OBJECTIVE: To investigate the feasibility and prognostic implications of assessing volume status during early fluid resuscitation in septic patients based on estimated plasma volume status (ePVS). METHODS: A prospective study was conducted. Patients with sepsis admitted to intensive care unit (ICU) of the First Affiliated Hospital of Kunming Medical University from March to December in 2023 were enrolled. The general information and laboratory indicators at ICU admission were recorded, and ePVS, sequential organ failure assessment (SOFA) score, acute physiology and chronic health status evaluation II (APACHE II) score were calculated. The vital signs, arterial blood gas analysis and volume status related indicators before liquid resuscitation (T0h) and 3 hours (T3h) and 6 hours (T6h) of fluid resuscitation were recorded. The diameter and variability of the inferior vena cava (IVC) were measured by ultrasound, and ePVS, percentage change value of estimated plasma volume status (ΔePVS%), difference in central venous-to-arterial partial pressure of carbon dioxide (Pcv-aCO₂), and lactate clearance rate (LCR) were calculated. Patients were divided into sepsis group and septic shock group based on the diagnosis at ICU admission, and septic patients were subdivided into survival group and death group based on their 28-day survival status. The differences in clinical data between the groups were compared. The correlation between ePVS or ΔePVS% and volume status related indicators during early liquid resuscitation was analyzed by Spearman rank sum correlation test. The predictive value of each variable for 28-day survival in patients with sepsis was analyzed by receiver operator characteristic curve (ROC curve), and 28-day death risk factors were analyzed by Logistic regression method. RESULTS: Fifty-four septic patients were enrolled in the final analysis, including 17 with sepsis and 37 with septic shock; 34 survived at 28 days and 20 died, with a 28-day survival rate of 63.0%. Compared with the sepsis group, the septic shock group had a lower venous ePVS at ICU admission [dL/g: 4.96 (3.67, 7.15) vs. 7.55 (4.36, 10.07), P < 0.05]. Compared with the death group, the survival group had higher T6h arterial and venous ΔePVS%, and albumin [Alb; T6h arterial ΔePVS% (%): 11.57% (-1.82%, 31.35%) vs. 0.48% (-5.67%, 6.02%), T6h venous ΔePVS%: 9.62% (3.59%, 25.75%) vs. 1.52% (-9.65%, 7.72%), Alb (g/L): 27.57±4.15 vs. 23.77±6.97, all P < 0.05], lower SOFA score, APACHE II score, AST, T0h Lac, and T3h and T6h norepinephrine dosage [SOFA score: 9.00 (8.00, 10.00) vs. 11.50 (9.25, 14.50), APACHE II score: 18.00 (14.75, 21.25) vs. 25.50 (21.00, 30.00), AST (U/L): 34.09 (23.20, 56.64) vs. 79.24 (25.34, 196.59), T0h Lac (mmol/L): 1.75 (1.40, 2.93) vs. 3.25 (2.33, 5.30), norepinephrine dosage (mg): 0.98 (< 0.01, 3.10) vs. 4.60 (1.05, 8.55) at T3h, 1.82 (0.38, 5.30) vs. 8.20 (2.80, 17.73) at T6h, all P < 0.05]. While there were no significantly differences in other basic data and ePVS at all of the time points before and after resuscitation between the two groups. Correlation analysis showed that T6h venous ePVS was significantly positively correlated with T6h IVC variability in septic patients (r = 0.360, P < 0.05), T0h arterial ePVS was significantly negatively correlated with T3h and T6h liquid intake volume (r₁ = -0.367, r₂ = -0.280, both P < 0.05), and venous ePVS at ICU admission was significantly positively correlated with NT-proBNP at ICU admission (r = 0.409, P < 0.05). T6h venous ΔePVS% was significantly positively correlated with T3h liquid intake volume and T6h LCR (r₁ = 0.286, r₂ = 0.286, both P < 0.05), and significantly negatively correlated with T6h urine volume and T6h change value of Pcv-aCO₂ (ΔPcv-aCO₂; r₁ = -0.321, r₂ = -0.371, both P < 0.05). ROC curve analysis showed that the area under the ROC curve (AUC) of T6h venous ΔePVS% for predicting 28-day survival in septic patients was 0.726 [95% confidence interval (95%CI) was 0.578-0.875, P = 0.006], with a sensitivity of 82.4%, a specificity of 60.0%, and an optimal cut-off value of 3.09%. Binary multifactorial Logistic regression analysis showed that an increase in T6h venous ΔePVS% was a protective factor for 28-day death in patients with sepsis on early fluid resuscitation [odds ratio (OR) = 0.900, 95%CI was 0.834-0.972, P = 0.007]. CONCLUSIONS ePVS may have potential for assessing the volume status of septic patients during early fluid resuscitation. The ΔePVS% during early fluid resuscitation may help to identify septic patients with a poor prognosis.
Humans ; Prognosis ; Fluid Therapy ; Sepsis/physiopathology* ; Prospective Studies ; Plasma Volume ; Intensive Care Units ; Resuscitation ; Male ; Female ; Middle Aged ; Shock, Septic/therapy*

