Guillain-Barré Syndrome (GBS) is a rare disorder where the body’s immune system damages its peripheral nerves, which connect the brain to the rest of the body. The cause is not always clear, but it often follows a minor infection, such as a respiratory or digestive illness. Initial symptoms include weakness and tingling in the legs, which can spread to the arms and upper body.
The progression of symptoms can be rapid, developing over days or weeks. While many individuals experience a significant recovery, GBS can lead to serious complications. The most severe is respiratory failure, which occurs when nerve damage affects the breathing muscles, requiring immediate medical intervention.
How Guillain-Barré Syndrome Affects Breathing
Guillain-Barré Syndrome compromises breathing by attacking the nerves controlling the respiratory muscles, including the diaphragm and the intercostal muscles between the ribs. The immune system’s assault strips nerves of their protective myelin sheath, disrupting the transmission of signals. This is similar to how a damaged electrical cord can no longer effectively transmit power.
The phrenic nerve, which controls the diaphragm, is particularly important for breathing. If this nerve is affected, the diaphragm cannot contract properly, making it difficult to draw air into the lungs. This weakness in both inspiratory (breathing in) and expiratory (breathing out) muscles causes breathing to become shallow.
This also makes it difficult to clear secretions from the airways, increasing the risk of pneumonia and atelectasis, a condition where air sacs in the lungs collapse. In about 20-30% of GBS cases, the weakness becomes so severe that the individual cannot breathe independently and requires mechanical ventilation. The involvement of bulbar muscles, which control swallowing, can lead to aspiration, where saliva or food is inhaled into the lungs, causing a serious infection.
Signs of Impending Respiratory Failure
One of the first signs of respiratory distress is shortness of breath, which may be more pronounced when lying flat. As the muscles weaken, breathing may become rapid and shallow. An individual might find it difficult to speak in full sentences or have a weak cough, indicating that the expiratory muscles are losing strength.
In a hospital, medical staff use specific measurements to monitor respiratory function. One is Forced Vital Capacity (FVC), which measures the amount of air a person can forcefully exhale. A rapid decline in FVC is a strong indicator that the respiratory muscles are weakening and intervention may be needed.
Another measurement is Negative Inspiratory Force (NIF), which assesses the strength of the inspiratory muscles. This test measures the maximum pressure a person can generate when trying to inhale against a blocked airway. A low NIF value also indicates significant muscle weakness and potential respiratory failure.
Clinicians also monitor blood oxygen levels with pulse oximetry, though a drop can be a late sign of distress. Other indicators include a rapid progression of overall muscle weakness, difficulty lifting the head, and involvement of the facial muscles.
Management in the Intensive Care Unit
When a person with GBS develops respiratory failure, they are admitted to an intensive care unit (ICU). The primary treatment is mechanical ventilation, where a machine takes over the work of breathing. This allows the individual’s body to rest and provides time for the damaged nerves to begin healing.
A patient is connected to a ventilator through either endotracheal intubation, where a tube is passed through the mouth into the windpipe, or a tracheostomy. A tracheostomy is a surgical procedure that creates an opening in the neck for a breathing tube and is used when prolonged ventilation is expected.
ICU care extends beyond respiratory support. Nutritional needs are often met through a feeding tube, as swallowing difficulties are common. To prevent complications from immobility, such as blood clots and pressure sores, patients are repositioned frequently and may receive blood-thinning medications.
Many individuals with severe GBS also experience autonomic dysfunction, where the system controlling involuntary functions like heart rate and blood pressure becomes unstable. This can lead to dramatic fluctuations in these vital signs, requiring careful monitoring and management. Preventing infections, particularly ventilator-associated pneumonia, is also a high priority.
Weaning from Ventilation and Long-Term Recovery
As nerve function returns, the process of liberating a patient from the ventilator, known as weaning, can begin. Respiratory therapists slowly reduce the level of support from the ventilator, allowing the patient to take on more of the work of breathing. This is often done through daily trials of spontaneous breathing.
Physical and occupational therapy are started early, even while the patient is on the ventilator. Therapists perform passive range-of-motion exercises to keep joints flexible. As strength returns, therapy becomes more active, focusing on rebuilding muscle in the limbs, core, and respiratory system with specific breathing exercises.
The recovery timeline for GBS varies. While most individuals who require ventilation eventually breathe independently again, the process can take weeks or months. Some may need non-invasive ventilation, such as a mask-based device, for a period after the breathing tube is removed.
Even after successful weaning, some people may experience long-term effects like shortness of breath with exertion or persistent fatigue. Most people continue to see improvements for 6 to 12 months, and some for up to three years. The recovery process requires patience and a multidisciplinary rehabilitation team to regain as much function as possible.