22.13g Types of Ventilators

Simple out-of-hospital ventilator devices are designed for convenience and ease of use during short transports of relatively uncomplicated adult and older pediatric patients.

The devices generally allow for control of ventilatory rate and tidal volume only.

Most of these units deliver controlled ventilation only (breathe only for patients who are not breathing on their own) whereas other units function as intermittent mandatory ventilators (assisting spontaneously breathing patients), which revert to controlled mechanical ventilation in patients who are not breathing.

The inspired oxygen concentration is usually fixed at 100 percent, but it can be adjusted.

Oxygen consumption on long transports can be substantial.

Few of these devices provide CPAP.

They also offer little ability to monitor airway pressures or delivered volumes and usually do not have warning alarms but instead have a pop-off valve that prevents pressure-related injury.

When airway pressure exceeds a preset level (typically, 60 cm H2O), the valve opens, venting some of the tidal volume.

This safety feature can actually hinder ventilation in patients who require higher positive pressure, such as those with significant lung pathology (e.g., cardiogenic pulmonary edema, ARDS, pulmonary contusion, and bronchospasm).

Consider using a bag-valve device if this problem occurs.

In contrast to the simple units just described, critical care transport ventilators offer a host of features such as different ventilator modes, enhanced monitoring, alarms, and more The increased adjustability allows for keeping the patient more comfortable with less sedation, analgesia, and paralysis.

Some of these devices can be used to provide mask CPAP as well.

Inspired oxygen concentration can usually be adjusted.

These critical transport devices can be used on most pediatric patients and some neonates.

The trade-offs for these features are much higher cost and their increased complexity requires much more extensive training.

These advanced ventilators are worth considering for systems that have long transports, do a lot of interfacility transports, or have a large pediatric population.