Canadian Anaesthetists’ Society Journal

, Volume 33, Issue 1, pp 32–35 | Cite as

Negative pressure in the middle ear in children after nitrous oxide anaesthesia

  • Derek Blackstock
  • Mark A. Gettes


A study was conducted to measure the pressure in the middle ear in healthy children, following nitrous oxide anaesthesia,

Premedication with chloral hydrate and scopolamine orally was similar in all patients and awake patients received thiopentone 4–5 mg·kg’-1for induction of anaesthesia.

All received nitrous oxide (66 per cent) in oxygen and halothane or isoflurane as required. Exposure to nitrous oxide varied from 17—100 minutes, mean 47 minutes.

All patients developed negative pressure in one or both ears in the first day following anaesthesia. This is a higher incidence than previously reported and may be explained by the inability of children to equilibrate negative middle ear pressure via the eustachian tube. Many children complain of difficulty hearing in the first 24 hours after nitrous oxide anaesthesia. An increase in middle ear pressure during anaesthesia with nitrous oxide has been described by many investigators.1-5 Complications including rupture of the tympanic membrane, graft displacement, stapes displacement, haemotympanum and temporary or permanent hearing impairment, have been attribut-

Key words

kanaesthetics gases nitrous oxide ear middle anaesthesia paediatrics 


Nous avons procédé à une étude dans le but d’évaluer le changement de pression dans l’oreille moyenne après une anesthésie au protoxyde d’azote.

Une prémédication oralle d’hydrate de chloral et de scopolamine a été donnée à tous les patients. Les patients éveillés ont reçu du thiopentone 4–5 mg·kg-1 à l’induction de l’anesthésie. Le protoxyde d’azote (66pour cent) associe à l’oxygen et l’halothane ou l’isofturane ont été administrés à tous les patients selon leurs besoins. La durée d’administration du protoxyde d’azote varie de 17 à 100 minutes, avec une moyenne de 47 minutes.

Tous les patients ont développé une pression négative dans une ou les deux oreilles durant la première journée après /’anesthésie générale. Les résultats représentent une incidence accrue qui pourraient être expliquée par le manque d’adaptation chez les enfants à équilibrer la pression négative de l’oreille moyenne via les trompes d’eustache.


  1. 1.
    Davis I, Moore JRM, Lahiri SK. Nitrous oxide and the middle ear. Anaesthesia 1979; 34:147–51.PubMedCrossRefGoogle Scholar
  2. 2.
    Matz GJ, Rattenborg CG, Holaday DA. Effects of nitrous oxide on middle ear pressure. Anesthesiology 1967; 28: 5:948–50.Google Scholar
  3. 3.
    Patterson ME, Bartlett PC. Hearing impairment caused by intratympanic pressure changes during general anaesthesia. Laryngoscope 1976; 86:399–404.PubMedCrossRefGoogle Scholar
  4. 4.
    Drake-Lee AB, Casey WF. Anaesthesia and tympanometry. International Journal of Pédiatric Otorhinolaryngology 1983; 6:171–8.PubMedGoogle Scholar
  5. 5.
    Perreault L, Normandin N, Plamondon L, et al. Tympanic membrane rupture after anaesthesia with nitrous oxide. Anesthesiology 1982; 57:325–6.PubMedCrossRefGoogle Scholar
  6. 6.
    White PF. Spontaneous rupture of the tympanic membrane occurring in the absence of middle ear disease. Anesthesiology 1983; 59:368–9.PubMedCrossRefGoogle Scholar
  7. 7.
    Waun JE, Sweitzer RS, Hamilton WK. Effect of nitrous oxide on middle ear mechanics and hearing acuity. Anesthesiology 1967; 28:846–50.PubMedCrossRefGoogle Scholar
  8. 8.
    Singh CB, Kirk R. The effect of nitrous oxide on middle ear pressure in children during anaesthesia. J Laryngol Otol 93:1979; 349–56.Google Scholar
  9. 9.
    Perreault L, Normandin N, Plamondon L, et al. Middle ear pressure variations during nitrous oxide and oxygen anaesthesia. Can Anaesth Soc J 1982; 29:428–34.PubMedCrossRefGoogle Scholar
  10. 10.
    Eliachar I. Northern JL. Studies in tympanometry: validation of the present technique for determining intra-tympanic pressures through the intact eardrum. Laryngoscope 1974; 84:247–55.PubMedCrossRefGoogle Scholar
  11. 11.
    Alexander GD, Skupski JN, Brown EM. The role of nitrous oxide in post-operative nausea and vomiting. Anesth Analg 1984; 63:175.Google Scholar
  12. 12.
    Palazzo MGA, Strunin L. Anaesthesia and emesis. I. Etiology. Can Anaesth Soc J 1984; 31: 2:178–877.Google Scholar

Copyright information

© Canadian Anesthesiologists 1986

Authors and Affiliations

  • Derek Blackstock
    • 1
  • Mark A. Gettes
    • 1
  1. 1.Department of Anaesthesia - 1H13Children’s HospitalVancouver

Personalised recommendations