BOOK EXCERPT
Clinical Management Notes and Case Histories in Cardiopulmonary Physical Therapy
W. Darlene Reid, BMR(PT), PhD; Frank Chung, BSc(PT), MSc

CHAPTER TWELVE
Breathing Exercises

OBJECTIVES

Upon completion of this chapter, the therapist should be able to:

1. Describe the therapeutic rationale for different breathing exercise techniques
2. Describe the level of evidence to support different breathing exercise techniques
3. Effectively prescribe and instruct breathing exercises for acute medical and surgical patients and those with chronic respiratory disease

BRIEF DESCRIPTION

Breathing exercises can be used to optimize gas exchange, promote lung expansion, minimize atelectasis, decrease dyspnea, and promote secretion removal. This chapter will focus on 2 major types of breathing exercises:

1. Those used to promote lung expansion and minimize atelectasis. These techniques include deep breathing, deep breathing with breath stacking, deep breathing with inspiratory hold, and incentive spirometry.
2. Those used to reduce dyspnea and to promote lung expansion or minimize atelectasis in individuals with moderate to severe chronic respiratory disease. These include breathing control and pursed lip-breathing techniques.

RATIONALE — FACTORS THAT AFFECT VENTILATION

Time Constants

A time constant is the product of the compliance and resistance of an alveolar unit. In healthy individuals, the time constants of the 3 million alveolar units in the lungs are relatively uniform. In lung disease, the alveoli may become more or less compliant (less or more stiff) and the small airways leading to these alveoli can develop increased resistance. Those alveolar units with increased resistance will take longer to fill. Those alveoli that are stiffer will take a greater inspiratory effort to fill.

Inspiratory Flow Rate

Slower deeper breaths allow regions with long time constants to fill more. This is thought to be a major reason why breathing control and pursed lip breathing techniques result in improved gas exchange; however, the evidence supporting this postulate is speculative. It has been shown that slow inspiration (<0.2 L/s) from FRC will fill lower lung regions and a faster inspiration will fill upper lung regions in subjects with healthy lungs.¹ Slow deep inspiration with an inspiratory hold also tends to produce a more uniform distribution of ventilation with a minimal gradient between the apices and bases when compared to rapid inspiration.

Voluntarily Altering Regional Ventilation—Can We Instruct Patients to Ventilate a Specific Lung Region?

In the 1970's, unilateral breathing techniques by applying pressure with either a hand or a towel over 1 side in order to facilitate regional lung expansion were considered to be viable treatment options^2,3; however, Martin et al⁴ showed that instruction to enhance or restrict unilateral breathing had no effect on rate of ventilation, perfusion, nor oxygen uptake. Subsequent research has shown that healthy people are able to direct inspiration to upper or lower lung regions upon instruction.^5-7 Whether this technique may be of benefit in patients has not yet been shown.

Gravity and Closing Volume

Both gravity and closing volume have profound effects on regional ventilation. See Chapter 13 for more details.

EVIDENCE

Grade B—Evidence from small, randomized trials support the use of breathing exercises and incentive spirometry^8,9 to promote lung expansion postoperatively.¹⁰ A similar level of evidence supports the use of breathing control/pursed lip techniques but not diaphragmatic breathing in people with chronic respiratory disease.^11-13

BREATHING EXERCISES OR MOBILIZATION ONLY IN ACUTE CARE PATIENTS

The answer to that question is to do both. After upper abdominal surgery, patients who did deep breathing exercises had significantly larger increases in tidal volume whereas ambulation alone did not result in a significant increase.¹⁴ Of likely greater benefit, the therapist should instruct patients to breathe deeply while ambulating.

