Venturi mask


Venturi mask

The venturi mask, also known as an air-entrainment mask, is a medical device to deliver a known oxygen concentration to patients on controlled oxygen therapy. Venturi masks are considered high-flow oxygen therapy devices. This is because venturi masks are able to provide total inspiratory flow at a specified FIO2 to patients itherapy. The kits usually include multiple jets in order to set the desired FIO2 which are usually color coded. The color of the device reflects the delivered oxygen concentration, for example: blue = 24%; white = 28%; orange = 31%; yellow = 35%; red = 40%; green = 60%. The color however varies with different brands and the user must check the instructions to determine the correct color for the desired FIO2.

Other brands of masks have a rotating attachment that controls the air entrainment window, affecting the concentration of oxygen. This system is often used with air-entrainment nebulizers to provide humidification and oxygen therapy.

Mechanism

The mechanism of action depends on the venturi effect.

Flow Problems

Air entrainment masks, although considered high flow systems, are not always able to guarantee the total flow with oxygen percentages above 35% in patients with high inspiratory flow demands. The problem with air entrainment systems is that as the FIO2 is increased, the air to oxygen ratio decreases. For example, for 30% the ratio is 8 parts air to 1 part oxygen. For 40% the ratio decreases to 3 to 1. Since the jets in venturi masks generally limit oxygen flow at 12 to 15 liters per minute the total flow decreases as the ratio decreases. At an oxygen flow rate of 12 liters per minute and a 30% FIO2 setting, the total flow would be 108 L/min. At a 40% FIO2 setting, the total flow would decrease to 48 L/min. As a rule of thumb, 60 L/min is considered the minimum flow rate to qualify as a high flow device. [Egan's Fundamentals of Respiratory Care, Eighth Edition, Page 841, Mosby, Inc., 2003.]

Notes


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • Venturi mask — Ven·tu·ri mask (ven tooґre) [Giovanni Battista Venturi, Italian physicist, 1746–1822] see under mask …   Medical dictionary

  • Venturi mask — a face mask used in oxygen therapy, delivering a controlled mixture of oxygen and air …   Medical dictionary

  • Venturi — may refer to:People*Giovanni Battista Venturi, (b 1746) physicist. *Ken Venturi, (b 1931) professional golfer. *Remo Venturi, Italian motorcycle racer. *Rick Venturi, American football coach. *Robert Venturi, (b 1925) architect. Fictional… …   Wikipedia

  • Venturi effect — The Venturi effect is the fluid pressure that results when an incompressible fluid flows through a constricted section of pipe. The Venturi effect may be derived from a combination of Bernoulli s principle and the equation of continuity. The… …   Wikipedia

  • venturi — noun /vɛnˈtjʊəri/ a) Short of venturi tube. , 1973: He’s at the age where mucus is a daily companion, a culture of mucus among the old, mucus in a thousand manifestations, appearing in clots by total surprise on a friend’s tablecloth, rimming his …   Wiktionary

  • Simple face mask — instead.The final oxygen concentration delivered by a simple face mask is dependent upon the amount of room air that mixes with the oxygen the patient breathes. The air mixing is determined by how much air any individual is breathing at the… …   Wikipedia

  • FiO2 — FiO2, in the field of medicine, is the fraction of inspired oxygen in a gas mixture.The FiO2 is expressed as a number from 0 (0%) to 1 (100%). The FiO2 of normal room air is 0.21 (21%).A patient s FiO2 may be varied through the use of different… …   Wikipedia

  • Moran Campbell — Edward James Moran Campbell Born August 31, 1925(1925 08 31) Yorkshire, England Died April 12, 2004(2004 04 12) (aged 78) Edward James Moran Campbell, OC, FRSC (August 31, 1925 – April 12, 2004) …   Wikipedia

  • Diving regulator — and Octopus Other names Demand valve Uses Reduces pressurized breathing gas to ambient pressure and delivers it to the diver Inventor Manuel Théodore Guillaumet (1838), Benoît Rouquayrol (1860) …   Wikipedia

  • Oxygen therapy — Intervention ICD 9 CM 93.96 MeSH …   Wikipedia