Hygroscopy is the phenomenon of attracting and holding water molecules via either absorption or adsorption from the surrounding environment, which is usually at normal or room temperature. If water molecules become suspended among the substance's molecules, adsorbing substances can become physically changed, e.g. changing in volume, boiling point, viscosity or some other physical characteristic or property of the substance. For example, a finely dispersed hygroscopic powder, such as a salt, may become clumpy over time due to collection of moisture from the surrounding environment.
Mechanical ventilation or assisted ventilation is the medical term for using a machine called a ventilator to fully or partially provide artificial ventilation. Mechanical ventilation helps move air into and out of the lungs, with the main goal of helping the delivery of oxygen and removal of carbon dioxide. Mechanical ventilation is used for many reasons, including to protect the airway due to mechanical or neurologic cause, to ensure adequate oxygenation, or to remove excess carbon dioxide from the lungs. Various healthcare providers are involved with the use of mechanical ventilation and people who require ventilators are typically monitored in an intensive care unit.
Positive airway pressure (PAP) is a mode of respiratory ventilation used in the treatment of sleep apnea. PAP ventilation is also commonly used for those who are critically ill in hospital with respiratory failure, in newborn infants (neonates), and for the prevention and treatment of atelectasis in patients with difficulty taking deep breaths. In these patients, PAP ventilation can prevent the need for tracheal intubation, or allow earlier extubation. Sometimes patients with neuromuscular diseases use this variety of ventilation as well. CPAP is an acronym for "continuous positive airway pressure", which was developed by Dr. George Gregory and colleagues in the neonatal intensive care unit at the University of California, San Francisco. A variation of the PAP system was developed by Professor Colin Sullivan at Royal Prince Alfred Hospital in Sydney, Australia, in 1981.
Oxygen therapy, also referred to as supplemental oxygen, is the use of oxygen as medical treatment. Supplemental oxygen can also refer to the use of oxygen enriched air at altitude. Acute indications for therapy include hypoxemia, carbon monoxide toxicity and cluster headache. It may also be prophylactically given to maintain blood oxygen levels during the induction of anesthesia. Oxygen therapy is often useful in chronic hypoxemia caused by conditions such as severe COPD or cystic fibrosis. Oxygen can be delivered via nasal cannula, face mask, or endotracheal intubation at normal atmospheric pressure, or in a hyperbaric chamber. It can also be given through bypassing the airway, such as in ECMO therapy.
In medicine, a nebulizer or nebuliser is a drug delivery device used to administer medication in the form of a mist inhaled into the lungs. Nebulizers are commonly used for the treatment of asthma, cystic fibrosis, COPD and other respiratory diseases or disorders. They use oxygen, compressed air or ultrasonic power to break up solutions and suspensions into small aerosol droplets that are inhaled from the mouthpiece of the device. An aerosol is a mixture of gas and solid or liquid particles.
Esophageal speech, also known as esophageal voice, is an airstream mechanism for speech that involves oscillation of the esophagus. This contrasts with traditional laryngeal speech, which involves oscillation of the vocal folds. In esophageal speech, pressurized air is injected into the upper esophagus and then released in a controlled manner to create the airstream necessary for speech. Esophageal speech is a learned skill that requires speech training and much practice. On average it takes 6 months to a year to learn this form of speech. Because of the high level of difficulty in learning esophageal speech, some patients are unable to master the skill.
Laryngectomy is the removal of the larynx. In a total laryngectomy, the entire larynx is removed with the separation of the airway from the mouth, nose and esophagus. In a partial laryngectomy, only a portion of the larynx is removed. Following the procedure, the person breathes through an opening in the neck known as a stoma. This procedure is usually performed by an ENT surgeon in cases of laryngeal cancer. Many cases of laryngeal cancer are treated with more conservative methods. A laryngectomy is performed when these treatments fail to conserve the larynx or when the cancer has progressed such that normal functioning would be prevented. Laryngectomies are also performed on individuals with other types of head and neck cancer. Less invasive partial laryngectomies, including tracheal shaves and feminization laryngoplasty may also be performed on transgender women and other female or non-binary identified individuals to feminize the larynx and/or voice. Post-laryngectomy rehabilitation includes voice restoration, oral feeding and more recently, smell and taste rehabilitation. An individual's quality of life can be affected post-surgery.
A humidifier is a household appliance or device designed to increase the moisture level in the air within a room or an enclosed space. It achieves this by emitting water droplets or steam into the surrounding air, thereby raising the humidity.
The nasal cannula (NC) is a device used to deliver supplemental oxygen or increased airflow to a patient or person in need of respiratory help. This device consists of a lightweight tube which on one end splits into two prongs which are placed in the nostrils curving toward the sinuses behind the nose, and from which a mixture of air and oxygen flows. The other end of the tube is connected to an oxygen supply such as a portable oxygen generator, or a wall connection in a hospital via a flowmeter. The cannula is generally attached to the patient by way of the tube hooking around the patient's ears or by an elastic headband, and the prongs curve toward the paranasal sinuses. The earliest, and most widely used form of adult nasal cannula carries 1–3 litres of oxygen per minute.
