ventilation

ventilation,

process of supplying fresh air to an enclosed space and removing from it air contaminated by odors, gases, or smoke.

Proper ventilation requires also that there be a movement or circulation of the air within the space and that the temperature and humidity be maintained within a range that allows adequate evaporation of perspiration from the skin. It was formerly believed that the discomfort, headache, and lethargy commonly associated with poor ventilation were caused entirely by the increase in the amount of carbon dioxide and the decrease in the oxygen content of the air. There is evidence to show, however, that the deleterious effects result largely from interference with the heat-regulating mechanism of the body. Lack of air currents and the increase in relative humidity and temperature (especially noticeable in crowded, poorly ventilated places) prevent normal evaporation of perspiration and loss of heat from the surface of the skin.

Natural ventilation depends on winds outside and convection currents inside a building. Winds raise air pressure slightly on the windward side of a building and lower it slightly on the lee side. The pressure difference promotes circulation into the building on the windward side and out of it on the lee side. Convection currents are caused by the sinking of colder and therefore heavier air, which displaces the warmer air. A building may have a roof ventilator to allow the rising warm air to escape. If there is an opening to the outside at the bottom of the building, fresh, cool air will be drawn in.

A simple roof ventilator is essentially an opening in the roof with a cover to keep out rain and to prevent winds from interfering with its functioning. Natural convection is an appreciable aid to ventilation in a large building only if it contains sources of large amounts of heat. A further useful adjunct is a fanfan,
device for agitating air or gases or moving them from one location to another. Mechanical fans with revolving blades are used for ventilation, in manufacturing, in winnowing grain, to remove dust, cuttings, or other waste, or to provide draft for a fire.
..... Click the link for more information. in the roof ventilator. The addition of distribution ducts to the fan and a system for forcing air into the building provides greater efficiency. Outlets are designed to attain maximum mixing of air and to move large amounts of air at low velocity so that temperature layers are eliminated. Factories have special suction hoods and enclosures to draw away localized dust, fumes, and heat. Incoming air may be cleaned of dust by filters or electrostatic precipitators.

Deep mines, underwater tunnels, and other subterranean and submarine environments require elaborate mechanically operated systems for maintaining the air supply in a healthful condition. The lives of those working in, or traveling through, such areas depend upon a constant supply of fresh air; not only must the systems used be highly efficient, but there should be provision for emergencies in case of failure of the apparatus in operation. An outgrowth of studies of problems of ventilation is the development of methods of air conditioningair conditioning,
mechanical process for controlling the humidity, temperature, cleanliness, and circulation of air in buildings and rooms. Indoor air is conditioned and regulated to maintain the temperature-humidity ratio that is most comfortable and healthful.
..... Click the link for more information. . Such systems, unlike ordinary methods of ventilation, are independent of outdoor atmospheric conditions and can, therefore, maintain the indoor atmosphere at the most healthful temperature and humidity and can free the air of dust and other undesirable materials. They accomplish this, however, at a considerable cost in energy.

Bibliography

See F. Porges, Handbook of Heating, Ventilating, and Air Conditioning (1982).

Ventilation

The supply of clean outdoor air to a space for the purpose of cooling; a process of changing the air in a room by either natural or artificial means; any provision for removing contaminated air or gases from a room and replacing it with fresh air.

Ventilation

the controlled exchange of air in an area; also, the equipment and installations creating such an exchange. Ventilation is designed to provide the necessary purity, temperature, humidity, and circulation of air. These requirements are determined by health standards: the presence of noxious substances in the air (gases, vapors, or dust) is restricted to permissible concentrations (those which are harmless to human health); and the temperature, humidity, and circulation of the air are determined in relation to the conditions required for optimum human comfort. For many industrial areas (shops for the assembly of precision instruments, radio-electronics equipment, and so on), air purity, temperature, and humidity are also determined by the special requirements of the technological processes involved. In a number of cases (museum storage facilities, archives, or warehouses) the air temperature and humidity in an area must correspond to the conditions required for the best preservation of objects and materials, equipment, or construction components contained in it.

In industrial areas, the principal source of emission of noxious substances, heat, and moisture is the technological process taking place within the area. In residential dwellings, these emissions occur primarily in lavatories and kitchens, especially during the use of gas ranges. The activity of the human organism is also accompanied by the emission of noxious substances (carbon dioxide), odors, heat, and moisture. The preparation of food, bathing, and the washing of dishes and clothing raise the temperature and humidity of room air and increase its dust content and bacterial contamination (particularly if sick persons are present). All of these substances may be removed by means of ventilation. In cases of pollution of the air basin (for example, by exhaust fumes from automobile traffic or industrial discharges), noxious substances may enter room areas with the outside air.

Solar radiation (chiefly through windows) and artificial lighting are sources of additional heat accumulation. The reduction of emissions of noxious substances and of excess heat and moisture is an important factor in improving the condition of the air in industrial environments, and it also creates more favorable conditions for the operation of ventilation. Nontoxic or low-toxicity materials are used for these purposes in industrial processes, production equipment and distribution supply lines are hermetically sealed, and surfaces that give off heat are covered with thermal insulation. The reduction of excess heat is achieved by the use of window-mounted sun protection devices, heat-absorbing glass, the use of forced heat-dissipation lamps for lighting, and other methods. Current health standards in the USSR specify that the air of living spaces must be as follows (during the winter season): temperature, 18°–22° C; relative humidity, 40-60 percent; circulation, 0.1-0.2 m/sec; and maximum C0₂ content, 0.1 percent. Noxious gas contaminants are not permitted in the air.

A distinction is made between forced, exhaust, suction-and-exhaust, general-exchange, local, natural, and mechanical types of ventilation.

Forced ventilation. Forced ventilation provides only a clean air supply to an area; the removal of air from the space occurs primarily through leakage in the surrounding structures and through open doors owing to the generation of excess pressure.

Exhaust ventilation. Exhaust ventilation is designed to remove air from a ventilated area and to create a negative pressure within it so that outside air and air from adjoining spaces can enter the area through doors and leaks in enclosures.

Suction-and-exhaust ventilation. Suction-and-exhaust ventilation provides simultaneous air supply and systematic air removal in an area; with this method, a positive or negative pressure can exist in the area depending on the ratio between the quantities of air being supplied and exhausted. The positive and negative air pressures in adjoining spaces prevent the infiltration of contaminated air from one space to another (for example, from a smoking room to a lobby, from a kitchen to a dining room, or from a galvanizing section to an assembly shop). For this method to be effective, it is necessary that the positive or negative pressure in the ventilated spaces be created and maintained by a continuous, intense air exchange. The indicator of the rate of air exchange, which can take place without ventilating equipment (through enclosure leaks or under the influence of wind or a difference between inside and outside air temperatures), is the frequency of air exchange—that is, the ratio of the volume of air entering or leaving over a period of 1 hour to the volume of the air space.

General-exchange ventilation. With general-exchange ventilation, which is used in all residential and public buildings, noxious substances released in an air space are diluted to permissible concentrations by supplying clean air to the area; excess heat and moisture are dissipated by the air supply, which in this case must be of lower temperature and humidity.

Local forced ventilation. Local forced ventilation creates the necessary conditions for the air environment in confined areas of industrial installations by means of spot cooling units, air oases, and such. With local exhaust ventilation, noxious impurities are collected and removed from their points of origin by means of local exhaust systems such as laboratory fume hoods, furnace hoods, or side-slot hood exhausts. Processing equipment giving off noxious substances is equipped with built-in local exhaust units and housings, which are an integral part of the unit.

