End-tidal and arterial carbon dioxide measurements correlate across all levels of physiologic dead space.
BACKGROUND: End-tidal carbon dioxide (P(ETCO(2))) is a surrogate, noninvasive measurement of arterial carbon dioxide (P(aCO(2))), but the clinical applicability of P(ETCO(2)) in the intensive care unit remains unclear. Available research on the relationship between P(ETCO(2)) and P(aCO(2)) has not taken a detailed assessment of physiologic dead space into consideration. We hypothesized that P(ETCO(2)) would reliably predict P(aCO(2)) across all levels of physiologic dead space, provided that the expected P(ETCO(2))-P(aCO(2)) difference is considered. METHODS: Fifty-six mechanically ventilated pediatric patients (0-17 y old, mean weight 19.5 +/- 24.5 kg) were monitored with volumetric capnography. For every arterial blood gas measurement during routine care, we measured P(ETCO(2)) and calculated the ratio of dead space to tidal volume (V(D)/V(T)). We assessed the P(ETCO(2))-P(aCO(2)) relationship with Pearson's correlation coefficient, in 4 V(D)/V(T) ranges. RESULTS: V(D)/V(T) was
Duke Scholars
Published In
ISSN
Publication Date
Volume
Issue
Start / End Page
Location
Related Subject Headings
- Tidal Volume
- Retrospective Studies
- Respiratory System
- Respiratory Dead Space
- Respiration, Artificial
- Intensive Care Units
- Infant, Newborn
- Infant
- Humans
- Cross-Sectional Studies
Citation
Published In
ISSN
Publication Date
Volume
Issue
Start / End Page
Location
Related Subject Headings
- Tidal Volume
- Retrospective Studies
- Respiratory System
- Respiratory Dead Space
- Respiration, Artificial
- Intensive Care Units
- Infant, Newborn
- Infant
- Humans
- Cross-Sectional Studies