A bag valve mask (BVM), sometimes known by the proprietary name Ambu bag or generically as a manual resuscitator or "self-inflating bag", is a hand-held device commonly used to provide positive pressure ventilation to patients who are not breathing or not breathing adequately. The device is a required part of resuscitation kits for trained professionals in out-of-hospital settings (such as ambulance crews) and is also frequently used in hospitals as part of standard equipment found on a crash cart, in emergency rooms or other critical care settings. Underscoring the frequency and prominence of BVM use in the United States, the American Heart Association (AHA) Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiac Care recommend that "all healthcare providers should be familiar with the use of the bag-mask device." Manual resuscitators are also used within the hospital for temporary ventilation of patients dependent on mechanical ventilators when the mechanical ventilator needs to be examined for possible malfunction or when ventilator-dependent patients are transported within the hospital. Two principal types of manual resuscitators exist; one version is self-filling with air, although additional oxygen (O2) can be added but is not necessary for the device to function. The other principal type of manual resuscitator (flow-inflation) is heavily used in non-emergency applications in the operating room to ventilate patients during anesthesia induction and recovery.
Positive end-expiratory pressure (PEEP) is the pressure in the lungs above atmospheric pressure that exists at the end of expiration. The two types of PEEP are extrinsic PEEP and intrinsic PEEP. Pressure that is applied or increased during an inspiration is termed pressure support. PEEP is a therapeutic parameter set in the ventilator, or a complication of mechanical ventilation with air trapping (auto-PEEP).
A tracheo-esophageal puncture is a surgically created hole between the trachea (windpipe) and the esophagus in a person who has had a total laryngectomy, a surgery where the larynx is removed. The purpose of the puncture is to restore a person’s ability to speak after the vocal cords have been removed. This involves creation of a fistula between trachea and oesophagus, puncturing the short segment of tissue or “common wall” that typically separates these two structures. A voice prosthesis is inserted into this puncture. The prosthesis keeps food out of the trachea but lets air into the esophagus for oesophageal speech.
Mucociliary clearance (MCC), mucociliary transport, or the mucociliary escalator describes the self-clearing mechanism of the airways in the respiratory system. It is one of the two protective processes for the lungs in removing inhaled particles including pathogens before they can reach the delicate tissue of the lungs. The other clearance mechanism is provided by the cough reflex. Mucociliary clearance has a major role in pulmonary hygiene.
Respiratory gas humidification is a method of artificially conditioning respiratory gas for the patient during therapy, and involves humidification, warming, and occasionally filtration of the gas being delivered. If these three measures are not performed to compensate for the natural conditioning of air by the respiratory system, lung infections and lung tissue damage may occur. This is particularly problematic in high gas-flow therapies such as [mechanical ventilation], in patient populations with highly sensitive respiratory tracts, or among those requiring ventilation for longer periods of time. The two methods currently available for this purpose are active or passive respiratory gas humidification.
Pulmonary hygiene, also referred to as pulmonary toilet, is a set of methods used to clear mucus and secretions from the airways. The word pulmonary refers to the lungs. The word toilet, related to the French toilette, refers to body care and hygiene; this root is used in words such as toiletry that also relate to cleansing.
Hyperinflation therapy (HIT) is a very common therapy performed on patients who have some sort of respiratory distress. The therapy involves applying volumes greater than normal to reinflate the collapsed alveoli in the lungs. There are many different techniques used to administer hyperinflation therapy. The respiratory therapist typically decides which method is best for each patient.
A voice prosthesis is an artificial device, usually made of silicone that is used in conjunction with voice therapy to help laryngectomized patients to speak. During a total laryngectomy, the entire voice box (larynx) is removed and the windpipe (trachea) and food pipe (esophagus) are separated from each other. During this operation an opening between the food pipe and the windpipe can be created. This opening can also be created at a later time. This opening is called a tracheo-esophageal puncture. The voice prosthesis is placed in this opening. Then, it becomes possible to speak by occluding the stoma and blowing the air from the lungs through the inside of the voice prosthesis and through the throat, creating a voice sound, which is called tracheo-esophageal speech. The back end of the prosthesis sits at the food pipe. To avoid food, drinks, or saliva from coming through the prosthesis and into the lungs, the prosthesis has a small flap at the back. There are two ways of inserting the voice prosthesis: through the mouth and throat with the help of a guide wire, or directly through the tracheostoma (anterograde) manner. Nowadays, most voice prosthesis are placed anterograde, through the stoma.
Heat and moisture exchangers (HME) are used after laryngectomy to help reduce breathing restrictions and compensate nasal functions.
Surgical humidification is the conditioning of insufflation gas with water vapour (humidity) and heat during surgery. Surgical humidification is used to reduce the risk of tissue drying and evaporative cooling.
A breathing apparatus or breathing set is equipment which allows a person to breathe in a hostile environment where breathing would otherwise be impossible, difficult, harmful, or hazardous, or assists a person to breathe. A respirator, medical ventilator, or resuscitator may also be considered to be breathing apparatus. Equipment that supplies or recycles breathing gas other than ambient air in a space used by several people is usually referred to as being part of a life-support system, and a life-support system for one person may include breathing apparatus, when the breathing gas is specifically supplied to the user rather than to the enclosure in which the user is the occupant.
