An anaesthetic vaporizer must deliver a safe, reliable concentration of volatile agent to the patient. Anaesthetists should understand the basic principles of. Vaporizers are an integral part of modern-day anaesthesia, allowing the delivery of safe concentrations of volatile anaesthetic agent. Over time, vaporizer design. Anaesthesia vaporizers for inhalational anaesthetic agents. Principal, classification, types, hazards.

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Fundamentals The operator adjusts the fraction of the total fresh gas that is diverted into the vapourising anaestheska. Pop-up div Successfully Displayed This div only appears when the trigger link is hovered over.

It has two sections, a plug in vapourising module, which is specific for a particular gaporizers and a built in gas supply module that is a part of the anaesthesia machine. Partial or complete obstruction to gas flow from problems with the mounting system has been reported and leaks may occur.

Category WikiProject Pharmacy portal. In vapourisers with top fill designs, this can be prevented by filling only up to the top indicator level with the vapouriser turned off and in the vertical position. The SVP of an agent vaporizerx hence the vaporizer output decreases non-linearly with decreasing temperature.

Chamber only contains 50ml of agent.

Simultaneous administration of more than one vapour: As fresh gas flow rate increases, it becomes more difficult to achieve full saturation of gas leaving the vaporizing chamber. Standard anaesrhesia for particular requirements for anesthesia workstations and their components ASTM F As a result, ‘upstream’ pressure increases in proportion to FGF. However, many designs have a lever which adjusts the amount of fresh gas which enters the vaporising chamber.

Anesthesia Gas Machine- Vaporizers

Cross-threading the filler cap vporizers a common cause of vapouriser leakage. For a very detailed mathematical approach from which the above calculations were deriveddownload Steve Shafer’s ” How Vapourisers Work “. Oxygen mask and Vaporixers cannula Oxygen concentrator Anaesthetic machine Relative analgesia machine. The DIVA anaesthetic vapouriser is also a measured flow vapouriser but can be used for all modern inhalational anaesthetics including desflurane.


Alarms sound if the vaporizer is nearly empty. Please review our privacy policy. They have several features designed to compensate for temperature changes especially cooling by evaporation. The Sevoflurane vapour pressure in the vapour chamber is 15kPa. Anaesthetic vapourisers, used for the administration of volatile anaesthetics, have evolved from the vaporizere masks used for open ether anaesthesia to the present day modern electronically controlled vapourisers designed to deliver potent modern inhalation aesthetic agents.

Modern Anaesthesia Vapourisers

It consists of two parts: American Society for Testing and Materials. It is tippable and robust. Modern vaporizers are relatively immune older vaporizers were certainly not immune due to check valves between the vaporizer outlet and the common gas outlet, smaller vaporizing chambers, or tortuous inlet chambers. A fan blows warm air over the cassette if its temperature falls below 18 degrees, as may happen with gaseous inductions Sevo or Des.

Vapoeizers on the thumbnail, or on the underlined text, to see the larger version 15 KB. There is an alarm for low liquid level.

Understanding vaporizers | BJA Education | Oxford Academic

Underfilling of anaesthetic vapourisers can result in an abrupt decrease in output if used under conditions of high fresh gas flow and high dial settings. The most recent vaporizers have been in use for over a decade and have brought computer-assisted control to maximize accurate agent delivery, particularly at low flow rates. Clinically significant effects require: Loss of anesthetic gases due to defective safety equipment.

It works by controlling the vaporisation of anaesthetic agents from liquid, and then accurately controlling the concentration in which these are added to the fresh gas flow.

The output of modern vaporizers is linear from degrees C, due to. The output of older vaporizers varies slightly with changes in fresh gas mixture, whereas the Aladin compensates for this automatically. This article’s lead section does not adequately summarize key vapofizers of its contents.


The performance of the plenum anaesthesoa depends extensively on the saturated vapour pressure of the volatile agent. This is unique to each agent, so it follows that each agent must only be used in its own specific vaporizer. The liquid level indicator vapprizers the filling port are located on the front. In addition, the resistance generated by the flow splitting valve becomes more significant at low flow rates—this results in more gas bypassing the vaporizing chamber.

A resistance in the bypass line increases upstream pressure. At or below this critical temperature, it can exist in both its liquid and gaseous forms; the latter is called a vapour. Please enter User Name.

The characteristics of the modern vapourisers with their special construction and operation are discussed below. This site uses cookies to provide, maintain and improve your experience. Flow-over including the Aladin for desflurane, which does not require added heat like the Tec 6. The Tec 6 desflurane vaporizer is not a variable bypass vaporizer, it is anawsthesia gas-vapor blender. By injecting the vapour directly to the total fresh gas flow without any split — measured flow vapourisers.

The copper abaesthesia and Vernitrol probably strictly museum pieces at this point are measured-flow, bubble-through, non-temperature compensated, multiple agent, and out of circuit.

Selectatec-type mountings Vapourisers ‘stand’ on a pair of vertical pins, one for the gas inlet and one for the outlet.