Carbon Dioxide Levels When Starting High Frequency Ventilation in Neonates

摘要

Objective: High-frequency ventilation (HFV) is an effective means to achieve gas exchange in neonates. Adequate carbon dioxide (pCO2) levels are best achieved immediately after starting HFV, avoiding either hypercapnia or hypocapnia. We aimed to determine the initial pCO2 levels after starting HFV, and the time taken to obtain the initial blood gas. Methods: We conducted an observational retrospective study on neonates that required their first episode of HFV. Data included the first blood gas result after starting HFV and when the gas was taken after starting HFV. Results: This study included 112 neonates with a median birth weight of 938 (IQR: 692 - 1549) grams and gestational age of 27.2 (24.6 - 30.7) weeks. The first pCO2 after starting HFV (mean (SD)) was 53.7 (22) mmHg. Of 112, 15 (13.4%) showed initial hypocapnia (pCO2 35 mmHg), and 17 (15.2%) showed hypercapnia (pCO2 > 65 mmHg)—a total of 28.6% unacceptable pCO2 levels. Of 112, the first blood gas was obtained within 30 minutes in 47 (42%) and within one hour in 85 (76%), with a significant delay of two or more hours in eight (7.1%). Conclusion: Many neonates had unacceptable pCO2 levels upon starting first-time HFV. There were significant delays in obtaining the initial gas.