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Background: Clearance of tissue carbon dioxide by circulation is measured by venous to arterial carbon dioxide partial pressure difference (AVCO2 ) and is correlated with cardiac output (CO) in critically ill adult patients. This study aimed to correlate AVCO2 with other CO indices like arteriovenous oxygen saturation difference (AVO2 ), central venous oxygen saturation (ScVO2 ), and serum lactate in pediatric patients undergoing intracardiac repair (ICR) for tetralogy of Fallot (TOF). Methods: We conducted a prospective observational study in 50 patients, of age 5months to 5 years, undergoing ICR for TOF and analyzed AVO2 , AVCO2 , ScVO2 , and lactate from arterial and venous blood gas pairs obtained at different time intervals from admission to pediatric intensive care unit(PICU)(T0 ), at 6 h (T1 ), 12 h (T2 ), 24 h (T3 ), and 48 h (T4 ) postoperatively. Bivariate correlations were analyzed using Pearson for parametric variables. Results: Admission AVCO2 was not correlated with AVO2 (R2 = 0.166, P = 0.246), ScVO2 (R2 = ?2.2, P = 0.124), and lactate (R2 = ?0.07, P = 0.624). At T1 , AVCO2 was correlated with AVO2 (R2 = 0.283, P = 0.0464) but not with ScVO2 (R2 = ? 0.25, P = 0.079) and lactate (R2 = ?0.07, P = 0.623). At T2 , T3 and T4 , AVCO2 was correlated with AVO2 (R2 = 0.338,0.440 & 0.318, P = 0.0162, 0.0013, and 0.024), ScVO2 (R2 = ? 0.344, ? 0.488, and ?0.366; P = 0.0143, <0.0001, and 0.017), and lactate (R2 = 0.305, 0.467 and 0.607; P = 0.0314, 0.00062 and <0.0001). AVCO2 was negatively correlated with ScVO2 . No correlation observed between admission AVCO2 and mechanical ventilation duration. Two nonsurvivors had higher value of admission AVCO2 compared to survivors. Conclusion: AVCO2 is correlated with other CO surrogates like AVO2 , ScVO2 , and lactate in pediatric patients undergoing ICR for TOF.
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Objective:To investigate the prognostic value of the ratio of veno-arterial carbon dioxide partial pressure difference to arterio-venous oxygen content difference (Pv-aCO 2/Ca-vO 2) in children with primary peritonitis-related septic shock. Methods:A retrospective study was conducted. Sixty-three children with primary peritonitis-related septic shock admitted to department of intensive care unit of the Children's Hospital Affiliated to Xi'an Jiaotong University from December 2016 to December 2021 were enrolled. The 28-day all-cause mortality was the primary endpoint event. The children were divided into survival group and death group according to the prognosis. The baseline data, blood gas analysis, blood routine, coagulation, inflammatory status, critical score and other related clinical data of the two groups were statistics. The factors affecting the prognosis were analyzed by binary Logistic regression, and the predictability of risk factors were tested by the receiver operator characteristic curve (ROC curve). The risk factors were stratified according to the cut-off, Kaplan-Meier survival curve analysis compared the prognostic differences between the groups.Results:A total of 63 children were enrolled, including 30 males and 33 females, the average age (5.6±4.0) years old, 16 cases died in 28 days, with mortality was 25.4%. There were no significant differences in gender, age, body weight and pathogen distribution between the two groups. The proportion of mechanical ventilation, surgical intervention, vasoactive drug application, and procalcitonin, C-reactive protein, activated partial thromboplastin time, serum lactate (Lac), Pv-aCO 2/Ca-vO 2, pediatric sequential organ failure assessment, pediatric risk of mortality Ⅲ in the death group were higher than those in the survival group. Platelet count, fibrinogen, mean arterial pressure were lower than those in the survival group, and the differences were statistically significant. Binary Logistic regression analysis showed that Lac and Pv-aCO 2/Ca-vO 2 were independent risk factors affecting the prognosis of children [odds ratio ( OR) and 95% confidence interval (95% CI) were 2.01 (1.15-3.21), 2.37 (1.41-3.22), respectively, both P < 0.01]. ROC curve analysis showed that the area under curve (AUC) of Lac, Pv-aCO 2/Ca-vO 2 and their combination were 0.745, 0.876 and 0.923, the sensitivity were 75%, 85% and 88%, and the specificity were 71%, 87% and 91%, respectively. Risk factors were stratified according to cut-off, and Kaplan-Meier survival curve analysis showed that the 28-day cumulative probability of survival of Lac ≥ 4 mmol/L group was lower than that in Lac < 4 mmol/L group [64.29% (18/28) vs. 82.86% (29/35), P < 0.05]. Pv-aCO 2/Ca-vO 2 ≥ 1.6 group 28-day cumulative probability of survival was less than Pv-aCO 2/Ca-vO 2 < 1.6 group [62.07% (18/29) vs. 85.29% (29/34), P < 0.01]. After a hierarchical combination of the two sets of indicator variables, the 28-day cumulative probability of survival of Pv-aCO 2/Ca-vO 2 ≥ 1.6 and Lac ≥ 4 mmol/L group significantly lower than that of the other three groups (Log-rank test, χ2 = 7.910, P = 0.017). Conclusion:Pv-aCO 2/Ca-vO 2 combined with Lac has a good predictive value for the prognosis of children with peritonitis-related septic shock.
