Breathing into a Paper Bag for Respiratory Alkalosis: NOT RECOMMENDED
Rebreathing from a paper bag is dangerous and should NOT be used as a treatment for hyperventilation, even in anxiety-induced cases. 1
Why This Practice Is Harmful
The British Thoracic Society (BTS) explicitly states in their 2017 oxygen guidelines that "rebreathing from a paper bag can be dangerous and is NOT advised as a treatment for hyperventilation" 1. This recommendation supersedes the traditional practice based on compelling safety evidence:
Documented Hypoxic Hazards
Research demonstrates severe oxygen desaturation occurs rapidly during paper bag rebreathing 2:
- After just 60 seconds: oxygen drops by an average of 20.5 mmHg from room air
- At 3 minutes: mean oxygen drop of 26 mmHg (with some individuals experiencing drops up to 42 mmHg)
- Many subjects never achieved adequate CO2 correction despite dangerous hypoxemia
Three deaths have been documented when paper bag rebreathing was applied to patients who were actually hypoxemic or had myocardial ischemia, not pure anxiety-induced hyperventilation 2.
The Critical Clinical Pitfall
The fundamental danger is misdiagnosis. What appears to be anxiety-induced hyperventilation may actually represent:
- Pulmonary embolism
- Myocardial infarction
- Pneumothorax
- Metabolic acidosis with compensatory tachypnea
- Other organic causes of dyspnea
The BTS guidelines emphasize: "Organic illness must be excluded before making a diagnosis of hyperventilation" 1.
Appropriate Management Instead
For confirmed anxiety-induced hyperventilation with respiratory alkalosis:
Immediate Assessment
- Monitor oxygen saturation continuously - patients with pure hyperventilation will have normal or high SpO2 1
- Patients with normal/high SpO2 do NOT require oxygen therapy 1
- Exclude organic causes through clinical evaluation and appropriate testing
Therapeutic Interventions
- Reassurance and calming techniques - the primary intervention
- Benzodiazepines for severe cases with clinical deterioration 3
- Controlled breathing instruction - teaching slower, regular breathing patterns without rebreathing devices
- Breathing exercises (pursed lip, diaphragmatic breathing) have demonstrated safety and efficacy for respiratory symptoms 4
When Oxygen IS Indicated
If hypoxemia is present (SpO2 <94%), this indicates the problem is NOT simple hyperventilation:
- Target saturation 94-98% for most patients 1
- Use nasal cannulae at 2-6 L/min or simple face mask at 5-10 L/min 1
- Urgent investigation for underlying organic cause
Bottom Line
There is no safe scenario for paper bag rebreathing in modern clinical practice. The risk of inducing dangerous hypoxemia—particularly when the diagnosis of pure anxiety-induced hyperventilation may be incorrect—far outweighs any theoretical benefit of CO2 retention. Alternative breathing techniques and anxiolytic medications provide safer, evidence-based management.