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 cmH2O, FiO2: 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 PaCO2. Integrated time-window analysis of the data was performed retrospectively on data collected prospectively. Results Analysis included 195 measurements. The correlation of dCap with PaCO2 (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 PaCO2 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 PaCO2.
- high frequency ventilation
- premature infants