The Association Between Upper Airway Patency and Speaking Valve Trial Tolerance for Patients With Tracheostomy: A Clinical Retrospective Study and an In Vitro Study.

ABSTRACT

Purpose Upper airway patency is crucial in a patient's ability to tolerate a one-way speaking valve (SV). Traditional assessment of airway patency is mainly subjective. We developed four noninvasive methods to assess patency (leak volume, transtracheal pressure [TTP], end-tidal CO2, and Mallampati score) in our institution. This study was aimed to evaluate the effectiveness of the four methods and explore the relationship between the patient's upper airway patency and SV trial tolerance. Method A retrospective cohort study was conducted to enroll adult patients with tracheostomies eligible for an SV trial from April 2019 through January 2020. An in vitro study was also implemented to explore the relationship between upper airway patency and noninvasive measurements. Results Forty patients (22 men and 18 women) were included; 16 used SV in-line with mechanical ventilation. Twenty-four patients tolerated an SV trial of > 10 min; they had lower TTP (3.0 [2.0-9.0] vs. 15.0 [9.3-21.3] cm H2O, p < .001), higher leak volume (268.5 ± 177.2 vs. 88.6 ± 99.6 ml, p = .038), and lower percentage of patients with Mallampati Classification IV (16.7 vs. 50.0%, p = .035), compared to the 16 patients who did not tolerate an SV trial. Twenty-two patients with a TTP of ≤ 9 cm H2O had higher percentage tolerating an SV trial than those with a TTP of > 9 cm H2O (86.4 vs. 35.3%, p = .002). The in vitro study demonstrated a strong correlation between upper airway patency and TTP, peak inspiratory flow, and tidal volume inhaled from the upper airway. Conclusions TTP, Mallampati classification, and leak volume can be used to assess upper airway patency for adult patients with tracheostomies undergoing an SV trial. A TTP of ≤ 9 cm H2O might indicate adequate upper airway patency to tolerate the SV trial.