A ventilator is a medical device that supports breathing when a person’s lungs or respiratory muscles cannot function adequately. It moves air in and out of the lungs, taking over or assisting respiration. Its primary purpose is to ensure the body receives sufficient oxygen and expels carbon dioxide during severe respiratory impairment.
Understanding Ventilator Use
Patients may require ventilator support for medical conditions that impair breathing. Severe pneumonia, for instance, can lead to widespread inflammation and fluid in the lungs, hindering gas exchange. Acute respiratory distress syndrome (ARDS) involves diffuse lung injury, causing fluid to leak into air sacs and impairing oxygen absorption. These conditions prevent effective lung function.
Other respiratory illnesses such as severe asthma attacks or acute exacerbations of chronic obstructive pulmonary disease (COPD) can cause narrowing of airways, trapping air and preventing proper ventilation. Breathing becomes unsustainable, requiring mechanical assistance. Neurological events like a stroke or severe traumatic brain injury can disrupt the brain’s control over respiratory muscles, leading to inadequate breathing efforts. Spinal cord injuries may also directly impair the muscles responsible for breathing, requiring support.
Major surgery often requires temporary ventilator support, as general anesthesia can suppress natural breathing. Severe trauma, especially to the chest or lungs, can also compromise respiratory function, requiring a ventilator. Support is needed when there is an inability to move air, a failure to exchange gases, or insufficient respiratory effort.
How Ventilators Work
A mechanical ventilator delivers controlled breaths to a patient’s lungs, assisting or taking over breathing. It generates positive pressure, pushing a measured volume of air, often with oxygen, into the airways and allowing for passive exhalation. This mimics natural breathing, ensuring gas exchange.
To deliver air, a breathing tube, an endotracheal tube, is inserted into the patient’s trachea. This tube passes through the mouth or nose into the airway, connecting the patient to the ventilator. It ensures air reaches the lungs directly, without leakage.
Healthcare professionals, including respiratory therapists and doctors, set the ventilator’s parameters. These settings include the number of breaths per minute, the volume of air delivered with each breath, and the pressure at which the air is pushed into the lungs. The ventilator can provide full support, initiating every breath, or partial assistance, allowing the patient to initiate some breaths while the machine helps complete them.
Patient Experience and Management
Patients on a ventilator are sedated for comfort and cooperation. The endotracheal tube can be uncomfortable and trigger a gag reflex, requiring sedation to prevent the patient from pulling it out or fighting the ventilator. Medications like propofol or midazolam achieve a calm state.
The breathing tube passes through vocal cords, preventing speech while intubated. Communication is a challenge, requiring methods like writing, hand gestures, or eye movements to respond. Nurses and family members interpret these non-verbal cues.
The healthcare team monitors vital signs, like heart rate, blood pressure, and oxygen saturation, to assess ventilation response. Ventilator settings are under review, with adjustments made to optimize oxygen and carbon dioxide removal. Monitoring helps manage complications and ensures appropriate support.
Prolonged periods on a ventilator can lead to challenges, including muscle weakness, especially affecting the diaphragm, the primary breathing muscle. This condition, ventilator-induced diaphragm dysfunction, can prolong the need for support. Delirium, acute confusion and altered awareness, is common in critically ill patients, influenced by sedatives, sleep disruption, and the ICU environment.
Weaning and Recovery
Weaning involves gradually reducing ventilator support as the patient’s breathing improves. This approach strengthens respiratory muscles and prepares them to breathe independently. The healthcare team assesses readiness by evaluating medical condition, lung function, and overall strength.
Weaning begins with spontaneous breathing trials, where the ventilator provides minimal support, allowing the patient to do most breathing work. If the patient tolerates this, ventilator settings like breaths per minute or pressure assistance are decreased. The goal is to progressively increase respiratory effort while ensuring stability.
When the patient can breathe effectively with minimal or no ventilator support, the breathing tube is removed in a procedure called extubation. This step allows the patient to speak and swallow normally. The team monitors the patient after extubation for signs of respiratory distress.
Following extubation, patients may experience a sore throat, hoarseness, or a weak cough for a few days due to tube irritation. Physical and respiratory therapy are initiated promptly to help patients regain muscle strength, improve lung capacity, and recover from prolonged bed rest. Recovery duration varies widely, depending on initial illness severity and time on the ventilator.