How does the Select Valve prevent hyperventilation?
When the Select Valve is activated, it restricts bag refill to approximately 4 seconds. This mechanical restriction means the provider physically cannot deliver more than approximately 10 breaths per minute — the bag simply will not have refilled sufficiently to deliver another breath within a shorter interval. This eliminates the most common BVM failure mode without requiring the provider to continuously self-monitor and correct breathing rate. The valve has two modes: activated (rate-controlled) and standard (unrestricted, standard BVM behavior).
What is the PEEP valve and when should it be used?
PEEP stands for Positive End-Expiratory Pressure. The adjustable PEEP valve on the VT Select maintains a baseline positive pressure in the airway at the end of each breath, preventing alveolar collapse between breaths. PEEP is used clinically for patients with severe hypoxemia, pulmonary edema, or ARDS where alveoli tend to collapse during exhalation. Note: the 2024 CoTCCC update found insufficient evidence to recommend routine PEEP use in the tactical/prehospital setting, and CoTCCC does not currently support routine PEEP for the tactical provider population. PEEP use should be guided by medical director authorization and specific patient indication.
What is the manometer used for?
The dial manometer monitors real-time airway pressure during manual ventilation. This helps providers detect excessive peak pressure (indicating potential barotrauma risk or airway obstruction) and monitor for changes in lung compliance. In patients with pulmonary contusion, known lung disease, or suspected pneumothorax, airway pressure monitoring can guide ventilation adjustments and provide early warning of deteriorating lung compliance. The manometer is optional — the BVM functions normally without it if pressure monitoring is not required.
Why is the VT Select bag volume only 1,200 mL instead of the standard 1,900 mL?
The smaller 1,200 mL bag is intentional. Standard adult BVMs with 1,900 mL bags consistently produce provider over-squeeze and tidal volumes of 800–1,000 mL — significantly above the AHA-recommended 500–600 mL. Research shows that even with smaller 1,000 mL pediatric BVMs, providers delivered more appropriate adult tidal volumes. The VT Select's 1,200 mL bag, combined with the Select Valve, creates a system where correct tidal volumes are the natural outcome of normal squeeze technique — rather than requiring precise technique override.
Does the filter add significant resistance to ventilation?
The bacterial/viral filter adds minimal inspiratory resistance — the VT Select has an inspiratory resistance of less than 5 cm H₂O at 50 LPM total (including the filter), which is within the acceptable range for manual resuscitators. The filter provides bidirectional pathogen protection, protecting both the patient from the provider's exhaled air and the provider from patient expiratory secretions. For trauma patients with unknown infectious status, the filter is an important infection control component.
