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Measurement of endotracheal tube secretions volume by micro computed tomography (MicroCT) scan: an experimental and
Andrea Coppadoro, Giacomo Bellani, Alfio Bronco
1Department of Health Sciences, University of Milan-Bicocca, Monza, Italy. antonio.pesenti@unimib.it.
Background:
Biofilm accumulates within the endotracheal tube (ETT) early after intubation. Contaminated secretions in the ETT are associated with increased risk for microbial dissemination in the distal airways and increased resistance to airflow. We evaluated the effectiveness of micro computed tomography (MicroCT) for the quantification of ETT inner volume reduction in critically ill patients.
Methods:
We injected a known amount of gel into unused ETT to simulate secretions. We calculated the volume of gel analyzing MicroCT scans for a length of 20 cm. We then collected eleven ETTs after extubation of critically ill patients, recording clinical and demographical data. We assessed the amount of secretions by MicroCT and obtained ETT microbiological cultures.
Results:
Gel volumes assessed by MicroCT strongly correlated with injected gel volumes (p < 0.001, r2 = 0.999).MicroCT revealed the accumulation of secretions on all the ETTs (median 0.154, IQR:0.02-0.837 mL), corresponding to an average cross-sectional area reduction of 1.7%. The amount of secretions inversely correlated with patients' age (p = 0.011, rho = -0.727) but not with days of intubation, SAPS2, PaO2/FiO2 assessed on admission. Accumulation of secretions was higher in the cuff region (p = 0.003). Microbial growth occurred in cultures from 9/11 ETTs, and did not correlate with secretions amount. In 7/11 cases the same microbes were identified also in tracheal aspirates.
Conclusions:
MicroCT appears as a feasible and precise technique to measure volume of secretions within ETTs after extubation. In patients, secretions tend to accumulate in the cuff region, with high variability among patients.
Insights
Micro computed tomography (MicroCT) precisely quantifies endotracheal tube (ETT) secretions, revealing accumulation near the cuff. This technique aids in understanding biofilm buildup in critically ill patients.
Area of Science:
- Medical Imaging
- Critical Care Medicine
- Respiratory Therapy
Background:
- Biofilm and secretions accumulate in endotracheal tubes (ETTs) early after intubation.
- Contaminated secretions increase microbial dissemination risk and airflow resistance.
- Evaluating micro computed tomography (MicroCT) for quantifying ETT inner volume reduction is crucial.
Purpose of the Study:
- To assess the effectiveness of micro computed tomography (MicroCT) for quantifying endotracheal tube (ETT) inner volume reduction.
- To measure the volume of secretions within ETTs from critically ill patients.
- To investigate the correlation between secretions, patient demographics, and microbial presence.
Main Methods:
- Simulated secretions using gel in unused ETTs, with volume analysis via MicroCT.
- Collected 11 ETTs post-extubation from critically ill patients.
- Assessed secretions using MicroCT and performed microbiological cultures on ETTs.
Main Results:
- MicroCT accurately quantified gel volumes, showing strong correlation (r²=0.999).
- All ETTs showed secretions (median 0.154 mL), reducing cross-sectional area by 1.7%.
- Secretions correlated inversely with patient age and were highest in the cuff region; microbial growth was common but uncorrelated with secretion volume.
Conclusions:
- MicroCT is a feasible and precise method for measuring ETT secretions post-extubation.
- Secretions predominantly accumulate in the ETT cuff region.
- Significant patient-to-patient variability in secretion accumulation exists.
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