Natural ventilation. With natural ventilation, air enters and leaves an area owing to temperature differences (and, consequently, density differences between outside and inside air) and wind action. Nonsystematic natural ventilation occurs by infiltration and exfiltration of air through leaks in building enclosures, windows, doors, and such, and systematic natural ventilation is accomplished by supplying and exhausting air circulated through air ducts and adjustable vent openings in walls, windows, and skylights.

Mechanical ventilation. Mechanical ventilation (Figure 1) is performed primarily by electrically driven fans or blowers. In the supply systems, outside air is prepared by equipment that is usually located in an air-supply chamber near the intake. The air from the chamber is distributed through ducts to the areas to be ventilated and is then supplied to the spaces through louvers, perforated ceilings, decorative grilles, and other types of supply ventilation outlets. In general-exchange ventilation, air is removed through a network of ducts with grilles into an exhaust duct system, and in local ventilation it is removed through local exhausts, which are usually connected to separate exhaust systems. Air that is contaminated by particularly toxic substances or local exhausts must be cleaned. Air-cleaning equipment, such as dust collectors or filters, is installed for this purpose directly before the discharge of the contaminated air into the atmosphere. Equipment for exhaust ventilating systems is located in exhaust chambers; exposed installations are possible at industrial plants under favorable climatic conditions. Ventilating equipment may be installed directly in the area to be ventilated if the noise from the ventilating equipment does not significantly interfere with the work to be performed in a shop, warehouse, or other industrial area. Forced, heating, and exhaust ventilating units mounted on floors, columns, or walls are also used in these instances.

Figure 1. Mechanical suction-and-exhaust ventilation system: (1) air intake shaft, (2) dust-removal chamber, (3) oil filter, (4) air heaters, (5) humidifying nozzles, (6) drip eliminator, (7) fan or blower, (8) supply ducts, (9) exhaust fan, (10) exhaust ducts, (11) exhaust chamber, (12) supply chamber.

Exhaust ventilation with natural induction from kitchens and lavatories and with the intake of outside air through adjustable window vents, fortochki (small hinged panes), leaks in walls, is most widely used in residential dwellings. Mechanically induced suction-and-exhaust ventilation is widely used in modern industrial facilities and public buildings. In a number of cases, forced ventilation is combined with hot-air heating, for which the system is furnished with a more powerful air preheater that heats the air supply to a temperature higher than that in the area. In this way, the excess heat carried along by the forced air supply makes up for the heat loss of the area. Air conditioning is used if the air parameters in an area must be maintained constantly in accordance with strictly specified conditions (quality requirements). In this method, the prescribed air parameters are maintained in the areas by means of automatically controlled air-treatment processes within the air-conditioners that are regulated depending on the condition of the outside air and the loss of heat and moisture in the interior air spaces. The development and expansion of air-conditioning applications and improvements in the methods of its distribution to air spaces contribute to a further increase in ventilation efficiency.

REFERENCES

Livehak, I. F. Ventiliatsiia mnogoetazhnykh zhilykh domov. Moscow, 1951.
Kamenev, P. N. Otoplenie i ventiliatsiia,2nd ed., part 2. Moscow, 1964.
Baturin, V. V. Osnovy promyshlennoi ventiliatsii,3rd ed. [Moscow] 1965.
Retter, E. I., and S. I. Strizhenov. Aerodinamika zdanii. Moscow, 1968.
Marzeev, A. N., and V. M. Zhabotinskii. Kommunal’naia gigiena, 3rd ed. Moscow, 1968.

I. F. LIVCHAK

ventilation

[‚vent·əl′ā·shən] (engineering) Provision for the movement, circulation, and quality control of air in an enclosed space. (meteorology) The process of causing representative air to be in contact with the sensing elements of observing instruments; especially applied to producing a flow of air past the bulb of a wet-bulb thermometer.

Ventilation

The supplying of air motion in a space by circulation or by moving air through the space. Ventilation may be produced by any combination of natural or mechanical supply and exhaust. Such systems may include partial treatment such as heating, humidity control, filtering or purification, and, in some cases, evaporative cooling. More complete treatment of the air is generally called air conditioning. See Air conditioning

Natural ventilation may be provided by wind force, convection, or a combination of the two. Although largely supplanted by mechanical ventilation and air conditioning, natural ventilation still is widely used in homes, schools, and commercial and industrial buildings.

Mechanical supply ventilation may be of the central type consisting of a central fan system with distributing ducts serving a large space or a number of spaces, or of the unitary type with little or no ductwork, serving a single space or a portion of large space. Outside air connections are generally provided for all ducted systems. Outside air is needed in controlled quantities to remove odors and to replace air exhausted from the various building spaces and equipment.

Exhaust ventilation is required to remove odors, fumes, dust, and heat from an enclosed occupied space. Such exhaust may be of the natural variety or may be mechanical by means of roof or wall exhaust fans or mechanical exhaust systems. The mechanical systems may have minimal ductwork or none at all, or may be provided with extensive ductwork which is used to collect localized hot air, gases, fumes, or dust from process operations. Where it is possible to do so, the process operations are enclosed or hooded to provide maximum collection efficiency with the minimum requirement of exhaust air.

ventilation

The process of supplying or removing air, by natural or mechanical means, to or from any space; such air may or may not have been conditioned.

ventilation

i. Starting a jet engine without putting on LP (low pressure) and HP (high pressure) cocks with a view to drain out any fuel in the jet pipe.
ii. Biologically, the aeration of the lungs and blood by breathing. The inhalation and exhalation of air in the process of respiration.

