Ideal Tidal Volume for Patients with Brown-Sequard Syndrome
The ideal tidal volume for patients with Brown-Sequard syndrome is 6-8 mL/kg of predicted body weight (PBW), with a target of 6 mL/kg PBW being preferred for lung protection. 1
Rationale for Tidal Volume Selection
- For patients with neurological conditions including Brown-Sequard syndrome, a lung-protective ventilation strategy using low tidal volumes (6-8 mL/kg PBW) should be implemented to prevent ventilator-induced lung injury 1
- Predicted body weight should be used rather than actual body weight, as lung size correlates better with height than with actual weight 2
- For males, PBW can be calculated as 50 + 2.3 (height in inches - 60) 2
- For females, PBW can be calculated as 45.5 + 2.3 (height in inches - 60) 2
Special Considerations for Brown-Sequard Syndrome
Brown-Sequard syndrome is a neurological condition resulting from hemisection of the spinal cord. When ventilating these patients:
- Target tidal volumes closer to 6 mL/kg PBW to minimize the risk of ventilator-induced lung injury, especially if there are signs of acute lung injury 1, 3
- Maintain plateau pressure <30 cmH2O to prevent barotrauma and further neurological compromise 1
- Monitor driving pressure (plateau pressure minus PEEP), aiming to keep it below 15 cmH2O 2
- Consider the potential impact of hypercapnia on intracranial pressure when using low tidal volumes 1
Ventilation Parameters
- Initial tidal volume: 6 mL/kg PBW 1, 3
- Respiratory rate: 15-25 breaths/minute for neuromuscular disease and chest wall deformity 1
- I:E ratio: 1:1 to 1:2 1
- PEEP: Consider low to moderate PEEP (6-8 cmH2O) to prevent alveolar collapse while minimizing hemodynamic effects 1
- Oxygenation target: SaO2 >92% 1
Monitoring and Adjustments
- Monitor plateau pressure, keeping it <30 cmH2O even if this requires further reduction in tidal volume 1
- If the patient has elevated intracranial pressure, monitor ICP closely when adjusting ventilator settings 1
- Permissive hypercapnia may be necessary when using lower tidal volumes, but maintain pH >7.2 1, 4
- If the patient has ineffective cough or secretion clearance issues, consider mechanical insufflation and exsufflation techniques 1
Avoiding Common Pitfalls
- Avoid visual estimation of height: Measure height accurately to calculate correct PBW, as errors in height estimation can lead to inappropriate tidal volumes 5
- Avoid excessive tidal volumes: Using actual body weight instead of PBW can result in harmful ventilation, especially in patients with higher BMI 6
- Avoid delayed recognition of respiratory deterioration: Monitor closely for signs of respiratory muscle fatigue or worsening gas exchange 1
- Avoid excessive PEEP: High PEEP can impede venous return and potentially affect spinal cord perfusion 1
By following these guidelines, clinicians can provide optimal ventilatory support for patients with Brown-Sequard syndrome while minimizing the risk of ventilator-induced lung injury and optimizing outcomes.