What is the recommended management for pneumonia in patients with Duchenne muscular dystrophy?

Pneumonia Management in Duchenne Muscular Dystrophy

Patients with DMD and pneumonia require immediate low-threshold antibiotic treatment, aggressive airway clearance with mechanical insufflation-exsufflation (MI-E), and non-invasive ventilation (NIV), with urgent specialist respiratory team involvement due to high risk of rapid decompensation. 1

Immediate Recognition and Risk Assessment

DMD patients with pneumonia present atypically and deteriorate rapidly:

• These patients cannot demonstrate typical signs of respiratory distress (labored breathing, accessory muscle use) due to profound muscle weakness 1
• Recurrent chest infections indicate loss of respiratory muscle strength, ineffective cough, or silent aspiration requiring bulbar function assessment 1
• Patients with FVC <80% have exceptionally high risk of complications and rapid decompensation 1
• Contact the patient's primary respiratory and neuromuscular teams immediately upon acute admission 1

Antibiotic Management

Initiate antibiotics with a lower threshold than typical pneumonia patients:

• Develop an individualized care plan specifying when antibiotics are indicated, which antibiotic to use, and duration of treatment 1
• Consider subcutaneous administration of antibiotics (ceftazidime, tobramycin) when IV access is difficult, though this is off-label 2
• Azithromycin is appropriate for community-acquired pneumonia from Chlamydia pneumoniae, Haemophilus influenzae, Mycoplasma pneumoniae, or Streptococcus pneumoniae in patients suitable for oral therapy 3
• Do not use azithromycin in patients with moderate-to-severe illness, hospitalization needs, bacteremia, or significant underlying health problems 3

Airway Clearance: Critical Intervention

Mechanical insufflation-exsufflation (MI-E) is essential and should be used regularly during pneumonia:

• MI-E prevents atelectasis, reduces pneumonia incidence, and prevents hospitalization 1
• Settings must be individualized by an expert physiotherapist with appropriate interface 1
• Urgent assessment by a physiotherapist experienced in airway clearance is mandatory upon admission 1
• Manually assisted cough techniques should supplement MI-E 1
• Peak cough flow <270 L/min in adults indicates need for assisted cough techniques 1
• MI-E use allows 95.6% of full-time NIV patients to avoid tracheostomy and continue oral intake 4

MI-E Contraindications to Monitor:

• Unmanaged dysphagia or gastroesophageal reflux increases aspiration risk with MI-E 1

Ventilatory Support

NIV is the initial treatment of choice for pneumonia with respiratory compromise:

• Initiate NIV if oxygen saturations <95% or hypercapnia >45 mm Hg (>6 kPa) 1
• Never administer oxygen alone without NIV—this worsens hypercapnia in diaphragmatic weakness 1
• Manage in critical care or respiratory support unit due to sudden deterioration risk 1
• Monitor CO2 levels continuously; capnography is ideal, or obtain capillary/arterial blood gas 1
• Nasal intermittent positive pressure ventilation treats both upper airway obstruction and chronic respiratory insufficiency 1

Monitoring Requirements

Enhanced monitoring is mandatory during acute pneumonia:

• Pulse oximetry with continuous CO2 monitoring 1
• Increased frequency of observations due to rapid decompensation risk 1
• Serial assessment of respiratory muscle strength (maximum inspiratory/expiratory pressures) 1
• Monitor for signs of ventilatory failure: awake PaCO2 elevation, declining FVC 1

Prevention Strategies

All DMD patients require:

• Annual influenza vaccination (inactivated, not live nasal spray if on corticosteroids) 1
• Pneumococcal vaccination (Prevenar13 and 23-valent polysaccharide vaccine per national guidance) 1
• Twice-yearly pulmonary specialist visits after wheelchair confinement, FVC <80%, or age ≥12 years 1
• Every 3-6 months if requiring mechanically assisted airway clearance or ventilation 1

Aspiration Assessment

Recurrent pneumonia mandates evaluation for silent aspiration:

• Formal speech and language therapy referral to assess bulbar function 1
• Evaluate for gastroesophageal reflux and oropharyngeal aspiration 1

Critical Pitfalls to Avoid

• Never use oxygen therapy alone without ventilatory support—this causes CO2 retention and worsening respiratory failure 1
• Do not wait for typical signs of respiratory distress; muscle weakness masks these findings 1
• Avoid negative-pressure ventilators during acute illness due to upper airway obstruction risk 1
• Do not delay specialist respiratory team consultation; transfer to specialized center if unavailable locally 1
• Recognize that normal oxygen saturations do not exclude hypoventilation; always assess CO2 1

Specialist Consultation Triggers

Immediate respiratory specialist involvement required for:

• Any pneumonia in patients with FVC <80% predicted 1
• Oxygen saturations <95% 1
• Evidence of hypercapnia or hypoventilation 1
• Recurrent chest infections (≥2 episodes requiring antibiotics) 1