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Objective:To investigate the effects of aerosol therapy with budesonide suspension combined with compound ipratropium bromide on partial pressure of carbon dioxide (PaCO 2) and tumor necrosis factor α (TNF-α) in children with bronchiolitis. Methods:A total of 124 children with bronchiolitis admitted to Gujiao Central Hospital from January 2019 to December 2021 were included in this study. These children were randomly divided into two groups using the coin-tossing method. The control group ( n = 62) was treated with routine symptomatic treatment, and the study group ( n = 62) was treated with aerosol therapy of budesonide suspension combined with compound ipratropium bromide based on routine symptomatic treatment. The time at which clinical symptoms disappear, clinical efficacy, inflammatory reaction, and blood gas index were determined in each group. Results:After treatment, the time at which asthma, cough, pulmonary rales, and fever in the study group were (2.28 ± 0.71) days, (3.30 ± 0.82) days, (5.25 ± 1.03) days, and (19.01 ± 2.65) hours, respectively, which were significantly shorter than (2.71 ± 0.89) days, (3.81 ± 0.98) days, (5.72 ± 1.37) days, and (20.76 ± 3.12) hours in the control group ( t = 2.97, 3.14, 2.15, 3.36, all P < 0.05). Total response rate and PaO 2 in the study group were 91.94% and (83.94 ± 4.02) mmHg, respectively, which were significantly higher than 77.42% and (81.25 ± 5.53) mmHg in the control group ( χ2 = 5.03, t = 3.09, both P < 0.05). Interleukin-18, interleukin-33, TNF-α, and PaCO 2 in the study group were (141.03 ± 34.69) ng/L, (143.87 ± 38.43) ng/L, (75.49 ± 18.43) ng/L, and (41.85 ± 3.31) mmHg, respectively, which were significantly lower than (158.64 ± 47.92) ng/L, (162.75 ± 50.32) ng/L, (83.22 ± 21.75) ng/L, and (43.58 ± 4.46) mmHg in the control group ( t = -2.34, -2.34, -3.23, -2.45, all P < 0.05). Conclusion:Aerosol therapy with budesonide suspension combined with compound ipratropium bromide based on routine symptomatic treatment is more effective on bronchiolitis than routine symptomatic treatment alone. The combined therapy can effectively decrease PaCO 2 and TNF-α levels.
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Objective:To investigate the relationship between central venous-arterial blood carbon dioxide partial pressure difference (Pcv-aCO 2) and left ventricular ejection fraction(LVEF) in acute myocardial infarction. Methods:Clinical data of patients with acute myocardial infarction admitted to the Intensive Care Unit of Fujian Provincial Hospital from November 2019 to October 2021 were retrospectively analyzed. LVEF was measured by bedside echocardiogram. The patients were divided into the normal LVEF group (LVEF ≥ 52%) and decreased LVEF group (LVEF < 52%) according to LVEF. The differences in general information and hemodynamic parameters between the two groups were compared. The normality of the above data was tested by the Jarque-Bera test. Correlation analysis of hemodynamic indices with LVEF was performed. Binary logistic regression was used to analyze the risk factors associated with the decrease in LVEF. The feasibility of diagnosing LVEF decline with Pcv-aCO 2 was assessed using receiver operating characteristic (ROC) curve. Results:Seventy-two patients with acute myocardial infarction were included for analysis, including 25 patients in the normal LVEF group and 47 patients in the decreased LVEF group. Pcv-aCO 2 was significantly higher in the decreased LVEF group than that in the normal LVEF group [(7.13±1.19) mmHg vs. (5.41±1.23) mmHg, P<0.01]. There was a negative correlation between LVEF and Pcv-aCO 2 ( rs= -0.740, P<0.01). The area under the ROC curve for Pcv-aCO 2 was 0.849 (95% CI: 0.758-0.939, P<0.01). The binary logistic regression analysis showed that Pcv-aCO 2 was an independent risk factor for decreased LVEF ( OR=2.251, 95% CI: 1.326-3.820). Conclusions:To a certain extent, the increase of Pcv-aCO 2 can predict the decrease of LVEF in acute myocardial infarction.
