Emergencies nitrous oxide

Inhalation via a demand valve of nitrous oxide and oxygen, as in obstetrics, may be used temporarily in other situations e.g. urinary lithiasis, trigeminal neuralgia, during postoperative chest physiotherapy, for changing painful dressings and in emergency ambulances. 

Uses. Nitrous oxide is used to maintain surgical anaesthesia in combination with other anaesthetic agents, e.g., isoflurane or propofol, and, if required, muscle relaxants. Entonox provides analgesia for obstetric practice, for emergency management of injuries, and during postoperative physiotherapy. 

Miller MA, Martinez V, McCarthy R, and Patel MM (2004) Nitrous oxide whippit abuse presenting as clinical B12 deficiency and ataxia. The American Journal of Emergency Medicine 22 124-126. 

O Sullivan I and Benger J (2003) Nitrous oxide in emergency medicine. Emergency Medicine Journal 20 214-217. 

Triner WR, Bartfield JM, Birdwell M, Robak N. Nitrous oxide for the treatment of acute migraine headache. Am J Emerg Med 1999 17 278-281. 

Further evidence for photoassisted interconversions between nitrous oxides, nitric oxide and other nitrogen oxides on metal oxide surfaces emerged from studies with the dynamic mass spectrometer system of flash-initiated changes at N O/ZnO interfaces. Fig. 13(a) illustrates mass spectra of the gas mixture adjacent to an 14N1SN160/Zn0 interface prior to a flash and then 100 ms after a flash, and the broken line demonstrated that a quite different mass spectrum was detected by the DMS system 100 ms after flash illumination. The large enhancement of m/e = 30 (14N160+), smaller enhancement of m/e = 31 (1SN160+), and absence of... 

Nitrous oxide is very insoluble in blood and other tissues (Table 13-1). This results in rapid equilibration between delivered and alveolar anesthetic concentrations and provides for rapid induction of anesthesia and rapid emergence following discontinuation of administration. The rapid uptake of N2O from alveolar gas serves to concentrate coadministered halogenated anesthetics this effect (the second gas effect ) speeds induction of anesthesia. On discontinuation of administration, nitrous oxide gas can diffuse from blood to the alveoli, diluting Oj in the lung. This can produce an effect called diffusional hypoxia. To avoid hypoxia, 100% Oj rather than air should be administered when N O is discontinued. 

Respiratory An audit of a case register of a large pediatric emergency department has shown that of 2002 patients receiving pediatric procedural sedation (60% male, median age 6 years), 81% received nitrous oxide and 1% received nitrous oxide + midazolam [18 ]. There were serious adverse events in... 

Babl FE, Belousoff J, Deasy C, Hopper S, Theophilus T. Paediatric procedural sedation based on nitrous oxide and ketamine sedation registry data from Australia. Emerg Med J 2010 27 607-12. 

Richardson PG. Peripheral neuropathy following nitrous oxide abuse. Emerg Med Australas 2010 22(1) 88-90. 

Babl FE, Oakley E, Puspitadewi A, Sharwood LN. Limited analgesic efficacy of nitrous oxide for painful procedures in children. Emerg Med J 2008 25(11) 717-21. 

Huang MY, Tsai W, Chang WH. Nitrous oxide-induced polyneuropathy in a teenager. Emerg Med J 2009 26(3) 186. 

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