ventilation

[ven″tĭ-la´shun] 1. the process or act of supplying a house or room continuously with fresh air.2. in respiratory physiology, the process of exchange of air between the lungs and the ambient air; see alveolar ventilation and pulmonary ventilation. See also respiration (def. 1). Called also breathing.3. in psychiatry, verbalization of one's problems, emotions, or feelings.alveolar ventilation a fraction of the ventilation" >pulmonary ventilation, being the amount of air that reaches the alveoli and is available for gas exchange with the blood.assist/control mode ventilation ventilation" >positive pressure ventilation in the mode" >assist-control mode; if the spontaneous ventilation rate falls below a preset level, the ventilator enters the mode" >control mode.assisted ventilation artificial respiration.assist mode ventilation ventilation" >positive pressure ventilation in which the ventilator is in the mode" >assist-control mode; see also ventilation" >control mode ventilation and ventilation" >assist/control mode ventilation.controlled ventilation (control mode ventilation) ventilation" >positive pressure ventilation in which the ventilator is in mode" >control mode, with its cycle entirely controlled by the apparatus and not influenced by the patient's efforts at spontaneous ventilation.high-frequency ventilation a technique of mechanical ventilation that uses very high rates (over 80 breaths per minute) and small tidal volumes (equal to or less than dead space); it may either be positive pressure ventilation or be delivered in the form of frequent jets of air. It is used to lower the peak airway pressure applied to the lung, thus decreasing the risk of barotrauma.high-frequency jet ventilation a type of ventilation" >high-frequency ventilation characterized by delivery of gas through a small catheter in the tube" >endotracheal tube.high-frequency percussive ventilation a type of ventilation" >high-frequency ventilation characterized by delivery of pressure-limited breaths in short bursts of gas from a venturi mask.high-frequency positive pressure ventilation a type of ventilation" >high-frequency ventilation characterized by low compressible volume circuit and volume" >tidal volume delivery of 3 to 4 mL per kg.impaired spontaneous ventilation a nursing diagnosis accepted by the North American Nursing Diagnosis Association, defined as a state in which an individual's decreased energy reserves result in inability to maintain breathing adequate to support life. See also ventilation" >spontaneous ventilation.intermittent mandatory ventilation (IMV) a type of control mode ventilation in which the patient breathes spontaneously while the ventilator delivers a prescribed tidal volume at specified intervals and allows the patient to breathe spontaneously between cycles. The ventilator rate is set to maintain the patient's Pa_CO_₂ at desired levels and is reduced gradually to zero as the patient's condition improves. See also intermittent positive-pressure breathing.intermittent mandatory ventilation, synchronized (SIMV) ventilation" >positive pressure ventilation in which the patient breathes spontaneously while the ventilator delivers a positive-pressure breath at intervals that are predetermined but synchronized with the patient's breathing.intermittent positive pressure ventilation (IPPV) intermittent positive pressure breathing.maximal voluntary ventilation (maximum voluntary ventilation (MVV)) the maximum volume that can be exhaled per minute by the patient breathing as rapidly and deeply as possible. Called also maximal breathing capacity.mechanical ventilation 1. ventilation accomplished by extrinsic means, usually distinguished as either negative pressure or positive pressure ventilation. See also ventilation" >spontaneous ventilation.2. in the nursing interventions classification, a intervention" >nursing intervention defined as the use of an artificial device to assist a patient to breathe.minute ventilation the total volume of gas in liters expelled from the lungs per minute. See also volume" >minute volume. Called also total ventilation.negative pressure ventilation a type of mechanical ventilation in which negative pressure is generated on the outside of the patient's chest and transmitted to the interior of the thorax in order to expand the lungs and allow air to flow in; used primarily with patients having paralysis of the chest muscles. See also ventilator.noninvasive ventilation mechanical ventilation that does not use an artificial airway, such as ventilation" >positive pressure ventilation with a nasal or face mask.partial liquid ventilation ventilatory support in which the lungs are filled to the level of the capacity" >functional residual capacity with a liquid perfluorocarbon; mechanical ventilation is then superimposed and oxygen and carbon dioxide are transferred through the liquid.positive pressure ventilation any of numerous types of mechanical ventilation in which gas is delivered into the airways and lungs under positive pressure, producing positive airway pressure during inspiration; it may be done via either an endotracheal tube or a nasal mask. See also ventilator.pressure control ventilation positive pressure ventilation in which breaths are augmented by air at a fixed rate and amount of pressure, with tidal volume not being fixed; used particularly for patients with acute respiratory distress syndrome.pressure support ventilation positive pressure ventilation in which the patient breathes spontaneously and breathing is augmented with air at a preset amount of pressure, with tidal volume not being fixed.proportional assist ventilation positive pressure ventilation in which the ventilator can sense the patient's level of inspiratory flow and deliver pressure support to achieve a given tidal volume.pulmonary ventilation a measure of the rate of ventilation, referring to the total exchange of air between the lungs and the ambient air, usually in liters per minute.spontaneous ventilation term used to denote breathing accomplished naturally, without any artificial aids, as opposed to mechanical ventilation and other forms of artificial respiration" >artificial respiration.total ventilation minute ventilation.

ven·ti·la·tion

(ven-ti-lā'shŭn), 1. Replacement of air or other gas in a space by fresh air or gas.
See also: respiration. 2. Movement of gas(es) into and out of the lungs.
See also: respiration. Synonym(s): oxidative metabolism, respiration (2) 3. In physiology, the tidal exchange of air between the lungs and the atmosphere that occurs in breathing.
See also: respiration. [see ventilate]

ventilation

(vĕn′tl-ā′shən)n.1. a. The replacement of stale or noxious air with fresh air.b. The mechanical system or equipment used to circulate air or to replace stale air with fresh air.2. See respiration.3. a. The maintenance of breathing by artificial means.b. A breath that is induced by artificial means.

ventilation

Pulmonology The exchange of air between the lungs and the outside air. See Dead space, High-frequency ventilation, Jet ventilation, Maximum voluntary ventilation, Mechanical ventilation, Noninvasive positive pressure ventilation, Partial ventilation, Staircase ventilation Public health The circulation of air from one space to another, usually understood to mean the replacement of ambient air with fresh air from another source. See General exhaust, Local exhaust, Mechanical exhaust.

ven·ti·la·tion

(ven'ti-lā'shŭn) 1. Replacement of air or other gas in a space by fresh air or gas. 2. Movement of gases into and out of the lungs.
Synonym(s): respiration (2) . 3. physiology The tidal exchange of air between the lungs and the atmosphere that occurs in breathing.
See also: respiration

ventilation

(vent?i-la'shon) [ ventilatio, an airing] 1. The movement of air into and out of the lungs.2. Circulation of fresh air in a room and withdrawal of foul air.3. In physiology, the amount of air inhaled per day. This can be estimated by spirometry, multiplying the tidal air by the number of respirations per day. An average figure is 10,000 L. This must not be confused with the total amount of oxygen consumed, which is on the average only 360 L/day. These volumes are more than doubled during hard physical labor.

abdominal displacement ventilation

A noninvasive type of artificial ventilation that relies on displacement of the abdominal contents to move the patient's diaphragm.

adaptive support ventilation

Abbreviation: ASV
A mode of mechanical ventilation in which the minute ventilation is not allowed to fall below a set threshold (e.g., in adults, below 100 ml/kg/min), but the inspiratory pressure, inspiratory time, and tidal volume are all adjusted by the ventilator to the patient's needs.

airway pressure release ventilation

A type of mechanical ventilation in which patients breathe spontaneously at any phase of the ventilator's duty cycle at high continuous positive airway pressures (CPAP). Periodically, the level of CPAP is lowered to eliminate waste gases from the circuit.

alveolar ventilation

The movement of air into and out of the alveoli. It is a function of the size of the tidal volume, the rate of ventilation, and the amount of dead space present in the respiratory system. It is determined by subtracting the dead space volume from the tidal volume and multiplying the result by the respiratory rate.

assist-control ventilation

A type of mechanical ventilation with a minimum frequency of respirations determined by ventilator settings. It also permits the patient to initiate ventilation at the same tidal volume or pressure as set on the ventilator.

asynchronous ventilation

In emergency cardiac or critical care, the administration of artificial breaths to a patient that are timed independently of chest compressions.

continuous positive-pressure ventilation

A method of mechanically assisted pulmonary ventilation. A device administers air or oxygen to the lungs under a continuous pressure that never returns to zero.

differential lung ventilation

The use of different ventilatory strategies in each lung in a patient with focal lung disease, e.g., a patient undergoing surgery to remove a tumor in one lobe of a lung but not another, or a patient with more severe COPD on one side of the chest than another. This technique requires a double-lumen endotracheal tube.

dual control ventilation

Mechanical ventilation initiated by either a change in airway pressures or by a change in gas flowing through the ventilator circuit. Dual control is asserted when pressure limited breaths are delivered and the pressure changes from breath to breath to meet a desired delivered tidal volume. It improves the coordination between the patient's respiratory efforts and machine-generated breaths.

high-frequency jet ventilation

A type of ventilation that continuously ventilates at 100 to 150 cycles/min. It is used in respiratory failure to provide continuous ventilation without the side effects of positive-pressure ventilation.

high-frequency oscillatory ventilation

Abbreviation: HFOV
Pulmonary ventilation with multiple rapid breaths given at small tidal volumes. It limits the stretching and collapse of the alveoli that occur in conventional mechanical ventilation.