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Objective To investigate the improvement of oxygenation after the treatment of prone position in patients with severe acute respiratory distress syndrome (ARDS) caused by pneumocystis jirovecii pneumonia (PJP) after kidney transplantation. Methods Clinical data of 5 cases of moderate and severe ARDS caused by PJP after kidney transplantation were analyzed retrospectively, and clinical characteristics, treatment regimen and prognosis were summarized. Results Clinical manifestations of 5 patients were fever, dry cough, chest tightness, shortness ofbreath,sweating and fatigue, and body temperature fluctuated between 38 ℃ and 39 ℃, percutaneous arterial oxygen saturation(SpO2) was gradually decreased, and respiratory distress symptoms were worsened. Pulmonary CT scan showed diffuse ground-glass shadow. After transfer to intensive care unit (ICU), immunosuppressive drugs were terminated, and all patients were given with compound sulfamethoxazole, caspofungin, low-dose glucocorticoids against pneumocystis jirovecii (PJ), oxygen therapy and other symptomatic supportive treatments. Four patients diagnosed with severe ARDS upon admission to ICU were treated in a prone position. One patient with moderate ARDS was not kept in a prone position. At 1 d after treatment in a prone position, partial pressure of arterial oxygen (PaO2) and oxygenation index were increased, whereas alveolar-arterial oxygen difference (A-aDO2) was decreased compared with before treatment (allP<0.05). Compared with 1 d after treatment, SpO2, PaO2 and oxygenation index were all increased, while A-aDO2 was decreased at 4 d after treatment (all P<0.05). Box diagram showed that oxygenation index showed an overall upward trend after prone-position treatment, whereas A-aDO2 showed an overall downward trend. The length of ICU stay of 5 patients was 14 (8, 29) d. All patients in a prone position did not develop complications, such as skin pressure sore, tube detachment and tube displacement, etc. Among 5 patients, 4 patients were mitigated, and 1 patient died of septic shock and multiple organ failure. Conclusions For both conscious and intubated patients, a prone position may significantly improve oxygenation and prognosis of patients with severe ARDS caused by PJP after kidney transplantation. Early diagnosis and accurate and standardized treatment play a pivotal role in enhancing cure rate.
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Objective:To explore the clinical value of arterial partial pressure of carbon dioxide (PaCO 2) combined with Wells score in predicting acute pulmonary embolism (PE). Methods:Patients with suspected acute PE admitted to Emergency Department of Beijing Chaoyang Hospital, Capital Medical University from January 1, 2016 to August 31, 2021 were screened. Patients with positive computed tomography pulmonary angiography (CTPA) results were classified as the PE group, and those with negative CTPA results were classified as the non-PE group. Demographic characteristics, symptoms, vital signs, underlying diseases, risk factors for venous thrombosis, arterial blood gas analysis and Wells scores were statistically analyzed and compared between the two groups, and the clinical efficacy of PaCO 2 combined with Wells score in predicting acute PE was evaluated. Results:A total of 1 869 patients with suspected acute PE were screened, and 1 492 patients were finally selected. There were 537 cases in the PE group and 955 cases in the non-PE group. The frequency of chest pain, dyspnea, unilateral lower limb edema, history of PE or deep venous thrombosis, history of surgery or immobilization within 3 months, history of fracture within 3 months, active malignant tumor, elevated Wells score and reduced PaCO 2 in the PE group was significantly higher than that in the non-PE group (all P< 0.05). The area under receiver operating characteristic (ROC) curve (AUC) of Wells score was 0.784 (95% CI: 0.758-0.810), and the sensitivity and specificity of predicting acute pulmonary embolism were 61.64% and 88.48%, respectively. The AUC of reduced PaCO 2 was 0.679 (95% CI: 0.651-0.707), and the sensitivity and specificity of predicting acute pulmonary embolism were 79.89% and 55.92%, respectively. The AUC of reduced PaCO 2 combined with Wells score was 0.837 (95% CI: 0.816-0.858), and the sensitivity and specificity of predicting acute pulmonary embolism were 74.12% and 77.07%, respectively. The AUC of reduced PaCO 2 combined with Wells score was significantly greater than the AUC of Wells score ( P<0.001) and the AUC of reduced PaCO 2 ( P<0.001). Conclusions:The efficacy of PaCO 2 reduction combined with Wells score in predicting acute PE was superior to that of either of them alone. This was a beneficial supplement to the screening of patients with acute PE, and would also help reduce the abuse of CTPA in the emergency department.
