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Published on: January 29, 2011
Endoscopic intratracheal carbon dioxide measurements during pediatric flexible bronchoscopy
Anne B Chang1, Gregory E Moloney, Peter J Harms
1Department of Respiratory Medicine, Royal Children's Hospital, Herston, Queensland, Australia. annechang@ausdoctors.net
Insights
Endoscopic intratracheal CO2 monitoring accurately estimates blood CO2 in children during flexible bronchoscopy. Airway lesions, not age, significantly impact CO2 changes, aiding respiratory status assessment.
Area of Science:
- Pediatric Anesthesiology
- Respiratory Physiology
- Medical Instrumentation
Background:
- CO2 monitoring is crucial for pediatric thoracic procedures and spontaneous breathing general anesthesia.
- Current CO2 measurement methods during flexible bronchoscopy (FB) in children are limited.
- The impact of airway lesions on CO2 fluctuations during FB is not well understood.
Purpose of the Study:
- To describe and validate a novel endoscopic intratracheal method for CO2 measurement in children undergoing FB.
- To assess the relationship between airway lesions and CO2 changes during FB.
- To compare intratracheal CO2 measurements with arterial blood gas values.
Main Methods:
- A new endoscopic intratracheal method was used for end-tidal CO2 (P(E)CO2) measurements in 100 children during FB.
- Blood gas sampling was performed simultaneously in 28 children for validation.
- Data were analyzed using Bland-Altman analysis, intraclass correlation, and repeatability testing.
Main Results:
- Intratracheal CO2 measurements showed good agreement with arterial blood gas values (Intraclass Correlation: 0.69).
- Significant differences in CO2 change were observed in children with airway lesions (P=0.038).
- CO2 rise was associated with airway lesions, not patient age.
Conclusions:
- Midtracheal P(E)CO2 is a reliable estimate of P(a)CO2 for monitoring pediatric patients during FB.
- Airway lesions are a key factor influencing CO2 variations during flexible bronchoscopy in children.
- This method enhances respiratory status assessment in pediatric FB procedures.
Background:
CO2 monitoring is recommended for thoracic telescopic procedures and for spontaneous breathing general anesthesia in children. During flexible bronchoscopy (FB) in children, the various currently available methods of CO2 measurements are limited. The CO2 falls and increases have been reported in FB but it is unknown whether airway lesions predispose to CO2 change. The aim of this study was to describe and validate endoscopic intratracheal CO2 measurements in children undergoing FB under spontaneously breathing GA.
Methods:
Endtidal CO2 (P(E)CO2) measurements at the start (Start-CO2) and end (End-CO2) of FB on 100 consecutive children were performed using a newly designed endoscopic intratracheal method. To validate the method blood gas sampling was simultaneously performed in 28 children and results analyzed using the Bland and Altman method, intraclass correlation and 95% range for repeatability.
Results:
End-CO2 and CO2-change (End-CO2 minus Start-CO2) were significantly different in children with airway lesions (CO2 change: no lesion = 3 mmHg, extrathoracic airway lesion = 4.5, intrathoracic airway lesion = 8, P = 0.038). There was no significant difference in Start-CO2 values among the groups. CO2-change in those aged < or =12 months was similar to those >12 months. Intratracheal CO2 measurements were comparable with arterial blood values in the Bland and Altman plots. The intraclass correlation was 0.69 and 95% range for repeatability was 3.7-4.17 mmHg.
Conclusions:
Midtracheal P(E)CO2 provides a useful estimate of P(a)CO2 for monitoring the respiratory status of children undergoing FB. The presence of airway lesions rather than age is associated with significant increased PCO2 rise.
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