Continuous positive airway pressure ( CPAP ) is a form of positive respiratory pressure ventilator, which applies continuous light air pressure to keep the airways open in people able to breathe spontaneously alone. This is an alternative to positive end-expiratory pressure (PEEP). Both modalities clog the open lung alveoli and thus recruit more surface area of ​​the lung for ventilation. But while PEEP refers to a device that imposes a positive pressure only at the end of breathing, the CPAP device implies continuous positive airway pressure throughout the respiratory cycle. Thus, the ventilator itself does not cycle during CPAP, no additional pressure above the CPAP level is provided, and the patient should start all of their breath.
CPAP is usually used for people who have respiratory problems, such as sleep apnea. CPAP can also be used to treat premature babies whose lungs have not been fully developed. For example, doctors may use CPAP in infants with respiratory distress syndrome. This is associated with decreased incidence of bronchopulmonary dysplasia. In some premature infants whose lungs are not fully developed, CPAP improves survival and reduces the need for steroid treatment for their lungs. In resource-limited settings where CPAP improves respiratory rate and survival in children with primary lung disease, researchers have found that nurses can start and manage treatment with doctor rounds once or twice daily.
CPAP therapy uses a specially designed machine to provide constant pressure flow. Some CPAP machines have other features as well, such as a hot humidifier. CPAP is the most effective treatment for obstructive sleep apnea, where mild pressure from CPAP prevents airways from collapsing or becoming blocked.
Although CPAP delivery via nasal mask is the most common treatment modality, other systems exist to interact with adults and children. CPAP nose is often used in infants, although its use is controversial. Studies have shown CPAP nose reduces ventilator time but increased incidence of pneumothorax is also prevalent. A mouth mask and a naso-oral mask are often used when nasal congestion or obstruction is a problem. Devices that combine nasal pressure with the maxillary advancement device (MAD) also exist.
Video Continuous positive airway pressure
High flow therapy
Respiratory nasal passages of respiratory nasal passages are a method of providing high respiratory gas volume per minute through nasal cannula. Respiratory gas is heated to near body temperature and moisturized, usually for saturated vapor pressure. This form of respiratory support is commonly referred to as high flow therapy (HFT). HFT is also referred to as transnasal insufflation (TNI), especially when used for the treatment of sleep apnea.
The nasal cannula usually used for oxygen delivery usually gives 1-6 liters of oxygen per minute. FiO 2 - the percentage of oxygen inhaled by the patient - typically in the range of from about 24% to 35%, since 100% O 2 delivered from the cannula is diluted with air of about 21 % oxygen. The flow rate for oxygen delivery using a typical nasal cannula is limited due to anhydrous medical oxygen, and when sent from a pressurized source, the gas cools as it expands with a decrease to atmospheric pressure. Cold delivery, a dry gas that irritates the respiratory mucosa, can cause drying and nasal mucosal bleeding, may trigger bronchospasm in asthmatics, and may increase metabolic demand by cooling the body. Thus oxygen delivery by the nasal cannula is limited to less than 6 liters per minute.
Even with quiet breathing, the inspiratory flow rate in adult nares usually exceeds 12 liters per minute, and can exceed 30 liters per minute for someone with mild respiratory distress. The typical upper limit for oxygen delivery through the six liters nasal cannula per minute does not meet the average adult flow rate of inspiration, and therefore oxygen is diluted with room air during inspiration. Prior to the emergence of HFT, when high FiO 2 is required for respiratory support, special facial mask or intubation is required. With HFT, respiratory gas flow volumes are supplied that meet or exceed the patient's inspiratory flow rate, and are heated and moisturized, allowing convenient respiratory support.
For HFT, the oxygen source is usually mixed with compressed air. Hospitals typically have 350 kPa (50 psi) compression O 2 and air is available for therapeutic use. This allows air delivery, air mix and O 2 from 22% to 99%, or 100% oxygen delivery with the use of oxygen blender. The gas is then heated, generally up to about 37 Â ° C (98.6 Â ° F), and moisturized to nearly 100% relative humidity using a humidifier. The gas is transported to the patient via a heated delivery tube to prevent cooling and condensation of water vapor that has been added to the gas of breathing (ice).
HFT requires the use of a special nasal cannula and tubing large enough to provide respiratory gas flow rates of up to 50 liters per minute in adults. At the same time, the nasal cannula should be small enough so it does not close inside the nares, as this allows the flow during respiration and excess gas flow during inhalation to escape. If the cannula is closed, high flow volume may produce excessive pressure in the airways and may trigger barotrauma.
Benefits
Since the flow rate sent from the HFT can satisfy the inspiratory flow rate, the delivered gas is not diluted by the room air. FiO 2 is controlled by a doctor, and can be adjusted from 21% to 100% oxygen. High nasal flow therapy reduces breathing dead space, and results in some positive airway pressure resulting from the expiratory resistance generated by continuous high flow gas delivery. Flow rates that exceed the demand for inspiration can also provide positive pressure during inspiration. The hot humidification of the respiratory gas facilitates secretion expenditure and decreases the development of bronchial hyper-response symptoms. Some patients who require respiratory support for the benefits of bronchospasm from using air delivered by HFT without additional oxygen. HFT is useful in the treatment of sleep apnea.
Neonatus
Nasal HFT has proven useful in regulating neonatal intensive care for premature infants with respiratory infant respiratory syndrome (RDS), as it prevents many infants being intubated, and allows safe breathing management at lower FiO2 levels, thereby reducing the risk of retinopathy of prematurity or form of toxicity other oxygen.
Maps Continuous positive airway pressure
Complications
- Ingestion of air into the stomach can occur.
Settings and measurements
- CPAP
- This is a pressure applied without pause or end of airway. Generally utilize flow to produce pressure.
- PEEP
- The positive end-expiratory pressure (PEEP) is the pressure in the lungs (alveolar pressure) above the atmospheric pressure (pressure outside the body) present at the end of expiration.
- Ramp
- This feature is present in many devices and allows the user to reduce the pressure to the lowest setting and gradually increase to the set pressure. This allows the user to fall asleep with the pressure on a more comfortable setting.
- FIO2
- The percentage of O2 fractions - that is, the fraction of inspired oxygen added to the air delivered.
History
HFT was originally developed for use on race horses.
References
External links
- How to Stop Snoring, By Catherine Winters, December 25, 2016
- Find reviews of the Best CPAP Machine Guide - ConsumerAffairs.com
Source of the article : Wikipedia
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