Mapping the Epidemiologic Features of Endotracheal Tube Obstruction

Background Endotracheal tube blockages (ETBs) are a common yet often overlooked cause of weaning failure, ventilator dyssynchrony, and hypoxia in the ICU, with limited studies on their prevalence, clinical factors, and outcomes. Research Question What are the incidence, risk factors, and associated clinical and ventilator factors of ETBs in ventilated patients in the ICU? Study Design and Methods We assessed 369 endotracheal tubes (ETTs) of mechanically ventilated patients after extubation. This prospective observational study was conducted at the tertiary cardiothoracic ICUs (CICUs) and medical ICUs (MICUs) of Narayana Health City, Bengaluru, India. Tubes were inspected visually and were cut at the point of maximum blockage, and cross-sectional images captured with a 12-megapixel camera were analyzed for ETB percentage using the SketchAndCalc algorithm. Results Of the 369 ETTs assessed, ETBs were categorized as showing low (0%-9%), moderate (10%-49%), and severe (> 50%) occlusion. In the CICU, severe ETBs was observed in < 2% of patients, compared with 4% of patients in the MICU, whereas moderate ETBs were present in 27.9% of patients in the CICU and 16.5% of patients in the MICU. On univariable analysis, suction type (β = 9.62 [95% CI, 5.27-13.98]; P < .01), peak pressure (P peak ; β = 1.73 [95% CI, 1.38-2.08]; P < .01), coagulopathy (β = 9.42 [95% CI, 4.22-14.62]; P < .01), and ICU type (β = 9.62 [95% CI, 5.28-13.96]; P < .01) were statistically significant. Multivariable regression analysis showed only P peak (β = 1.65 [95% CI, 1.28-2.02]; P < .01), coagulopathy (β = 8.02 [95% CI, 3.26-12.79]; P < .01) and larger number of days receiving invasive mechanical ventilation (β = 0.02 [95% CI, 0.01-0.03]; P < .01) to be significant factors associated with ETB percentage. Interpretation Moderate ETB was more prevalent in patients in the ICU, with significant factors including coagulopathy, closed suction practice, and mechanical ventilation duration. P peak alarms lacked clinical impact, despite statistical significance. Clinical Trial Registry Clinical Trial Registry-India; No.: CTRI/2023/10/058184; URL: www.ctri.nic.in