Canadian Anaesthetists’ Society Journal

, Volume 19, Issue 6, pp 647–650 | Cite as

The effect of posture on gas exchange following cardiac surgery

  • Fred I. Rabow
  • P. Dwane
  • Hlllasy Don


Gas exchange and cardiac output was measured in twelve patients the day after cardiac surgery involving total cardio-pulmonary bypass. Measurements made with the trunk of the patient flexed at 35° to the horizontal were compared with those made in the horizontal position,

There was no significant difference in arterial Po2, alveolar-arterial oxygen gradient (Aado 2) or cardiac output. Arterial Pco2 decreased slightly but significantly in the 35° head-up position. We concluded that the 35° head-up position could be safely used to make patients subjectively more comfortable, but there was no evidence of any improvement in cardiorespiratory parameters.


Cardiac Output Functional Residual Capacity Arterial Carbon Dioxide Tension Closing Volume Systemic Oxygen Transport 
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Chez douze malades, le jour suivant de la chirurgie cardiaque, impliquant une circulation cardio-pulmonaire totale extracorporelle, nous avons mesuré les échanges gazeux et le débit cardiaque. Ces études ont été faites alors que les malades étaient assis à 35° par rapport à ľhorizontale et une comparaison a été faite avec les résultats obtenus alors que les malades étaient en position horizontale.

On a noté peu de différence dans la Po2 artérielle, la différence alvéolo-artérielle en oxygène (Aado2) et le débit cardiaque. La PCo2 a diminué légèrement mais de façon valable en position assise à 35°.

Nous concluons que la position assise à 35° peut être acceptée pour le comfort subjectif des malades, mais qu’il n’existe pas ďévidence ďamélioration des paramètres cardio-respiratoire.


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Copyright information

© Canadian Anesthesiologists 1972

Authors and Affiliations

  • Fred I. Rabow
    • 1
  • P. Dwane
    • 1
  • Hlllasy Don
    • 2
  1. 1.the Department of AnaesthesiaRoyal Victoria Hospital and McGill UniversityMontreal, P.Q.Canada
  2. 2.Department of AnaesthesiaPeter Bent Brigham HospitalBostonCanada

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