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This paper briefly reviewed blood substitutes, focusing on the background, history of research and development(R&D), types, functions, characteristics, the indications that will be mainly targeted in clinical, and their special status and role in the future, especially in the rescue of war/trauma patients using hemoglobin-based oxygen carriers(HBOCs). Additionally, the authors put forward unique insights and suggestions on some key concepts and R&D bottlenecks in the development of HBOCs through combining the authors′ own R&D experience for decades with efforts and lessons given by many scholars in this field at home and abroad, hoping to provide some new inspirations and ideas for colleagues to innovate and develop blood substitutes to benefit the clinical as soon as possible.
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Objective:To investigate the effect of continuous intracranial pressure (ICP) and brain oxygen partial pressure (PbtO 2) monitoring and guiding treatment after the application of standard large bone flap decompression and microhematoma removal in patients with severe traumatic brain injury (TBI). Methods:A retrospective analysis was done of 41 patients with TBI in Department of Neurosurgery in the Inner Mongolia People's Hospital from January 2018 to May 2020. Patients with Glasgow coma scale (GCS)<8 points were treatesd with microscopical removal of hematoma and contusion brain tissue and standard large bone flap decompression. Intraoperative intracranial pressure and brain tissue oxygen partial pressure monitoring probes were placed. Postoperatively, continuous intracranial pressure monitoring and partial oxygen pressure monitoring of brain tissue were performed, and target-based treatment under ICP and PbtO 2 monitoring was performed. According to the Glasgow Outcome (GOS) score after six months, patients were divided into a good outcome group (4-5 scores) and a poor outcome group (1-3 scores). There were 26 cases in good prognosis group and 15 cases in poor prognosis group. Linear regression analysis was used to further evaluate the relationship between PbtO 2, ICP and GOS score. The measurement data of normal distribution were compared by independent sample t-test. The counting data were expressed in cases (%), and the comparison between groups was adopted χ 2 inspection. The general linear bivariate Pearson correlation test was used. Results:The mean value of PbtO 2 (17.42±5.34) mmHg in the poor prognosis group was lower than that in the good prognosis group (24.65±5.61) mmHg, with statistical significance ( t=4.04, P<0.001). The mean value of ICP (22.32±3.45) mmHg in the poor prognosis group was higher than that (17.32±3.23) mmHg in the good prognosis group, with statistical significance ( t=4.15, P<0.001). Using PbtO 2 and ICP as independent variables and GOS score after 6 months as dependent variable, a regression equation was established ( Y=4.040 X+7.497; Y=-2.549 X+28.63). The mean value of PbtO 2 was positively correlated with GOS scores after 6 months in patients with severe head injury ( r=0.75, P<0.001). The mean value of ICP was negatively correlated with the prognosis of patients with severe head injury ( r=-0.87, P<0.001). Conclusion:The treatment guided by ICP combined with PbtO 2 monitoring is valuable in improving the prognosis of patients with severe traumatic brain injury after standard decompressive craniectomy, and may improve the prognosis 6 months after the injury.
