Low Wall Suction Settings
The recommended setting for low wall suction is 80-100 mmHg for most clinical applications, particularly in pediatric patients. 1
Evidence-Based Recommendations for Different Clinical Scenarios
Tracheostomy and Endotracheal Suctioning
- For pediatric patients with tracheostomies, pressures of 80-100 mmHg are typically used 1
- For adult endotracheal suctioning:
- 80-120 mmHg for thin secretions (grade I viscosity)
- 150 mmHg for moderate viscosity secretions (grade II)
- 200 mmHg for thick secretions (grade III) 2
Chest Tube Management
- For chest tubes in pneumothorax management, high volume, low pressure systems of -10 to -20 cm H₂O (approximately 7-15 mmHg) are recommended 1
- For chest tubes after cardiac surgery, -20 cm H₂O (approximately 15 mmHg) is commonly used 3
Wound Management
- For negative pressure wound therapy in fistula management, 50-80 mmHg is recommended, with lower settings (50 mmHg) for vulnerable patients 4
Factors Affecting Suction Efficiency
The vacuum delivered to the tip of the suction catheter varies based on multiple factors:
- Viscosity of secretions
- Length and diameter of tubing
- Size of the collection bottle
- Catheter size 1
Clinical Considerations and Pitfalls
Potential Complications of Excessive Suction
- Higher suction pressures can lead to:
- Airway mucosal damage
- Atelectasis during lengthy suctioning
- Hypoxemia
- Perpetuation of persistent air leaks 1
Duration of Suctioning
- Limit deep suctioning to 15 seconds or less
- For premeasured technique, limit to 5 seconds or less
- Rapid technique completed in less than 5 seconds is recommended to prevent atelectasis 1
Catheter Selection
- Use the largest size catheter that will fit inside the tracheostomy tube for efficient secretion removal
- This contradicts older recommendations of using a catheter half the internal diameter of the tracheostomy tube 1
Special Considerations
Pediatric Suctioning
- Adjust suction device to -80 to -120 mmHg for suctioning the airway via an endotracheal tube
- Higher suction pressures can be used for oropharyngeal suctioning 1
Wound Management
- For fistula management with NPWT, use lower settings (50 mmHg) for vulnerable patients to balance fluid removal and prevent tissue damage 4
In summary, while specific settings vary by clinical context, the general range for low wall suction is 80-100 mmHg for most applications, with adjustments based on the specific clinical scenario, patient factors, and type of secretions being suctioned.