Assist/Control Mode of Ventilation
– Ventilator operation in which a machine breath is delivered
when an inspiratory effort by the patient is sensed by
the ventilator (Assist), or at set time intervals if the
rate of occurrence of inspiratory efforts falls below
a set rate (Control).
Alternating Current having
standard frequencies of 60 Hz in North America and possibly
other frequencies in other locations internationally.
Airway Pressure (Paw)
Pressure at a specified
point in the patient’s airway.
Pressure Release Ventilation
Airway Pressure Release
Ventilation (APRV) is a mode of ventilation that provides
two levels of CPAP and allows spontaneous ventilation
at both levels. APRV is different from other modes of
ventilation in that it based on an intermittent decrease
in airway pressure, rather than an increase, to provide
ventilation. Source: RT Corner
here for full description
A means of alerting the
operator that a specified abnormal condition exists; examples:
high pressure alarm, apnea alarm.
Alveolar Pressure (PA)
in the alveoli.
Alveolus (p. alveoli)
Termination of the airways
in the lungs; primary site of gas exchange with the blood.
pertaining to data in the
form of continuously variable physical qualities in contrast
to digital data represented in discrete form.
the volume of the airways
filled with inspired gas that does not take part in gas
exchange with the blood during normal breathing.
A device that measures flow
by its cooling of a heated element.
Cessation of breathing
Ventilator operation in
which an machine breath is delivered only when an inspiratory
effort by the patient is sensed by the ventilator.
American Society for Testing
and Materials: A scientific and technical organization
formed for the development of standards on characteristics
and performance of materials, products, systems, and services.
The following published ASTM standards pertain to ventilators
and mechanical ventilation:
ASTM F 1246-91
Electrically Powered Home
Care Ventilators, Part 1 – Positive-Pressure Ventilators
and Ventilator Circuits
ASTM F 896-90 (1995)
Flexible Fiberoptic Bronchoscopes
ASTM F 920-93
Minimum Performance and
Safety Requirements for Resuscitators Intended for Use
ASTM F 927-86 (1994)
Pediatric Tracheostomy Tubes
ASTM F 965-85 (1993)
Rigid Laryngoscopes for
Tracheal Intubation – Hook-on Fittings for Laryngoscope
Handles and Blades with Lamps
ASTM F1100-90 (1997)
Ventilators Intended for
Use in Critical Care
ASTM F1195-88 (1993)
Rigid Laryngoscopes for
Tracheal Intubation – Hook-on Fittings for Fiberilluminated
Blades and Handles
Tracheal Tubes, Cuffed and
ASTM F1243-89 (1995)
Tracheal Tube Connectors
Alarm Signals In Medical
Equipment Used in Anesthesia and Respiratory Equipment
Tracheostomy Tube Connectors
Tracheostomy Tubes – Pediatric
Adult Tracheostomy Tubes
Auto Positive End-Expiratory
Pressure (also Inadvertent PEEP) – Residual alveolar pressure
above the preset baseline pressure at the end of expiration
caused by the occlusion of airways and the consequent
trapping of gas behind the occlusions.
Unintended, repeated delivery
of machine breaths caused by the dropping of pressure
in the patient circuit below the pressure trigger point.
This typically occurs if the trigger point (sensitivity)
is set too high, or if the circuit cannot hold pressure
at the end of exhalation.
AutoFlow is a ventilator feature pioneered by Draeger
Medical that changes the control strategy for a volume-controlled
breath to a pressure controlled breath under the constraint
that the breath reaches the operator-set volume. It
is defined as delivering a volume-targetted, pressure-controlled
breath. In AutoFlow, the ventilator uses algorithms
to try to determine the right peak pressure that will
allow the set volume to be delivered with the minimum
pressure. AutoFlow is a registered trademark of Draeger
A means by which that portion
of the work of breathing associated with the movement
of gas through an endotracheal or tracheostomy tube (connecting
the breathing circuit to the patient’s airway) is reduced
or eliminated by the ventilator with no, or minimal, intervention
by the operator (care giver).