Continuous integrated distal capnography in infants ventilated with high frequency ventilation.

OBJECTIVE

To assess within a feasibility study the correlation, agreement, and trending of continuous integrated distal capnography (dCap) with PaCO(2) in infants on HFV.

STUDY DESIGN

Sixteen premature infants [median (range) gestational age: 26.5 (24.7-34.7) weeks], ventilated with HFV (mean ± SD airway pressure: 8.1 ± 2.1 cmH(2) O, FiO(2) : 0.39 ± 0.21) for RDS, intubated with a double-lumen endotracheal-tube and whose data were recorded on a bedside computer participated in the study. Side-stream dCap was measured via the extra-port of a double-lumen endotracheal-tube by a Microstream capnograph, with a specially designed software for HFV and compared with simultaneous PaCO(2) . Integrated time-window analysis of the data was performed retrospectively on data collected prospectively.

RESULTS

Analysis included 195 measurements. The correlation of dCap with PaCO(2) (r = 0.68, P < 0.0001) and the agreement (bias ± precision: -2.0 ± 10.7 mmHg) were adequate. Area under the ROC curves for dCap to detect high (>60 mmHg) or low (<35 mmHg) PaCO(2) was 0.79 (CI: 0.70-0.89) and 0.87 (CI: 0.73-1.00), respectively; P < 0.0001. Changes in dCap and in PaCO(2) for consecutive measurements within each patient were adequately correlated (r = 0.65, P < 0.0001).

CONCLUSIONS

Continuous integrated dCap is feasible in premature infants ventilated with HFV and can be helpful for trends and alarm for unsafe levels of PaCO(2) .