Evaluation of Endotracheal Tube Scraping on Airway Resistance.

BACKGROUND

Spontaneous breathing trials (SBTs) are used to assess the readiness for discontinuation of mechanical ventilation. When airway resistance (R) is elevated, the imposed work of breathing can lead to prolongation of mechanical ventilation. Biofilm and mucus build-up within the endotracheal tube (ETT) can increase R. Scraping the ETT can remove the biofilm build-up and decrease mechanical R. The primary aim of this study was to evaluate the impact of ETT scraping on R. The secondary aim was to determine whether decreasing R would impact subsequent SBT success.

METHODS

Intubated, mechanically ventilated subjects were enrolled if they failed an SBT and had an R of > 10 cm HO/L/s. SBT failure was based on institutional guidelines, and R was calculated by subtracting the difference between the measured peak and plateau pressures using a square flow waveform with an inspiratory flow set at 60 L/min. The endOclear device was inserted into the ETT and withdrawn per manufacturer's guidelines. Scraping was repeated until the ETT was cleared. Change in R was compared pre- and post-ETT scraping using a paired test. A Mann-Whitney U test evaluated the difference in percentage change in R between SBT groups.

RESULTS

Twenty-nine subjects completed the study. The mean pre- and post-ETT scraping R values were 15.17 ± 3.83 and 12.05 ± 3.19 cm HO/L/s, respectively ( < .001). Subsequent SBT success was 48%; however, there was no difference in percentage change in R between subsequent passed SBT (18.61% [interquartile range 8.90-33.93%]) and failed SBT (23.88% [interquartile range 0.00-34.80%]), U = 78.5, z = -0.284, = .78. No adverse events were noted with ETT scraping.

CONCLUSIONS

This study demonstrated that ETT scraping can reduce R. The decrease in R post-ETT scraping did not affect subsequent SBT success.