Airway Pressure and Lumen Changes During NIV With Flexible Bronchoscopy

Department of Pediatrics, Taipei Veterans General Hospital, Taipei, Taiwan

Introduction: The non-invasive ventilation (NIV) of continuous nasopharyngeal O2 with intermittent close/open nose and abdomen compression (PO2-NC-AC) can provide effective oxygenation, ventilation and circulation. It needs no any instruments, therefore no limits upper and lower airways. Both animal, clinical studies and experiences have already demonstrated its safety and efficacy in high risky and severe asphyxiated conditions. Making pressure (PEEP and PIP) changes is an essential for creating assist PPV. In children, airway lumen images are dynamic and positively correlate to the intraluminal pressure levels, such as the lumen open or close pressure. Closely measuring and monitoring these airway pressures and associated lumen image changes can benefit for making accurate diagnosis and enhance clinical management.

Purpose: Prospective study to evaluate the dynamic changes of upper and lower airway: 1) PEEP and PIP levels; and 2) the associated changes of lumen image by using FB with this NIV technique in small children with airway anomaly.

Study candidates: Children who: a) need FB examination or management for clinical reasons; b) age ≤5 year-old; and c) with airway anomaly; will enroll to this study. Expect enrolls a total of 30 children in one-year period.

Methods: As usually doing the FB with cardiopulmonary monitor and this NIV support in pediatric intensive care unit settings. A small catheter connects the inner cannel of FB and links to a pressure monitor. During course of FB, records the intra-airway lumen pressures (PEEP, PIP) and takes associated images. Total record (study) time in each enrolled case about 5 minutes. This study will not prolong the FB time. Finally, analysis these associated data.

Prediction: This study (30 enrolled cases) can smoothly complete in one-year period.

Benefits: This modality of FB with NIV may: 1) more safely doing; 2) get scientific data to prove it's efficacy; and 3) benefit for both clinical diagnosis and management; in children with airway anomaly.

• As usually doing the FB with cardiopulmonary monitor and this NIV support in pediatric intensive care unit settings.
• A small catheter connects the inner cannel of FB and links to a pressure monitor.
• During course of FB, records the intra-lumen pressures (PEEP, PIP) and takes associated images at assigned 6 airway locations, if possible.
• These 6 locations are: Oropharynx, Supra-glottis, Mid-trachea, Supra-carina Right main bronchus, and Left main bronchus.
• Thus, a complete FB would involve 6 pairs of measurements in each child.
• Both results of PIP levels and images were then stored in a computer for later analysis.
• Total record (study) time in each enrolled case about 5 minutes. This study will not prolong the FB time. Finally, analysis these associated data.
• For objective evaluation of the lumen changes, three captured images were grouped by 6 locations in each child. These lumen dimensions were independently judged on a five-point Likert scale (1 to 5: very collapse, collapse, average, expansion, very expansion) within one week by four qualified pediatric bronchoscopists who were blinded to the source of these images. The final scores were averaged and analyzed.
• Statistical Analysis: The categorical variables were described as percentages and compared with the Chi-square or Fisher's exact test as appropriate. A two-tailed p <0.05 was considered to be statistically significant.

Inclusion Criteria:

• age no more than 3 years old
• a natural airway lumen without prior plasty;
• difficult weaning from current respiratory support and therefore
• scheduled for elective FB for highly suspected airway problems.

Exclusion Criteria:

• uncontrollable cardiopulmonary failure
• body weight less than 2.0 kg
• bleeding tendency.
• fixed/ too narrowed airways where the FB (OD 3.8 mm) could not pass through