Continuous control of tracheal cuff pressure and microaspiration of gastric contents in critically ill patients.

RATIONALE

Underinflation of the tracheal cuff frequently occurs in critically ill patients and represents a risk factor for microaspiration of contaminated oropharyngeal secretions and gastric contents that plays a major role in the pathogenesis of ventilator-associated pneumonia (VAP).

OBJECTIVES

To determine the impact of continuous control of tracheal cuff pressure (P(cuff)) on microaspiration of gastric contents.

METHODS

Prospective randomized controlled trial performed in a single medical intensive care unit. A total of 122 patients expected to receive mechanical ventilation for at least 48 hours through a tracheal tube were randomized to receive continuous control of P(cuff) using a pneumatic device (intervention group, n = 61) or routine care of P(cuff) (control group, n = 61).

MEASUREMENTS AND MAIN RESULTS

The primary outcome was microaspiration of gastric contents as defined by the presence of pepsin at a significant level in tracheal secretions collected during the 48 hours after randomization. Secondary outcomes included incidence of VAP, tracheobronchial bacterial concentration, and tracheal ischemic lesions. The pneumatic device was efficient in controlling P(cuff). Pepsin was measured in 1,205 tracheal aspirates. Percentage of patients with abundant microaspiration (18 vs. 46%; P = 0.002; OR [95% confidence interval], 0.25 [0.11-0.59]), bacterial concentration in tracheal aspirates (mean ± SD 1.6 ± 2.4 vs. 3.1 ± 3.7 log(10) cfu/ml, P = 0.014), and VAP rate (9.8 vs. 26.2%; P = 0.032; 0.30 [0.11-0.84]) were significantly lower in the intervention group compared with the control group. However, no significant difference was found in tracheal ischemia score between the two groups.

CONCLUSIONS

Continuous control of P(cuff) is associated with significantly decreased microaspiration of gastric contents in critically ill patients.