We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
End-inspiratory rebreathing reduces the end-tidal to arterial PCO gradient in mechanically ventilated pigs.
- Authors
Fierstra, Jorn; Machina, Matthew; Battisti-Charbonney, Anne; Duffin, James; Fisher, Joseph Arnold; Minkovich, Leonid
- Abstract
Purpose: Noninvasive monitoring of the arterial partial pressures of CO (PaCO) of critically ill patients by measuring their end-tidal partial pressures of CO (P etCO) would be of great clinical value. However, the gradient between P etCO and PaCO (P et-aCO) in such patients typically varies over a wide range. A reduction of the P et-aCO gradient can be achieved in spontaneously breathing healthy humans using an end-inspiratory rebreathing technique. We investigated whether this method would be effective in reducing the P et-aCO gradient in a ventilated animal model. Methods: Six anesthetized pigs were ventilated mechanically. End-tidal gases were systematically adjusted over a wide range of P etCO (30-55 mmHg) and P etO (35-500 mmHg) while employing the end-inspiratory rebreathing technique and measuring the P et-aCO gradient. Duplicate arterial blood samples were taken for blood gas analysis at each set of gas tensions. Results: P etCO and PaCO remained equal within the error of measurement at all gas tension combinations. The mean ± SD P et-aCO gradient (0.13 ± 0.12 mmHg, 95% CI −0.36, 0.10) was the same ( p = 0.66) as that between duplicate PaCO measurements at all P etCO and P etO combinations (0.19 ± 0.06, 95% CI −0.32, −0.06). Conclusions: The end-inspiratory rebreathing technique is capable of reducing the P et-aCO gradient sufficiently to make the noninvasive measurement of P etCO a useful clinical surrogate for PaCO over a wide range of P etCO and P etO combinations in mechanically ventilated pigs. Further studies in the presence of severe ventilation-perfusion (V/Q) mismatching will be required to identify the limitations of the method.
- Subjects
CRITICALLY ill; REBREATHING; TERMINAL care; LABORATORY swine; CARBON dioxide in the body
- Publication
Intensive Care Medicine, 2011, Vol 37, Issue 9, p1543
- ISSN
0342-4642
- Publication type
Article
- DOI
10.1007/s00134-011-2260-y