high-frequency percussive ventilation

Mechanical ventilation that decreases peak and end-expiratory pressure by delivering hundreds of shallow (low tidal volume) breaths per minute. It is a time-cycled, pressure-limited mode of ventilation.

intermittent mandatory ventilation

Abbreviation: IMV
Machine ventilation that delivers pressurized breaths at intervals while allowing for spontaneous breathing.

intermittent positive-pressure ventilation

A mechanical method of assisting pulmonary ventilation, using a device that inflates the lungs under positive pressure. Exhalation is usually passive. Synonym: breathing, intermittent positive-pressure

inverse ratio ventilation

Abbreviation: IRV
Mechanical ventilation in which the normal temporal relationship between inspiration and expiration is reversed (the inspiration time is longer than the expiratory time). It is sometimes used in severely hypoxemic patients who have not responded to other ventilatory maneuvers. Because it is uncomfortable for patients, paralysis and sedation are needed.

liquid ventilation

A ventilatory technique used to treat both premature infants with surfactant-deficient lungs and adults with acute respiratory distress syndrome.

mandatory minute ventilation

Ventilatory support that provides mechanical breaths when the patient's spontaneous breathing does not achieve the preset mechanical ventilatory rate.

maximum sustainable ventilation

The normal maximum breathing pattern that can be maintained for 15 min (usually approx. 60% of maximum voluntary ventilation).

maximum voluntary ventilation

The maximum amount of gas that can be ventilated into and out of the lungs in a voluntary effort in a given time, measured in liters per minute.

mechanical ventilation

Any form of artificially supplied ventilation.

minute ventilation

Abbreviation: MV
The volume of air inhaled and exhaled in 60 sec. See: minute volume

NONINVASIVE POSITIVE PRESSURE VENTILATION

noninvasive ventilation

The use of airway support administered through a face (nasal) mask instead of an endotracheal tube. Inhaled gases are given with positive end-expiratory pressure often with pressure support or with assist control ventilation at a set tidal volume and rate. Numerous studies have shown this technique to be as effective as, and better tolerated than, intubation and mechanical ventilation in patients with exacerbations of COPD. See: illustration

positive-pressure mechanical ventilation

Mechanical ventilatory support that applies positive pressure to the airway. The objectives include improving pulmonary gas exchange, relieving acute respiratory acidosis, relieving respiratory distress, preventing and reversing atelectasis, improving pulmonary compliance, preventing further lung injury, and avoiding complications. Positive-pressure ventilation can be life saving, but complications such as toxic effects of oxygen, laryngeal injury, tracheal stenosis, alveolar injury, barotrauma, pneumonia, and psychological problems may occur. See: pressure, positive end-expiratory

pressure support ventilation

A type of assisted ventilation that supplements a spontaneous breath. The patient controls the frequency and the duration and flow of inspiration from the ventilator.

protective ventilation

A type of mechanical ventilation in which tidal volumes are set to avoid overstretching the alveoli, and pressures at the end of an inhaled breath are set to avoid alveolar collapse.

pulmonary ventilation

The inspiration and expiration of air from the lungs.

reduced ventilation

Respiratory depression.

synchronized intermittent mandatory ventilation

Abbreviation: SIMV
Periodic assisted ventilation with positive pressure initiated by the patient and coordinated with spontaneous patient breaths. See: intermittent mandatory ventilation

transtracheal catheter ventilation

An emergency procedure in which a catheter is placed percutaneously through the cricothyroid membrane and attached to a high-pressure, high-flow jet ventilator. This form of ventilation is used for patients with an upper airway obstruction who cannot be intubated.

volume-controlled ventilation

A form of mechanical ventilation in which the peak inspiratory flow rate, fraction of inspired oxygen, positive end-expiratory pressure, respiratory rate, and tidal volume are preset and delivered to the patient. Synonym: volume-cycled ventilation; volume-limited ventilation

volume-cycled ventilation

Volume-controlled ventilation.

volume-limited ventilation

Volume-controlled ventilation.

ven·ti·la·tion

(ven'ti-lā'shŭn) 1. Replacement of air or other gas in a space by fresh air or gas. 2. Movement of gas(es) into and out of the lungs.
Synonym(s): respiration (2) .

Patient discussion about ventilation

Q. Help her to breathe. My sixteen year old cousin (girl) who is wondering if she is suffering from asthma, anxiety or both. She is thin, healthy girl and have been very worried She have asthma and have been thinking about it constantly. When she exercise, she get more out of breath, more worn out, and her heart beats faster than other people. Sometimes her chest hurts, but people tell me that is from my chest muscles being worked. She get a little dizzy also. When she go to bed at night sometimes it seems hard to breathe. She can take a deep breath and everything but it seems hard or something. I know there isn't anything wrong with my heart because she had an EKG done recently and chest x-rays. That was fine. When it is hot humid and muggy outside she find it hard to breath. Do you think she have asthma. She don't have any coughing or any known wheezing. Could thinking about every breath she take seem like she have asthma? She really want to know and me too, what is going on! Please help her to breathe!!!!A. PS--alcohol and cigarettes can cause this problem to(drugs)mrfoot56.

Q. What causes bad breath? I have bad breath for a long time. What causes it?A. Here are some causes of bad breath:
A Dry mouth- Saliva helps cleanse and moisten your mouth. A dry mouth enables dead cells to accumulate on your tongue, gums and cheeks. These cells then decompose and cause odor. Dry mouth naturally occurs during sleep. It's what causes "morning breath." Dry mouth is even more of a problem if you sleep with your mouth open. Some medications as well as smoking can lead to a chronic dry mouth, as can a problem with your salivary glands.
Some Diseases can also cause bad breath- Chronic lung infections and lung abscesses can produce very foul-smelling breath. Other illnesses, such as some cancers and certain metabolic disorders, can cause a distinctive breath odor. Kidney failure can cause a urine-like odor, and liver failure may cause an odor described as "fishy." People with uncontrolled diabetes often have a fruity breath odor. Chronic reflux of stomach acids from your stomach (gastroesophageal reflux disease, or GERD)

Q. How to get rid of bad breath? My wife complains that I have bad breath. How can I get rid of it?A. Consider that candida infection can make your breath worse. You might try cutting down on sugar and carbs.
"Bad breath can also be caused by a candida (yeast infection), you may have a constant white furry tongue. Look at cutting down your intake of sugars and processed foods, as well as those containing yeast. - Search for Anti-Candida diet on a search engine for more info"
http://www.wikihow.com/Fix-Bad-Breath-on-the-Spot

