Influence of the cuff pressure on the swallowing reflex in tracheostomized ICU patients

Introduction

Because recovery of an efficient swallowing reflex is determining factor for patient's spontaneous rehabilitation of airway protective reflexes, we have studied the influence of cuff pressure of the tracheostomy tube on the swallowing reflex elicited in tracheostomized ICU patients.

Methods

Twelve conscious eupneic adult patients were studied. Simultaneous electromyography of submental muscles [1] and acceleromyography of laryngeal elevation [2] were measured during reflex swallows elicited by pharyngeal injection of distilled water. After cuff deflation, instrumental characteristics of the swallowing reflex (latency time, electromyography and acceleromyography peak and amplitude) were measured at 10, 15, 20, 25, 30, 40, 50, and 60 cmH₂O of air-filled induced randomly imposed cuff pressure.

Results

Cuff pressure was inversely correlated to both electromyography and acceleromyography characteristics of the swallowing reflex. Latency time of the swallowing reflex and cuff pressure were linearly correlated. Instrumental characteristics of the swallowing reflex deteriorated for a cuff pressure threshold >22 cmH₂O (extremes 15 to 40).

Conclusions

We have demonstrated that instrumental characteristics of the swallowing reflex were influenced by cuff pressure in the tracheostomy tube. Increasing cuff pressure affected both the setting and the muscular activity of submental muscles during reflex swallows. Our data suggest that peripheral mechanical constraints and centrally controlled inhibition may be involved in cuff pressure rise induced deterioration of the swallowing reflex. Our report has several implications for intensive care daily clinical practice. In case of dysphagia, swallowing function should be evaluated and re-educated with a cuff pressure tidily controlled at 20 cmH₂O.