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Objective:To investigate the value of partial pressure of end-tidal carbon dioxide (P ETCO 2) combined with passive leg raising test (PLR) in predicting volume responsiveness in patients with septic shock. Methods:A total of 43 patients with septic shock admitted to the second department of critical care medicine, People's Hospital of Xinjiang Uygur Autonomous Region from December 2019 to June 2021 were selected as the research subjects. P ETCO 2, cardiac index (CI), stroke volume variation (SVV), mean arterial pressure (MAP) and other hemodynamic indexes were monitored before and after PLR and volume stress test (VE). Subjects were grouped according to the CI variation rate (ΔCI) after VE test. Patients with ΔCI ≥ 15% were the responding group, and patients with ΔCI < 15% were the non-responding group. The receiver operator characteristic curve (ROC curve) was drawn to analyze the evaluation value of the change in P ETCO 2 after PLR on the evaluation value of fluid responsiveness. Results:Among the 43 patients, 22 cases were in the responding group, accounting for 51.2%; 21 cases were in the non-responding group, accounting for 48.8%. After the PLR test, the change values of MAP, SVV, CI and P ETCO 2 in the responding group were higher than those in the non-responding group, and the differences were statistically significant [MAP (mmHg): 3.8±2.1 vs. 1.4±2.0, SVV (%): -5.3±2.5 vs. 2.7±2.0, CI (mL·s -1·m -2): 0.48±0.13 vs. 0.14±0.18, P ETCO 2 (mmHg): 3.4±1.8 vs. 1.1±1.0, all P < 0.05, 1 mmHg≈0.133 kPa]. After the VE test, the changes of HR, MAP, SVV, CI and P ETCO 2 in the responding group were higher than those in the non-responding group [HR (times/min): -8.3±2.8 vs. -2.3±3.7, MAP (mmHg): 3.8±2.4 vs. 1.2±1.7, SVV (%): -6.3±3.1 vs. -3.3±2.0, CI (mL·s -1·m -2): 0.51±0.14 vs. 0.16±0.12, P ETCO 2 (mmHg): 3.3±1.2 vs. 1.3±1.1, all P < 0.05]. The area under the ROC curve (AUC) of the change in P ETCO 2 before and after the PLR test (ΔP ETCO 2 PLR) for evaluating fluid responsiveness was 0.881. When the critical value was 5.9%, the sensitivity was 76.7%, the specificity was 89.5%, and the correct index was 0.68; the AUC for SVV baseline assessment of fluid responsiveness was 0.835, and when the cut-off value was 12.8%, the sensitivity was 84.6%, the specificity was 80.0%, and the correct index was 0.65. The predictive value of ΔP ETCO 2 was not lower than the SVV baseline. Conclusion:After the PLR test, the change of P ETCO 2 can be used as a non-invasive, simple, safe and reliable indicator for predicting the volume responsiveness of patients with septic shock.
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Objective:To investigate the effect of inferior vena cava variability (IVCV) combined with difference of central venous-to-arterial partial pressure of carbon dioxide (Pcv-aCO 2) on guiding fluid resuscitation in septic shock. Methods:Patients with septic shock admitted to the department of critical care medicine of Jiangxi Provincial People's Hospital from January 1, 2018 to December 31, 2020 were enrolled, and they were divided into control group and observation group according to random number table method. Patients in both groups were given fluid resuscitation according to septic shock fluid resuscitation guidelines. The patients in the control group received fluid resuscitation strictly according to the early goal-directed therapy (EGDT) strategy. Resuscitation target: central venous pressure (CVP) 12-15 cmH 2O (1 cmH 2O≈0.098 kPa), mean arterial pressure (MAP) > 65 mmHg (1 mmHg≈0.133 kPa), mean urine volume (UO) > 0.5 mL·kg -1·h -1, central venous oxygen saturation (ScvO 2) > 0.70. In the observation group, the endpoint of resuscitation was evaluated by IVCV dynamically monitored by bedside ultrasound and Pcv-aCO 2. Resuscitation target: fixed filling of inferior vena cava with diameter > 2 cm, IVCV < 18%, and Pcv-aCO 2 < 6 mmHg. The changes in recovery indexes before and 6 hours and 24 hours of resuscitation of the two groups were recorded, and the 6-hour efficiency of fluid resuscitation, 6-hour lactate clearance rate (LCR) and 6-hour and 24-hour total volume of resuscitation were also recorded; at the same time, the duration of mechanical ventilation, length of intensive care unit (ICU) stay, 28-day mortality and the incidence of acute renal failure and acute pulmonary edema between the two groups were compared. Results:A total of 80 patients were enrolled in the analysis, with 40 in the control group and 40 in the observation group. The MAP, CVP and ScvO 2 at 6 hours and 24 hours of resuscitation in the two groups were significantly higher than those before resuscitation, while Pcv-aCO 2 and blood lactic acid (Lac) were significantly decreased, and UO was increased gradually with the extension of resuscitation time, indicating that both resuscitation endpoint