Respiratory Failure Guidelines

Assessment and Diagnosis

The European Respiratory Society recommends measuring respiratory rate, observing chest and abdominal wall movement, and obtaining arterial blood gases in the initial assessment of patients at risk of acute respiratory acidosis 1
Counting the respiratory rate over a full minute and observing the breathing pattern, specifically looking for rapid shallow breathing, is crucial in assessing respiratory failure 1, 2
The American Thoracic Society suggests that observing chest and abdominal wall movement for paradoxical motion, use of accessory muscles, or asymmetry is essential in evaluating respiratory muscle function 1
In COPD patients, preservation of expiratory time indicates severe flow limitation 3, 4
Obtaining arterial blood gases immediately is the single most important test to determine which system is failing, with pH ≤7.35 and elevated PaCO₂ indicating acute respiratory acidosis from ventilatory failure 1, 5, 6

The European Respiratory Society recommends calculating A-a gradient to confirm pulmonary parenchymal disease rather than simple hypoventilation 5
Monitoring parameters such as respiratory rate trend, pH trajectory, and work of breathing is essential in assessing the severity and trajectory of respiratory failure 1, 6
Identifying the underlying cause of respiratory failure, such as COPD exacerbations or pneumonia, is crucial in guiding treatment 1, 6
The American Thoracic Society suggests that initiating non-invasive ventilation (NIV) when pH <7.35 and PaCO₂ >45 mmHg despite optimal medical therapy, and preparing for intubation if pH and PaCO₂ fail to improve after 4-6 hours of NIV 1, 6

Never relying on pulse oximetry alone in COPD patients, as they can maintain adequate SpO₂ while developing severe hypercapnic respiratory acidosis 5, 6
Avoiding excessive oxygen in COPD, targeting SpO₂ 88-92% to prevent worsening V/Q mismatch and hypoventilation 7
Recognizing that chest radiography often lags behind clinical deterioration, and radiographic worsening is common even with appropriate treatment 8