Postural drainage is a non-invasive physical therapy technique that helps people clear excess mucus from their lungs. This technique is a component of airway clearance therapy, which is often necessary when the body’s natural defense mechanisms are not sufficient to manage secretions. The entire process relies on using gravity to assist in moving accumulated mucus out of the airways. By strategically positioning the body, gravity can direct secretions from the smaller, harder-to-reach areas of the lungs toward the larger, central airways where they can be effectively coughed out.
Defining the Gravity-Assisted Technique
Postural drainage operates on a straightforward physiological principle: the strategic use of gravity to overcome the stickiness and density of excessive lung secretions. The primary goal is to move thick mucus from the peripheral airways into the central airways, specifically the trachea and main bronchi. The lungs are structured into distinct segments, and each segment drains toward its corresponding bronchus.
When a person maintains a specific body posture, gravity pulls the secretions from the targeted lung segment toward the larger, more vertical airways. Once the mucus reaches the central airways, the body’s natural cough reflex or an assisted coughing technique can more easily expel it. This mechanical assistance is necessary because diseases can impair the function of cilia, the tiny hair-like structures that normally sweep mucus upward. Regular clearance is important for maintaining respiratory health, as neglecting this buildup can foster a cycle of infection and inflammation.
Conditions That Benefit from Postural Drainage
Postural drainage is recommended for individuals who produce an excessive amount of mucus that their body struggles to clear naturally. A primary condition that benefits from this technique is bronchiectasis, a chronic disease where the airways are damaged and widened, leading to frequent infections and mucus accumulation. Patients with cystic fibrosis also routinely use postural drainage as part of their comprehensive airway clearance regimen because the disease causes the production of thick, sticky secretions.
The technique is also indicated for certain cases of severe pneumonia, where localized secretions can hinder recovery, and for some types of Chronic Obstructive Pulmonary Disease (COPD) characterized by significant mucus hypersecretion. People with neuromuscular disorders or those recovering from major thoracic or abdominal surgery may also benefit, as they often have a weakened cough reflex. For these patients, the gravity-assisted technique is a valuable tool for preventing atelectasis and infection.
Specific Body Positions and Duration
The practical application of postural drainage involves assuming various positions designed to target each of the lung’s five lobes and their numerous segments. Since the goal is to drain a specific segment, the patient is positioned so that the bronchus draining that segment is pointed downward. This often requires the patient to be tilted, sometimes with the head lower than the hips, a position known as the Trendelenburg position.
To drain the lower lobes, the patient often lies on their side or back with their hips elevated by a wedge or pillows, ensuring the chest is lower than the hips. Draining the upper lobes may involve a more upright position, such as sitting and leaning slightly forward or backward. Each position is maintained for approximately five to fifteen minutes to allow sufficient time for gravity to work on the secretions. A full treatment session involves a sequence of positions to target all affected lung segments and is frequently combined with chest physiotherapy methods, like rhythmic clapping or vibration, to help loosen the mucus further.
Important Safety Considerations and Timing
While postural drainage is a beneficial technique, it is not appropriate for everyone, and certain medical conditions serve as contraindications. Individuals with unstable blood pressure or acute cardiovascular instability, such as severe heart failure or cardiac arrhythmia, should avoid the technique, especially the head-down positions. Similarly, recent neurosurgery, head trauma, or any condition that increases intracranial pressure makes the head-down tilt unsafe.
Other precautions include active coughing up of blood (hemoptysis), recent rib fractures, or significant osteoporosis, which can be aggravated by the physical manipulation sometimes accompanying the drainage. Patients should always consult a physician or respiratory physical therapist before beginning postural drainage to determine the appropriate positions and ensure safety. The treatment is best timed to maximize effectiveness, often performed first thing in the morning to clear overnight secretions or one and a half to two hours after a meal to prevent the risk of vomiting or aspirating stomach contents.