Application of high-flow nasal cannula in fibreoptic bronchoscopy after congenital heart surgery: a retrospective cohort study

Abstract

Background: The purpose of this study was to compare the effectiveness and safety of high-flow nasal cannula (HFNC) and conventional oxygen therapy (COT) in fibreoptic bronchoscopy (FB) after congenital heart surgery (CHS) in children.

Methods: We did a retrospective cohort study using patients from the electronic medical record system of Fujian Children's Hospital in China. The study population was children who underwent FB in the cardiac intensive care unit after CHS for 1 year (May 2021-May 2022). Children were classified into HFNC and COT groups according to their oxygen therapy during FB. The primary outcome was oxygenation indices during FB, including pulse oximeter oxygen saturation (SpO₂) and transcutaneous oxygen tension (TcPO₂) during FB. Secondary outcomes were the number of interruptions during FB and their causes, and complications after FB.

Results: We identified 107 children from the electronic medical record system, and 102 children after CHS were finally included in the study (53 in the HFNC group and 49 in the COT group). During the FB examination, TcPO₂ and SpO₂ were significantly higher in the HFNC group than in the COT group (TcPO₂: 90.3±9.3 vs 80.6±11.1 mm Hg; SpO₂: 95.6±2.5 vs 92.1%±2.0%, p<0.001) and the transcutaneous carbon dioxide tension was significantly lower than in the COT group (39.6±3.0 vs 43.5±3.9 mm Hg, p<0.001). During the FB, a total of 20 children in the COT group had 24 interruptions, and 8 children in the HFNC group had 9 interruptions (p=0.001). In terms of postoperative complications, eight cases had complications in the COT group and four complications in the HFNC group (p=0.223).

Conclusions: Among children undergoing FB after CHS, the application of HFNC was associated with better oxygenation and fewer procedural interruptions compared with COT, without an increased risk of postoperative complications.

Keywords: cardiology; therapeutics.

Figure 1

Vital signs and monitoring data 30 min before (T0), during (T1) and 30 min after (T2) bronchoscopy. (A) Respiratory rate (RR); (B) heart rate (HR); (C) mean blood pressure (MBP); (D) pulse oximeter oxygen saturation (SpO₂); (E) transcutaneous oxygen tension (TcpO₂); (F) transcutaneous carbon dioxide tension (TcPCO₂); high‐flow nasal cannula oxygen (HFNC); conventional oxygen therapy (COT). *Indicates that the difference between the two groups is statistically significant. For comparison of data at each time point, repeated measures analysis of variance was used first, and then simple effects analysis was performed on the data with significant interaction.