INDICATIONS FOR BREATHING EXERCISES
IN PATIENTS WITH NO CHRONIC LUNG DISEASE

• Postoperatively especially in high-risk individuals:
  • Elderly
  • Smokers
  • Obese
  • Compounding medical conditions—eg, immunosuppressed, neuromuscular dysfunction

• Postoperatively especially in those following high-risk surgeries:
  • Thoracic or upper abdominal surgery
  • Long duration of general anesthetic and surgery

• Clinical signs of atelectasis or lung infection:
  • Elevated temperature
  • Chest x-ray signs consistent with atelectasis or lung infection
  • Abnormal physical and auscultatory signs consistent with atelectasis or lung infection
  • Hypoxemia

INDICATIONS FOR INCENTIVE SPIROMETRY

Same indications as those shown previously and:

• Those who are high-risk cases, including patients with restricted mobility
• The use of incentive spirometry in patients with sickle cell anemia was shown to decrease pulmonary complication rate⁸
• Routine use of incentive spirometer in conjunction with respiratory physical therapy is questionable¹⁵
• Contraindicated in patients with moderate to severe COPD and acute asthma who have an increased respiratory rate and hyperinflation. In these patients, if the incentive spirometer technique does not allow the patient to fully expire, it should not be used

IS INCENTIVE SPIROMETRY SUPERIOR TO BREATHING EXERCISES?

Two systematic reviews^16,17 reported no advantage of the use of incentive spirometry over other treatment techniques such as deep breathing exercise, and continuous positive airway pressure. A common problem with the studies selected by these reviews was small sample sizes, resulting in a lack of statistical power to identify a significant difference if a difference existed. In other words, with the small sample sizes used in these studies, only treatments with very large effect size could have been identified. In addition, it is difficult to control other confounding factors such as deep breathing, coughing, and ambulation in clinical studies, which will likely affect the effectiveness of incentive spirometry.

Two recent randomized control trials that reported beneficial effects with the use of incentive spirometer were not included in the 2 systematic reviews. Bellet et al⁸ compared incentive spirometry to no incentive spirometry in patients with sickle cell diseases. The incidence of pulmonary complications was significantly lower in the incentive spirometry group—1/19 in spirometry group versus 8/19 in the nonspirometry group. This study showed an important decrease in complication rate for those patients who used incentive spirometry. Whether this benefit will be shown in other patient groups needs to be tested. Weiner et al⁹ compared the use of incentive spirometry and inspiratory muscle training on pulmonary function after lung resection. They reported improvement in pulmonary function 2 weeks before surgery and 3 months after surgery between the treatment and nontreatment groups. However, it is not known whether incentive spirometry or inspiratory muscle training alone was more beneficial.

INDICATIONS FOR BREATHING EXERCISES
IN PATIENTS WITH CHRONIC RESPIRATORY DISEASE

Pursed lip breathing exercises have primarily been shown to be effective in patients with chronic obstructive respiratory diseases but may also benefit those with other chronic respiratory problems. These techniques can be used for in- and outpatients with chronic respiratory disease based on the following criteria:

• Clinically significant dyspnea at rest or with activities and exercise
• Atelectasis
• Pneumonia
• As an adjunct for relaxation techniques
• As an adjunct for secretion removal techniques

Figure 12-1. Volumetric type incentive spirometer. Voldyne, Sherwood Medical, St. Louis, Mo.	Figure 12-2. Flow rate type incentive spirometer. Portex incentive spirometer, Sims Portex Inc, Fort Myers, Fla.
	Figure 12-3. Flow rate type incentive spirometer. Tri Ball, Leventon, Barcelona, Spain.

Breathing Exercises

For all breathing exercises, position patient in an upright position when possible.

1. Those to promote basal lung expansion and minimize atelectasis—use when patient has no chronic obstructive pulmonary disease

• Assesses the inspiratory effort of the patient and position the patient accordingly.
• Frequent position change and deep breathing in different positions are encouraged.
• Deep breathing exercises with slow sustained inspiration:
  • Emphasize diaphragmatic and lateral costal expansion. Place hands over lower lateral aspects of chest wall.
  • Emphasize minimal upper chest movement.

• Deep breathing exercises with maximum end-inspiratory hold.
  • Same as above—deep breathing exercises with slow sustained inspiration—except inspiration is to a full vital capacity with an end inspiratory hold for 3 to 5 seconds to maximize alveolar expansion.

