fixed flow devices variable flow devices
Venturi Adapter Variable flow devices
The venturi adapter delivers a fixed amount of oxygen to the patient. The Variable flow devices deliver an uncontrolled amount of oxygen, in other words, they are the
system allows for mixing of the oxygen with air drawn into the system opposite to fixed flow devices. They are used in cases where the patient does not need a controlled
through holes in the adaptor. amount of oxygen.
Hudson delivery device
This is the mask shown in the first image above. There is no venturi adapter connected to this
therefore the mask is variable flow. The is one of the most common masks used in hospitals.
The adaptors come with
varying sized holes that
allow different amounts Nasal cannulae
of oxygen through. The Another type of variable flow device is the nasal cannula. This consists of a ribbed plastic tubing
percentages are: 24, 28, 35, that allows the oxygen to be delivered through nasal prongs instead of a mask. This is used to give
40 and 65. patients a break from the mask.
The strap can cause a lot of
issues with users. After an
extended period of time, the While the mask is being worn, if not fitted
irritates the bridge of the ear. correctly, the strap can catch the ear and fold
This can lead to skin sores and it over while in use. This is not comfortable for
can be very uncomfortable for the user and adds to the discomfort of wearing
the patient. the mask.
The nasal cannula is used for the
patient to give them a break from
Another area of the mask that can cause the mask. It is also used when a Preferred device for nurses
problems is the bridge that sits on the patient is eating or drinking. The to use
nose. Due to the variety of people, the nasal cannula is a lot less restricting
mask can also cause irritation. than the mask but as it is a variable
flow device, it can not be used all of
the time for the patient.
Oxygen is turned on and passed
through a humidifier
In order to change the adapter, the
system has to be removed
The patient requires to be lifted
from to fit the cannula