ABSTRACT
BACKGROUND: High-flow nasal cannula oxygen therapy (HFNC) is recommended for patients with COVID-19. However, the increasing use of HFNC brings a risk of delayed intubation. The optimal timing of switching from HFNC to invasive mechanical ventilation (IMV) remains unclear. An effective predictor is needed to assist in deciding on the timing of intubation. Respiratory rate and oxygenation (ROX) index, defined as (SpO2/FiO2) / respiratory rate, has already shown good diagnostic accuracy. Modified ROX (mROX) index, defined as (PaO2 /FiO2) / respiratory rate, might be better than the ROX index in predicting HFNC failure. OBJECTIVE: The aim was to evaluate the predictive value of mROX for HFNC failure in patients with COVID-19. METHODS: Severe or critical patients with COVID-19 treated with HFNC were enrolled in two clinical centers. Laboratory indicators, respiratory parameters, and mROX index at 0 h and 2 h after initial HFNC were collected. Based on the need for IMV after HFNC initiation, the patients were divided into an HFNC failure group and an HFNC success group. The predictive value of mROX index for IMV was evaluated by the area under the receiver operating characteristic curve (AUROC) and logistic regression analysis. We performed Kaplan-Meier survival analysis using the log-rank test. RESULTS: Sixty patients with COVID-19 (mean ± SD age, 62.8 ± 14.1 years; 42 patients were male) receiving HFNC were evaluated, including 18 critical and 42 severe cases. A total of 33 patients had hypertension; 14 had diabetes; 17 had chronic cardiac disease; 11 had chronic lung disease; 13 had chronic kidney disease; and 17 had a history of stroke. The AUROC of mROX index at 2 h was superior to that of other respiratory parameters to predict the need for IMV (0.959; p < 0.001). At the mROX index cutoff point of 4.45, predicting HFNC failure reached the optimal threshold, with specificity of 94% and sensitivity of 92%. Logistic regression analysis showed that 2-h mROX index < 4.45 was a protective factor for IMV (odd radio 0.18; 95% CI 0.05-0.64; p = 0.008). In the HFNC failure group, the median time from HFNC to IMV was 22.5 h. The 28-day mortality of the late intubation patients (≥ 22.5 h) was higher than that of the early intubation patients (< 22.5 h) (53.8% vs. 8.3%; p = 0.023). CONCLUSIONS: mROX at 2 h is a good early warning index of the need for IMV in patients with COVID-19 after HFNC initiation. Early intubation may lead to better survival in patients with 2-h mROX index < 4.45.
Subject(s)
COVID-19 , Cannula , Humans , Male , Middle Aged , Aged , Female , Respiratory Rate , COVID-19/therapy , Oxygen Inhalation Therapy , Intubation, IntratrachealABSTRACT
Electrical impedance tomography (EIT) is a gradually maturing medical imaging technique that relies on computational algorithms for reconstructing and visualizing internal conductivity distributions within the human body. To provide a comprehensive and objective understanding of the current state and trends in the EIT algorithm research, we conducted bibliometric analysis on a 25-year EIT algorithm research dataset sourced from Web of Science Core Collections. We visualized publication characteristics, collaboration patterns, keywords, and co-cited references. The results indicate a steady increase in annual publications over recent decades. The United States, United Kingdom, China, and South Korea contributed 60% of the articles collaboratively. Keyword analysis unveiled three distinct stages in the evolution of EIT algorithm research: the establishment of fundamental algorithm frameworks, optimization for improved imaging performance, and the development of algorithms for clinical applications. Additionally, there has been a shift in research focus from traditional theories to the incorporation of new methods, such as artificial intelligence. Co-cited references suggest that integrating EIT with other established imaging techniques may emerge as a new trend in EIT algorithm research. In summary, EIT algorithms have been a consistent research focus, with current efforts centered on optimizing algorithms to enhance imaging performance. The emerging research trend involves utilizing more diverse and intersecting algorithms.
ABSTRACT
BACKGROUND: This study was designed to explore the early predictive value of the respiratory rate oxygenation (ROX) index modified by PaO2 (mROX) in high-flow nasal cannula (HFNC) therapy in patients with acute hypoxemia respiratory failure (AHRF). METHOD: Seventy-five patients with AHRF treated with HFNC were retrospectively reviewed. Respiratory parameters at baseline and 2 h after HFNC initiation were analyzed. The predictive value of the ROX (ratio of pulse oximetry/FIO2 to respiratory rate) and mROX (ratio of arterial oxygen /FIO2 to respiratory rate) indices with two variations by adding heart rate to each index (ROX-HR and mROX-HR) was evaluated. RESULTS: HFNC therapy failed in 24 patients, who had significantly higher intensive care unit (ICU) mortality and longer ICU stay. Both the ROX and mROX indices at 2 h after HFNC initiation can predict the risk of intubation after HFNC. Two hours after HFNC initiation, the mROX index had a higher area under the receiver operating characteristic curve (AUROC) for predicting HFNC success than the ROX index. Besides, baseline mROX index of greater than 7.1 showed a specificity of 100% for HFNC success. CONCLUSION: The mROX index may be a suitable predictor of HFNC therapy outcomes at the early phase in patients with AHRF.
