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Objective:To investigate and evaluate if pulse oxygen saturation/fraction of inhaled oxygen (SpO 2/FiO 2) can be used, as replacement of arterial partial pressure of oxygen/fraction of inhaled oxygen (PaO 2/FiO 2), to assess oxygenation in acute respiratory distress syndrome (ARDS) patients at different high altitudes in Yunnan Province, and to find a rapid and non-invasive method for the diagnosis of ARDS at different altitudes. Methods:Patients with ARDS at different high altitudes in Yunnan Province from January 2019 to December 2020 were enrolled. The patients were divided into three groups according to different altitudes, and received different oxygen therapies according to their respective medical conditions. Group 1 consisted of patients with moderate to severe ARDS from the department of critical care medicine of the First Affiliated Hospital of Kunming Medical University (average altitude approximately 1 800 m), and received mechanical ventilation to maintain SpO 2 of 0.90-0.96 with a low FiO 2 for more than 30 minutes, and SpO 2, FiO 2, PaO 2 were recorded. Group 2 consisted of patients with moderate to severe ARDS at the department of critical care medicine of People's Hospital of Diqing Tibetan Autonomous Prefecture (mean altitude about 3 200 m), and received oxygen with an attached reservoir mask to maintain SpO 2 of 0.90-0.96 for 10 minutes, and then SpO 2, FiO 2, and PaO 2 were recorded. Group 3 consisted of patients with mild to moderate-severe ARDS who admitted to the emergency department of the People's Hospital of Lijiang (average altitude approximately 2 200 m); when SpO 2 < 0.90, patients received oxygen with the oxygen storage mask, and the FiO 2 required to maintain SpO 2 ≥ 0.90 was recorded, and SpO 2, FiO 2, PaO 2 were recorded after oxygen inhalation for 10 minutes. Spearman coefficient was used to analyze the correlation between SpO 2/FiO 2 and PaO 2/FiO 2 in each group. Linear analysis was used to derive the linear equation between SpO 2/FiO 2 and PaO 2/FiO 2, and to evaluate arterial pH, arterial partial pressure of carbon dioxide (PaCO 2), FiO 2, tidal volume (VT), positive end-expiratory pressure (PEEP) and other related factors which would change the correlation between SpO 2/FiO 2 and PaO 2/FiO 2. The receiver operator characteristic curve (ROC curve) was plotted to calculate the sensitivity and specificity of using SpO 2/FiO 2 instead of PaO 2/FiO 2 to assess oxygenation of ARDS patients. Results:Group 1 consisted of 24 ARDS patients from whom 271 blood gas analysis results were collected; group 2 consisted of 14 ARDS patients from whom a total of 47 blood gas analysis results were collected; group 3 consisted of 76 ARDS patients, and a total of 76 blood gas analysis results were collected. The PaO 2/FiO 2 (mmHg, 1 mmHg = 0.133 kPa) in groups 1, 2 and 3 were 103 (79, 130), 168 (98, 195) and 232 (146, 271) respectively, while SpO 2/FiO 2 were 157 (128, 190), 419 (190, 445) and 319 (228, 446) respectively. Among the three groups, patients in group 1 had the lowest PaO 2/FiO 2 and SpO 2/FiO 2, while patients in group 3 had the highest. Spearman correlation analysis showed that PaO 2/FiO 2 was highly correlated with SpO 2/FiO 2 in groups 1, 2 and 3 ( r values were 0.830, 0.951, 0.828, all P < 0.05). Regression equation was fitted according to linear analysis: in group 1 SpO 2/FiO 2 = 58+0.97×PaO 2/FiO 2 ( R2 = 0.548, P < 0.001) ; in group 2 SpO 2/FiO 2 = 6+2.13×PaO 2/FiO 2 ( R2 = 0.938, P < 0.001); in group 3 SpO 2/FiO 2 = 53+1.33×PaO 2/FiO 2 ( R2 = 0.828, P < 0.001). Further analysis revealed that PEEP, FiO 2, and arterial blood pH could affect the correlation between SpO 2/FiO 2 and PaO 2/FiO 2. ROC curve analysis showed that the area under ROC curve (AUC) was 0.848 and 0.916 in group 1 with moderate to severe ARDS; based on the regression equation, the corresponding SpO 2/FiO 2 cut-off values at a PaO 2/FiO 2 of 100 mmHg and 200 mmHg were 155, 252 with a sensitivity of 84.9% and 100%, specificity of 87.2% and 70.6%, respectively. Patients with moderate to severe ARDS in group 2 (AUC was 0.945 and 0.977), the corresponding SpO 2/FiO 2 cut-off values at PaO 2/FiO 2 of 100 mmHg and 200 mmHg were 219 and 432 with the sensitivity of 100% and 85.2%, specificity of 82.5% and 100%, respectively. Patients with mild to moderate-severe ARDS in group 3 (AUC was 0.903 and 0.936), the corresponding SpO 2/FiO 2 cut-off values at a PaO 2/FiO 2 of 200 mmHg and 300 mmHg were 319 and 452 with the sensitivity of 100% and 100%, specificity of 80.9% and 86.2%, respectively. Conclusion:SpO 2/FiO 2 and PaO 2/FiO 2 in ARDS patients at different high altitudes in Yunnan Province have a good correlation, and non-invasive SpO 2/FiO 2 can be used to replace PaO 2/FiO 2 to assess the oxygenation in ARDS patients.