More discussions about ventilation

单词	ventilation
释义	ventilation ventilation, process of supplying fresh air to an enclosed space and removing from it air contaminated by odors, gases, or smoke. Proper ventilation requires also that there be a movement or circulation of the air within the space and that the temperature and humidity be maintained within a range that allows adequate evaporation of perspiration from the skin. It was formerly believed that the discomfort, headache, and lethargy commonly associated with poor ventilation were caused entirely by the increase in the amount of carbon dioxide and the decrease in the oxygen content of the air. There is evidence to show, however, that the deleterious effects result largely from interference with the heat-regulating mechanism of the body. Lack of air currents and the increase in relative humidity and temperature (especially noticeable in crowded, poorly ventilated places) prevent normal evaporation of perspiration and loss of heat from the surface of the skin. Natural ventilation depends on winds outside and convection currents inside a building. Winds raise air pressure slightly on the windward side of a building and lower it slightly on the lee side. The pressure difference promotes circulation into the building on the windward side and out of it on the lee side. Convection currents are caused by the sinking of colder and therefore heavier air, which displaces the warmer air. A building may have a roof ventilator to allow the rising warm air to escape. If there is an opening to the outside at the bottom of the building, fresh, cool air will be drawn in. A simple roof ventilator is essentially an opening in the roof with a cover to keep out rain and to prevent winds from interfering with its functioning. Natural convection is an appreciable aid to ventilation in a large building only if it contains sources of large amounts of heat. A further useful adjunct is a fanfan, device for agitating air or gases or moving them from one location to another. Mechanical fans with revolving blades are used for ventilation, in manufacturing, in winnowing grain, to remove dust, cuttings, or other waste, or to provide draft for a fire. ..... Click the link for more information. in the roof ventilator. The addition of distribution ducts to the fan and a system for forcing air into the building provides greater efficiency. Outlets are designed to attain maximum mixing of air and to move large amounts of air at low velocity so that temperature layers are eliminated. Factories have special suction hoods and enclosures to draw away localized dust, fumes, and heat. Incoming air may be cleaned of dust by filters or electrostatic precipitators. Deep mines, underwater tunnels, and other subterranean and submarine environments require elaborate mechanically operated systems for maintaining the air supply in a healthful condition. The lives of those working in, or traveling through, such areas depend upon a constant supply of fresh air; not only must the systems used be highly efficient, but there should be provision for emergencies in case of failure of the apparatus in operation. An outgrowth of studies of problems of ventilation is the development of methods of air conditioningair conditioning, mechanical process for controlling the humidity, temperature, cleanliness, and circulation of air in buildings and rooms. Indoor air is conditioned and regulated to maintain the temperature-humidity ratio that is most comfortable and healthful. ..... Click the link for more information. . Such systems, unlike ordinary methods of ventilation, are independent of outdoor atmospheric conditions and can, therefore, maintain the indoor atmosphere at the most healthful temperature and humidity and can free the air of dust and other undesirable materials. They accomplish this, however, at a considerable cost in energy. Bibliography See F. Porges, Handbook of Heating, Ventilating, and Air Conditioning (1982). Ventilation The supply of clean outdoor air to a space for the purpose of cooling; a process of changing the air in a room by either natural or artificial means; any provision for removing contaminated air or gases from a room and replacing it with fresh air. Ventilation the controlled exchange of air in an area; also, the equipment and installations creating such an exchange. Ventilation is designed to provide the necessary purity, temperature, humidity, and circulation of air. These requirements are determined by health standards: the presence of noxious substances in the air (gases, vapors, or dust) is restricted to permissible concentrations (those which are harmless to human health); and the temperature, humidity, and circulation of the air are determined in relation to the conditions required for optimum human comfort. For many industrial areas (shops for the assembly of precision instruments, radio-electronics equipment, and so on), air purity, temperature, and humidity are also determined by the special requirements of the technological processes involved. In a number of cases (museum storage facilities, archives, or warehouses) the air temperature and humidity in an area must correspond to the conditions required for the best preservation of objects and materials, equipment, or construction components contained in it. In industrial areas, the principal source of emission of noxious substances, heat, and moisture is the technological process taking place within the area. In residential dwellings, these emissions occur primarily in lavatories and kitchens, especially during the use of gas ranges. The activity of the human organism is also accompanied by the emission of noxious substances (carbon dioxide), odors, heat, and moisture. The preparation of food, bathing, and the washing of dishes and clothing raise the temperature and humidity of room air and increase its dust content and bacterial contamination (particularly if sick persons are present). All of these substances may be removed by means of ventilation. In cases of pollution of the air basin (for example, by exhaust fumes from automobile traffic or industrial discharges), noxious substances may enter room areas with the outside air. Solar radiation (chiefly through windows) and artificial lighting are sources of additional heat accumulation. The reduction of emissions of noxious substances and of excess heat and moisture is an important factor in improving the condition of the air in industrial environments, and it also creates more favorable conditions for the operation of ventilation. Nontoxic or low-toxicity materials are used for these purposes in industrial processes, production equipment and distribution supply lines are hermetically sealed, and surfaces that give off heat are covered with thermal insulation. The reduction of excess heat is achieved by the use of window-mounted sun protection devices, heat-absorbing glass, the use of forced heat-dissipation lamps for lighting, and other methods. Current health standards in the USSR specify that the air of living spaces must be as follows (during the winter season): temperature, 18°–22° C; relative humidity, 40-60 percent; circulation, 0.1-0.2 m/sec; and maximum C0₂ content, 0.1 percent. Noxious gas contaminants are not permitted in the air. A distinction is made between forced, exhaust, suction-and-exhaust, general-exchange, local, natural, and mechanical types of ventilation. *Forced ventilation.* Forced ventilation provides only a clean air supply to an area; the removal of air from the space occurs primarily through leakage in the surrounding structures and through open doors owing to the generation of excess pressure. *Exhaust ventilation.* Exhaust ventilation is designed to remove air from a ventilated area and to create a negative pressure within it so that outside air and air from adjoining spaces can enter the area through doors and leaks in enclosures. *Suction-and-exhaust ventilation.* Suction-and-exhaust ventilation provides simultaneous air supply and systematic air removal in an area; with this method, a positive or negative pressure can exist in the area depending on the ratio between the quantities of air being supplied and exhausted. The positive and negative air pressures in adjoining spaces prevent the infiltration of contaminated air from one space to another (for example, from a smoking room to a lobby, from a kitchen to a dining room, or from a galvanizing section to an assembly shop). For this method to be effective, it is necessary that the positive or negative pressure in the ventilated spaces be created and maintained by a continuous, intense air exchange. The indicator of the rate of air exchange, which can take place without ventilating equipment (through enclosure leaks or under the influence of wind or a difference between inside and outside air temperatures), is the frequency of air exchange—that is, the ratio of the volume of air entering or leaving over a period of 1 hour to the volume of the air space. *General-exchange ventilation.* With general-exchange ventilation, which is used in all residential and public buildings, noxious substances released in an air space are diluted to permissible concentrations by supplying clean air to the area; excess heat and moisture are dissipated by the air supply, which in this case must be of lower temperature and humidity. *Local forced ventilation.