Glossary

ARDS

Acute respiratory distress syndrome (ARDS) is a type of respiratory failure characterized by rapid onset of widespread inflammation in the lungs. Symptoms include shortness of breath, rapid breathing, and bluish skin coloration.

ASSIST-CONTROL VOLUME-CYCLED (AC/VC)

Assist-Control (AC) mode is one of the most common methods of mechanical ventilation. AC ventilation is a volume-cycled mode of ventilation. It works by setting a fixed Tidal Volume (TV) that the ventilator will deliver at set intervals of time or when the patient initiates a breath.

BILEVEL POSITIVE AIRWAY PRESSURE (BIPAP)

BiPAP (also referred to as BPAP) stands for Bilevel Positive Airway Pressure and is very similar in function and design to a CPAP machine (continuous positive airway pressure). Similar to a CPAP machine, the BPAP machine is a non-invasive form of therapy for patients suffering from sleep apnea.

BREATHS PER MINUTE (BPM)

The normal respiration rate for an adult at rest is 12 to 20 breaths per minute. A respiration rate under 12 or over 25 breaths per minute while resting is considered abnormal.

CONTINUOUS MANDATORY VENTILATION (CMV)

A mode of mechanical ventilation in which breaths are delivered based on set variables. The ventilator is set to deliver breaths according to parameters selected by the operator to a patient who is sedated and/or paralyzed.

CONTINUOUS POSITIVE AIRWAY PRESSURE (CPAP)

CPAP is an acronym for Continuous Positive Airway Pressure.

EXHALATION VALVE CONTROL

In the context of a ventilator, a control signal or pressure would operate a valve on the Patient Circuit, opening a valve to allow the patient to exhale, and closing during inhalation to prevent loss of inhalation pressure.

I/E RATIO

Inspiratory - Expiratory ratio refers to the ratio of inspiratory time to expiratory time. In normal spontaneous breathing, the expiratory time is about twice as long as the inspiratory time.

INTENSIVE CARE UNIT (ICU)

A special department of a hospital or health care facility that provides intensive treatment medicine for patients with severe or life-threatening illnesses and injuries, which require constant care, close supervision, life support equipment and medication in order to ensure normal bodily functions.

INTUBATION

In the context of ventilation, this is the medical procedure of involving the insertion of a tube into the trachea for the delivery of air to the lungs. Intubation is invasive intervention.

LMIC

Low to Middle Income Country.

MANOMETER

A manometer measures pressure of the air being inhaled into or exhaled from the patient’s lungs and is normally in the range of 0 to 60 cm H20.

NASAL CANNULA

A device used to deliver supplemental oxygen or increased airflow to a patient or person in need of respiratory help.

NEGATIVE PRESSURE

In the context of an ICU, this is a low-level suction of air from the unit to prevent pathogens from escaping the ICU as medical staff enter and exit the unit.

NON-INVASIVE BREATHING ASSISTANCE

Refers to the administration of ventilatory support without using an invasive artificial airway (endotracheal tube or tracheostomy tube).

PATIENT AIRWAY PRESSURE (PAP)

Positive airway pressure (PAP) is a mode of respiratory ventilation used in the treatment of sleep apnea. CPAP is an acronym for Continuous Positive Airway Pressure.

PATIENT CIRCUIT

In the context of a ventilator, the Patient Circuit is the tubing that delivers air from the ventilator to the patient and may include an exhalation valve for exhausting the exhaled air without pushing it back into the ventilator.

PEEP

Positive End-Expiratory Pressure (PEEP) is the pressure in the lungs (alveolar pressure) above atmospheric pressure (the pressure outside of the body) that exists at the end of expiration. The two types of PEEP are extrinsic PEEP (PEEP applied by a ventilator) and intrinsic PEEP (PEEP caused by an incomplete exhalation).

POSITIVE PRESSURE

Pressure within a system that is greater than the environment that surrounds that system. Consequently, if there is any leak from the positively pressured system it will egress into the surrounding environment.

SPONTANEOUS BREATHING TEST/TRIAL

Assessment of the patient's ability to breathe while receiving minimal or no ventilator support.

TIDAL VOLUME (TV)

The volume of air moved into and out of the lungs during each ventilation cycle.

VENTILATOR

A machine that provides mechanical ventilation by moving breathable air into and out of the lungs, to deliver breaths to a patient who is physically unable to breathe or breathing insufficiently.

WEAN OR WEANING (FROM MECHANICAL VENTILATION)

Weaning or withdrawal from mechanical ventilation is to gradually decrease ventilator support for a patient. A patient can only be considered for weaning (withdrawal) if they are able to support their own ventilation and oxygenation.