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Objective:To explore the feasibility of using pulse oxygen saturation (SpO 2) to evaluate the condition of patients with acute respiratory distress syndrome (ARDS) in the Lijiang region. Methods:Patients with ARDS who visited the department of emergency of People's Hospital of Lijiang from August to December 2020 were selected as study subjects. Patients were divided by severity into mild ARDS group [200 mmHg (1mmHg = 0.133 kPa)≤oxygenation index (PaO 2/FiO 2, P/F)≤300 mmHg] and moderate to severe ARDS group (P/F≤200 mmHg). The general condition, clinical diagnosis, arterial blood gas analysis results of the patients were recorded, and the differences of the above indexes between the two groups of ARDS were compared. Spearman correlation analysis was used to analyze the correlation between SpO 2 and arterial oxygen saturation (SaO 2). SpO 2 was carried into the Ellis equation and the Rice equation to calculate the derived P/F and analyze the correlation between the derived P/F and the P/F measured in arterial blood gas analysis; receiver operator characteristic curve (ROC curves) were plotted, the sensitivity and specificity of SpO 2/fraction of inspiration oxygen (SpO 2/FiO 2, S/F) instead of P/F to assess oxygenation in patients with ARDS was calculated. To evaluate the feasibility of SpO 2 for the condition evaluation of patients with ARDS in the Lijiang region. Results:Compared with the mild ARDS group, the arterial partial pressure of oxygen (PaO 2), SaO 2 and hemoglobin (Hb) were significantly decreased in the moderate to severe ARDS group [PaO 2 (mmHg): 50.5 (39.3, 56.5) vs. 60.0 (55.0, 67.5), SaO 2: 0.86 (0.73, 0.91) vs. 0. 93 (0.90, 0.96), Hb (g/L): 142±27 vs. 156±24, respectively, all P < 0.05]. Correlation analysis revealed a significant positive correlation between SpO 2 and SaO 2 in ARDS patients residing at high altitude ( R = 0.650, P = 0.000). The P/F derived by the Rice formula was significantly and positively correlated with the P/F derived from arterial blood gas analysis ( R = 0.802, P = 0.000). The deduced P/F in mild and moderate to severe ARDS groups were all significantly correlated with the measured P/F ( R values were 0.562, 0.647, both P = 0.000). The P/F derived using the Ellis formula showed a significant positive correlation with the P/F derived from arterial blood gas analysis ( R = 0.822, P = 0.000). The deduced P/F of mild ARDS group and moderate to severe ARDS group were all positively correlated with the measured P/F ( R values were 0.556, 0.589, P values were 0.000, 0.010). There was a significant positive correlation between S/F and P/F in ARDS patients ( R = 0.828, P = 0.000), and the regression equation was S/F = 1.33 P/F+52.41. ROC curve analysis showed that S/F had some predictive value for patients with mild and moderate to severe ARDS, and area under ROC curve (AUC) and 95% confidence interval (95% CI) were 0.903 (0.829-0.977), 0.936 (0.870-1.000), both P = 0.000. When the cut-off value was 452 mmHg, S/F had a sensitivity of 100% and a specificity of 80.9% for predicting mild ARDS. When the cut-off value was 319 mmHg, S/F predicted moderate to severe ARDS with 95.1% sensitivity and 86.2% specificity. Conclusions:At high altitude, SpO 2 and SaO 2 have been correlated in patients with ARDS, and P/F derived using SpO 2 and measured P/F were significantly correlated in patients with ARDS, especially in those with moderate to severe ARDS. SpO 2 may be useful in the assessment of severity of illness in patients with ARDS at high altitude.
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<p><b>OBJECTIVE</b>To investigate the expression of HERC4 in human breast cancer tissues and its relationship with the clinicopathological features.</p><p><b>METHODS</b>RT-qPCR was used to detect mRNA expression of HERC4, and Western blotting and immunohistochemistry were employed to detect protein expression of HERC4 in 67 breast cancer tissues and adjacent breast tissues.</p><p><b>RESULTS</b>The results of RT-qPCR showed a significantly higher mRNA expression of HERC4 in breast cancer tissues than in the adjacent breast tissues (P<0.05). Western blotting demonstrated HERC4 over-expression in breast cancer tissues compared with the adjacent breast tissues (P<0.05). Immunohistochemistry revealed HERC4 expression located predominantly in the cell cytoplasm. Positive HERC4 expression was detected in 61.2% of the breast cancer tissues as compared to 19.4% in the adjacent breast tissues, and its expression level was closely correlated with TNM stage and the histological grade (P<0.05).</p><p><b>CONCLUSION</b>HERC4 is correlated with the tumorigenesis and progression of breast cancer and may serve as a potential biomarker for early diagnosis and also as a potential therapeutic target in breast cancer.</p>