RESUMO
OBJECTIVE: To test the hypothesis that end-tidal CO(2) (PETCO(2)) varies with tidal volume (Vt) in preterm infants. DESIGN: Intervention study, nonrandomized trial. SETTING: Neonatal ICU, regional referral center. SUBJECTS: 29 preterm infants 790 to 2135 g in weight requiring mechanical ventilation studied on 73 occasions. INTERVENTION: Measurement of PETCO(2) during variations of Vt. MEASUREMENT: Statistical correlation of PETCO(2) to Vt. RESULT: PETCO(2) is minimal when Vt is either too low or too high. CONCLUSION: Vt, through its effect on dead space/Vt (Vd/Vt) ratios and arterial-alveolar CO(2) differences, has a significant effect on PETCO(2). Observation of PETCO(2) across a range of Vt can be used to select an appropriate Vt for preterm infants requiring mechanical ventilation.