* Local forced ventilation creates the necessary conditions for the air environment in confined areas of industrial installations by means of spot cooling units, air oases, and such. With local exhaust ventilation, noxious impurities are collected and removed from their points of origin by means of local exhaust systems such as laboratory fume hoods, furnace hoods, or side-slot hood exhausts. Processing equipment giving off noxious substances is equipped with built-in local exhaust units and housings, which are an integral part of the unit. *Natural ventilation.* With natural ventilation, air enters and leaves an area owing to temperature differences (and, consequently, density differences between outside and inside air) and wind action. Nonsystematic natural ventilation occurs by infiltration and exfiltration of air through leaks in building enclosures, windows, doors, and such, and systematic natural ventilation is accomplished by supplying and exhausting air circulated through air ducts and adjustable vent openings in walls, windows, and skylights. *Mechanical ventilation.* Mechanical ventilation (Figure 1) is performed primarily by electrically driven fans or blowers. In the supply systems, outside air is prepared by equipment that is usually located in an air-supply chamber near the intake. The air from the chamber is distributed through ducts to the areas to be ventilated and is then supplied to the spaces through louvers, perforated ceilings, decorative grilles, and other types of supply ventilation outlets. In general-exchange ventilation, air is removed through a network of ducts with grilles into an exhaust duct system, and in local ventilation it is removed through local exhausts, which are usually connected to separate exhaust systems. Air that is contaminated by particularly toxic substances or local exhausts must be cleaned. Air-cleaning equipment, such as dust collectors or filters, is installed for this purpose directly before the discharge of the contaminated air into the atmosphere. Equipment for exhaust ventilating systems is located in exhaust chambers; exposed installations are possible at industrial plants under favorable climatic conditions. Ventilating equipment may be installed directly in the area to be ventilated if the noise from the ventilating equipment does not significantly interfere with the work to be performed in a shop, warehouse, or other industrial area. Forced, heating, and exhaust ventilating units mounted on floors, columns, or walls are also used in these instances. Figure 1. Mechanical suction-and-exhaust ventilation system: (1) air intake shaft, (2) dust-removal chamber, (3) oil filter, (4) air heaters, (5) humidifying nozzles, (6) drip eliminator, (7) fan or blower, (8) supply ducts, (9) exhaust fan, (10) exhaust ducts, (11) exhaust chamber, (12) supply chamber. Exhaust ventilation with natural induction from kitchens and lavatories and with the intake of outside air through adjustable window vents, fortochki (small hinged panes), leaks in walls, is most widely used in residential dwellings. Mechanically induced suction-and-exhaust ventilation is widely used in modern industrial facilities and public buildings. In a number of cases, forced ventilation is combined with hot-air heating, for which the system is furnished with a more powerful air preheater that heats the air supply to a temperature higher than that in the area. In this way, the excess heat carried along by the forced air supply makes up for the heat loss of the area. Air conditioning is used if the air parameters in an area must be maintained constantly in accordance with strictly specified conditions (quality requirements). In this method, the prescribed air parameters are maintained in the areas by means of automatically controlled air-treatment processes within the air-conditioners that are regulated depending on the condition of the outside air and the loss of heat and moisture in the interior air spaces. The development and expansion of air-conditioning applications and improvements in the methods of its distribution to air spaces contribute to a further increase in ventilation efficiency. REFERENCES Livehak, I. F. Ventiliatsiia mnogoetazhnykh zhilykh domov. Moscow, 1951. Kamenev, P. N. Otoplenie i ventiliatsiia,2nd ed., part 2. Moscow, 1964. Baturin, V. V. Osnovy promyshlennoi ventiliatsii,3rd ed. [Moscow] 1965. Retter, E. I., and S. I. Strizhenov. Aerodinamika zdanii. Moscow, 1968. Marzeev, A. N., and V. M. Zhabotinskii. Kommunal’naia gigiena, 3rd ed. Moscow, 1968. I. F. LIVCHAK ventilation [‚vent·əl′ā·shən] (engineering) Provision for the movement, circulation, and quality control of air in an enclosed space. (meteorology) The process of causing representative air to be in contact with the sensing elements of observing instruments; especially applied to producing a flow of air past the bulb of a wet-bulb thermometer. Ventilation The supplying of air motion in a space by circulation or by moving air through the space. Ventilation may be produced by any combination of natural or mechanical supply and exhaust. Such systems may include partial treatment such as heating, humidity control, filtering or purification, and, in some cases, evaporative cooling. More complete treatment of the air is generally called air conditioning. See Air conditioning Natural ventilation may be provided by wind force, convection, or a combination of the two. Although largely supplanted by mechanical ventilation and air conditioning, natural ventilation still is widely used in homes, schools, and commercial and industrial buildings. Mechanical supply ventilation may be of the central type consisting of a central fan system with distributing ducts serving a large space or a number of spaces, or of the unitary type with little or no ductwork, serving a single space or a portion of large space. Outside air connections are generally provided for all ducted systems. Outside air is needed in controlled quantities to remove odors and to replace air exhausted from the various building spaces and equipment. Exhaust ventilation is required to remove odors, fumes, dust, and heat from an enclosed occupied space. Such exhaust may be of the natural variety or may be mechanical by means of roof or wall exhaust fans or mechanical exhaust systems. The mechanical systems may have minimal ductwork or none at all, or may be provided with extensive ductwork which is used to collect localized hot air, gases, fumes, or dust from process operations. Where it is possible to do so, the process operations are enclosed or hooded to provide maximum collection efficiency with the minimum requirement of exhaust air. ventilation The process of supplying or removing air, by natural or mechanical means, to or from any space; such air may or may not have been conditioned. ventilation i. Starting a jet engine without putting on LP (low pressure) and HP (high pressure) cocks with a view to drain out any fuel in the jet pipe. ii. Biologically, the aeration of the lungs and blood by breathing. The inhalation and exhalation of air in the process of respiration. ventilation ventilation [ven″tĭ-la´shun] 1. the process or act of supplying a house or room continuously with fresh air.2. in respiratory physiology, the process of exchange of air between the lungs and the ambient air; see alveolar ventilation and pulmonary ventilation. See also respiration (def. 1). Called also breathing.3. in psychiatry, verbalization of one's problems, emotions, or feelings.alveolar ventilation a fraction of the ventilation" >pulmonary ventilation, being the amount of air that reaches the alveoli and is available for gas exchange with the blood.assist/control mode ventilation ventilation" >positive pressure ventilation in the mode" >assist-control mode; if the spontaneous ventilation rate falls below a preset level, the ventilator enters the mode" >control mode.assisted ventilation artificial respiration.assist mode ventilation ventilation" >positive pressure ventilation in which the ventilator is in the mode" >assist-control mode; see also ventilation" >control mode ventilation and ventilation" >assist/control mode ventilation.controlled ventilation (control mode ventilation) ventilation" >positive pressure ventilation in which the ventilator is in mode" >control mode, with its cycle entirely controlled by the apparatus and not influenced by the patient's efforts at spontaneous ventilation.high-frequency ventilation a technique of mechanical ventilation that uses very high rates (over 80 breaths per minute) and small tidal volumes (equal to or less than dead space); it may either be positive pressure ventilation or be delivered in the form of frequent jets of air. It is used to lower the peak airway pressure applied to the lung, thus decreasing the risk of barotrauma.high-frequency jet ventilation a type of ventilation" >high-frequency ventilation characterized by delivery of gas through a small catheter in the tube" >endotracheal tube.high-frequency percussive ventilation a type of ventilation" >high-frequency ventilation characterized by delivery of pressure-limited breaths in short bursts of gas from a venturi mask.high-frequency positive pressure ventilation a type of ventilation" >high-frequency ventilation characterized by low compressible volume circuit and volume" >tidal volume delivery of 3 to 4 mL per kg.impaired spontaneous ventilation a nursing diagnosis accepted by the North American Nursing Diagnosis Association, defined as a state in which an individual's decreased energy reserves result in inability to maintain breathing adequate to support