CMV = Controlled Mechanical Ventilation or Continuous Mandatory Breath Trigger
ACV = Assist-Control Ventilation
IMV = Intermittent Mandatory Ventilation
SIMV = Synchronized IMV
PSV = Pressure Support Ventilation
PCV = Pressure Control Ventilation
CiPAP = Bi-level Positive Airway Pressure

*1. CPAP (continuous positive airway pressure) is an elevated baseline pressure throughout a spontaneous inspiratory and expiratory cycle that does not provide alveolar ventilation. PEEP (positive end-expiratory pressure) may be used with all vent. modes for improved oxygenation, improved lung compliance, FRC, shunt fraction and redistribution of lung water. PS (pressure support) may be added to spontaneous respiratory efforts.
*2. Spontaneous breaths are patient-cycled and patient-triggered. Mandatory breaths are always machine/time cycled and/or triggered. IMV and SIMV allow unassisted spontaneous respirations.
*3. Weaning modes refers to those methods that will allow patients to gradually share and to eventually assume completely, the work of breathing. May also consider progressive T-piece trials.
*4. I:E = Inspiratory:Expiratory ratio - I:E range 1:5 to 5:1. I:E ratio > 1:1, requires the use of Inverse Ratio Ventilation (IRV) and may require sedation and paralysis.
*5. NIPPV = Noninvasive positive pressure ventilation: Requiring the use of either nasal pillows, nasal mask or facial mask for delivery of CPAP, BiPAP, Pressure Support or Volume-cycled ventilatory support. Clinical indications may include COPD exacerbation, acute pulmonary edema, neuromuscular disease, control of breathing disorders (OSAS, OHS…) or thoracic cage deformity. Complications of NIPPV may include leaks at interface, skin abrasion/ulceration, conjunctivitis, aerophagia with possible risk of aspiration, claustrophobia, patient intolerance, rhinitis, nasal drying and transient periods of hypoxemia with removal of nasal/facial apparatus.
*6. Dynamic hyperinflation or pulmonary air trapping during mechanical ventilation occurs when there is insufficient expiratory time to allow the lungs to decompress to their FRC or relaxation volume before the next tidal volume inspiration. This alteration of normal lung mechanics may produce an auto-PEEP effect …an increased end-respiratory elastic recoil pressure. Auto-PEEP may occur with or without dynamic hyperinflation. Clinically, it may occur with COPD, asthma, or other ventilatory patterns incorporating shortened expiratory times. Corrective measures may include reduction of airflow obstruction, and/or expiratory time with flow rate. Addition of external PEEP may help ventilator triggering in patients with dynamic hyperinflation.