Hypercapnia. Hypercapnia or hypercapnea (from the Greek hyper = "above" or "too much" and kapnos = "smoke"), also known as hypercarbia, 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. Hypercapnia normally triggers a reflex which increases breathing and access to oxygen, such as arousal and turning the head during sleep. A failure of this reflex can be fatal, as in sudden infant death syndrome. Hypercapnia is the opposite of hypocapnia. Causes Hypercapnia is generally caused by hypoventilation, lung disease, or diminished consciousness. Symptoms and signs Laboratory values Hypercapnia is generally defined as a blood gas carbon dioxide level over 45 mmHg. Tolerance During diving Normal respiration in divers results in alveolar hypoventilation resulting in inadequate CO2 elimination or hypercapnia.
Skip breathing Rebreathers Stridor. Stridor (Latin for "creaking or grating noise") is a high-pitched musical breath sound resulting from turbulent air flow in the larynx or lower in the bronchial tree. It is not to be confused with 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. " Treatments The first issue of clinical concern in the setting of stridor is whether or not tracheal intubation or tracheostomy is immediately necessary. Expectant management with full monitoring, oxygen by face mask, and positioning the head on the bed for optimum conditions (e.g., 45 - 90 degrees).Use of nebulized racemic adrenaline epinephrine (0.5 to 0.75 ml of 2.25% racemic epinephrine added to 2.5 to 3 ml of normal saline) in cases where airway edema may be the cause of the stridor.
Causes Parapneumonic effusion. A parapneumonic effusion is a type of pleural effusion that arises as a result of a pneumonia, lung abscess, or bronchiectasis. There are three types of parapneumonic effusions: uncomplicated effusions, complicated effusions, and empyema. Uncomplicated effusions generally respond well to appropriate antibiotic treatment. The criteria for a complicated parapneumonic effusion include the presence of pus or Gram stain–positive pleural fluid or a pleural fluid pH <7.0. Appropriate management includes chest tube drainage (tube thoracostomy). Treatment of empyemas includes antibiotics, complete pleural fluid drainage, and reexpansion of the lung. Other treatments include the use of decortication. Diagnostic techniques available include plain film chest x-ray, computed tomography (CT), and ultrasound. Duke, J. Brittle asthma. Brittle asthma is a type of asthma distinguishable from other forms by recurrent, severe attacks. There are two subtypes divided by symptoms: Type 1 and Type 2, depending on the stability of the patient's maximum speed of expiration, or peak expiratory flow rate (PEFR).
Type 1 is characterized by sustained, chronic variability of PEFR, while type 2 is distinguished by sudden unpredictable drops in PEFR where asthma symptoms are otherwise well controlled and the function of the lungs is not substantially impaired. Brittle asthma is one of the "unstable" subtypes of "difficult asthma", a term used to characterize the less than 5% of asthma cases that do not respond to maximal inhaled treatment, including high doses of corticosteroids combined with additional therapies such as long-acting beta-2 agonists. Characteristics Treatment References Jump up ^ Holgate, Stephen T.; Homer Anton. Atelectasis. It is a very common finding in chest x-rays and other radiological studies.
It may be caused by normal exhalation or by several medical conditions. Although frequently described as a collapse of lung tissue, atelectasis is not synonymous with a pneumothorax, which is a more specific condition that features atelectasis. Acute atelectasis may occur as a post-operative complication or as a result of surfactant deficiency. In premature neonates, this leads to infant respiratory distress syndrome. Classification Atelectasis may be an acute or chronic condition.
In acute atelectasis, the lung has recently collapsed and is primarily notable only for airlessness. Chronic atelectasis Atelectasis of the middle lobe on a sagittal CT reconstruction Chronic atelectasis may take one of two forms—middle lobe syndrome or rounded atelectasis. Absorption atelectasis The atmosphere is composed of 78% nitrogen and 21% oxygen. Signs and symptoms Causes Diagnosis chest X-ray. High-altitude pulmonary edema.
High-altitude pulmonary edema (HAPE) (HAPO spelled oedema in British English) is a life-threatening form of non-cardiogenic pulmonary edema (fluid accumulation in the lungs) that occurs in otherwise healthy mountaineers at altitudes typically above 2,500 meters (8,200 ft). Some cases, however, have been reported also at lower altitudes (between 1,500–2,500 metres or 4,900–8,200 feet in highly vulnerable subjects), although what makes some people susceptible to HAPE is not currently known.
