Pursed Lip Breathing

Original Editor - Anas Mohamed Top Contributors - Anas Mohamed, Kim Jackson and Khloud Shreif

Introduction

Pursed-lip breathing is a simple technique which consists of inhaling through the nose and exhaling through the mouth with pursued lips. A patient is instructed to inhale through the nose for several seconds with the mouth closed and then exhale slowly over 4 to 6 seconds through lips held in a whistling or kissing position. This can be done with or without abdominal muscle contraction[1]

Significance

Pursed-lips breathing is an effective technique to

  • Improve gas exchange (both oxygen and carbon dioxide)[2]
  • Slow the rate of expiration[2]
  • Increase the volume of expired air[2]
  • Limit dynamic hyperinflation during periods of increased ventilatory demand, including daily activities and exercise[2]
  • Decrease the respiratory rate and minute ventilation[2]
  • Increase tidal volume, and reduce the work of breathing[2]
  • Relieve dyspnea and increasing exercise tolerance[2] 

Pursed-lip breathing is a technique that allows the control of oxygenation and ventilation. The technique requires a person to inspire through the nose and exhale through the mouth at a slow controlled flow. The expiratory phase of respiration is going to prolong when compared to inspiration to expiration ratio in normal breathing. This technique creates a back pressure producing a small amount of positive end-expiratory pressure (PEEP).[3]

The positive pressure created opposes the forces exerted on the airways from the flow of exhalation. As a result, pursed-lip breathing helps support breathing by the opening of the airways during exhalation and increasing excretion of volatile acids in the form of carbon dioxide preventing or relieving hypercapnia. Through purse-lip breathing, people can have relief of shortness of breath, decrease the work of breathing, and improve gas exchange. They also regain a sense of control over their breathing while simultaneously increasing their relaxation.[3]

For Pursed-lip breathing (PLB) to be effective, the individual must be able to perform the technique correctly. The technique requires proper coordination to maintain prolonged exhalation. As for the therapeutic effects, they are short-lived. The technique is limited to 3 to 5 breaths since prolonging the duration of the technique causes fatigue of the respiratory muscles and significantly lower than normal levels of carbon dioxide in a normal individual potentially leading to a decrease perfusion pressure in the brain causing syncope. Without the proper use of purse-lip breathing, an individual could exacerbate air trapping and carbon dioxide retention[3]

Technique

  1. The patient should assume a comfortable position as the therapist describes and demonstrates the technique for PLB and explains its expected benefits.[2]
  2. With a hand on the patient’s mid abdominal muscles, the therapist instructs the patient to inhale slowly through the nose.[2]
  3. The patient is then told to let the air escape gently through the pursed lips, avoiding excessive use of the abdominal muscles. Giving the patient a verbal cue, such as “imagine you want to make the flame flicker on a candle that is being held at arm’s length from you,” will enhance the patient’s understanding and performance.[2]
  4. The patient is directed to stop exhaling when an abdominal contraction is detected.[2]
  5. When able to perform PLB without cues, the patient substitutes their own hand for the therapist’s hand.[2]

References

  1. Ellen Hillegass. Essentials of Cardiopulmonary Physical Therapy. 4th edition. Elsevier. 2017
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 Joanne Watchie. Cardiovascular and pulmonary physical therapy. 2nd edition. Saunders Elsevier. 2010 
  3. 3.0 3.1 3.2 Nguyen J, Duong H. Pursed-lip Breathing. [Updated 2019 Sep 9]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan-.[1]
  4. JPursed American Lung Association. Lip Breathing. Available from: https://youtu.be/7kpJ0QlRss4
  5. Medical Cosmos. Clinical Pearl - COPD - Mechanism of Pursed Lip Breathing. Available from: https://youtu.be/PR4Z6QlYuy4