High-flow oxygen therapy in tracheostomized subjects with prolonged mechanical ventilation: A randomized crossover physiologic study

• Main Authors: Patharapan Lersritwimanmaen, Nuttapol Rittayamai, Jamsak Tscheikuna, Laurent J. Brochard
• Other Authors: Siriraj Hospital
• Format: Article
• Published: 2022
• Subjects: Medicine
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/78236
• Institution: Mahidol University

BACKGROUND: High-flow oxygen therapy via tracheostomy (HFT) can be used in tracheostomized patients during ventilator disconnection. The physiologic effects of this technique are unknown. We hypothesized that HFT would reduce inspiratory effort and improve breathing pattern compared to conventional oxygen therapy via T-tube. This study aimed to evaluate the physiologic effects of HFT compared to conventional O2 in patients with prolonged mechanical ventilation. METHODS: A randomized crossover physiologic study was conducted in adult tracheostomized patients who experienced temporary periods of ventilator disconnection. Subjects were ventilated with pressure support ventilation (PSV) for 15 min and were then randomly assigned to HFT or conventional O2 via T-tube for 30 min. After a washout period, subjects were switched to the other system. Esophageal pressure (Pes), breathing frequency, blood pressure, heart rate, SpO2, and transcutaneously measured pressure of carbon dioxide (PtcCO2) were recorded. The primary outcome was inspiratory effort as determined by the simplified esophageal pressure-time product (sPTPes). Secondary outcomes were Pes swing, breathing frequency, heart rate, mean arterial pressure, SpO2,andPtcCO2 between groups. RESULTS: Twenty-two subjects were enrolled: sPTPes per minute was significantly higher with HFT and conventional O2 compared to PSV (153.5 6 97.9, 163.5 6 111.3, and 86.8 6 51.1 cm H2O 3 s/min, respectively, P 5 .001), but it was not different between HFT and conventional O2 (P 5 .72). Breathing frequency increased significantly after switching from PSV to HFT and conventional O2 (23 6 4vs 26 6 6and236 4vs276 5 breaths/min, respectively, P 5 .001). SpO2 was higher with conventional O2 compared to HFT (P 5 .02). No differences in PtcCO2, mean arterial pressure, or heart rate were observed between HFT and conventional O2. CONCLUSIONS: Inspiratory effort and breathing frequency increased significantly during unassisted breathing compared to PSV in tracheostomized subjects, but HFT via tracheostomy provided no measurable additional physiologic benefit compared to O2 therapy via T-tube.