Advertisement

Canadian Anaesthetists’ Society Journal

, Volume 17, Issue 2, pp 135–144 | Cite as

Accuracy of halothane vaporizers in clinical use

  • William H. Noble
Article

Conclusions

The inaccuracy of several of the Mark ii vaporizers indicates the need for periodic maintenance. Cleansing of the spindle and soaking with ether were effective in restoring one vaporizer to accuracy and had no effect on another already accurate one. Recalibration by the manufacturer resulted in minimal improvement in accuracy after our cleansing. It is suggested that cleansing could be used as a temporary measure but that periodic recalibration as recommended by the manufacturer should be carried out.

The Drager-Vapor and Copper Kettle vaporizers apparently need little maintenance. Two new Mark iiis, the Mark ii Fluotecs, and one Copper Kettle vaporizer were the only ones which delivered no halothane when shut off, although all vaporizers studied had a specific mechanism to prevent halothane from leaking into the bypass gas. In the face of back pressure the Fluotec Mark iis delivered halothane at a 0 setting. If thereis a hepatitie reaction to halothane, and if this is a hypersensitivity phenomenon, then many patients coming to the operating theatre may be sensitized inadvertently.

The new Venturi circulator creates a very high back pressure and results in a lower concentration delivered by each of the vaporizers studied in accordance with the physical principles outlined.

Keywords

Halothane Back Pressure Soda Lime Fluothane Anaesthetic Machine 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Résumé

A la suite de certains doutes sur la précision des vaporisateurs en anesthésie clinique, nous avons entrepris une étude de plusieurs types de vaporisateurs ďhalothane en usage clinique afin ďétablir jusqu'à quel point ils étaient fiables. Nous avons également inclus le circulateur Neff Venturi pour déterminer son effet sur la précision.

Le manque de précision ďun grand nombre de vaporisateurs Mark ii implique le besoin ďun entretien périodique. Le nettoyage de la clef et un bain dans ľéther ont été suffisants pour rétablir la précision. A la suite de notre nettoyage, une récalibration par le manufacturier n’a apporté qu’une faible amélioration dans la précision. Comme mesure temporaire, on suggère de recourir au nettoyage mais, comme le recommande le manufacturier, une récalibratíon périodique s’impose.

Selon toute apparence, le Drager et le “Copper Kettle” requièrent peu ďentretien. Deux nouveaux vaporisateurs Mark iii, un Mark n Fluotec et un “Copper Kettle” sont les seuls qui, une fois fermés, ne laissaient pas passer ďHalothane, bien que tous les vaporisateurs étudiés possédaient un mécanisme spécifique pour prévenir les fuites ďhalothane dans le débit gazeux. Si ľon faisait une pression rétrograde, le fluotec Mark ii vaporisait de ľhalothane en position zéro. S’il survient une réaction hépatique à ľhialothane et que cette réaction est un phénomène ďhypersensibilité, il peut arriver, à notre insu, que plusieurs malades passant aux salles ďopération soient sensibilisés.

Le nouveau circulateur Venturi engendre une très haute pression rétrograde et il s’ensuit que les vaporisateurs étudiés débitent une concentration plus basse ďaprès les principes physiques énoncés.

References

  1. 1.
    MacKay, J. M. Clinical Evaluation of Fluothane with Special Reference to a Controlled Percentage Vaporizer. Canad. Anaesth. Soc. J.4: 235 (1957).PubMedGoogle Scholar
  2. 2.
    Hill, D. W. Halothane Concentrations Obtained with a Fluotec Vaporizer. Brit. J. Anaesth. 30:563(1958).PubMedCrossRefGoogle Scholar
  3. 3.
    Hill, D. W. Halothane Concentrations Obtained with a Drager “Vapor” Vaporizer. Brit. J. Anaes. 35: 285 (1963).CrossRefGoogle Scholar
  4. 4.
    Adner, M. &Hallen, B. Reliability of Halothane Vaporizers. Acta anaesth. scandinav.9: 233(1965).CrossRefGoogle Scholar
  5. 5.
    Gordh, T.;Hallen, B.;Okmian, L.;Wahlin, A.; &Stern, B. The Concentration of Halothane by the Combined Use of Fluotec Vaporizer and Engstrom Respirator. Acta anaesth. scandinav.8: 97 (1964).Google Scholar
  6. 6.
    Hill, D. W. &Lowe, H. J. Comparison of Concentration of Halothane in Closed and Semi- closed Circuits during Controlled Ventilation. Anesthesiology. 23: 291 (1962).PubMedCrossRefGoogle Scholar
  7. 7.
    Cole, J. R. The Use of Ventilators and Vaporizer Performance. Brit. J. Anaesth.38: 646 (1966).PubMedCrossRefGoogle Scholar
  8. 8.
    Andreesen, I. H. &Bay, J. Halothane Concentrations Obtained by the Combined Use of the Manley Ventilator and the Fluotec Vaporizer. Brit. J. Anaesth.38: 641 (1966).PubMedCrossRefGoogle Scholar
  9. 9.
    Neff, William B.;Simpson, F. B.; &Thompson, R. A Venturi Circulator for Anesthetic Systems. Anesthesiology.29: 838 (1968).PubMedCrossRefGoogle Scholar
  10. 10.
    Morris, L. E. A New Vaporizer for Liquid Anesthetic Agents. Anesthesiology.13: 587 (1952).PubMedCrossRefGoogle Scholar
  11. 11.
    Edmonson, W. Gas Analysis by Refractive Index Measurement. Brit. J. Anaesth.29: 570 (1957).CrossRefGoogle Scholar
  12. 12.
    Titel, J. H.;Lowe, H. J.;Elam, J. O.;Grosholz, B. S. Quantitative Closed-Circuit Halothane Anaesthesia. Anaesth. & Anal.47: 560 (1968).Google Scholar
  13. 13.
    Eger, E. I., ii;Larson, C. P.,Jr.; &Severinghaus, J. W. The Solubility of Halothane in Rubber, Soda Lime, and Various Plastics. Anesthesiology23: 356 (1962).PubMedCrossRefGoogle Scholar

Copyright information

© Canadian Anesthesiologists 1970

Authors and Affiliations

  • William H. Noble

There are no affiliations available

Personalised recommendations