What is the best approach to extend life in an adult patient with amyotrophic lateral sclerosis (ALS) experiencing respiratory issues and a history of progressive muscle weakness?

Noninvasive Ventilation (NIV) is the Best Approach to Extend Life in ALS Patients with Respiratory Issues

Noninvasive ventilation should be initiated when patients develop respiratory symptoms with FVC <80% of normal, FVC <50% predicted, or awake PaCO₂ >45 mmHg, as this intervention has been demonstrated to prolong survival by several months and improve quality of life more than any other currently available treatment for ALS. 1, 2, 3

Initiating NIV: Specific Criteria and Timing

Start NIV when any of the following are present:

• Forced vital capacity (FVC) drops below 80% of normal in symptomatic patients 1
• FVC falls below 50% of predicted regardless of symptoms 1
• Awake PaCO₂ exceeds 45 mmHg 1
• Respiratory symptoms develop (orthopnea, dyspnea, morning headaches, daytime fatigue) 2

Use bilevel positive airway pressure (BPAP) with backup respiratory rate as it achieves better patient-ventilator synchrony than other NIV modes. 1

Monitoring Strategy to Guide NIV Initiation

Perform pulmonary function testing every 6 months minimum, measuring:

• FVC or slow vital capacity (SVC) 1
• Maximum inspiratory pressure (MIP) - more sensitive than spirometry for detecting inspiratory muscle weakness 2, 4
• Sniff nasal inspiratory pressure (SNIP) - can be performed reliably by most ALS patients 2
• Maximum expiratory pressure (MEP) 1

Screen for sleep disturbances at each clinical visit, as these indicate respiratory insufficiency. 5

Assess awake carbon dioxide tension at least annually using capnography when available, as arterial blood gas analysis is not necessary for routine follow-up. 1

Critical Factors Affecting NIV Success

Bulbar dysfunction is the primary limitation to NIV effectiveness. Patients with significant bulbar impairment (severe dysphagia, dysarthria, sialorrhea) may not tolerate NIV or achieve adequate ventilation. 1, 6 However, do not withhold NIV trial based solely on bulbar symptoms - attempt NIV first as tolerance varies individually. 1

Cognitive impairment reduces NIV compliance - screen all patients for cognitive dysfunction before recommending NIV, as up to 40% of ALS patients have cognitive impairment that significantly impacts treatment adherence. 7

Airway Clearance: Essential Adjunct to NIV

Implement mechanical insufflation-exsufflation (MI-E) devices for secretion clearance when:

• Peak cough flow falls below effective levels 1, 5
• Patient develops ineffective coughing (the principal cause of NIV intolerance) 2

Use lung volume recruitment (breath stacking) techniques for patients with reduced lung function or cough effectiveness. 5

Manage sialorrhea aggressively:

• First-line: Anticholinergic medication 5
• Second-line: Botulinum toxin injection to salivary glands if anticholinergics inadequate or poorly tolerated 5

Survival Benefit: The Evidence

NIV prolongs survival by several months - observational studies demonstrate median survival differences of 60-90 days compared to no respiratory support, with some patients surviving much longer. 8, 2, 3 This survival benefit exceeds that of riluzole (the only FDA-approved disease-modifying medication, which extends survival by approximately 60-90 days). 8, 3

NIV improves quality of life more than any other currently available ALS treatment. 2, 9

When NIV Fails: Transition to Invasive Ventilation

Consider tracheostomy with invasive mechanical ventilation when:

• NIV fails or is not tolerated despite optimization 5
• Bulbar function worsens significantly preventing NIV use 5
• Frequent aspiration occurs 5
• Insufficient cough persists despite mechanical assistance 5
• Recurrent chest infections develop 5

This decision requires careful advance planning - only 4-9% of ALS patients choose invasive mechanical ventilation, with wide cultural variation. 7 Discuss this option early in the disease course, ideally at diagnosis, before communication becomes limited. 7

Multidisciplinary Care Framework

Refer to multidisciplinary ALS clinic immediately - this care model is associated with decreased healthcare utilization, prolonged survival, and higher quality of life compared to standard care. 1 The multidisciplinary team should coordinate:

• Respiratory support optimization (pulmonologist, respiratory therapist) 1
• Nutritional management - malnutrition is detrimental to survival; consider percutaneous endoscopic gastrostomy (PEG) before respiratory function deteriorates significantly (ideally when FVC >50%) 7, 5
• Speech-language pathology for dysphagia and communication 6
• Palliative care integration from diagnosis - not just end-of-life care 7

Common Pitfalls to Avoid

Do not delay NIV initiation in patients with respiratory symptoms - early intervention improves outcomes. 5 The outdated Medicare requirement of FVC <50% for respiratory assist device coverage is misaligned with current best practices. 1

Do not use "preventive" NIV in asymptomatic patients with preserved respiratory function (FVC 20-50% without symptoms) - one controlled trial showed increased mortality with this approach, possibly due to false sense of security and less diligent monitoring. 1

Do not underestimate quality of life of ventilator-dependent ALS patients - physicians markedly underestimate the quality of life perceived by these patients, which can inappropriately influence treatment discussions. 1

Avoid late referral to palliative services - this is the most common and harmful error, negatively impacting quality of life for both patients and caregivers. 7

Advance Care Planning

Initiate advance directive discussions at diagnosis, including preferences regarding:

• Long-term mechanical ventilation via tracheostomy 7
• Feeding tube placement 7
• End-of-life care preferences 7

Repeat these discussions as the disease progresses - patients value having meaningful conversations about mechanical ventilatory support repeatedly throughout their care. 1