Turning to critical illness is a common stage of various diseases and injuries before death. Patients usually have complex health conditions, while the treatment process involves a wide range of content, along with high requirements for doctor′s professionalism and multi-specialty teamwork, as well as a great demand for time-sensitive treatments. However, this is not matched with critical care professionals and the current state of medical care in China. Telemedicine, which shortens the distance of medical professionals and the gap of disease diagnosis and treatments in various regions through electronic information, can effectively solve the current problem. Therefore, there is an urgent need to develop a standardized, high-quality visualization telemedicine round system .Therefore, experts have been organized to search domestic and foreign literature on telemedicine round for critically ill patients and to form this consensus based on clinical experiences so as to further improve the level of critical care treatments in regions.

Turning to critical illness is a common stage of various diseases and injuries before death. Patients usually have complex health conditions, while the treatment process involves a wide range of content, along with high requirements for doctor′s professionalism and multi-specialty teamwork, as well as a great demand for time-sensitive treatments. However, this is not matched with critical care professionals and the current state of medical care in China. Telemedicine, which shortens the distance of medical professionals and the gap of disease diagnosis and treatments in various regions through electronic information, can effectively solve the current problem. Therefore, there is an urgent need to develop a standardized, high-quality visualization telemedicine round system .Therefore, experts have been organized to search domestic and foreign literature on telemedicine round for critically ill patients and to form this consensus based on clinical experiences so as to further improve the level of critical care treatments in regions.