• Deep breathing exercises using incentive spirometer.
  • There are 2 main types of incentive spirometers commercially available: flow and volume. Volumetric incentive spirometers (Figure 12-1) are theoretically better because they provide the appropriate feedback for a slow sustained inspiration and volume. In contrast a flow incentive spirometer (Figure 12-2, Figure 12-3) will have the marker reach the appropriate level with a quick or sustained deep breath so long as a sufficient flow is achieved. Slow sustained inspirations are much more effective to promote lung expansion rather than fast inspirations.
  • Instructions for the use of different incentive spirometers are provided in Table 12-1.
  • Clear and precise instructions need to be provided to patients. Frequently, patients have complained that their incentive spirometer does not work because they have blown into the device! Allowing the patient to practice incentive spirometry before surgery may facilitate patient learning.

• Deep breathing exercises with breath stacking:
  • Avoid forced exhalation below FRC because breathing may be below closing volume (see Chapter 13 for more explanation). Breath stacking is a series of deep breaths building on top of the previous one without expiration until a maximum volume tolerated by the patient is reached.¹⁸ Each inspiration consists of a few seconds of a brief inspiratory hold. It is often used when a large breath is too painful.

2. Breathing control/pursed lip breathing—is primarily used to promote relaxation and reduce dyspnea in patients who have significant chronic obstructive pulmonary disease (dyspnea and hyperinflation). These techniques can also be used by other patients who are dyspneic such as those with restrictive lung disease. The patient is instructed to :

• Breathe in through the nose and out through his or her mouth
• Gently expire and not to force expiration at all. Often expiration through pursed lips is promoted.
• Expire 2 to 3 times longer than inspiration
• Do not focus on the use of diaphragm. Many patients with COPD have a partially or totally flattened diaphragm; thus, they cannot use their diaphragm to any extent. Patients should not be criticized for not being able to do diaphragmatic/abdominal breathing.^19,20 Rather, they should be asked to fill air into the abdominal regions as much as possible.
• Promote optimal use of accessories by ensuring the shoulder girdle is relaxed. The therapist may instruct the patient to be positioned with arms supported in order to facilitate accessory muscle use (See Chapter 13 for positioning).

Pursed lip breathing can improve oxygenation in some COPD patients^13,21 and those with other respiratory disorders. The deleterious effects of breathing exercises, however, need to be considered when prescribing them to patients. In COPD, diaphragmatic breathing has been associated with decreased mechanical efficiency, a tendency for increased dyspnea^12,19,20 and a decrease in respiratory drive in some patients¹¹ when compared to their natural breathing pattern.

Because of the potential for deleterious effects from breathing exercises, the therapist should monitor SpO₂, dyspnea, and chest wall motion while the patient is performing pursed lip breathing, especially in those individuals with moderate to severe COPD associated with marked hyperinflation and/or poor arterial blood gases. Any instruction in modifying breathing pattern should not be associated with deterioration in SpO₂, increased dyspnea, and asynchronous chest wall motion.

Coordination of Breathing Exercises With Other Treatments

It is essential to coordinate physical therapy treatment with administration of medication in 2 cases:

• Pain medication in postoperative patients or those with significant chest trauma^22-24
• Bronchodilator medication in those with COPD, asthma, or other conditions that result in bronchoconstriction

Other Considerations

• Positioning in bed. If the patient has to rest in bed, side lying is best to preserve the FRC. Slumped sitting and supine tend to decrease the FRC. However, studies have been shown that sitting in the upright position and standing will increase the FRC and the vital capacity (VC). Avoid or minimize the period of bed rest. A rotation bed (see Chapter 13) or frequent position change might be beneficial for those patients requiring prolonged immobilization in bed.
• Mobilization used in conjunction with breathing exercises will often promote better lung expansion than breathing exercises alone. See Chapter 14 for more details about mobilization.
• Secretion removal. When the patient is congested and unable to expectorate by deep breathing and positioning alone, manual techniques should be used concurrently with deep breathing and must finish with deep breathing exercises to ensure full expansion of the treated area.

REFERENCES

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