Arterial blood, inspired and expired gas samples were taken from seven patients anaesthetized with halothane (1–2 per cent) and nitrous oxide in oxygen and who breathed spontaneously. Over a two hour period, the average arterial oxygen tension was 75 mm Hg and carbon dioxide tension 49 mm Hg. No significant deterioration of either blood gas value occurred during the two hours. The dead-space/tidal volume ratio and alveolar-arterial oxygen tension difference did not alter significantly during the period of the study.
References
1.
AdamsA. P. (1970): “The Effects of Mechanical Ventilation on Gas Transfer Within the Lungs”. Ph.D. Thesis, University of London.
2.
AskrogV. F., PenderJ. W., SmithT. C., and EckenhoffJ. E. (1964): “Changes in Respiratory Dead-space During Halothane, Cyclopropane, and Nitrous Oxide Anesthesia”, Anesthesiology, 25, 342.
3.
BendixenH. H., Hedley-WhyteJ., and LaverM. B. (1963): “Impaired Oxygenation in Surgical Patients During General Anesthesia with Controlled Ventilation”, New Engl. J. Med., 269, 991.
4.
ChalmersC., BirdB. D., and WhitwamJ. G. (1974): “Evaluation of a New Thin Film Tonometer”, Brit. J. Anaesth., 46, 253.
5.
GoldsteinA. (1964): Biostatistics, An introductory text. Macmillan, New York.
6.
HousleyE., LouzadaN., and BecklakeM. R. (1970): “To Sigh or not to Sigh”, Amer. Rev. resp. Dis., 101, 611.
7.
KelmanG. R., and NunnJ. F. (1966): “Nomograms for Correction of Blood PO2, PCO2, pH and Base Excess for Time and Temperature”, J. Appl. Physiol., 21, 1484.
8.
LevineM., GilbertR., and AuchinclossJ. H. (1972): “A Comparison of the Effects of Sighs, Large Tidal Volumes, and Positive End-expiratory Pressure in Assisted Ventilation”, Scand. J. resp. Dis., 53, 101.
9.
LouzadaN. L., and TropD. (1970): “Lung Mechanics and Blood Gases During Anaesthesia with Spontaneous Respiration”, Canad. Anaesth. Soc. J., 17, 370.
10.
LumleyJ., MorganM., and SykesM. K. (1969): “Changes in Arterial Oxygenation and Physiological Dead Space Under Anaesthesia”, Brit. J. Anaesth., 41, 279.
11.
MorganM., LumleyJ., and SykesM. K. (1970): “Arterial Oxygenation and Physiological Dead Space During Anaesthesia. Effects of Ventilation with a Pressure Preset Ventilator”, Brit. J. Anaesth., 42, 379.
12.
MorganM., and NormanJ. (1975): “The Effects of Epidural Analgesia Combined with Light General Anaesthesia and Spontaneous Ventilation on Arterial Blood Gases and Physiological Dead-space”, Brit. J. Anaesth., 47, 955.
13.
PandayJ., and NunnJ. F. (1968): “Failure to Demonstrate Progressive Falls in Arterial PO2 During Anaesthesia”, Anaesthesia, 23, 38.
14.
SykesM. K., YoungW. E., and RobinsonB. E. (1965): “Oxygenation During Anaesthesia with Controlled Ventilation”, Brit. J. Anaesth., 37, 314.