Objective:To analyze the clinical characteristics of dengue fever patients, summarize the course and characteristics of the disease, and analyze the risk factors that affect the condition.Methods:Retrospective collection of general information, clinical symptoms, medical history, laboratory tests, prognosis and other clinical data of dengue fever patients that admitted to Jinghong First People's Hospital and severe dengue fever patients at People's Hospital of Xishuangbanna Dai Autonomous Prefecture from June to December 2023 was conducted using a case report form (CRF). According to the diagnostic criteria of the World Health Organization (WHO), patients were divided into dengue fever group, dengue fever with warning signs group, and severe dengue fever group. The differences in clinical data between different groups of patients were analyzed and compared. Binary multiple factor Logistic regression analysis was used to explore the risk factors affecting the severity of dengue fever in patients. Receiver operator characteristic curve (ROC curve) was drawn to analyze the predictive value of prediction models constructed for various risk factors for severe dengue fever. Subgroup analysis was performed on the prognosis of severe dengue fever patients, and the differences in clinical data between two groups of patients with different prognoses were compared. Binary multivariate Logistic regression analysis was used to explore the risk factors affecting the prognosis of severe dengue fever patients. ROC curve was drawn to analyze the predictive value of prediction models constructed for various risk factors on the prognosis of severe dengue fever patients.Results:A total of 2 264 patients were included, including 499 cases in the dengue fever group, 1 379 cases in the dengue fever with warning signs group, and 386 in the severe dengue fever group (43 deaths and 343 survivors). The most common symptom of dengue fever patients was fever (94.70%), followed by muscle soreness (70.54%), headache (63.12%), fatigue (58.92%), and chills (46.02%). Compared with the dengue fever group and the dengue fever with warning signs group, the ratio of thalassemia and the levels of cardiac troponin (cTnI, cTnT), MB isoenzyme of creatine kinase (CK-MB), and myoglobin were significantly increased in patients with severe dengue fever group, albumin (Alb) was significantly decreased in patients with severe dengue fever group. The levels of cTnT and myoglobin in patients with dengue fever with warning signs group were significantly higher than those in the dengue fever group, and the level of Alb in patients with dengue fever with warning signs group was significantly lower than that in the dengue fever group, the differences were statistically significant (all P < 0.05). Binary multivariate Logistic regression analysis showed that thalassemia [odds ratio ( OR) = 6.214, 95% confidence interval (95% CI) was 2.337-16.524, P < 0.001], Alb ≤ 36 g/L ( OR = 6.297, 95% CI was 4.270-9.286, P < 0.001), and cTnT levels ( OR = 1.008, 95% CI was 1.002-1.015, P = 0.016) were risk factors for severe dengue fever. ROC curve analysis showed that the area under the ROC curve (AUC) for predicting severe dengue fever based on the prediction models constructed for the above risk factors was 0.856, with the best predictive value of 0.067, sensitivity of 67.1%, and specificity of 99.4%. In the subgroup analysis of patients with severe dengue fever, compared with the survival group, the levels of hematocrit (HCT), cTnT, and CK-MB in the death group patients were significantly increased, while the level of Alb was significantly decreased, and the differences were statistically significant. Binary multivariate Logistic regression analysis showed that Alb ( OR = 0.839, 95% CI was 0.755-0.932, P = 0.001), HCT ( OR = 1.086, 95% CI was 1.010-1.168, P = 0.025), elevated troponin level ( OR = 10.119, 95% CI was 2.596-39.440, P < 0.001), and CK-MB ( OR = 1.081, 95% CI was 1.032-1.133, P < 0.001) were risk factors for mortality in patients with severe dengue fever. ROC curve analysis showed that the AUC for predicting death in severe dengue fever patients based on the prediction models constructed for the above risk factors was 0.881, with the best predictive value of 0.113, sensitivity of 75.0%, and specificity of 88.9%. Conclusion:Thalassemia, Alb≤36 g/L, and cTnT level are risk factors for severe dengue fever, while HCT level, Alb level, CK-MB level, and elevated troponin level are risk factors for death in patients with severe dengue fever.

Background::Sepsis is a serious disease caused by infection. Aminophylline has anti-asthma and anti-inflammatory effects. We aimed to explore the safety and effect of aminophylline in sepsis.Methods::We conducted a clinical randomized controlled trial involving 100 patients diagnosed with sepsis within 48 h after intensive care unit (ICU) admission in two sites. All patients were randomized in a 1:1 ratio to receive standard therapy with or without aminophylline. The primary clinical outcome was all-cause mortality at 28 days.Results::From September 27, 2018 to February 12, 2020, we screened 277 septic patients and eventually enrolled 100 patients, with 50 assigned to the aminophylline group and 50 to the usual-care group. At 28 days, 7 of 50 patients (14.0%) in the aminophylline group had died, compared with 16 of 50 (32.0%) in the usual-care group ( P = 0.032). Cox regression showed that the aminophylline group had a lower hazard of death (hazard ratio = 0.312, 95% confidence interval: 0.129-0.753). Compared with the usual-care group, patients in the aminophylline group had a longer survival time ( P = 0.039 by the log-rank test). The effects of aminophylline on vasopressor dose, oxygenation index, and sequential organ failure assessment score were time-dependent with treatment. There were no significant differences in total hospitalization days, ICU hospitalization days, and rates of serious adverse events (all P > 0.05). No adverse events were observed in the trial. Conclusions::Aminophylline as an adjunct therapy could significantly reduce the risk of death and prolong the survival time of patients with sepsis.Trial registration::ChiCTR.org.cn, ChiCTR1800019173.