HAPE remains the major cause of death related to high-altitude exposure, with a high mortality rate in the absence of adequate emergency treatment. Symptoms Physiological and symptomatic changes often vary according to the altitude involved. The Lake Louise Consensus Definition for High-Altitude Pulmonary Edema has set widely used criteria for defining HAPE symptoms: Symptoms: at least two of: Signs: at least two of: Incidence Predisposing factors Research See also
Cyanosis. The name cyanosis, literally means "the blue disease" or "the blue condition. " It is derived from the color cyan, which comes from kyanos, the Greek word for blue. Definition A baby with a heart condition. Note purple nailbeds. Cyanosis is defined as a bluish discoloration, especially of the skin and mucous membranes, due to excessive concentration of deoxyhemoglobin in the blood caused by deoxygenation.
Cyanosis is divided into two main types: Central (around the core, lips, and tongue) and Peripheral (only the extremities or fingers). Causes Central cyanosis Acute cyanosis can be a result of asphyxiation or choking, and is one of the surest signs that respiration is being blocked. Central cyanosis may be due to the following causes: 1. 2. 3. 4. Methemoglobinemia * Note this causes "spurious" cyanosis, in that, since methemoglobin appears blue, the patient can appear cyanosed even in the presence of a normal arterial oxygen level. Polycythaemia 5. See also Asthma (disambiguation) Asthma, Asthmatic or Asthma attack may refer to: Asthma, a predisposition of the respiratory system in which the airways are predisposed to bronchoconstrictionAsthmatic, a song by Spineshank from their 2000 album Height of CallousnessAsthmatic, a song by King Adora from their 2001 album Vibrate YouAsthmatic, a person with the predispositionAsthma Attack, an instance of bronchioconstriction in an asthmaticAsthma Attack, a song by The Fiery Furnaces from their 2003 album Gallowsbird's BarkAsthma, a song by P.O.D. from their 2003 album Payable on DeathOccupational asthma or asthme is an occupational condition defined as: "a disease characterized by variable airflow limitation and/or airway hyper-responsiveness due to causes and conditions attributable to a particular occupational environment and not stimuli encountered outside the workplace"
CO₂ retention. CO2 retention is a pathophysiological process in which too little carbon dioxide is removed from the blood by the lungs. The end result is hypercapnia, an elevated level of carbon dioxide dissolved in the bloodstream. Various diseases may lead to this state; disturbed gas exchange may lead to impaired excretion of the gas. In addition, breathing air with a high carbon dioxide concentration may also lead to hypercapnia. The principal result of the increased amount of dissolved CO2 is acidosis (respiratory acidosis when caused by impaired lung function); other effects include tachycardia (rapid heart rate) seizures, coma, respiratory arrest and death. Causes As CO2 levels increase, patients exhibit a reduction in overall level of consciousness as well as respiratory effort. CO2 retention is the hallmark of type II respiratory failure.
In diving Symptoms include rapid respiration in 4-6%, rapid pulse rate, shortness of breath in 7-10% and convulsions and unconsciousness in 11-20%. Stertorous. Stertorous is a medical term used to express a respiratory sound characterized by heavy snoring or gasping. It is caused by partial obstruction of airway above the level of the larynx and by vibrations of tissue of the naso-pharynx, pharynx or soft palate. (This distinguishes it from stridor which is caused by turbulent air flow below or in the larynx). It is low pitched, nonmusical and occurs during the inspiratory phase only. In general terms it is a snoring or snuffly sound.
The patient is said to suffer from stertor. Stertorous breathing will be audible in the epileptic patient during the post-ictal phase following a tonic-clonic seizure. Causes See also Air trapping. Air trapping, also called gas trapping, is an abnormal retention of air in the lungs where it is difficult to exhale completely. It is observed in obstructive lung diseases such as asthma, bronchiolitis obliterans syndrome and chronic obstructive pulmonary diseases such as emphysema and chronic bronchitis.
