The Effects of High Plateau Pressures

Respiratory failure, sepsis, heart failure and other serious ailments can cause a person to be placed on a ventilator, a device that breathes for a patient when he is unable to breathe on his own. Health care providers who work with ventilated patients must have the ability to recognize an individuals' respiratory status. This ability includes knowledge of the variables associated with mechanical ventilation, including plateau pressure.

Mechanical Ventilators

• Mechanical ventilation is classified based on the pattern of respiratory support that a patient receives while on a ventilator. These devices are designed to alter, transmit and direct energy to a patient's lungs in a way that simulates the work of breathing a person would normally perform on her own. However, this type of ventilation is not perfect, so the functional performance of these machines is not a cure all. When a person's lungs have failed for one reason or another, applying mechanical intervention for respiratory support should be as short term as possible.

Ventilator Modes

• Pressure support ventilation is a spontaneous breathing mode that can be used alone or in combination with other modes of ventilation, such as continuous positive airway pressure, or CPAP. A preset level of inspiratory pressure is delivered by the ventilator above the baseline pressure with each spontaneous breath taken by the patient. Volume-support ventilation combines pressure support ventilation with the safety of a volume guarantee during spontaneous breathing. Regardless of the mode, a preset respiratory rate can be set enabling the ventilator to breath for the patient when he cannot breathe on his own.

Measuring the Plateau Pressure

• A respiratory therapist most often manages the hour-by-hour monitoring of a patient's breathing when she is on a ventiloator. The therapist will record the patient's ventilator parameters as a way of more easily recognizing changes in her respiratory status. One of these parameters is the patient's plateau pressure. To know a patient's actual plateau pressure, the therapist will initiate an inspiratory hold by pressing the inspiratory hold button for one-half to one second. This process measures the patient's airway pressure from the peak of her breath until it drops down to a plateau.

Effects of High Pressure

• Plateau pressure in positive pressure ventilation is the pressure applied within the lung and small airways. Too high a pressure will cause trauma to the air sacs or alveoli in the lungs, so it is important to keep the plateau pressure within a specific range while on the ventilator. High plateau pressures require changes in ventilator modes, including a change in the level of oxygen, referred to as the FI02, until the pressures fall within a more acceptable level.