Artificial Manual Breathing Unit

AMBU BAG Full Form in English, letter by letter

An Ambu bag is a hand-squeezed resuscitator that pushes air into the lungs of a person who is not breathing properly.

AMBU BAG Full Form in Indian Languages

Every ambulance, crash cart and labour room in India keeps an AMBU bag, a hand-squeezed resuscitator. Its name is usually expanded as Artificial Manual Breathing Unit, and it is also written in Hindi, Bengali, Tamil, Telugu, Marathi and Gujarati below.

A brand name that became a medical term

AMBU is the name of a device, and Indian textbooks and nursing exam guides expand it as Artificial Manual Breathing Unit. The company behind the original product, Ambu, is Danish, and some sources think the name was simply the company's brand rather than a formal abbreviation. For an exam, write the expansion your syllabus gives.

The device was developed in Denmark in the 1950s by the anaesthetist Henning Ruben and the engineer Holger Hesse, and it was sold by the company that became Ambu A/S. The brand became so common that in India any bag-valve-mask resuscitator is called an Ambu bag, whoever makes it.

The parts and how it works

An Ambu bag has a face mask that seals over the nose and mouth, a one-way valve, and a squeezable bag that springs back on its own. When you squeeze it, air goes through the valve and mask into the lungs. When you let go, the bag refills with fresh air, and the patient's breath out escapes through the valve.

Most units add an oxygen inlet and a reservoir bag, so that oxygen from a cylinder can raise the concentration of oxygen delivered. A PEEP valve can be attached in hospital use.

Because the bag refills itself, it works without electricity or a gas supply. That makes it the standard rescue tool in an ambulance, a ward or a village health centre.

Using it correctly

The best method is with two people. One holds the mask with both hands, using a C and E grip: thumb and index finger form a C over the mask while the other fingers lift the jaw, and the second person squeezes the bag. One person alone often gets a poor seal.

Squeeze for about one second, enough to see the chest rise, and no more. Squeezing hard or fast pushes air into the stomach, which can cause vomiting and inhaling of stomach contents. During CPR two breaths are given after every 30 compressions, and once an advanced airway is in place, one breath about every six seconds.

For a baby or small child, use the correct paediatric bag and mask size, and be even more gentle.

Where it is used in India

Intensive care units, operating theatres, emergency rooms and labour rooms keep one within reach, as do ambulances run by state and private operators. In a maternity ward the smallest neonatal version is often the first thing used on a baby who does not breathe at birth.

During the 2020 COVID-19 wave, several engineering colleges and startups built low-cost ventilators that compressed an Ambu bag mechanically on a timer. Manual bagging stayed in use as a back-up.

Learning to bag a patient properly is part of life support training for medical, nursing and paramedic students.

Ambu bag compared with an oxygen mask and a ventilator

An oxygen mask or nasal prong only adds oxygen to the air that a patient is breathing on their own, so it does nothing for a person who has stopped breathing. The bag pushes air in, which makes it a rescue device.

A mechanical ventilator does the same job automatically for hours or days, which is why an ICU patient is moved to a ventilator rather than kept on hand bagging. The bag bridges the gap while a patient is stabilised, intubated or shifted between a ward and an ambulance.

The cost gap is large too. A basic adult bag costs a few hundred rupees, and a hospital ventilator costs lakhs.

Mistakes that reduce its benefit

The commonest mistake is a poor mask seal, which lets air leak around the face. The second is squeezing too hard or too fast, which fills the stomach. The third is forgetting to open the airway: tilt the head and lift the jaw, unless a neck injury is suspected, in which case lift the jaw without tilting.

A fourth mistake is using an adult bag on a baby, which can overinflate the lungs. Check the size marked on the bag and mask before use, and practise on a training manikin, where the chest rise shows you when the volume is right.

The same skill is tested in ACLS courses, where trainees use a manikin and an AED trainer alongside the bag.

The Ambu bag stays in every emergency kit because it is cheap and works without power, but it only works well in trained hands. Medical and nursing students should practise the mask hold until it is automatic.

AMBU BAG Full Form: Common Questions