life. See also ventilation" >spontaneous ventilation.intermittent mandatory ventilation (IMV) a type of control mode ventilation in which the patient breathes spontaneously while the ventilator delivers a prescribed tidal volume at specified intervals and allows the patient to breathe spontaneously between cycles. The ventilator rate is set to maintain the patient's Pa_CO_₂ at desired levels and is reduced gradually to zero as the patient's condition improves. See also intermittent positive-pressure breathing.intermittent mandatory ventilation, synchronized (SIMV) ventilation" >positive pressure ventilation in which the patient breathes spontaneously while the ventilator delivers a positive-pressure breath at intervals that are predetermined but synchronized with the patient's breathing.intermittent positive pressure ventilation (IPPV) intermittent positive pressure breathing.maximal voluntary ventilation (maximum voluntary ventilation (MVV)) the maximum volume that can be exhaled per minute by the patient breathing as rapidly and deeply as possible. Called also maximal breathing capacity.mechanical ventilation 1. ventilation accomplished by extrinsic means, usually distinguished as either negative pressure or positive pressure ventilation. See also ventilation" >spontaneous ventilation.2. in the nursing interventions classification, a intervention" >nursing intervention defined as the use of an artificial device to assist a patient to breathe.minute ventilation the total volume of gas in liters expelled from the lungs per minute. See also volume" >minute volume. Called also total ventilation.negative pressure ventilation a type of mechanical ventilation in which negative pressure is generated on the outside of the patient's chest and transmitted to the interior of the thorax in order to expand the lungs and allow air to flow in; used primarily with patients having paralysis of the chest muscles. See also ventilator.noninvasive ventilation mechanical ventilation that does not use an artificial airway, such as ventilation" >positive pressure ventilation with a nasal or face mask.partial liquid ventilation ventilatory support in which the lungs are filled to the level of the capacity" >functional residual capacity with a liquid perfluorocarbon; mechanical ventilation is then superimposed and oxygen and carbon dioxide are transferred through the liquid.positive pressure ventilation any of numerous types of mechanical ventilation in which gas is delivered into the airways and lungs under positive pressure, producing positive airway pressure during inspiration; it may be done via either an endotracheal tube or a nasal mask. See also ventilator.pressure control ventilation positive pressure ventilation in which breaths are augmented by air at a fixed rate and amount of pressure, with tidal volume not being fixed; used particularly for patients with acute respiratory distress syndrome.pressure support ventilation positive pressure ventilation in which the patient breathes spontaneously and breathing is augmented with air at a preset amount of pressure, with tidal volume not being fixed.proportional assist ventilation positive pressure ventilation in which the ventilator can sense the patient's level of inspiratory flow and deliver pressure support to achieve a given tidal volume.pulmonary ventilation a measure of the rate of ventilation, referring to the total exchange of air between the lungs and the ambient air, usually in liters per minute.spontaneous ventilation term used to denote breathing accomplished naturally, without any artificial aids, as opposed to mechanical ventilation and other forms of artificial respiration" >artificial respiration.total ventilation minute ventilation. ven·ti·la·tion (ven-ti-lā'shŭn), 1. Replacement of air or other gas in a space by fresh air or gas. See also: respiration. 2. Movement of gas(es) into and out of the lungs. See also: respiration. Synonym(s): oxidative metabolism, respiration (2) 3. In physiology, the tidal exchange of air between the lungs and the atmosphere that occurs in breathing. See also: respiration. [see ventilate] ventilation (vĕn′tl-ā′shən)n.1. a. The replacement of stale or noxious air with fresh air.b. The mechanical system or equipment used to circulate air or to replace stale air with fresh air.2. See respiration.3. a. The maintenance of breathing by artificial means.b. A breath that is induced by artificial means. ventilation Pulmonology The exchange of air between the lungs and the outside air. See Dead space, High-frequency ventilation, Jet ventilation, Maximum voluntary ventilation, Mechanical ventilation, Noninvasive positive pressure ventilation, Partial ventilation, Staircase ventilation Public health The circulation of air from one space to another, usually understood to mean the replacement of ambient air with fresh air from another source. See General exhaust, Local exhaust, Mechanical exhaust. ven·ti·la·tion (ven'ti-lā'shŭn) 1. Replacement of air or other gas in a space by fresh air or gas. 2. Movement of gases into and out of the lungs. Synonym(s): respiration (2) . 3. physiology The tidal exchange of air between the lungs and the atmosphere that occurs in breathing. See also: respiration ventilation (vent?i-la'shon) [ ventilatio, an airing] 1. The movement of air into and out of the lungs.2. Circulation of fresh air in a room and withdrawal of foul air.3. In physiology, the amount of air inhaled per day. This can be estimated by spirometry, multiplying the tidal air by the number of respirations per day. An average figure is 10,000 L. This must not be confused with the total amount of oxygen consumed, which is on the average only 360 L/day. These volumes are more than doubled during hard physical labor. abdominal displacement ventilation A noninvasive type of artificial ventilation that relies on displacement of the abdominal contents to move the patient's diaphragm. adaptive support ventilation Abbreviation: ASV A mode of mechanical ventilation in which the minute ventilation is not allowed to fall below a set threshold (e.g., in adults, below 100 ml/kg/min), but the inspiratory pressure, inspiratory time, and tidal volume are all adjusted by the ventilator to the patient's needs. airway pressure release ventilation A type of mechanical ventilation in which patients breathe spontaneously at any phase of the ventilator's duty cycle at high continuous positive airway pressures (CPAP). Periodically, the level of CPAP is lowered to eliminate waste gases from the circuit. alveolar ventilation The movement of air into and out of the alveoli. It is a function of the size of the tidal volume, the rate of ventilation, and the amount of dead space present in the respiratory system. It is determined by subtracting the dead space volume from the tidal volume and multiplying the result by the respiratory rate. assist-control ventilation A type of mechanical ventilation with a minimum frequency of respirations determined by ventilator settings. It also permits the patient to initiate ventilation at the same tidal volume or pressure as set on the ventilator. asynchronous ventilation In emergency cardiac or critical care, the administration of artificial breaths to a patient that are timed independently of chest compressions. continuous positive-pressure ventilation A method of mechanically assisted pulmonary ventilation. A device administers air or oxygen to the lungs under a continuous pressure that never returns to zero. differential lung ventilation The use of different ventilatory strategies in each lung in a patient with focal lung disease, e.g., a patient undergoing surgery to remove a tumor in one lobe of a lung but not another, or a patient with more severe COPD on one side of the chest than another. This technique requires a double-lumen endotracheal tube. dual control ventilation Mechanical ventilation initiated by either a change in airway pressures or by a change in gas flowing through the ventilator circuit. Dual control is asserted when pressure limited breaths are delivered and the pressure changes from breath to breath to meet a desired delivered tidal volume. It improves the coordination between the patient's respiratory efforts and machine-generated breaths. high-frequency jet ventilation A type of ventilation that continuously ventilates at 100 to 150 cycles/min. It is used in respiratory failure to provide continuous ventilation without the side effects of positive-pressure ventilation. high-frequency oscillatory ventilation Abbreviation: HFOV Pulmonary ventilation with multiple rapid breaths given at small tidal volumes. It limits the stretching and collapse of the alveoli that occur in conventional mechanical ventilation. high-frequency percussive ventilation Mechanical ventilation that decreases peak and end-expiratory pressure by delivering hundreds of shallow (low tidal volume) breaths per minute. It is a time-cycled, pressure-limited mode of ventilation. intermittent mandatory ventilation Abbreviation: IMV Machine ventilation that delivers pressurized breaths at intervals while allowing for spontaneous breathing. intermittent positive-pressure ventilation A mechanical method of assisting pulmonary ventilation, using a device that inflates the lungs under positive pressure. Exhalation is usually passive. Synonym: breathing, intermittent positive-pressure inverse ratio ventilation Abbreviation: IRV Mechanical ventilation in which the normal temporal relationship between inspiration and expiration is reversed (the inspiration time is longer than the expiratory time). It is sometimes used in severely hypoxemic patients who have not responded to other ventilatory maneuvers. Because it is uncomfortable for patients, paralysis and sedation are needed. liquid ventilation A ventilatory technique used to treat both premature infants with surfactant-deficient lungs and adults with acute respiratory distress syndrome. mandatory minute ventilation Ventilatory support that provides mechanical breaths when the patient's spontaneous breathing does not achieve the preset mechanical ventilatory rate. maximum sustainable ventilation The normal maximum breathing pattern that can be maintained for 15 min (usually approx. 