Objective:To compare and analyze the clinical characteristics between acute fatty liver of pregnancy (AFLP) and the hemolysis, elevated liver enzymes and low platelets (HELLP) syndrome.Methods:This is a retrospective cohort study. The clinical data of 13 cases with AFLP and 34 cases with HELLP syndrome were collected from three tertiary referral centers in Yunnan (the First Affiliated Hospital of Kunming Medical University, the Second Affiliated Hospital of Kunming Medical University, and Yan'an Hospital of Kunming City) from January 2016 to December 2021. The patients were diagnosed to AFLP and HELLP syndrome according to the Swansea criteria and the Tennessee classification system. The general characteristics, clinical features, laboratory results within 24 hours after admission, complications, maternal and neonatal outcomes were compared to analysis the differences between the two groups.Results:① Maternal characteristics: compared with HELLP syndrome group, AFLP group had lower body mass index (BMI) and blood pressure at admission (both P < 0.01). ②Clinical features: the most common symptoms in AFLP patients were skin jaundice, abdominal pain, nausea and vomiting, edema. The main manifestations of patients with HELLP syndrome were albuminuria, hypertension, edema, headache. Some patients had multiple symptoms concurrently. ③ Laboratory results: compared with HELLP syndrome group, the levels of platelet count (PLT), total bilirubin (TBil), direct bilirubin (DBil), γ-glutamyl transferase (γ-GGT), alkaline phosphatase (ALP), total bile acid (TBA), serum creatinine (SCr) and international standardized ratio (INR) in AFLP group were significantly increased within 24 hours after admission [PLT (×10 9/L): 107.69±51.13 vs.76.71±43.25, TBil (μmol/L): 121.60 (83.20, 170.00) vs.15.25 (7.22, 29.05), DBil (μmol/L): 86.50 (58.60, 104.00) vs. 4.30 (2.22, 10.10), γ-GGT (U/L): 87.00 (37.00, 127.00) vs. 41.00 (19.00, 64.42), ALP (U/L): 199.10 (109.00, 349.20) vs. 125.50 (90.50, 155.25), TBA (μmol/L): 51.50 (16.20, 117.40) vs. 4.15 (2.02, 6.95), SCr (μmol/L): 155.80 (129.00, 237.00) vs. 79.00 (65.43, 113.70), INR: 1.28 (1.17, 1.63) vs. 0.94 (0.88, 1.08), all P < 0.05], prothrombin time (PT) was significantly prolonged [seconds: 16.10 (14.50, 19.20) vs. 12.40 (11.43, 13.40), P < 0.05]. The level of blood glucose (GLU), fibrinogen (FIB) and the activity of antithrombin Ⅲ (ATⅢ) decreased significantly [GLU (mmol/L): 5.18±1.33 vs. 6.33±1.19, FIB (g/L): 1.96±1.46 vs. 3.81±1.58, ATⅢ (%): 40.61±25.84 vs. 66.39±24.11, all P < 0.05]; ④ Complications: compared with HELLP syndrome group, the incidence of patients with hypoglycemia [30.77% (4/13) vs. 0% (0/34)], acute liver failure [53.85% (7/13) vs. 5.88% (2/34)], acute renal insufficiency [69.23% (9/13) vs. 8.82% (3/34)], coagulopathy [76.92% (10/13) vs. 38.24% (13/34)], disseminated intravascular coagulation (DIC) [53.85% (7/13) vs. 5.88% (2/34)], and multiple organ dysfunction syndrome (MODS) [53.85% (7/13) vs. 5.88% (2/34)] were significantly higher in AFLP group (all P < 0.05). ⑤ Maternal and neonatal outcome: all patients delivered after admission. The total length of hospital and intensive care unit stay were significantly longer in the AFLP group than in the HELLP syndrome group [days: 17.00 (11.00, 25.00) vs. 9.00 (7.00, 12.00), 12.00 (4.00, 22.00) vs. 3.91 (0, 7.00), both P < 0.01]. Two AFLP patients died, including one due to intracranial venous thrombosis and one due to multiple organ failure and cardiopulmonary arrest. There were no deaths in the HELLP syndrome group. Conclusions:There are significant differences in maternal characteristics, laboratory results and complications between AFLP and HELLP syndrome. TBil, γ-GGT, SCr, FIB, INR and ATⅢ activity may help to distinguish the two diseases.

