Activation of Automatic Tube Compensation Mode Attenuates Auto-PEEP in Chronic Obstructive Pulmonary Disease Patients

Introduction

Dynamic hyperinflation in chronic obstructive pulmonary disease (COPD) results in intrinsic positive end-expiratory pressure (auto-PEEP). Automatic tube compensation (ATC) is used to increase airway pressure in COPD and overcome endotracheal tube (ETT)–imposed respiratory workload. We aim to investigate effects of ATC activation on auto-PEEP decrease in COPD.

Methods

ATC was activated three times a day (1 min duration) in the morning, evening, and night shift. Auto-PEEP was measured for the 1 min period (every 6 s) following ATC activation. Linear mixed model (LMM) was used to measure changes in auto-PEEP and compare with baseline value. Age, gender, and COPD types were inserted in model as covariates and analyzed using SPSS.

Results

A total of 60 patients including COPD (n = 40) and COPD with exacerbation (n = 20) were included. Compared with exacerbated COPD, baseline auto-PEEP in COPD was significantly lower in morning (p = 0.011), evening (p = 0.043), and night shift (p = 0.007). After ATC activation, auto-PEEP decreased significantly in COPD in morning, evening, and night (p = 0.001), but magnitude of this decrease was notably larger in COPD than in exacerbated COPD (p = 0.001). Moreover, there was a significant relationship between COPD exacerbation and changes in auto-PEEP in morning (β = −0.27, p = 0.001), evening (β = −0.16, p = 0.001), and night (β = −0.26, p = 0.001).

Conclusion

The activation of ATC mode in COPD patients under mechanical ventilation could decrease the value of auto-PEEP. Nevertheless, COPD patients with an exacerbation appear to benefit less from ATC activation.