What is the pre‑shift working checklist for an ambulance bag‑valve‑mask (BVM) system?

Pre-Shift Ambulance Bag-Valve-Mask (BVM) Working Checklist

Every ambulance BVM system must be systematically checked before each shift to ensure all components are present, functional, and properly assembled, as equipment failures and misassembly have resulted in patient harm and death. 1, 2

Essential BVM Components to Verify

Bag Assembly and Integrity

• Confirm the self-inflating bag is intact with no visible cracks, tears, or deterioration 3, 2
• Verify bag size is appropriate: 1-2 L for adults (delivers ~600 mL tidal volume), smaller pediatric bags for children 3, 4
• Check the non-jam inlet valve is present and functioning - this prevents rebreathing of exhaled gases 3
• Inspect the non-rebreathing outlet valve for proper assembly and function - faulty valves are a common cause of adverse outcomes 2

Mask Components

• Ensure masks are transparent to allow detection of vomitus or regurgitation 3
• Verify multiple mask sizes are available (adult, pediatric, infant) with proper cushioned seals 1, 3
• Check that masks have standard 15-mm/22-mm fittings for universal compatibility 3

Oxygen Delivery System

• Confirm oxygen reservoir bag is attached and intact - this allows delivery of 60-95% oxygen concentration versus 21% room air 3
• Verify oxygen inlet connection with standard connector is present 3
• Check oxygen tubing is available and free from cracks or kinks 1

Pressure Relief Valve

• Ensure the pressure relief valve can be bypassed or is absent - some patients with high airway resistance (bronchospasm, poor compliance) require higher pressures to achieve chest rise 3, 5
• Test that the valve functions at the set pressure if present 1

Oxygen Supply Verification

Cylinder Checks (Critical Safety Items)

• Verify oxygen cylinders are in date - check expiry date before use 1
• Confirm cylinders are turned off/fully closed when not in use 1
• Check cylinder pressure gauge shows adequate supply: Front-line ambulances typically carry two HX cylinders (2300 L each) plus two CD cylinders (460 L each) 1
• Ensure cylinders are properly secured to prevent movement during transport 1

Flow Meters and Connections

• Test that flow meters function properly and can deliver 0-15 L/min 1
• Verify Schrader-type connections are intact on piped oxygen systems 1
• Confirm portable oxygen supply is functional for use at scene or during patient transfer 1

Functional Testing Protocol

Two-Bag Test (Recommended)

• Attach a test lung or bag to the patient-end of the BVM 1
• Set fresh gas flow to 5 L/min and ventilate manually 1
• Observe that the system is patent and unidirectional valves move (if present) 1
• Squeeze both bags to test system integrity - there should be no loss of volume 1

Valve Function Testing

• Perform occlusion test on inner tube for Bain-type and circle co-axial systems 1, 6
• Verify the APL valve (if present) can be fully opened and closed 1, 6
• Check that all valves are properly reassembled after sterilization - misassembly is a common cause of serious incidents 2

Additional Equipment Verification

Airway Adjuncts

• Confirm oropharyngeal airways are available in multiple sizes (adult and pediatric) 1
• Verify nasopharyngeal airways are present 1
• Check that bacterial/viral filters are available for the expiratory port 1

Suction Equipment

• Ensure hand-operated suction is present and functional 1
• Verify battery-powered suction is charged (front-line ambulances) 1
• Check suction catheters are available in appropriate sizes 1

Monitoring Devices

• Confirm pulse oximeter is functional with appropriate alarm settings 1
• Verify end-tidal CO2 detection capability is available 1
• Test that monitoring equipment has fresh batteries 1

Common Pitfalls to Avoid

Single-use devices are safer than reusable ones because they prevent disassembly problems that have caused patient deaths 2. If using reusable equipment:

• Never allow untrained personnel to reassemble valves after sterilization 2
• Always perform functional testing after any equipment cleaning or maintenance 1, 2
• Replace any component showing visible wear, cracks, or damage immediately 1, 6

Protect breathing systems with a test lung or bag when not in use to prevent intrusion of foreign bodies 1.

Documentation

• Record that the pre-shift check was completed with date, time, and provider signature
• Document any equipment deficiencies or replacements made 1
• Report any malfunctioning equipment immediately to prevent use on patients 2