Diagnostics is one of the most important bridge courses for medical students from basic to clinical. Doctor-patient communication runs through the whole process of patient diagnosis and treatment. How to improve medical students' ability of doctor-patient communication? Our teaching team has carried out continuous reform and explored the scientific effective teaching mode. Recently, through the construction of "doctor-patient communication skills" quality online course, efforts have made to build an online and offline blended learning mode, which has gradually realize the integration with diagnostics teaching, and has achieved remarkable results. It also provides a scientific practical basis for the integration of doctor-patient communication and other clinical courses, which is worthy of promotion.

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.

Objective:To analyze the clinical features of adult patients with extremely elevated erythrocyte sedimentation rate (ESR, ESR≥100 mm/1 h), so as improve the ability of clinicians to use erythrocyte sedimentation rate to assist in the diagnosis and treatment of diseases.Methods:A retrospective cohort study was conducted to examine the clinical data of patients with ESR ≥ 100 mm/1 h admitted to the First Affiliated Hospital of Kunming Medical University from January 1st 2019 to December 31st 2019. The age, gender, clinical diagnosis, first ESR level after admission, blood routine, liver function, renal function, coagulation function and C-reactive protein (CRP) within 24 hours after admission were collected. Patient cohorts were divided into youth group (18-65 years old), middle-aged group (66-79 years old) and elderly group (≥80 years old) according to the new standards of human age classification of World Health Organization (WHO) 2019. Patient cohorts were also divided into infectious disease group, hematological disease group, autoimmune disease group, renal failure group and others according to their respective clinical diagnosis. The distribution of extremely elevated ESR in each group, and the correlation between ESR and various laboratory indicators were analyzed.Results:① Among 429 patients with ESR≥ 100 mm/1 h, there were 236 males and 193 females. There was no significant difference in ESR levels between males and females [mm/1 h: 108.00 (103.00, 119.75) vs. 117.00 (105.50, 140.00), P = 0.234]. ② The age of 429 patients ranged from 18 to 98 years old, the average age was (53.70±18.70) years old. There were 310 cases in the youth group, 87 cases in the middle-aged group and 32 cases in the elderly group. The ESR level of the young group was significantly lower than that of the middle-aged group and the elderly group [mm/1 h: 108.00 (103.00, 120.00) vs. 119.00 (107.00, 140.00), 120.00 (110.25, 140.00), both P < 0.01]. ③ The main diagnoses associated with extremely elevated ESR were infectious diseases [157 cases (36.6%)], hematological system diseases [127 cases (29.6%)], autoimmune diseases [74 cases (17.2%)]. Pulmonary infection accounted for 58.0% (91/157) of infectious diseases. Hematopoietic stem cell diseases accounted for 45.7% (58/127), lymphocyte and plasma cell diseases accounted for [37.0% (47/127)] and erythrocyte diseases accounted for [11.0% (14/127)] of the hematological system diseases. Diffuse connective tissue diseases accounted for 75.7% (56/74) of autoimmune diseases. ④ Spearman correlation analysis showed that the extremely elevated ESR in all patients was significantly negatively correlated with the levels of red blood cell count (RBC), hemoglobin (HB) and hematocrit (HCT) (ρvalue was -0.395, -0.381 and -0.383, respectively, all P < 0.01), the ESR was significantly positively correlated with the level of fibrinogen (FIB; ρ= 0.345, P < 0.01). A total of 266 patients were tested for both ESR and CRP, and there was no significantly correlation between ESR and CRP level (ρ= -0.019, P = 0.756). Conclusions:The extremely elevated ESR was more common in pulmonary infections diseases, hematopoietic stem cell diseases, lymphocyte and plasma cell diseases, erythrocyte diseases and diffuse connective tissue diseases. The extremely elevated ESR was significantly correlated with the levels of RBC, HB, HCT and FIB.

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.