What are the next steps for a patient with a chest tube who continues to desaturate?

Management of Persistent Desaturation in a Patient with a Chest Tube

A patient with a chest tube who continues to desaturate requires urgent clinical reassessment to identify the underlying cause of deterioration, with immediate optimization of oxygen therapy and consideration of the chest tube's function and positioning. 1

Immediate Assessment Steps

Verify Chest Tube Function

• Confirm the chest tube is patent and draining appropriately - blockage is a common complication that can lead to reaccumulation of air or fluid and subsequent hypoxemia 2
• Check for air leaks, proper positioning, and adequate drainage output 2
• Ensure the drainage system is functioning correctly with appropriate suction (if applied) or water seal 2
• Consider imaging (bedside ultrasound or chest x-ray) to assess for residual pneumothorax, hemothorax, or pleural effusion that may require additional intervention 2

Optimize Oxygenation Immediately

• Increase oxygen concentration to maintain target saturations - for most patients without COPD risk, target SpO2 94-98%; for those at risk of hypercapnia, target 88-92% 3
• Adjust oxygen delivery upward as needed to achieve target range 1
• Monitor oxygen saturation continuously during titration 3

Rule Out Hypercapnia

• Obtain arterial blood gas analysis urgently to assess for hypercapnia, especially if the patient has underlying respiratory disease 1, 3
• This is critical because oxygen therapy alone in patients with ventilatory failure can worsen hypercapnia 1
• If hypercapnia is present (PaCO2 >45 mmHg), consider non-invasive ventilation rather than oxygen alone 1

Identify the Cause of Deterioration

When a patient requires higher oxygen concentrations than previously needed to maintain the same target saturation, urgent clinical review is mandatory to establish the cause. 1

Common Causes to Evaluate:

• Chest tube malfunction: dislodgment, blockage, or inadequate drainage 2
• Reaccumulation of pneumothorax or pleural effusion requiring repeat imaging 2
• Mucus plugging - particularly common and may require physiotherapy and airway clearance 1
• Underlying respiratory infection or pneumonia 1
• Pulmonary embolism 3
• Re-expansion pulmonary edema (a dreaded complication of chest tube drainage) 2
• Contralateral pneumothorax or other new pathology 2

Escalation of Respiratory Support

Consider Non-Invasive Ventilation (NIV)

• NIV should be considered if 1:
  • Hypoxemia persists (saturations <95%) despite supplemental oxygen
  • Hypercapnia is present (>45 mmHg/6 kPa)
  • Respiratory rate is elevated above normal for age
  • Patient shows signs of tiring or increased work of breathing

Invasive Ventilation

• If the patient cannot maintain adequate oxygenation despite NIV or high-flow oxygen, mechanical ventilation may be required 1, 3
• This should be undertaken in a critical care or respiratory support unit due to risk of sudden deterioration 1

Critical Monitoring Requirements

• Continuous pulse oximetry until the patient is stable 1, 3
• Frequent vital signs monitoring including blood pressure, heart rate, and respiratory rate 3
• Serial blood gas analysis if ventilatory support is being considered 1, 3
• Enhanced monitoring with low threshold for critical care admission if desaturation persists 1

Common Pitfalls to Avoid

• Never administer high-flow oxygen empirically without targeted saturation goals - this can worsen hypercapnia in patients with ventilatory failure 1
• Do not assume the chest tube is functioning properly without verification - blockage and malposition are common 2
• Avoid providing oxygen therapy alone without checking for hypercapnia in patients with underlying respiratory disease or diaphragmatic weakness 1
• Do not delay escalation to NIV or mechanical ventilation if the patient shows signs of respiratory fatigue or persistent hypoxemia despite oxygen 1
• Never suddenly withdraw oxygen once initiated - step down gradually while monitoring continuously 3

Specific Interventions Based on Findings

If Chest Tube Malfunction Identified:

• Reposition or replace the chest tube as needed 2
• Consider larger bore tube if small-bore tube is ineffective 2
• Ensure proper connection to drainage system 2

If Mucus Plugging Suspected:

• Urgent physiotherapy assessment with airway clearance techniques 1
• Consider mechanical insufflator-exsufflator if available 1

If Ventilatory Support Required:

• Transfer to critical care or respiratory support unit 1
• Initiate NIV as first-line treatment 1
• Have senior respiratory team involvement in decision-making 1