Acute Process: Having a rapid onset and following a short, but severe course. Ammonia: A colorless gas with a very sharp odor. Ammonia is irritating to the skin, eyes, nose, throat and lungs. Exposure to high concentrations in the air can severely burn the skin, eyes, throat or lungs. In extreme cases, blindness, lung damage or death can occur. Breathing lower concentrations causes coughing and nose and throat irritation. Swallowing ammonia may burn the mouth, throat and stomach.
Apnea (central): Episodes of cessation of breathing during sleep, caused by a temporary obstruction of the infant’s airway due to relaxation of throat muscles.
Apnea (obstruction): Continuation of breathing movement despite obstruction of the airways.
Apnea of Infancy: An unexplained episode of cessation of breathing for 20 seconds or longer or a shorter respiratory pause associated with bradycardia, cyanosis, pallor and/or marked hypotonia.
Apparent Life-Threatening Event (ALTE): An episode that is frightening to the observer and is characterized by some combination of apnea (central or occasionally obstructive), color change (usually cyanotic or pallid but occasionally erythematous or plethoric), marked change in muscle tone (usually marked limpness) and choking or gagging. An infant will require significant intervention, such as vigorous shaking, mouth-to-mouth breathing or full CPR, to be revived from an ALTE.
Arousal Response: Awakening in response to some varying stimulation.
Arsenic: A metallic element that forms a number of poisonous compounds, arsenic is found in nature at low levels mostly in compounds with oxygen, chlorine and sulfur. Arsenic damages many tissues including nerves, stomach and intestines and skin. Breathing high levels can give you a sore throat and irritated lungs.
Arterial Oxygen Saturation: The point at which the level of oxygen and acidity in the infant’s arterial blood supply exceeds a standard amount. This can be tested using a blood gas measurement test.
Asphyxia: Suffocation; a lack of oxygen that produces a potentially lethal build-up of carbon dioxide waste in the tissues. Asphyxia may arise from any one of a number of causes, including inhalation of smoke or poisonous gases, obstruction of the windpipe (by water, food, vomit or a foreign object), strangulation or smothering. If it is not quickly relieved, brain damage or death ensues.
Asthma: A common disorder in which chronic inflammation of the bronchial tubes (bronchi) makes them swell, narrowing the airways. Asthma involves only the bronchial tubes and does not affect the air sacs (alveoli) or the lung tissue (the parenchyma of the lung) itself.