable muscle contractions. The term convulsion has been used interchangeably with the word "seizure". Seizures may cause a person to have convulsions, but this is not always the case. Convulsion is a type of seizure that involves bursts of electrical activity in the brain. Occasionally the reason for a convulsion is unfamiliar. A convulsion may be caused ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
