摘要
Background Compared to conventional oxygen devices,high-flow oxygen treatment(HFOT)through the nasal cannulae has demonstrated clinical benefits.Limited data exist on whether such effects are also present in HFOT through tracheostomy.Hence,we aimed to examine the short-term effects of HFOT through tracheostomy on diaphragmatic function and respiratory parameters in tracheostomized patients on prolonged mechanical ventilation.Methods A randomized,crossover,physiological study was conducted in our ICU between December 2020 and April 2021,in patients with tracheostomy and prolonged mechanical ventilation.The patients underwent a 30-min spontaneous breathing trial(SBT)and received oxygen either via T-piece or by HFOT through tracheostomy,followed by a washout period of 15-min breathing through the T-piece and receipt of 30-min oxygen with the other modality in a randomized crossover manner.At the start and end of each session,blood gasses,breathing frequency(f),and tidal volume(VT)via a Wright's spirometer were measured,along with diaphragm ultrasonography including diaphragm excursion and diaphragmatic thickening fraction,which expressed the inspiratory muscle effort.Results Eleven patients were enrolled in whom 19 sessions were uneventfully completed;eight patients were studied twice on two different days with alternate sessions;and three patients were studied once.Patients were randomly assigned to start the SBT with a T-piece(n=10 sessions)or with HFOT(n=9 sessions).With HFOT,VT and minute ventilation(VE)significantly increased during SBT(from[465±119]mL to[549±134]mL,P<0.001 and from[12.4±4.3]L/min to[13.1±4.2]L/min,P<0.05,respectively),but they did not change significantly during SBT with T-piece(from[495±132]mL to[461±123]mL and from[12.8±4.4]mL to[12.0±4.4]mL,respectively);f/VT decreased during HFOT(from[64±31]breaths/(min∙L)to[49±24]breaths/(min∙L),P<0.001),but it did not change significantly during SBT with T-piece(from[59±28]breaths/(min∙L)to[64±33]breaths/(min∙L));partial pressure of a
基金
The study protocol was approved by the Evangelismos Hospital Ethics Committee(reference number:771/2019)
This study was registered in ClinicalTrials.gov(NCT04758910).