evaluation schemes could alleviate the shock state of patients. Compared with before resuscitation, IVCV at 6 hours and 24 hours of resuscitation in the observation group were decreased significantly [(17.54±4.52)%, (18.32±3.64)% vs. (27.49±10.56)%, both P < 0.05]. Compared with the control group, MAP and ScvO 2 at 6 hours of resuscitation in the observation group were significantly increased [MAP (mmHg): 69.09±4.64 vs. 66.37±4.32, ScvO 2: 0.666±0.033 vs. 0.645±0.035, both P < 0.05], 24-hour MAP was increased significantly (mmHg: 75.16±3.28 vs. 70.12±2.18, P < 0.05), but CVP was relatively lowered (cmH 2O: 9.25±1.49 vs. 10.25±1.05, P < 0.05), indicating that the fluid resuscitation efficiency was higher in the observation group. Compared with the control group, 6-hour LCR in the observation group was significantly increased [(55.64±6.23)% vs. (52.45±4.52)%, P < 0.05], 6-hour and 24-hour total volume of resuscitation was significantly decreased (mL: 2 860.73±658.32 vs. 3 568.54±856.43, 4 768.65±1 085.65 vs. 5 385.34±1 354.83, both P < 0.05), the duration of mechanical ventilation was significantly shortened (days: 6.78±3.45 vs. 8.45±2.85, P < 0.05), while the incidence of acute pulmonary edema was significantly decreased [2.5% (1/40) vs. 20.0% (8/40), P < 0.05]. There was no significant difference in the length of ICU stay, 28-day mortality or incidence of acute renal failure between the two groups. Conclusions:Dynamic monitoring of IVCV and Pcv-aCO 2 can effectively guide the early fluid resuscitation of patients with septic shock, and compared with EGDT, it can significantly shorten the duration of mechanical ventilation, reduce the amount of fluid resuscitation, and reduce the incidence of acute pulmonary edema. Combined with its non-invasive characteristics, it has certain clinical advantages.
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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 protective effects of hemoglobin base on oxygen carries (HBOCs) with different oxygen affinity on isolated rat hearts. 【Methods】 Using Langendorff isolated heart perfusion model, 45 adult male SD rats (SPF grade), perfused with 30 min KH solution baseline, were randomly divided into sham operation group and control group: St. Thomas (STS) solution perfusion volume was 3mL/100g body weight; high P50 HBOCs group: [STS + high P50 HBOCs (P50=35.0 mmHg, 2.5 mg/100 g) product] perfusion volume was 3mL/100g body weight; medium P50 HBOCs group: [STS + medium P50HBOCs (P50=26.5.0 mmHg, 2.5 mg/100 g) product] perfusion volume was 3 mL/100 g body weight; low P50 HBOCs group: [STS + low P50 HBOCs (P50=11.0 mmHg, 2.5 mg/100 g) product] perfusion volume was 3mL/100g body weight, and the heart was arrested and placed in a 37℃ water bath to make the heart ischemic for 35 minutes, and then reperfused for 2 hours. The left ventricular development pressure (LVDevP), left ventricular end diastolic pressure (LVEDP), the rate of change of left ventricular pressure (LVPCR) and heart rate (HR) in the rat heart during reperfusion were observed and recorded. 1 min perfusion fluid from each rat in the basic and reperfusion phase was taken, and blood gas analyzer was used to measure the blood gas indexes of rats, and the myocardial injury marker enzymes [cardiac enzyme creatine kinase (CK-MB), lactate dehydrogenase (LDH) and the release of α-hydroxybutyrate dehydrogenase (α-HBDH)] were measured by ELISA kit. 【Results】 The cardiac function and the release of myocardial enzymes in the 5 groups of rats in the basal cardiac perfusion stage were similar (P>0.05). However, in the reperfusion stage, except for the insignificant changes in HR (P>0.05), the heart LVDevP (mmHg) of the three P50 HBOCs groups and the control group were 10.69±3.65 vs 8.50±2.88, 23.26 ±5.62 vs 8.50±2.88, 35.60±3.82 vs 8.50±2.88, LVEDP (mmHg) were 43.34±8.08 vs 54.64±7.42, 39.43±8.30 vs 54.64±7.42, 31.46±4.11 vs 54.64±7.42, dp/dt were 12.09±9.96 vs 6.09±0.98, 25.65±8.87 vs 6.08±0.98, 35.32±9.33 vs 6.09±0.98, -dp/dt were 17.53±11.28 vs 11.39±2.16, 28.80±13.70 vs 11.39±2.16, 43.36±3.83 vs 11.39±2.16, respectively (all P<0.05); the rebound situation and the release of CK-MB, LDH, and α-HBDH in the three P50 HBOCs groups were better than those in the control group (P<0.05). Among the three P50HBOCs products, the low P50HBOCs group had the best cardiac function indexes. The myocardial enzyme indexes of the high, medium and low HBOCs groups were CK-MB (ng/mL): 110.47±4.04, 90.2±2.46, 77.1±3.51; LDH (U/L): 162.23±7.71, 135.13±23.69, 92.20±4.21; a-HBDH (U/L): 228.00±8.03, 172.30±8.99, 131.00±2.02. 【Conclusion】 STS solution containing HBOCs products can improve the function of the reperfused heart at normal temperature ischemia for 35 min and 2 h reperfusion, and reduce heart damage. The STS solution containing low P50 HBOCs has the most obvious protective effect in rat isolated heart perfusion.
