Nitrous Circuits

These are used to deliver analgesic gas to patients prepared in Maternity, Dentistry or Emergency departments.
The gas, Nitrous Oxide is commonly mixed with oxygen (a 50/50 mix Entonox is available) and can be delivered continuously or on demand.
The patients are usually breathing without ventilator support, expandable tubing is becoming the prefered choice, it can be expanded to the desired length to allow patient mobility, compressed to reduce clutter and when packed as a space saving presentation.

All components used in our circuits have been selected for their durability and quality, but not for reprocessing.

Southern Cross Hospital Supplies circuits feature two 'one-way valves' to ensure the patient is recieving the perscribed concentration rather than diluting the mixture with room air or exhaled gas.

All our circuits are supplied non-sterile and latex free, including the retainer bands used in packaging.


Our most popular products available include:
   E0130MF - single limb nitrous circuit, with filter, mouthpiece and dual one-way valves. 3.0m long.
   E2130MF - scavenging nitrous circuit, with filter, mouthpiece, dual one-way valves and 19mm male scavenging connection. 3.0m long.
Other products are available, please contact us for brochures or to discuss a customised circuit.

Our circuits are available in two configurations.
Single limb configuration contains one tube running from the gas source to the patient mouthpiece, with filters if required.
Scavenging configuration contains an additional tube to capture the expired gasses for an external scavenging or suction source to remove.

Featured below are two of our most popular nitrous circuits.

Nitrous Circuit E2130MF
Code E2130MF Nitrous Circuit, featuring expandable tube, filter, 2 one way valves and scavenging tube.

Nitrous Circuit E0130MF
Code E0130MF Nitrous Circuit, featuring expandable tube, filter and 2 one way valves.

Nitrous circuits are provided with a removable mouthpiece so that they can be attached to a mask if required.


Southern Cross Hospital Supplies nitrous circuits are made with expandable tubing.
This tubing can be stretched to the desired length and collapsed back as needed.

Our basic nitrous circuits have a maximum length of 3.0m, and can be extended further with an extension tube to reach any part of the birthing suite.

Scavenging Connectors

Circuits which include a scavenging limb are supplied with connectors for either a passive scavenging source such as a suction bottle or reservoir, or an active wall mounted suction source. Connectors fitting the wall mounted suction source are ported, allowing the suction system to draw on room air instead of continously drawing unused nitrous gas when not in use.

One Way Valves

Southern Cross Hospital Supplies nitrous circuits all contain two one way valves to control the flow direction through the circuit.
One is positioned at the end of the gas supply tube to prevent expired gasses being blown back through the system.
The other is positioned at the exhaust to ensure the expired gasses or room air are not drawn back by the patient (diluting the prescribed concentration of gas going to the patient).


All our nitrous circuits are available with or without a filter.
The filter is positioned just behind the patient mouthpiece to filter both incoming and exhaled gasses.

Normal Use & Reprocessing

These circuits are designed (through material selection) not to be reprocessed.
Regardless of the reprocessing procedure there may be an effect on the components which may reduce the integrity of the product.
We cannot be sure it would be fit or safe for it's intended use after reprocessing.

Determining when a circuit needs to be changed is reliant on individual hospital infection control policy.
Common customer practice in maternity is for the circuit to be changed between patients but may vary in other departments.

For enquiries about our circuits, please do not hesitate to contact us by phone or email.