When a doctor thinks that a patient with a medical condition needs to take in more oxygen, he or she may administer the extra oxygen through a Venturi mask. This is a plastic face mask that takes in air from the room but also mixes in pure oxygen from an oxygen storage canister. Each mask is only used once, but the doctor can adjust the concentration of oxygen for the patient. Commonly, this is a suitable treatment for those with longterm lung conditions.
A human body needs oxygen for normal functioning, and low concentrations of oxygen in the blood can be dangerous to health. Several different conditions can cause low oxygen levels, including problems with the lungs, as these organs normally take in oxygen efficiently from the air. A doctor typically assesses the patient for signs that he or she is not getting a healthy level of oxygen, and figures out how much extra oxygen the patient needs.
Venturi masks are made up of a soft plastic covering for the nose and mouth, with a tube attached to the front of the mask where the air and the oxygen are channeled up into the mask. The Venturi effect refers to a physical phenomenon where gas that goes into a narrow part of a tube is at low pressure, allowing higher pressure gas into the tube. In the case of the Venturi mask, the first gas is the oxygen and the second gas is the air from the room the patient is in.
Regular air contains 21% oxygen, which is a high enough concentration for healthy people. Sick people can receive much higher concentrations of oxygen, as it is the primary substance in the air that people need. The various settings that a doctor can apply to a Venturi mask range from 23% up to 40% oxygen. He or she can set these by placing specific adapters onto the mask tubing.
People who wear the mask may experience skin problems over time if the mask is too tight. The unnatural levels of oxygen can also make a patient breathe in shallow breaths or take in too little breaths, which can make the blood oxygen levels too low for safety. Another possibility, which is related to breathing problems, is that the person's lung may collapse. Although a Venturi mask is a common piece of equipment in hospital settings, it is not the only option for oxygen delivery via a mask, and different masks may be more suitable for individual patients than others.