Artificial Manual Breathing Unit Bag (AMBU)

Description

An Ambu Bag (short for Artificial Manual Breathing Unit), also known as a Bag-Valve Mask (BVM), is a handheld medical device used to provide positive pressure ventilation to patients who are not breathing adequately or at all. It is commonly used in emergency situations to assist or replace spontaneous breathing.

Key Components:

1. Self-Inflating Bag:
   • The bag is manually compressed to deliver air or oxygen to the patient’s lungs. After compression, it self-inflates, ready for the next breath.
   • The bag is usually made of silicone or rubber and has a standard volume of around 1600 mL for adults, though smaller sizes are available for children and infants.
2. Mask:
   • A clear mask is placed over the patient’s mouth and nose to form a seal, allowing air to be delivered when the bag is compressed.
   • Masks come in different sizes (adult, pediatric, infant) to ensure a proper fit and effective ventilation.
3. Reservoir Valve:
   • Some Ambu bags are equipped with a reservoir valve that attaches to an oxygen source, providing a higher concentration of oxygen to the patient when needed.
   • Without a reservoir, room air (about 21% oxygen) is delivered; with a reservoir and oxygen source, concentrations up to 100% oxygen can be achieved.
4. One-Way Valve:
   • The Ambu Bag features a one-way valve that prevents the patient’s exhaled air from entering the bag, ensuring that each breath delivered contains fresh air or oxygen.
5. Oxygen Port:
   • The bag has a port where an oxygen tube can be attached to supply oxygen from a tank or wall source, enhancing the oxygen concentration delivered to the patient.
6. Pressure Relief Valve (optional):
   • Some Ambu bags come with a pressure relief valve, which prevents excessive pressure from being delivered to the lungs, reducing the risk of barotrauma.

How It Works:

1. Application:
   • The Ambu Bag is used by placing the mask securely over the patient’s mouth and nose, ensuring a tight seal to prevent air leakage.
2. Ventilation:
   • The rescuer or healthcare provider squeezes the bag at regular intervals (typically 10-12 times per minute for adults) to manually force air or oxygen into the patient’s lungs.
3. Exhalation:
   • Once the bag is released, the patient exhales passively through the one-way valve, allowing carbon dioxide to escape while preventing re-inhalation of exhaled air.

Uses:

1. Emergency Resuscitation:
   • Used in cardiac arrest, respiratory arrest, or any emergency where the patient is not breathing adequately. It provides immediate life support until more advanced interventions can be performed.
2. During Surgery:
   • In operating rooms, the Ambu Bag may be used during anesthesia to manually assist breathing when mechanical ventilators are unavailable or during short procedures.
3. Transport:
   • It is often used during patient transport in ambulances, helicopters, or within hospitals when a mechanical ventilator is not available.
4. CPR:
   • During cardiopulmonary resuscitation (CPR), the Ambu Bag is used in conjunction with chest compressions to provide oxygen to the patient.
5. Airway Management:
   • The device is used in situations where patients have compromised airways or require temporary ventilation assistance, such as trauma, overdoses, or neurological emergencies.

Benefits:

• Portable: Ambu Bags are lightweight and portable, making them ideal for emergency situations outside the hospital.
• Manual Control: Allows for manual control of ventilation, giving healthcare providers the ability to adjust the rate and volume of breaths delivered.
• No Power Required: The bag works without electricity, making it useful in situations where power is unavailable or mechanical ventilators are not accessible.
• Effective for a Wide Range of Patients: Available in different sizes, the Ambu Bag can be used for infants, children, and adults, making it a versatile emergency tool.

Limitations:

• Requires Training: Proper use of the Ambu Bag requires skill and training, especially to avoid hyperventilation (over-breathing) or inadequate ventilation.
• Risk of Barotrauma: Excessive pressure or volume during ventilation can cause barotrauma (damage to the lungs), especially in patients with lung injuries or compromised lung function.

Conclusion:

The Ambu Bag is a critical device in emergency care, providing manual ventilation when a patient is unable to breathe on their own. Its portability, simplicity, and effectiveness make it a life-saving tool in both hospital and pre-hospital settings. By delivering essential oxygen to the lungs, it plays a vital role in resuscitation and maintaining a patient’s oxygenation until further medical treatment is available.