What is the management plan for a patient with respiratory failure?

Management of Respiratory Failure

The management of respiratory failure should follow a stepwise approach starting with oxygen therapy titrated to maintain saturations of 88-92%, followed by non-invasive ventilation for persistent hypercapnic respiratory failure (pH<7.35, pCO2>6.5 kPa), and escalating to invasive mechanical ventilation when necessary. 1

Initial Assessment and Management

• Assess severity of respiratory failure through clinical evaluation (patient comfort, conscious level, chest wall motion, accessory muscle use, respiratory rate, heart rate) and arterial blood gas analysis 1
• Identify and treat the underlying cause of respiratory failure (e.g., infection, bronchospasm, fluid overload) 1
• Obtain chest radiography to identify potential causes or complications, but do not delay treatment in severe cases 1
• Document an individualized treatment plan at the start, including measures to be taken if initial therapy fails 1

Oxygen Therapy

• Administer controlled oxygen therapy targeting saturation of 88-92% for all causes of acute hypercapnic respiratory failure 1
• Titrate oxygen carefully to improve hypoxemia without causing carbon dioxide retention or worsening acidosis 1
• Monitor oxygen saturation continuously for at least 24 hours after commencing treatment 1
• Check arterial blood gases after starting oxygen therapy to ensure adequate oxygenation without worsening hypercapnia 1
• For delivery devices, Venturi masks are preferred over nasal prongs as they better maintain adequate oxygenation over time 2

Pharmacological Management

• For COPD exacerbations, administer nebulized bronchodilators:
  • Moderate exacerbations: β-agonist (salbutamol 2.5-5 mg or terbutaline 5-10 mg) or anticholinergic (ipratropium bromide 0.25-0.5 mg) 1
  • Severe exacerbations: both β-agonist and anticholinergic medications 1
• Consider systemic corticosteroids (prednisolone 30 mg/day for 7-14 days) 1
• Prescribe antibiotics for patients with:
  • Three cardinal symptoms: increased dyspnea, sputum volume, and sputum purulence
  • Two cardinal symptoms if one is increased sputum purulence
  • Requirement for mechanical ventilation 1
• Recommended antibiotic duration is 5-7 days 1
• Consider intravenous methylxanthines (aminophylline 0.5 mg/kg/hour) if response to other treatments is poor 1
• Use diuretics if peripheral edema and raised jugular venous pressure are present 1

Non-Invasive Ventilation (NIV)

• Initiate NIV when pH<7.35 and pCO2>6.5 kPa persist despite optimal medical therapy 1
• NIV is preferred over invasive ventilation as the initial mode for treating acute respiratory failure in COPD exacerbations, with success rates of 80-85% 1
• Severe acidosis alone does not preclude a trial of NIV in an appropriate setting with access to staff who can perform safe endotracheal intubation 1
• Measure arterial blood gases after 1-2 hours of NIV and again after 4-6 hours if the earlier sample showed little improvement 1
• If there is no improvement in PaCO2 and pH after 4-6 hours of optimized NIV, consider invasive ventilation 1
• Monitor for signs of NIV failure: deteriorating physiological parameters (particularly pH and respiratory rate), patient condition, development of complications, or intolerance 1
• Maximize time on NIV in the first 24 hours depending on patient tolerance 1
• NIV can be discontinued when there has been normalization of pH and pCO2 and general improvement in the patient's condition 1

Invasive Mechanical Ventilation

• Consider invasive mechanical ventilation when:
  • NIV fails as initial therapy 1
  • Patient has contraindications to NIV (e.g., severe facial deformity, fixed upper airway obstruction) 1
  • Risk/benefit analysis favors better outcome with invasive ventilation 1
• Factors favoring use of invasive ventilation include:
  • Demonstrable remedial reason for current decline (e.g., pneumonia)
  • First episode of respiratory failure
  • Acceptable quality of life or habitual level of activity 1
• Factors discouraging use of invasive ventilation include:
  • Previously documented severe COPD unresponsive to therapy
  • Poor quality of life despite maximal therapy
  • Severe comorbidities 1

Advanced Strategies for Refractory Respiratory Failure

• For severe hypoxemic respiratory failure not responding to conventional therapy, consider:
  • Lung-protective ventilation strategies with low tidal volumes 3
  • Prone positioning to improve oxygenation 3
  • High-frequency oscillatory ventilation in selected cases 3
  • Extracorporeal membrane oxygenation (ECMO) as rescue therapy for severe ARDS unresponsive to conventional management 4

Monitoring and Follow-up

• Monitor arterial blood gases, vital signs, and clinical status regularly 1
• Record FEV1 before discharge and peak flow twice daily until clinically stable 1
• Check arterial blood gases on air before discharge in patients who presented with hypercapnic respiratory failure 1
• Plan early follow-up (<30 days) after discharge to review therapy and assess for complications 1
• Additional follow-up at 3 months is recommended to ensure return to stable state and review symptoms, lung function, and comorbidities 1

Common Pitfalls and Caveats

• Delaying NIV when indicated can increase mortality and morbidity 1
• Using NIV should not delay escalation to invasive mechanical ventilation when appropriate 1
• Failure to identify and treat reversible causes can lead to poor outcomes 1
• Excessive oxygen therapy can worsen hypercapnia in susceptible patients; always titrate to target saturation 1
• The rapid shallow breathing index (RSBI) >105 and failure to improve after 30 minutes of therapy are associated with NIV failure and increased mortality 5
• Clinicians often underestimate survival in COPD patients treated with invasive mechanical ventilation 1