Positive End Expiratory Pressure (P.E.E.P.)
Application and maintenance of pressure above atmospheric at the airway throughout the expiratory phas of positive pressure mechanical ventilation
Barotrauma
Physical injury sustained as a result of exposure to ambient pressures above normal, most commmonly secondary to positive pressure ventilation
Respiratory alternans
Altering between the use of diaphragm for short periods and use of the accessory muscles to breathe; indicative of end-stage respiratory muscle fatigue
Hypoxemic Respirtory Failure (Type 1)
Inability to maintain normal oxygenation in the arterial blood
Maximum Inspiratory Pressure (M.I.P.)
Measure of the output of the inspiratory muscles against a maximum stimulus, measured in cm H20 positive pressure
Maximum Expiratory Pressure (M.E.P.)
Measure of the output of expiratory muscles against a maximum stimulus, measured in cm H20 positive pressure
Maximum Voluntary Ventilation (M.V.V.)
Maximum volume of air in L/min that a subject can breathe during a 12-15 second period. It is a very patient-dependent test. Formally called the maximum breathing capacity
Muscle Fatigue
Condition involving loss of the capacity to develop force or velocity of a muscle resulting from muscle activity overload, which is reversible by rest
Tension-Time Index
Product of contractile force (ratio of diaphragmatic pressure to maximum diaphragmatic pressure) and contractile duration (ratio of inspiratory time to total breathing cycle time) used to indicate a level of contraction associated with fatigue
Work of Breathing (W.O.B.)
Amount of force needed to move a given volume into the lung with a relaxed chest wall; mathmatically, work is the integral of presssure times volume
Auto-PEEP
Pressure above atmospheric remaining at the alveoli at end-exhalation due to air trapping.
Also called intrinsic PEEP
Dynamic Hyperinflation
Increase in F.R.C. above the elastic equilibrium volume of the respiratory syste; causes include increased flow resistance, short inspiratory time, and increased postinspiratory muscle activity; see also auto-PEEP
Pressure Control Ventilation (P.C.V.)
Mode of ventilatory support in which mandatory support breaths are delivered to the patient at a set inspiratory pressure
High-Frequency Ventilation (H.F.V.)
Ventilatory support provided at rates significantly higher than normal breathing frequencies