Recall now that Type 2 respiratory failure defined by hypoxia AND hypercapnoea is due to ventilatory failure, treat the oxygenation by providing increased MAP.In addition, treat hypercapnoea by increasing the minute ventilation (MV) by increasing the tidal volume. (MV = Respiratory rate multiplied by Tidal Volume).Tidal volume can be manipulated by providing a further increase of pressure at beginning of inspiration, this is called inspiratory positive airway pressure (IPAP). It lasts only during inspiration.At expiration, the airway pressure drops to an elevated (compared to patients intrinsic) PEEP called expiratory positive airway pressure (EPAP).
Imagining that the alveoli collapses with every breath out, then must re-expand on inspiration shows why energy expenditure is increased in COVD pneumonia. Pulmonary infiltrates disturb the respiratory mechanics of ventilation, pulmonary infiltrates cause collapse of normally open alveolar units.CPAP delivers a continuous pressure (greater than the patient’s own (intrinsic) airway pressure (PEEP)) that splint airway, improving recruitment and reduced work of breathing.Remembering that Arterial oxygenation (Pa02) is proportional to the Mean Airway Pressure (MAP) multiplied by Fraction of Inspired Oxygen (Fi02) will help understand why delivery of pressurised air/oxygen mix will vastly improve hypoxia.
Recall now that Type 2 respiratory failure defined by hypoxia AND hypercapnoea is due to ventilatory failure, treat the oxygenation by providing increased MAP.
In addition, treat hypercapnoea by increasing the minute ventilation (MV) by increasing the tidal volume. (MV = Respiratory rate multiplied by Tidal Volume).
Tidal volume can be manipulated by providing a further increase of pressure at beginning of inspiration, this is called inspiratory positive airway pressure (IPAP). It lasts only during inspiration.
At expiration, the airway pressure drops to an elevated (compared to patients intrinsic) PEEP called expiratory positive airway pressure (EPAP). 