Evaluation of Differences between PaCO₂ and ETCO₂ by Age as Measured during General Anesthesia with Patients in a Supine Position

Figure 1

Comparison of arterial to end-tidal partial pressure gradient of carbon dioxide among groups according to age. (a) Comparison of patients aged 16 to <65 years (Group I) and patients aged ≥65 years (Group II). There is a significant difference between the two groups. (b) Comparison of arterial to end-tidal partial pressure gradient of carbon dioxide among groups according to patient age (16–84 years in one-decade increments). The arterial to end-tidal partial pressure gradient of carbon dioxide tends to increase with increasing age, and there is a significant difference between Group A and Groups F and G.

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