The diaphragm is a dome-shaped muscle at the base of the chest, serving as the primary muscle for respiration. When a person inhales, the muscle contracts and flattens, pulling air into the lungs. An elevated diaphragm rests higher in the chest cavity than normal, impairing its function. This mechanical restriction reduces the lung volume, leading to difficulty breathing and requiring medical evaluation to determine the cause and treatment.
Understanding Diaphragm Elevation and Its Causes
Diaphragm elevation typically results from diaphragmatic paralysis or diaphragmatic eventration. Diaphragmatic paralysis is an acquired condition caused by damage to the phrenic nerve, the sole nerve controlling the diaphragm’s movement. When the phrenic nerve is injured, the muscle loses its ability to contract, causing it to ride up into the chest.
Common causes of phrenic nerve damage include surgical trauma, such as after cardiac procedures, or tumors that compress the nerve. Traumatic injuries and certain neurological disorders are also causes. If the cause remains unknown, it is referred to as idiopathic paralysis. Because the diaphragm cannot contract, it moves paradoxically upward during inhalation, compressing the lung tissue.
In contrast, diaphragmatic eventration is usually a congenital condition, though it can be acquired. Eventration occurs due to structural weakness where muscle fibers are replaced by a thin, fibrous membrane. Although the nerve supply may be intact, the muscle lacks the strength to maintain its normal position.
This structural weakness causes the diaphragm to stretch high into the chest cavity. Both paralysis (nerve damage) and eventration (structural weakness) result in the characteristic elevation that compromises lung function. The distinction between the two conditions influences the long-term prognosis and treatment strategy.
Identifying the Symptoms and Physical Impact
The physical impact of an elevated diaphragm stems from its failure to descend properly during inspiration. This failure reduces the available space for the lung to expand, leading to reduced lung capacity. The most common symptom is dyspnea, or shortness of breath, which often worsens during physical exertion.
Orthopnea is the sensation of shortness of breath when lying flat. When a person is supine, abdominal contents push the elevated diaphragm further into the chest, exacerbating lung compression. This mechanical strain can lead to significant sleep disruption and poor sleep quality.
The reduced lung function and constant effort required for breathing contribute to chronic fatigue. In cases of unilateral paralysis, where only one side is affected, symptoms may be mild at rest but become pronounced with activity. Diagnosis is confirmed using imaging studies like a chest X-ray, followed by fluoroscopy, also known as a “sniff test,” to observe the diaphragm’s paradoxical movement.
Non-Surgical Management and Watchful Waiting
For many patients, especially those with recently acquired diaphragmatic paralysis, the initial approach involves non-surgical management. Since the phrenic nerve has the potential to recover spontaneously, a period of “watchful waiting” is recommended. This observation period typically lasts between six and twelve months to allow for potential nerve healing.
During this time, conservative measures manage symptoms and support respiratory function. Positional changes, such as sleeping with the head of the bed significantly elevated, help reduce the pressure of abdominal organs on the diaphragm. This adjustment often alleviates nighttime breathlessness.
Diaphragmatic breathing, often called “belly breathing,” is a supportive measure that serves as physical therapy. These exercises focus on conscious, slow inhalation through the nose, making the abdomen rise, followed by controlled exhalation through pursed lips. The goal is to strengthen the accessory breathing muscles and maximize the function of the unaffected parts of the diaphragm.
For patients experiencing severe nocturnal shortness of breath or sleep-disordered breathing, non-invasive ventilation (NIV) may be prescribed. While Continuous Positive Airway Pressure (CPAP) is sometimes used, Bi-level Positive Airway Pressure (BiPAP) is often more effective for diaphragmatic dysfunction. BiPAP delivers a higher pressure during inhalation and a lower pressure during exhalation, actively assisting the patient’s breathing effort and improving oxygenation during sleep.
Surgical Intervention: Diaphragmatic Plication
When non-surgical management fails and symptoms remain severe after watchful waiting, or if the condition is confirmed as chronic paralysis or eventration, surgical intervention is considered. The definitive procedure is diaphragmatic plication. This operation aims to permanently flatten the elevated diaphragm and eliminate its paradoxical motion.
Plication is indicated for patients with disabling dyspnea who have confirmed permanent paralysis or symptomatic eventration. The procedure involves surgically folding the redundant, weakened portion of the diaphragm onto itself and securing it with sutures. This folding and suturing effectively tightens the diaphragm, restoring it to a lower, more normal anatomical position.
The strategic flattening of the diaphragm achieves two main goals: it increases the volume of the chest cavity, allowing the compressed lung to fully expand, and it prevents the paradoxical upward movement during inhalation. The procedure is most commonly performed using minimally invasive techniques, such as Video-Assisted Thoracoscopic Surgery (VATS) or robotic-assisted approaches. These methods involve small incisions, which generally lead to reduced post-operative pain and faster recovery times.
Patients undergoing plication typically spend only one to two nights in the hospital. Significant improvements in pulmonary function, measured by forced vital capacity (FVC), and a marked reduction in shortness of breath are common outcomes. While patients may resume normal daily activities within two weeks, the full recovery of energy and breathing capacity can continue for several months, leading to a substantial improvement in overall quality of life.