60% of maximum voluntary ventilation). maximum voluntary ventilation The maximum amount of gas that can be ventilated into and out of the lungs in a voluntary effort in a given time, measured in liters per minute. mechanical ventilation Any form of artificially supplied ventilation. minute ventilation Abbreviation: MV The volume of air inhaled and exhaled in 60 sec. See: minute volumeNONINVASIVE POSITIVE PRESSURE VENTILATION noninvasive ventilation The use of airway support administered through a face (nasal) mask instead of an endotracheal tube. Inhaled gases are given with positive end-expiratory pressure often with pressure support or with assist control ventilation at a set tidal volume and rate. Numerous studies have shown this technique to be as effective as, and better tolerated than, intubation and mechanical ventilation in patients with exacerbations of COPD. See: illustration positive-pressure mechanical ventilation Mechanical ventilatory support that applies positive pressure to the airway. The objectives include improving pulmonary gas exchange, relieving acute respiratory acidosis, relieving respiratory distress, preventing and reversing atelectasis, improving pulmonary compliance, preventing further lung injury, and avoiding complications. Positive-pressure ventilation can be life saving, but complications such as toxic effects of oxygen, laryngeal injury, tracheal stenosis, alveolar injury, barotrauma, pneumonia, and psychological problems may occur. See: pressure, positive end-expiratory pressure support ventilation A type of assisted ventilation that supplements a spontaneous breath. The patient controls the frequency and the duration and flow of inspiration from the ventilator. protective ventilation A type of mechanical ventilation in which tidal volumes are set to avoid overstretching the alveoli, and pressures at the end of an inhaled breath are set to avoid alveolar collapse. pulmonary ventilation The inspiration and expiration of air from the lungs. reduced ventilation Respiratory depression. synchronized intermittent mandatory ventilation Abbreviation: SIMV Periodic assisted ventilation with positive pressure initiated by the patient and coordinated with spontaneous patient breaths. See: intermittent mandatory ventilation transtracheal catheter ventilation An emergency procedure in which a catheter is placed percutaneously through the cricothyroid membrane and attached to a high-pressure, high-flow jet ventilator. This form of ventilation is used for patients with an upper airway obstruction who cannot be intubated. volume-controlled ventilation A form of mechanical ventilation in which the peak inspiratory flow rate, fraction of inspired oxygen, positive end-expiratory pressure, respiratory rate, and tidal volume are preset and delivered to the patient. Synonym: volume-cycled ventilation; volume-limited ventilation volume-cycled ventilation Volume-controlled ventilation. volume-limited ventilation Volume-controlled ventilation. ven·ti·la·tion (ven'ti-lā'shŭn) 1. Replacement of air or other gas in a space by fresh air or gas. 2. Movement of gas(es) into and out of the lungs. Synonym(s): respiration (2) . Patient discussion about ventilation Q. Help her to breathe. My sixteen year old cousin (girl) who is wondering if she is suffering from asthma, anxiety or both. She is thin, healthy girl and have been very worried She have asthma and have been thinking about it constantly. When she exercise, she get more out of breath, more worn out, and her heart beats faster than other people. Sometimes her chest hurts, but people tell me that is from my chest muscles being worked. She get a little dizzy also. When she go to bed at night sometimes it seems hard to breathe. She can take a deep breath and everything but it seems hard or something. I know there isn't anything wrong with my heart because she had an EKG done recently and chest x-rays. That was fine. When it is hot humid and muggy outside she find it hard to breath. Do you think she have asthma. She don't have any coughing or any known wheezing. Could thinking about every breath she take seem like she have asthma? She really want to know and me too, what is going on! Please help her to breathe!!!!A. PS--alcohol and cigarettes can cause this problem to(drugs)mrfoot56. Q. What causes bad breath? I have bad breath for a long time. What causes it?A. Here are some causes of bad breath: A Dry mouth- Saliva helps cleanse and moisten your mouth. A dry mouth enables dead cells to accumulate on your tongue, gums and cheeks. These cells then decompose and cause odor. Dry mouth naturally occurs during sleep. It's what causes "morning breath." Dry mouth is even more of a problem if you sleep with your mouth open. Some medications as well as smoking can lead to a chronic dry mouth, as can a problem with your salivary glands. Some Diseases can also cause bad breath- Chronic lung infections and lung abscesses can produce very foul-smelling breath. Other illnesses, such as some cancers and certain metabolic disorders, can cause a distinctive breath odor. Kidney failure can cause a urine-like odor, and liver failure may cause an odor described as "fishy." People with uncontrolled diabetes often have a fruity breath odor. Chronic reflux of stomach acids from your stomach (gastroesophageal reflux disease, or GERD) Q. How to get rid of bad breath? My wife complains that I have bad breath. How can I get rid of it?A. Consider that candida infection can make your breath worse. You might try cutting down on sugar and carbs. "Bad breath can also be caused by a candida (yeast infection), you may have a constant white furry tongue. Look at cutting down your intake of sugars and processed foods, as well as those containing yeast. - Search for Anti-Candida diet on a search engine for more info" http://www.wikihow.com/Fix-Bad-Breath-on-the-Spot More discussions about ventilation FinancialSeeQSee V See VENT ventilation Related to ventilation: mechanical ventilation, pulmonary ventilation noun Synonyms for ventilation noun an exchanging of views Synonyms conference discussion rap Synonyms for ventilation noun the act of supplying fresh air and getting rid of foul air Synonyms airing Related Words improvement noun a mechanical system in a building that provides fresh air Synonyms ventilating system ventilation system Related Words mechanical system ventilation shaft ventilator noun free and open discussion of (or debate on) some question of public interest Synonyms public discussion Related Words give-and-take discussion word noun the bodily process of inhalation and exhalation Synonyms breathing external respiration respiration Related Words artificial respiration abdominal breathing eupnea eupnoea hyperpnea hypopnea hyperventilation panting heaving Cheyne-Stokes respiration periodic breathing smoking smoke breathing out exhalation expiration snoring stertor snore sniffle snuffle snivel wheeze second wind breathing in inhalation intake aspiration inspiration bodily function bodily process body process activity
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abdominal displacement ventilation

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airway pressure release ventilation

alveolar ventilation

assist-control ventilation

asynchronous ventilation

continuous positive-pressure ventilation

differential lung ventilation

dual control ventilation

high-frequency jet ventilation

high-frequency oscillatory ventilation

high-frequency percussive ventilation

intermittent mandatory ventilation

intermittent positive-pressure ventilation

inverse ratio ventilation

liquid ventilation

mandatory minute ventilation

maximum sustainable ventilation

maximum voluntary ventilation

mechanical ventilation

minute ventilation

noninvasive ventilation

positive-pressure mechanical ventilation

pressure support ventilation

protective ventilation

pulmonary ventilation

reduced ventilation

synchronized intermittent mandatory ventilation

transtracheal catheter ventilation

volume-controlled ventilation

volume-cycled ventilation

volume-limited ventilation

ven·ti·la·tion

Patient discussion about ventilation

ventilation

Synonyms for ventilation

noun an exchanging of views

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Synonyms for ventilation

noun the act of supplying fresh air and getting rid of foul air

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noun a mechanical system in a building that provides fresh air

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noun free and open discussion of (or debate on) some question of public interest

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noun the bodily process of inhalation and exhalation

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