Mechanical ventilation is the process by which the fraction of inspired oxygen (FiO2) is at 21 % room air or greater and moved into and out of the lungs by a mechanical ventilator. Mechanical ventilation is not curative. It is used as a means of supporting patients until they recover the ability to breathe independently, as a bridge to long-term mechanical ventilation, or until a decision is made to withdraw ventilatory support. Indications for mechanical ventilation include (1) apnea or impending ability to breathe; (2) acute respiratory failure [pH <7.25 with PaCO2 >50mmHg]; (3) severe hypoxia; and (4) respiratory muscle fatigue.
The two types of mechanical ventilation are negative-pressure ventilation and positive-pressure ventilation. Negative pressure ventilation involves the use of chambers that encase the chest or body and surround it with intermittent subatmospheric or negative pressure. It is delivered non-invasively and does not require an aritificial airway. Positive pressure ventilation is the primary method used with acutely ill paitents. Durig inspiration, the ventilator pushes air into the lungs under positive pressure. Unlink sponstaneous ventilation, intrathoracic pressure is raised rather than lowered. Expiration occurs passively as in normal expiration.
My patient was initially intubated as protocol for a transesophageal echocardiogram. Following the procedure, it was determined that she would most benefit from adaptive support ventilation (ASV). The respiratory therapist set it to a RR25, PEEP of 5%, FiO2 of 40%, and 430ml VT. After 48 hours she was extubated. Her ABGs continued to display respiratory alkalosis. See Table 1-2. There was some controversy to why she was extubated so I am not sure of the exact reason for why she was extubated. There was no apnea or oxygen desaturations following extubation. After suctioning, she appeared to be stable. For the remainder of her stay, she maintained...