CO2 driven endotracheal tube cuff control in critically ill patients: A randomized controlled study

Abstract

Background: To determine the safety and clinical efficacy of an innovative integrated airway system (AnapnoGuard™ 100 system) that continuously monitors and controls the cuff pressure (Pcuff), while facilitating the aspiration of subglottic secretions (SS).

Methods: This was a prospective, single centre, open-label, randomized, controlled feasibility and safety trial. The primary endpoint of the study was the rate of device related adverse events (AE) and serious AE (SAE) as a result of using AnapnoGuard (AG) 100 during mechanical ventilation. Secondary endpoints were: (1) mechanical complications rate (2) ICU staff satisfaction; (3) VAP occurrence; (4) length of mechanical ventilation; (5) length of Intensive Care Unit stay and mortality; (6) volume of evacuated subglottic secretions. Sixty patients were randomized to be intubated with the AG endotracheal-tube (ETT) and connected to the AG 100 system allowing Pcuff adjustment and SS aspiration; or with an ETT combined with SS drainage and Pcuff controlled manually.

Results: No difference in adverse events rate was identified between the groups. The use of AG system was associated with a significantly higher incidence of Pcuff determinations in the safety range (97.3% vs. 71%; p<0.01) and a trend to a greater volume of aspirated SS secretions: (192.0[64-413] ml vs. 150[50-200], p = 0.19 (total)); (57.8[20-88.7] ml vs. 50[18.7-62] ml, p = 0.11 (daily)). No inter-group difference was detected using AG system vs. controls in terms of post-extubation throat pain level (0 [0-2] vs. 0 [0-3]; p = 0.7), hoarseness (42.9% vs. 75%; p = 0.55) and tracheal mucosa oedema (16.7% vs. 10%; p = 0.65). Patients enrolled in the AG group had a trend to reduced VAP risk of ventilator-associated pneumonia(VAP) (14.8% vs. 40%; p = 0.06), which were more frequently monomicrobial (25% vs. 70%; p = 0.03). No statistically significant difference was observed in duration of mechanical ventilation, ICU stay, and mortality.

Conclusions: The use AG 100 system and AG tube in critically ill intubated patients is safe and effective in Pcuff control and SS drainage. Its protective role against VAP needs to be confirmed in a larger randomized trial.

Trial registration: ClinicalTrials.gov NCT01550978. Date of registration: February 21, 2012.

Fig 1. Flow chart of study inclusion process.

ED, Emergency Department; BMI, Body Mass Index *Patients connected to either AG 110 system or subglottic suction system after 6 hours from tracheal intubation **The reasons for excluding patients at admission were: suspicion of pneumonia and lung contusion on chest X ray (n = 375); mechanical ventilation during previous three months (n = 58); facial, oropharingeal and neck trauma (n = 123); difficult intubation (n = 28); BMI >40 (n = 16).

Fig 2. Comparison between AG group and control group according to total SS drained.

Fig 3. Comparison between AG group and control group according to daily SS drained.

AG, Anapnoguard; P_cuff, Cuff Pressure; SS, Subglottic Secretions.

Fig 4. Cumulative rates of patients remaining free of VAP in the AG group and control group, using the Kaplan-Meier method.

VAP, Ventilator-Associated Pneumonia; AG, Anapnoguard.

Fig 5. AnapnoGuard 100 system overview.

Fig 6. Automatic endotracheal tube cuff pressure closed loop adjustment.

Fig 7. Subglottic secretions drainage based on rinsing and suctioning.