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*

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.

Objective:To isolate and identify SARS-CoV-2 epidemic strains and analyze the sequence characteristics of the virus strains following serial passages.Methods:Eleven nasopharyngeal swabs positive for SARS-CoV-2 antigen were collected from December 2022. Quantitative real-time PCR was used to detect SARS-CoV-2 nucleic acid, and positive specimens were inoculated onto Vero cells for virus isolation. The isolated strains were identified by Western blot and indirect immunofluorescence assay. The morphology of the isolated strains was observed using transmission electron microscopy. Nucleic acid was extracted from the isolates and passaged viruses for further sequencing and analysis.Results:All 11 specimens tested positive for SARS-CoV-2 using quantitative real-time PCR. SARS-CoV-2 strains were successfully isolated from seven specimens, and could be adaptively cultured, passaged, and expanded on Vero cells, achieving a peak titer exceeding 10 6.25 50% cell culture infectious dose (CCID 50)/ml. Western blot and indirect immunofluorescence results showed that the isolates could be specifically recognized by monoclonal antibodies and convalescent serum against SARS-CoV-2. Transmission electron microscopy revealed oval-shaped viral particles with diameters of approximately 100 nm. Next-generation sequencing of the viral isolates demonstrated a sequence homology greater than 99.50% with the Wuhan-Hu-1 reference strain (NC_045512) and 99.98% among the seven isolated strains, and all of the isolates belonged to the Omicron BF.7 variant. Sequence analysis after continuous passage and plaque purification of the BJ-NVSI-20230005 isolate showed that compared with passages 1-3, passages 4-6 had one nucleotide site mutation (C→T) in the ORF1ab gene and a deletion of 3 bp in the E gene, which resulted in a change from leucine to phenylalanine and the deletion of valine, respectively. Polymorphisms were observed in the sequences of plaque-purified clones. Conclusions:The seven successfully isolated SARS-CoV-2 strains all belong to the SARS-CoV-2 BF.7 variant, which is consistent with the prevalence trend in mainland China in December 2022.

Objective:To explore the effects of body mass index (BMI) on the incidence of nocturnal hypertension in patients with hypertension.Methods:Totally 341 hospitalized hypertensive patients treated at the Affiliated Hospital of Jining Medical University from February to May 2023 were selected by convenience sampling. Patients' general information, clinical data, and 24-hour ambulatory blood pressure results were collected. A binomial Logistic regression analysis was conducted to investigate the factors affecting the occurrence of nocturnal hypertension in these patients. The relationship between BMI and the incidence of nocturnal hypertension was examined using threshold effect tests and smooth curve fitting.Results:The binomial Logistic regression analysis indicated that blood phosphate level was a factor influencing the occurrence of nocturnal hypertension in hypertensive patients ( P<0.05). Smooth curve fitting and threshold effect test results showed that the relationship between BMI and the incidence of nocturnal hypertension was curve-correlated, with a turning point at 24.61 kg/m 2. To the left of the turning point, there was no correlation ( P=0.130) ; to the right, there was a correlation ( P=0.016) . Conclusions:When the BMI of hypertensive patients exceeds 24.61 kg/m 2, the likelihood of nocturnal hypertension increases with rising BMI, providing a precise intervention target for weight management-based patient care in hypertension.

Objective:To explore the current situation of nursing human caring in hospital wards and analyze its influencing factors, so as to facilitate the development of nursing human caring practice.Methods:From July to November 2022, a total of 107 hospitals were surveyed through stratified convenience sampling method, and 4 072 ward nursing managers were recruited to finish the general information questionnaire and the ward nursing human caring status questionnaire. The general information included the region, class and type of the hospital, etc. The ward nursing human caring status questionnaire included 38 items in 5 dimensions of nursing human caring system and process, humanistic quality and training of nursing staff, humanistic environment and facilities, human caring procedures and measures, and human caring quality evaluation and improvement, with a full score of 190 points. Descriptive statistics were used to analyze the general data, independent samples t-test, ANOVA and correlation analysis were used to analyze the factors influencing the current status of nursing human caring in the ward, while multiple linear regression analysis was used to conduct a multivariate analysis. Results:The score of nursing human caring in hospital wards was 156.91±27.78. Whether the hospital had carried out nursing human caring pilot(demonstration) wards, whether the ward had previously been a hospital nursing human caring pilot(demonstration) nursing unit, the type of ward, and whether nursing managers had participated in human caring training were the influencing factors of the implication of nursing humanistic caring in wards( P<0.05). Conclusions:The practice of nursing human caring in hospital wards is at a good level, but needs to be further strengthened. Nursing managers should take systematically strategies to promote the development of nursing human caring practice.

Objective:To explore the effect of auricular acupressure therapy on postoperative pain and early rehabilitation of patients with total knee arthroplasty.Methods:From March to June 2021, 68 patients who underwent unilateral total knee arthroplasty for the first time under general anesthesia combined with peripheral nerve block in Liaocheng People's Hospital were selected by convenient sampling. According to the random number method, the patients were divided into observation group (35 cases) and control group (33 cases) . Both groups received routine pain management and early postoperative rehabilitation nursing after operation, and the Chinese medicine doctors pasted the Wangbuliuxing seed adhesive tape at the auricular points one day before operation. The control group did not take any pressing operation. The observation group was pressed at the time of 1 day before operation to 3 days after operation, 3 times a day. The pressing frequency was 60 times/min, and the pressing time was 1 minute per acupoint. The dosage of analgesics used immediately after leaving the Anesthesia Recovery Room and at 4, 24, 48 and 72 hours after operation, as well as the visual analog pain scores of rest and activity at each follow-up time point were recorded and compared between the two groups. The knee range of motion of the two groups on the second, the fourth and seventh days after operation was compared.Results:The dosage of patient-controlled intravenous analgesia analgesics in the observation group were lower than those in the control group at 24, 48 and 72 hours after operation, with statistically significant differences ( P<0.05) . The pain score of the patients in the observation group at rest 24 hours after operation was lower than that in the control group, and the pain scores of the patients in the active state at 24, 48 and 72 hours after operation were lower than those in the control group, and the differences were statistically significant ( P<0.05) . The knee range of motion in the observation group were higher than those in the control group on the second, fourth and seventh days after operation, and the differences were statistically significant ( P<0.05) . Conclusions:Auricular acupressure therapy can reduce the dosage of analgesics used after total knee arthroplasty, relieve the degree of pain, and promote the early recovery of patients.

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.

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 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.