This chapter discusses the management of mechanical ventilation. The different modes of ventilation are controlled mandatory ventilation (CMV), assist volume control, synchronized intermittent mandatory ventilation (SIMV), pressure control (PC), and pressure support (PS). The two ventilation strategies that can be used in critically ill patients in the emergency department are lung protective strategy and obstructive strategy. Both of these strategies utilize the assist control (AC) volume cycled mode of ventilation. The lung protective strategy is designed for patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS), or who are at risk for lung injury. Obstructive strategy is designed for patients with obstructive lung disease (i.e., asthma or COPD) whose airways are constricted and therefore require a longer time to fully exhale. There are two basic pressures that should be monitored in mechanically ventilated patients: peak inspiratory pressure and plateau pressure.

This chapter discusses the management of airway. Oxygenation is the primary concern in airway management. As hemoglobin and oxygen bind cooperatively, desaturation is slow above SpO2 90%. Below 90%, hemoglobin molecules quickly lose bound oxygen, and critical hypoxia can occur in seconds. Due to the technical aspects of pulse oximetry, there is a lag of up to 2 minutes in the measured SpO2. Therefore, reading in the 80-90% range may indicate that the actual SpO2 is much lower. Laryngoscopy should be abandoned when SpO2 reads 90% in order for the patient to be reoxygenated. The goal of preoxygenation is not merely to achieve a SpO2 of 100%, but also to de-nitrogenate the lungs, completely filling the lungs with oxygen to act as an oxygen reservoir during laryngoscopy. Principles of laryngoscopy are identical for direct and video laryngoscopy, with the exception of different positioning.