Introduction

Background on pulmonary rehabilitation

Pulmonary rehabilitation (PR) is a health program aiming to assist in improving the symptoms of chronic lung diseases. It is an intervention including personalised therapies like, education, exercise training and behavior change. The program therapies are designed for the improvement of the physical and psychological condition of people suffering from chronic respiratory diseases as well as to promote the long-term adherence to health-enhancing behaviors as per the official American Thoracic Society/ European Respiratory Society statement.¹

PR has the potential to benefit people diagnosed with conditions such as COPD (chronic obstructive pulmonary disease), pulmonary hypertension, bronchiectasis, interstitial lung disease, and other chronic pulmonary disorders.

The technique is designed to guide you in understanding your breathing pattern, along with learning the way to live better with your condition, and how to improve your stamina, strength, and endurance. PR is very likely to reduce breathlessness, improve energy levels, and increase your ability to exercise and stay active.

Overview of breathing dysfunction in pulmonary diseases

Breathing Pattern Disorders (BPDs) or Dysfunctional Breathing are abnormal patterns of respiration and specifically related to over-breathing. They range from simple upper chest breathing to hyperventilation (HVS).

Dysfunctional breathing (DB) can be a result of chronic or recurrent conditions involving the disruption of the normal breathing mechanisms, that subsequently results in conditions like dyspnea (shortness of breath) and other non-respiratory symptoms associated with it. Instead of being a disease process, it involves alterations in patterns of breathing, in turn, interfering with normal respiratory processes. 

Physiology of Pursed Lip Breathing (PLB)

What is PLB?

Pursed-lip breathing (PLB) helps individuals improve their control over the processes of oxygenation and ventilation. 

This breathing technique involves breathing in through the nose followed by a slow and deep exhalation that is controlled along with being carried out through puckered or pursed lips. This leads to the “breathing out” time being longer than normal which leads to the generation of a small amount of positive end-expiratory pressure (PEEP). 

In PLB, respiratory accessory muscles, such as neck and shoulder muscles, undergo relaxation while slow and deep air inhalation is occurring through the nose followed by gentle exhalation through rounded lips. The positive pressure generated in the upper airway has effective transfer to the lower airway, helping to stop bronchial obstruction and accumulated secretions, thereby enhancing respiratory efficiency and reducing dyspnea.

During exhalation, there is increased airway resistance, leading to the trapping of carbon dioxide. 

Elevated CO₂ levels result in the stimulation of central chemoreceptors to increase the respiratory rate so that pH balance is restored to approximately 7.4. While this compensatory mechanism results in the clearance of CO₂ efficiently, it may also cause the exacerbation of air trapping and respiratory muscle tiredness. By creation of an artificial splint, PEEP leads to the prevention of airway collapse, increases surface area for the purpose of gas exchange, provides support to alveolar patency, and recruits additional alveoli for effective ventilation.

The positive pressure generated as a result of practicing PLB counteracts the inward forces during exhalation, resulting in the reduction of hypercapnia (high carbon dioxide levels) by CO₂ excretion. This technique has the potential for providing relief with shortness of breath, in addition to improving overall gas exchange. Beyond the physiological benefits provided by PLB, it also alleviates respiratory distress, enhances relaxation and empowers individuals with a sense of control over their breathing patterns.²

Role of PLB in pulmonary rehabilitation

PLB is an effective technique with considerable clinical applications, particularly for individuals suffering from dyspnea and air trapping. When carried out correctly, PLB provides significant relief due to patients regaining control over their breaths, reduces the effort required for breathing, and alleviates respiratory distress. The primary role of PLB is to relieve the retention of CO₂ and improve oxygenation, however, it is also an excellent relaxation tool, helping patients in the management of anxiety as well as overall well-being.

Apart from being an effective technique, PLB is low-cost as well supporting respiratory health across various pulmonary conditions, including chronic obstructive pulmonary disease (COPD), COVID-19 and asthma. The proven efficacy of this technique makes it an indispensable tool for the management and rehabilitation of respiratory diseases.²

Clinical evidence and studies

Comparative analysis

A crossover clinical trial was conducted with an aim to compare the diaphragmatic breathing (DB) effects and pursed-lip breathing (PLB) exercises on the quality of sleep in elderly patients with COPD. 

The study reported both variants of exercises leading to the enhancement of sleep quality in elderly patients with COPD without demonstrating significant differences. It is advisable to follow these exercises as an effective non-pharmacological approach for the improvement of sleep quality in this population.³

Another study investigated the effect of PLB exercise and diaphragmatic breathing in COPD patients, in addition to determining improvements in pulmonary function and exercise frequency and, reported that no difference in efficacy.⁴

Role of PLB in exercise training

A meta-analysis conducted by Mayer and colleagues investigated the effects of acute use of PLB in exercise performance, ventilatory parameters, dyspnoea and oxygen saturation during exercise in patients with COPD. This study reported the effectiveness of PLB leading to reduced minute ventilation and respiratory rate during exercise in patients with COPD.⁵

Summary

• Pulmonary rehabilitation (PR) is a health program aiming to assist in improving the symptoms of chronic lung diseases. It is an intervention including personalised therapies like, education, exercise training and behavior change. 
• PR is very likely to lead to reduced shortness of breath (breathlessness), lead to improvements in energy levels, and increase your ability to exercise and stay active
• Dysfunctional breathing (DB) can be a result of chronic or recurrent conditions involving the disruption of the normal biomechanical pattern of breathing, that subsequently results in conditions like dyspnea and other non-respiratory symptoms associated with it
• Pursed-lip breathing (PLB) has been designed to help individuals improve their control over the processes of oxygenation and ventilation. This breathing technique involves inhalation through the nose followed by a slow and deep exhalation that is controlled along with being carried out through puckered or rather pursed lips
• The primary role of PLB is to relieve the retention of CO2 and improve oxygenation, however, it is also an excellent relaxation tool, helping patients in the management of anxiety as well as overall well-being
• According to a few studies, it is advisable to follow these DB and PLB as an effective non-pharmacological approach for the improvement of sleep quality, exercise frequency and pulmonary function in people with COPD