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 . Pediatr Pulmonol. 2012. 47:876–883. © 2012 Wiley Periodicals, Inc.