Anaes Cases · Medical gases & gas supply
Entonox separation in the cold
A focused case on the Entonox (50:50 N2O-O2) separation below minus 7 degrees — the liquefaction of the N2O produces a hypoxic or a concentrated N2O output. Rewarm and invert.
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ANZCAFRCAABAEDAIC
Prompt
An Entonox cylinder stored outside in winter is brought to the ED for a patient with a suspected fracture. The Entonox appears to deliver less analgesia than expected. Discuss.
Presentation
An Entonox cylinder (the 50:50 nitrous oxide-oxygen mixture) stored in the ambulance bay at sub-zero temperatures is brought to the ED for a patient with a suspected femoral fracture. The patient reports that the Entonox is providing less analgesia than expected. The flow from the demand valve is intermittent.
References2ShowHide
- [1]AAGBI. Checking anaesthetic equipment 2012. Anaesthesia, 2012.PMID 22563957
- [22563958]Bersten AD, Soni N (eds) Oh's Intensive Care Manual. 8th edition, Elsevier, 2018.