oxegyn therapy as ordered? need an answer !

I am a nursing student (BSN) and was assigned a patient with a tonsillectomy last week.
She also had asthma and was on oxygen therapy. The order was for 7 liters, but the gauge was set on 9.5. I asked the charge nurse about it, and she said that since the pt was on a Venturi / (charted as venti) mask that a certain amount was lost and it was necessary to elevate the amount in order to deliver the prescribed rate.

I have not been able to find anything...anywhere recommending this ... and .. doesn’t a Venturi mask have little green disks on the sides with holes in them ... or a cylinder at the bottom in which to regulate the flow?

The patient was obese, and needed a large mask, the mask she was wearing was a extra large, solid clear plastic with no regulators anywhere.

Could that amount of 02 cause harm or was the explanation correct?
Thanks for your help!

O2 is not harmful to anyone. It's in our atmoshpere. Never withhold oxygen from any patient. They may have had to titrate up on the O2 for this patient. Venti systems can come in a variaty of set ups. I've seen them with dials and I've seen specific inserts for each % O2 needed. Personally, I'd ask the next RT person I saw.

[ QUOTE ]
MedicRN said:
O2 is not harmful to anyone. It's in our atmoshpere. Never withhold oxygen from any patient.

[/ QUOTE ]

Oh, my dear MedicRN, how wrong you are! Oxygen is very beneficial to an extent and yes it is in our environment. However, oxygen can be VERY TOXIC when used for too long and inappropriately. Please, do some research before making statements such as the one you have made in your post about oxygen. It is a wise thing to use RT as a valuable resource in determining if oxygen flow is appropriate to the mask on your patient if you have a question. Most often, though, the mask has a regulatory dial which states the liter flow if it is a precise quanitiy of oxygen such as 40%, etc. A simple mask is a different story and flows at just a liter flow, same thing as a nonrebreather. Please refer to an article such as the one in this link if you have questions about the dangers of oxygen to the human body when used for too long or inappropriately:

http://www.vspn.org/vspnsearch/aow/oxygentoxicity.htm

Agreed. The original statement would apply for the oxygen we get from air, but definitely not for oxygen administered at different flowrates and percentages. If oxygen therapy were snap and have no complications for anyone, all of these specialists, expensive equipment and doctor's orders wouldn't be necessary. But they are.

For one, oxygen therapy could cause a COPD patient to stop breathing. Food for thought.

As for the original question, I'm of no help.

So far as I know, oxygen by venti mask is never ordered in liters. It should be ordered as a percentage of inspired air, such as 35%, 50%, etc. The rate of flow on the meter is determined by which percentage oxygen you want to deliver. The venti masks I have used have markings on the sides that indicate where to set the flow rate according to the percentage of oxygen you want to give.