Linear versus Turbulent Airflow Tracheostomy Heat and Moisture Exchangers: A Crossover Study.

Objective: This study aimed to evaluate the impact of two tracheostomy heat and moisture exchangers (HMEs), namely the Shikani Oxygen HME™ (S-O HME, ball type, turbulent airflow) and Mallinckrodt Tracheolife II DAR HME (M-O HME; flapper type, linear airflow) on tracheobronchial mucosal health, oxygenation, humidification, and patient preference.

Methods: A randomized cross-over study was conducted with HME-naïve long-term tracheostomy subjects at two academic medical centers. Bronchoscopy assessments of mucosal health were performed at baseline and day 5 of HME application, along with oxygen saturation (S ) and breathed air humidity at four oxygen flow rates (1, 2, 3, and 5 lpm). Patient preference was assessed on study conclusion.

Results: Both HMEs were associated with improved mucosal inflammation and decreased mucus production (p < 0.0002), with greater improvements in the S-O HME group (p < 0.007). Both HMEs improved humidity concentration at each oxygen flow rate (p < 0.0001), without significant differences between groups. S was greater for the S-O HME versus the M-O HME across all measured oxygen flow rates (p = 0.003). At low oxygen flow rates (1 or 2 lpm), the S in the S-O HME group was similar to that of the M-O HME at higher oxygen flow rates (3 or 5 lpm; p = 0.6). Ninety percent of subjects preferred the S-O HME.

Conclusion: Tracheostomy HME uses correlated with improved indicators of tracheobronchial mucosal health, humidity, and oxygenation. The S-O HME outperformed the M-O HME with respect to tracheobronchial inflammation, S , and patient preference. Regular HME use by tracheostomy patients is recommended to optimize pulmonary health. Newer ball-type speaking valve technology additionally allows concomitant HME and speaking valve application.

Level Of Evidence: 2 Laryngoscope, 133:3422-3428, 2023.