How to manage respiratory problems in patients with Parkinson's disease?

Managing Respiratory Problems in Parkinson's Disease

Implement respiratory muscle strength training (RMST) as the primary intervention for respiratory dysfunction in Parkinson's disease, as it significantly improves both inspiratory and expiratory muscle strength, with expiratory muscle strength training (EMST) showing the strongest evidence for improving cough effectiveness and reducing aspiration risk. 1, 2

Initial Assessment and Monitoring

Evaluate respiratory function systematically in all PD patients, focusing on:

• Inspiratory and expiratory muscle strength using maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) measurements, as these decline progressively with disease advancement 1, 3
• Peak cough flow (PCF) to assess airway clearance capacity, with values <270 L/min indicating need for assisted cough techniques 4
• Spirometry measures including forced vital capacity (FVC) and peak expiratory flow (PEF), as both obstructive and restrictive patterns occur in PD 3
• Dyspnea perception using standardized scales, as subjective breathlessness often precedes objective respiratory decline 1, 5
• Sleep-disordered breathing symptoms including nocturnal hypoventilation, as these predict respiratory complications 4, 6

Monitor respiratory function every 6 months minimum, with more frequent assessments if FVC falls below 80% predicted or symptoms worsen 4

Primary Treatment: Respiratory Muscle Strength Training

Expiratory Muscle Strength Training (EMST)

Prescribe EMST as first-line therapy using threshold devices with resistance set at 50-75% of maximal expiratory pressure, performed 5 days per week for 4-8 weeks 2. EMST demonstrates:

• Mean improvement in expiratory muscle strength of 18.97 cm H₂O (95% CI 7.79-30.14) 1
• Enhanced peak expiratory flow by 72.21 L/min (95% CI 31.19-113.24) 1
• Improved swallowing safety and reduced aspiration risk 2

Inspiratory Muscle Strength Training (IMST)

Add IMST using threshold devices at 50-75% of maximal inspiratory pressure, 5 days weekly 2. IMST produces:

• Mean improvement in inspiratory muscle strength of 19.68 cm H₂O (95% CI 8.49-30.87) 1
• Reduced dyspnea perception during activities of daily living 1, 2

The combination of EMST and IMST provides superior outcomes compared to either intervention alone 2

Airway Clearance Strategies

When Peak Cough Flow <270 L/min

Implement assisted cough techniques immediately when PCF drops below 270 L/min or MEP <60 cm H₂O 4:

• Mechanical insufflation-exsufflation (MI-E) as the primary assisted cough device, delivering positive pressure (30-40 cm H₂O) followed by rapid negative pressure to simulate effective cough 4, 7
• Breath-stacking technique using a manual resuscitation bag or volume ventilator to achieve maximal insufflation before cough attempt 4, 7
• Manually assisted cough with abdominal thrust timed to exhalation, which enhances effectiveness when combined with breath-stacking 7

Secretion Management

For excessive secretions or sialorrhea:

• Start oral anticholinergic medication (glycopyrrolate 1-2 mg three times daily) as first-line therapy 7
• Escalate to botulinum toxin injections to salivary glands if anticholinergics fail or cause intolerable side effects 7
• Use high-frequency chest wall oscillation (HFCWO) combined with assisted cough techniques for secretion mobilization 4

Breathing Exercises and Lung Expansion

Prescribe daily breathing exercises to maintain lung volumes and prevent atelectasis:

• Incentive spirometry performed 10 repetitions every 2 hours while awake to encourage maximal inspiration 8
• Positive expiratory pressure (PEP) therapy at 10-20 cm H₂O to open airways and promote secretion clearance 8
• Postural training with head elevated at least 30 degrees to improve lung expansion 8, 2

Ventilatory Support Considerations

Indications for Noninvasive Ventilation (NIV)

Initiate NIV when any of the following occur 4:

• FVC <50% predicted with symptoms of hypoventilation
• Nocturnal oxygen saturation <88% for >5 consecutive minutes
• Morning headaches, daytime hypersomnolence, or cognitive changes suggesting nocturnal hypoventilation
• PaCO₂ >45 mmHg on arterial blood gas

Use bilevel positive airway pressure (BiPAP) rather than CPAP, as PD patients require ventilatory support, not just airway patency 4. Start with inspiratory pressure 8-12 cm H₂O and expiratory pressure 4-6 cm H₂O, titrating based on sleep study or nocturnal oximetry 4, 7

Critical Caveat for Bulbar Dysfunction

If significant bulbar symptoms are present (dysphagia, dysarthria, sialorrhea), anticipate NIV failure and consider earlier discussion of invasive ventilation via tracheostomy 7. Bulbar impairment significantly limits NIV tolerance and increases aspiration risk 7

Physical Activity and Exercise

Encourage aerobic exercise and functional training as adjunctive therapy:

• Aerobic exercise at moderate intensity 3-5 days per week improves respiratory muscle endurance and reduces dyspnea perception 1
• Early mobilization prevents further respiratory decline, as immobility accelerates loss of lung function 8
• Qigong or yoga may provide additional benefits for breathing control and dyspnea management 1

Pharmacological Considerations

Avoid medications that suppress respiratory function, particularly:

• Opiates, benzodiazepines, and sedatives, especially when FVC <80% predicted 4
• Cough suppressants, which temporarily reduce secretion clearance 4

Use supplemental oxygen cautiously, as it corrects hypoxemia without treating underlying hypoventilation and may impair central respiratory drive 7. Maintain FiO₂ <0.4 when possible to reduce atelectasis formation 8

Common Pitfalls to Avoid

• Do not wait for symptomatic respiratory failure before initiating RMST—begin training early in the disease course when patients are asymptomatic, as respiratory muscle weakness progresses insidiously 1, 3
• Do not rely solely on spirometry—respiratory muscle strength (MIP/MEP) and PCF decline before significant spirometric changes occur 3
• Do not perform airway clearance techniques without proper instruction—inadequate technique reduces effectiveness and may cause patient frustration 8
• Do not assume dyspnea is purely cardiac or deconditioning—systematically evaluate respiratory muscle strength and pulmonary function in all dyspneic PD patients 5

Multidisciplinary Team Involvement

Coordinate care with respiratory physiotherapists experienced in neuromuscular disease management for optimal implementation of RMST and airway clearance techniques 4. Consider pulmonology referral when FVC <80% predicted or symptoms of nocturnal hypoventilation develop 4