The Ventilator

The Ventilator


The ventilator is a very complex machine, but it essentially has two jobs…to put oxygen into the body and to get carbon dioxide out of the body. It does its job typically through a breathing tube that is inserted through mouth, but can also be used with face masks of various shapes and sizes. As with the monitor, there are a lot of colorful lines and numbers that can get very confusing. There are also a lot of reasons for the machine to alarm, but most of the time those alarms don’t indicate a serious problem. Here are the settings and numbers that parents are usually most interested in.

Oxygen: Normal air in the environment is 21% oxygen and 79% other stuff (like nitrogen). The ventilator can deliver air, however, that contains much more oxygen, sometimes 100%. This is technically called the “Fraction of Inspired Oxygen,” so you’ll probably hear it referred to as the “FiO2.” Increasing this number, or percentage, helps put more oxygen into the lungs so that more is available to be picked up by the blood and taken out to the body. Generally, the closer the number is to 21%, the healthier your child’s lungs are.

Breathing Rate: The medical team can tell the ventilator how many breaths to give your child each minute. If they aren’t too sick or too sedated, however, your child may be able to take more breaths than what is dialed in to the machine. You can tell if your child is breathing more than what’s ordered by comparing the actual number of breaths to the ordered number of breaths. You can also look for a pink color at the beginning of some of the waves on the screen. Feel free to ask your nurse or respiratory therapist how to know if your child is starting their own breaths.

Peak Pressure: The ventilator delivers a breath by pushing air into the lungs, and this takes a varying amount of pushing pressure depending on how sick and stiff your child’s lungs are. You can think of it like blowing up a balloon…if the balloon is very stiff you will have to blow harder to get air to go in. The total amount of pressure being used can be found in the upper right hand corner. A normal number is around 20, but less than 35 is ok.

Tidal Volume: The tidal volume is the amount of air that goes in and out of the lungs with each breath. This volume will vary depending on the age and size of your child.