Physiology of Ventilation and Mechanical Ventilation
Positive Pressure Ventilation
Monitoring During Mechanical Ventilation
Complications of Positive Pressure Ventilation
Patient-Focused Mechanical Ventilation
Weaning and Liberation From Ventilation
Summary and Conclusions
Review the determinants of oxygenation and ventilation.
Compare the different modes of mechanical ventilatory support.
Examine the role and methods for noninvasive positive pressure ventilation.
Examine the value of monitoring and ventilator graphics in understanding patient-ventilator asynchrony.
Describe the complications associated with mechanical ventilatory support, including auto-PEEP (positive end-expiratory pressure) and ventilator-associated lung injury.
Review the importance of patient-focused ventilation, particularly differentiating ventilation strategies for obstructive lung disease and for ARDS.
Review the rationale and results of studies supporting a lung protective ventilation strategy for acute lung injury/ARDS.
Examine structured protocols on liberation from mechanical ventilation and the endotracheal tube.
Mechanical ventilatory support is used as a key component of the management of both hypoxemic respiratory failure and hypercapnic respiratory failure—topics discussed in more detail in other chapters. The principal techniques for providing artificial ventilation have changed over the past century. Negative pressure support achieved widespread use in the polio epidemic in the 1920s with the Drinker “Iron Lung,” followed by introduction of other negative pressure devices. However, positive pressure ventilation, typically delivered through an artificial tracheal airway, has achieved broad acceptance, while negative pressure ventilation is rarely used in current practice. While the patient-ventilator interface for positive pressure ventilation is most often an endotracheal tube or tracheostomy tube, the less invasive approach of using a tightly fitting full oronasal or nasal mask has achieved widespread use for selected forms of respiratory failure. Advances in mechanical ventilator technology during the past 50 years have included efficient demand valves for triggered ventilation delivery, computerized integration of physiologic measurements and gas delivery parameters, accurate gas blending systems, and advanced monitoring and safety systems that have resulted in more options for the clinician to match mechanical ventilation to patient needs, better patient-ventilator interactions, and greater patient safety. Recent experience with mechanical ventilation (MV) for ARDS illustrates that proper MV influences not just gas exchange, but also survival and other important outcomes.