Intermittent positive pressure ventilation (IPPV) is a medical technique used to assist or control a patient’s breathing. It involves the controlled delivery of air into the lungs to support respiratory function, ensuring sufficient oxygen intake and carbon dioxide removal for patients with compromised respiratory systems.
Understanding Positive Pressure Breathing
The fundamental principle of positive pressure ventilation involves actively pushing air into the lungs. This contrasts with natural breathing, where the diaphragm and intercostal muscles contract, creating negative pressure within the chest cavity that draws air in. A machine generates positive pressure, forcing air into the airways and expanding the lung tissue.
The “intermittent” aspect of IPPV means air delivery is cyclical, mimicking natural breathing patterns. Air is pushed into the lungs during inspiration, then pressure drops for passive exhalation. This cycling ensures lungs inflate and deflate rhythmically, preventing continuous pressure that would hinder exhalation and gas exchange. The machine controls parameters like air volume or pressure, allowing precise respiratory support.
When Intermittent Positive Pressure Ventilation is Used
Intermittent positive pressure ventilation is employed when a patient’s ability to breathe effectively is compromised. A primary indication is respiratory depression, from medications like anesthetics or weakened respiratory muscles. IPPV helps prevent hypoventilation, which can lead to excess carbon dioxide in the blood.
This method is also used for patients experiencing apnea or those in cardiorespiratory arrest. For individuals with acute respiratory insufficiency due to disease or injury, IPPV ensures adequate oxygen supply. It is also indicated for patients at risk of developing atelectasis, a condition where parts of the lung collapse.
IPPV can benefit patients with severe lung conditions such as chronic obstructive pulmonary disease (COPD) exacerbations or acute cardiogenic pulmonary edema. It may also be considered when simpler therapies have failed to improve conditions like atelectasis or in cases of severe bronchospasm. The technique can reduce the work of breathing, making it easier for exhausted patients to inhale sufficient air.
Different Ways IPPV is Delivered
Intermittent positive pressure ventilation can be delivered through non-invasive or invasive interfaces. Non-invasive methods use masks or nasal pillows that fit snugly over the patient’s face or nose. These include devices like Continuous Positive Airway Pressure (CPAP) and Bilevel Positive Airway Pressure (BiPAP) machines, which deliver positive pressure to keep airways open.
CPAP provides a constant positive pressure, while BiPAP offers two levels of pressure: one for inhalation and a lower one for exhalation.
Invasive methods involve direct access to the patient’s airway, such as an endotracheal tube inserted into the windpipe through the mouth or nose, or a tracheostomy, a surgical opening in the neck leading to the windpipe. Mechanical ventilators are used with these invasive approaches, precisely controlling the volume or pressure of air delivered. The choice depends on the patient’s condition, severity of respiratory compromise, and need for long-term ventilatory support.
What to Expect with IPPV
When undergoing intermittent positive pressure ventilation, patients typically experience the sensation of air being pushed into their lungs. The machine often produces a consistent noise. Medical professionals closely monitor parameters, including oxygen saturation, carbon dioxide levels, and blood gases, to ensure ventilation effectiveness.
IPPV is generally administered in a medical setting, such as a hospital or intensive care unit, where continuous monitoring and adjustments are made by healthcare providers. The duration of treatment varies depending on the underlying condition and the patient’s response. The goal of IPPV is to temporarily support breathing until the patient’s respiratory function improves, allowing for gradual weaning from the device. Some patients may recall the experience, while others may have limited memory of the treatment.