Patient ventilation involves providing breathing support to individuals who cannot adequately breathe on their own. This support is delivered by a machine called a ventilator, which assists or completely takes over the natural breathing process. Ventilation is employed in various medical scenarios, such as during surgical procedures, in cases of respiratory failure due to lung conditions or infections, or following brain injuries where the communication between the brain and lungs is impaired. Its primary purpose is to ensure the body receives sufficient oxygen and effectively removes carbon dioxide.
Non-Invasive Ventilation: The Initial Approach
Non-invasive ventilation (NIV) provides breathing support without the need for a tube inserted directly into the patient’s airway. Instead, it uses a mask that fits over the nose or both the nose and mouth. This method delivers positive airway pressure, helping to keep the air sacs in the lungs open and improving oxygen transfer.
Common forms of NIV include Continuous Positive Airway Pressure (CPAP) and Bilevel Positive Airway Pressure (BiPAP). CPAP delivers a single, continuous level of positive pressure throughout the breathing cycle, which is effective for conditions like obstructive sleep apnea and acute pulmonary edema. BiPAP provides two distinct pressure levels: a higher pressure during inhalation (inspiratory positive airway pressure, IPAP) and a lower pressure during exhalation (expiratory positive airway pressure, EPAP), which helps reduce the work of breathing.
NIV is frequently the initial choice due to its advantages. It avoids the risks associated with invasive procedures, such as infection, and does not require heavy sedation, allowing patients to remain conscious, communicate, and eat. This approach also helps preserve the patient’s natural airway reflexes. NIV is often used for conditions like chronic obstructive pulmonary disease (COPD) exacerbations, acute heart failure with pulmonary edema, and acute hypoxic respiratory failure.
Invasive Mechanical Ventilation: When It’s Necessary
Invasive mechanical ventilation (IMV) involves providing breathing support through a tube inserted directly into the patient’s trachea, typically via a procedure called intubation. During intubation, a healthcare provider guides an endotracheal tube through the mouth or nose and into the windpipe, connecting it to a ventilator. This tube allows the ventilator to completely take over breathing.
IMV becomes necessary in situations where a patient cannot breathe adequately on their own or protect their airway. This includes severe respiratory failure, loss of consciousness, or during major surgeries requiring general anesthesia. It is also used when non-invasive methods fail.
Unlike NIV, IMV requires sedation to ensure patient comfort and prevent the patient from fighting the ventilator. While life-saving, IMV carries risks, such as ventilator-associated pneumonia, vocal cord damage from the tube, and lung injury from the pressure or volume delivered by the ventilator. The care involved with IMV is more intensive, requiring monitoring in an intensive care unit.
Considerations for Method Selection
Medical professionals consider several factors when deciding between non-invasive and invasive ventilation. The patient’s underlying condition and the cause and severity of their respiratory failure are primary considerations. For instance, NIV is preferred for COPD exacerbations, while severe acute respiratory distress syndrome (ARDS) necessitates IMV.
The patient’s overall health, including any existing medical conditions, plays a role in the decision-making process. The level of consciousness and the ability to protect their airway, such as having an intact gag reflex, are also important. Patients who are cooperative and can protect their airway are better candidates for NIV.
The goals of care are also discussed, ensuring the chosen method aligns with the patient’s wishes and prognosis. The “preferred” method is a dynamic choice, individualized to each patient’s changing needs and treatment response. Continuous monitoring of the patient’s respiratory status and gas exchange is performed, allowing for transitions between ventilation methods if the patient’s condition changes.