Results difficult to apply to North American patients
David L. Bowton, MD, FCCP, a professor specializing in critical care at Wake Forest University, Winston-Salem, N.C., said in an interview the results of this trial may not be applicable for patients with infection-related respiratory failure and COPD in North America “due to the differences in common weaning practices between North America and China.”
Dr. David L. Bowton
For example, the trial used the pulmonary infection control (PIC) window criteria for extubation, which requires a significant decrease in radiographic infiltrates, improvement in quality and quantity of sputum, normalizing of leukocyte count, a synchronized intermittent mandatory ventilation (SIMV) rate of 10-12 breaths per minute, and pressure support less than 10-12 cm/H2O (Int J Chron Obstruct Pulmon Dis. 2017;12:1255-67).
“The process used to achieve these measures is not standardized. In North America, daily awakening and screening for spontaneous breathing trials would be usual, but this was not reported in the current trial,” he explained.
Differences in patient population also make the application of the results difficult, Dr. Bowton said. “Only 60% of the patients had spirometrically confirmed COPD and fewer than half were on at least dual inhaled therapy prior to hospitalization with only one-third taking beta agonists or anticholinergic agents,” he noted. “The cause of respiratory failure was infectious, requiring an infiltrate on chest radiograph; thus, patients with hypercarbic respiratory failure without a new infiltrate were excluded from the study. On average, patients were hypercarbic, yet alkalemic at the time of extubation; the PaCO2 and pH at the time of intubation were not reported.
“This study suggests that in some patients with COPD and respiratory failure requiring invasive mechanical ventilation, HFO [high-flow oxygen] may be better tolerated and equally effective as NIPPV [noninvasive positive-pressure ventilation] at mitigating the need for reintubation following extubation. In this patient population where hypoxemia prior to extubation was not severe, the mechanisms by which HFO is beneficial remain speculative,” he said.
This study was funded by the Rui E special fund for emergency medicine research and the Yangzhou Science and Technology Development Plan. The authors report no relevant conflicts of interest. Dr. Bowton reports no relevant conflicts of interest.
SOURCE: Tan D et al. Crit Care. 2020 Aug 6. doi: 10.1186/s13054-020-03214-9.