What is the approach to managing respiratory and sleep issues in a patient with Amyotrophic Lateral Sclerosis (ALS)?

Respiratory Management in Patients with ALS

Regular pulmonary function testing every 6 months is essential for ALS patients, with early initiation of noninvasive ventilation when indicated by respiratory decline to improve survival and quality of life. 1

Assessment of Respiratory Function

• Perform pulmonary function tests (PFTs) at a minimum of every 6 months to monitor respiratory decline 1

• Include the following measurements in respiratory assessment:

  • Forced vital capacity (FVC) or slow vital capacity (SVC) - both are interchangeable in predicting functional decline 2
  • Maximum inspiratory pressure (MIP) or maximum expiratory pressure (MEP) 1
  • Sniff nasal inspiratory pressure (SNIP) - shows the greatest decline within 3 months before NIV indication 3
  • Peak cough flow (PCF) - significantly differentiates patients needing NIV from those who don't yet need it 3

• Screen for symptoms of respiratory insufficiency at each visit:

  • Morning headaches (most important symptom to assess) 4
  • Daytime sleepiness 4
  • Orthopnea 4
  • Dyspnea 4
  • Sleep disturbances 1

Indications for Noninvasive Ventilation (NIV)

• Consider NIV when any of the following are present:

  • FVC < 80% of predicted in symptomatic patients 1
  • FVC < 50% of predicted 1
  • MIP < -60 cm H₂O 1
  • MEP < 40 cm H₂O 1
  • PCF < 270 L/min 1
  • Evidence of sleep-disordered breathing on polysomnography 1
  • Hypercapnia (awake PaCO₂ > 45 mm Hg) 1
  • Symptoms of hypoventilation 3

• Polysomnography or overnight oximetry can help guide NIV initiation when resources allow, but is not necessary for adult patients 1

NIV Implementation and Optimization

• Individualize NIV treatment to achieve optimal ventilation goals 1:

  • Adjust parameters including mode of ventilation, inspiratory time, and inspiratory/expiratory pressures
  • Include backup respiratory rate for better patient-ventilator synchrony and improved gas exchange
  • Assess sleep quality, digital downloads, unintentional leaks, and oximetry (capnography when available)
  • Optimize secretion management

• For patients with preserved bulbar function, consider mouthpiece ventilation (MPV) for daytime ventilatory support as an adjunct to nocturnal mask NIV 1

• Be aware that bulbar impairment may limit NIV tolerance but should not be a reason to withhold NIV referral 4

Management of Secretions and Sialorrhea

• For patients with sialorrhea (excessive saliva):

  • Start with a trial of anticholinergic medication as first-line therapy 1
  • Consider botulinum toxin therapy to salivary glands if anticholinergics are inadequate or poorly tolerated 1

• For patients with reduced lung function or cough effectiveness:

  • Implement lung volume recruitment techniques (breath stacking) 1
  • Consider mechanical insufflation-exsufflation devices for secretion clearance 1

Nutritional Considerations

• Screen for malnutrition (BMI, weight loss) at diagnosis and every 3 months during follow-up 1
• Consider gastrostomy for nutritional support when dysphagia develops:
  • Percutaneous endoscopic gastrostomy (PEG) is preferred for patients with good respiratory function (FVC > 50%) 1
  • Radiologically inserted gastrostomy (RIG) may be preferred for more frail patients with moderate or severe respiratory impairment 1
  • Discuss gastrostomy early in disease progression 1

Progression to Invasive Ventilation

• Consider invasive home mechanical ventilation via tracheostomy when 1:

  • NIV fails or is not tolerated
  • Bulbar function worsens
  • Frequent aspiration occurs
  • Insufficient cough persists despite adequate secretion management
  • Recurrent chest infections occur despite secretion management
  • Lung function continues to decline

• Start discussions regarding invasive ventilation early in the disease course, including goals of care, potential need for institutionalization, and caregiver burden 1

Common Pitfalls to Avoid

• Delaying NIV initiation - early implementation improves survival and quality of life 5
• Relying solely on FVC when SNIP and PCF may be more sensitive for early detection of respiratory decline 3
• Failing to assess for morning headaches and sleep disturbances, which are early indicators of nocturnal hypoventilation 4
• Withholding NIV due to bulbar impairment alone 4
• Neglecting secretion management, which is critical for preventing respiratory complications 1
• Waiting for symptoms to appear before initiating respiratory monitoring 1