Gastric volume and pH in out-patients

  • Bill Y. Ong
  • Richard J. Palahniuk
  • Maureen Cumming


We measured the volume and pH of the gastric content of 21 out-patients and 21 in-patients under general anaesthesia. Gastric tubes were inserted after induction of anaesthesia, and gastric fluids were withdrawn for pH determinations. Gastric volumes were measured by a dilution technique using polyethylene glycol as the indicator and also by measurement of the volume aspirated through agastric tube. Out-patients had a mean gastric volume of 69 ± 17 ml while inpatients had a mean volume of 33 ± 4 ml. The average gastric pH for the out-patients was 1.8 ± 0.2 and for the in-patients 2.0 ± 0.3. Four outpatients had more than 75 ml of gastric fluid of pH less than 2.0. Aspiration through a gastric tube did not empty the stomach completely and the volume thus obtained gave a falsely low estimate of the gastric volume.


Nous avons déterminé le pH et le volume du liquide gastrique chez 21 malades hospitalisés, opérés sous anesthésie générale, et chez 21 autres patients ambulatoires, soumis à une anesthésie générale pour chirurgie. A cet effet, nous avons mis en place une sonde nasogastrique avant ľinduction de ľanesthésie et avons prélevé du liquide gastrique pour en déterminer le pH. Nous avons également fait la mesure du volume liquidien gastrique au moyen ďune technique de dilution, le polyéthylène glycol servant ďindicateur, ainsi que par la mesure directe du volume total que nous pouvions aspirer.

Les malades ambulatoires avaient un volume moyen de 69 ± 17 ml, alors que les patients hospitalisés avaient un volume de 33 ± 4 ml. Le pH du liquide gastrique des malades non hospitalisés était de 1.8 ± 0.2, alors qu’il était de 2.0 ± 0.3 chez les malades hospitalisés. Quatre des patients ambulatoires avaient plus de 75 ml de liquide dans ľestomac et à un pH de moins de 2.0. La succion appliquée à la sonde naso-gastrique ne permettait pas de vider complètement ľestomac et les volumes ainsi obtenus donnaient des résultats inférieurs à la réalité.


  1. 1.
    Bannister, W.K. &Sattilaro, A.J. Vomiting and aspiration during anesthesia. Anesthesiology23: 25(1962).CrossRefGoogle Scholar
  2. 2.
    Clifton, B.S. &Hotten, W.I.T. Deaths associated with anaesthesia. Br. J. Anaesth.35: 250 (1963).PubMedCrossRefGoogle Scholar
  3. 3.
    Dinnick, O.P. Deaths associated with anaesthesia. Observations on 600 cases. Anaesthesia19: 536 (1964).PubMedCrossRefGoogle Scholar
  4. 4.
    Edwards, G., Morton, H.J.V., Pask, E.A., &Wylie, W.D. Deaths associated with anaesthesia. A report on 1000 cases. Anaesthesia11: 194 (1956).PubMedCrossRefGoogle Scholar
  5. 5.
    Malawar, S.J. &Powell, D.W. An improved turbidimetric analysis of polyethylene glycol utilizing an emulsifier. Gastroenterology53: 250(1967).Google Scholar
  6. 6.
    Bloom, D.S., Jacobson, E.D., &Grossman, M.I. Validation of dilution indicators in the stomach. Gastroenterology52: 205 (1967).PubMedGoogle Scholar
  7. 7.
    Ivey, K.H. &Schedl, H.P. Gastric nonabsorbable indicators for studies in man. Gastroenterology59: 234(1970).PubMedGoogle Scholar
  8. 8.
    Guyton, A.C. Textbook of Medical Physiology. Philadelphia: W.B. Saunders Co., p. 876(1976).Google Scholar
  9. 9.
    Chaikof, L., Janke, W.H., Pesaros, P.C., Panka, J.L., &Brush, B.F. Effects of Prednisone and Corticotropin on gastric secretion. Arch. Surg. 83: 32(1961).PubMedGoogle Scholar
  10. 10.
    Gray, S.J., Benson, J.A., &Reifenstein, R.W. Chronic stress and peptic ulcer. I. Effect of corticotropin (ACTH) and cortisone on gastric secretion. J.A.M.A.147: 1529(1951).Google Scholar
  11. 11.
    Menguy, R. &Masters, Y.F. Effects of cortisone on mucoprotein secretion by gastric antrum of dogs: pathogenesis of steroid ulcer. Surgery54: 19 (1953).Google Scholar
  12. 12.
    Christensen, K.C. &Stadil, F. Effect of epinephrine and norepinephrine on gastric release and gastric secretion of acid in man. Scand. J. Gastroenterology Suppl.37: 87 (1976).Google Scholar
  13. 13.
    Goodman, L.S. &Gilman, A. The pharmacological basis of therapeutics. New York: Macmillan (1976).Google Scholar
  14. 14.
    Christensen, V. &Skovsted, P. Effects of general anaesthetics on the pH of gastric contents in man during surgery: a survey of halothane, fluoroxene and cyclopropane anaesthesia. Acta Anaesth. Scand.19: 49(1975).PubMedCrossRefGoogle Scholar
  15. 15.
    Teabeaut, J.R. Aspiration of gastric content: an experimental study. Am. J. Pathol.28: 51 (1952).PubMedGoogle Scholar
  16. 16.
    Roberts, R.B. &Shirley, M.A. Reducing the risk of acid aspiration during cesarean section. Anesth. & Analg.58 859 (1974).CrossRefGoogle Scholar
  17. 17.
    Taylor, G. &Pryse-Davies, J. The prophylactic use of antacids in the preventive treatment of acid-pulmonary-aspiration syndrome. Acta Anaesthesiol. Scand. Suppl.25: 399(1966).PubMedGoogle Scholar

Copyright information

© Canadian Anesthesiologists 1978

Authors and Affiliations

  • Bill Y. Ong
    • 1
  • Richard J. Palahniuk
    • 1
  • Maureen Cumming
    • 1
  1. 1.Department of AnaesthesiaUniversity of Manitoba, Health Sciences CentreWinnipegCanada
  2. 2.Canadian Anaesthetist’s SocietySaskatoon

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