Air trapping is not a diagnosis but is a presentation of an illness and can be used to find an appropriate diagnosis. Measurement and Function Exhaled volumes are measured by a pulmonary function test or simple spirometry, leading to an elevated residual volume and a measurement of forced expiratory volume. Air trapping is often incidentally diagnosed on computed tomography (CT) scanning. On expiratory films, retained hyperlucent gas will be visualised in cases of air trapping. Air trapping represents poorly aerated lung, but on its own is clinically benign.
It is a common problem for smokers who dive. References Jump up ^ U. Bronchospasm. Bronchospasm or a bronchial spasm is a sudden constriction of the muscles in the walls of the bronchioles. It is caused by the release (degranulation) of substances from mast cells or basophils under the influence of anaphylatoxins. It causes difficulty in breathing which can be very mild to severe. Inflamed airways and bronchoconstriction in asthma.
Airways narrowed as a result of the inflammatory response cause wheezing. Bronchospasms appear as the feature of asthma, chronic bronchitis, anaphylaxis, as a possible side effect of the drug pilocarpine (which is used to treat illness resulting from the ingestion of deadly nightshade as well as other things) and also as a side effect for beta blockers (used to treat hypertension) and other drugs. It can present as a sign of giardiasis. Bronchospasms are one of several conditions associated with cold housing. Bronchospasms are a serious potential complication of placing a breathing tube during general anesthesia. Cause Treatment Periodic breathing. Asthma. Asthma is thought to be caused by a combination of genetic and environmental factors. Its diagnosis is usually based on the pattern of symptoms, response to therapy over time and spirometry. It is clinically classified according to the frequency of symptoms, forced expiratory volume in one second (FEV1), and peak expiratory flow rate. Asthma may also be classified as atopic (extrinsic) or non-atopic (intrinsic) where atopy refers to a predisposition toward developing type 1 hypersensitivity reactions. Signs and symptoms Associated conditions A number of other health conditions occur more frequently in those with asthma, including gastro-esophageal reflux disease (GERD), rhinosinusitis, and obstructive sleep apnea. Psychological disorders are also more common, with anxiety disorders occurring in between 16–52% and mood disorders in 14–41%. However, it is not known if asthma causes psychological problems or if psychological problems lead to asthma. Causes Others.
Mechanical ventilation. Medical uses Respiratory therapist examining a mechanically ventilated patient on an Intensive Care Unit. Mechanical ventilation is indicated when the patient's spontaneous ventilation is inadequate to maintain life. It is also indicated as prophylaxis for imminent collapse of other physiologic functions, or ineffective gas exchange in the lungs. Because mechanical ventilation serves only to provide assistance for breathing and does not cure a disease, the patient's underlying condition should be correctable and should resolve over time. In addition, other factors must be taken into consideration because mechanical ventilation is not without its complications (see below) Common medical indications for use include: Associated risk Barotrauma — Pulmonary barotrauma is a well-known complication of positive-pressure mechanical ventilation. This includes pneumothorax, subcutaneous emphysema, pneumomediastinum, and pneumoperitoneum. Complications Positive pressure
Central sleep apnea. Definition In pure central sleep apnea, the brain's respiratory control centers are imbalanced during sleep. Blood levels of carbon dioxide, and the neurological feedback mechanism that monitors them, do not react quickly enough to maintain an even respiratory rate, with the entire system cycling between apnea and hyperpnea, even during wakefulness.
The sleeper stops breathing for up to two minutes and then starts again. There is no effort made to breathe during the pause in breathing: there are no chest movements and no struggling. After the episode of apnea, breathing may be faster (hyperpnea) for a period of time, a compensatory mechanism to blow off retained waste gases and absorb more oxygen. There are symptoms that one can find for the two different types of sleep apnea (central versus obstructive) as follows. Symptoms of central sleep apnea observed breathing pauses during sleep lack of abdominal and thoracic movement for 10 seconds or longer Diagnosis Treatment Obstructive sleep apnea. Pulmonary interstitial emphysema. Bronchoconstriction. Central neurogenic hyperventilation. Kussmaul breathing. Pea soup fog. Respiratory acidosis. Wheeze. Biphasic cuirass ventilation. Blackdamp. Smog. Particulates. Air pollution. Cheyne–Stokes respiration. Orthopnea.
Tachypnea. Hyperventilation. Hypercapnia. Hypoxia (medical) Acute respiratory distress syndrome.