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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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OBJECTIVES@#To evaluate the accuracy and safety of measurements of transcutaneous carbon dioxide partial pressure (TcPCO@*METHODS@#A total of 45 very low birth weight infants were enrolled. TcPCO@*RESULTS@#There was no significant difference in TcPCO@*CONCLUSIONS@#Lower electrode temperatures (38-41℃) can accurately measure blood carbon dioxide partial pressure in very low birth weight infants, and thus can be used to replace the electrode temperature of 42°C. Transcutaneous measurements at the lower electrode temperatures may be helpful for understanding the changing trend of blood oxygen partial pressure.
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Humans , Infant , Infant, Newborn , Blood Gas Monitoring, Transcutaneous , Carbon Dioxide , Electrodes , Infant, Very Low Birth Weight , Oxygen , Partial Pressure , TemperatureABSTRACT
Background and Purpose: Hie-symptom is more common in women, with complains of strong cold sensation of fingers and lower limbs during cold weather. From the cyanotic findings of hands and thighs and dark venous blood, blood stasis due to excessive peripheral vein contraction was suspected. Then we studied the changes of sublingual and body surface temperature, venous gas partial pressure in the warm and cold conditions. To examine the role of thermo-dilating effects of nitric oxide (NO), the effects oral administration PDE 5 inhibitor Tadarafil (TDF) were also studied. Subjects and Methods: The subjects were 10 women (31 +- 8.8 yrs) with Hie-symptom and 7 women (26+-3.7 yrs) without Hie-symptom, BMI, blood pressure, heart rate,sublingual and peripheral body surface temperature (hand and lower limb), venous and arterial blood gas partial pressure, and fingertip arterial oxygen saturation were measured. The measurement was carried out at warm indoors (about 23°C) and cold outdoors (about 12°C). Then 10 mg TDF tablet was taken and all measurements were repeated again at the same time on the next day. Results: There was no difference in fingertip arterial blood oxygen saturation in both groups either at indoor or outdoor conditions, and even after taking TDF. In the cold outdoor, the subjects with Hie-symptom, compared to without Hie-symptom, showed significantly lower body surface temperature and venous blood pO2, and increased pCO2. After taking TDF, although sublingual temperature and the decrease in body surface temperature outside the room improved in both groups, the improvement was greater in Hie-symptom. Consideration and Conclusion: Because of normal fingertip arterial blood oxygen saturation, Hie-symptom is not considered to be a disorder of the cardiopulmonary/arterial system. From a significant decrease in peripheral body surface temperature, and peripheral venous blood pO2, and an increase in pCO2 of Hie-symptom in cold outdoors, it is considered that blood stasis by excessive constriction of peripheral veins or arteriovenous anastomosis (AVA) by the cold. The better effects of oral TDF, in Hie-symptom seems to predict the involvement of NO or cGMP in blood stasis.
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BACKGROUND: Although blood donation by healthy people can relieve the urgent need of clinical blood to some extent, it is impossible to fundamentally solve the problem of blood shortage and blood safety by relying solely on blood donation by healthy people. OBJECTIVE: In combination with the significance of the development of biological oxygen-carrying therapeutics, to expound the unique characteristics of biological oxygen-carrying therapeutics, and to summarize the research status and application progress of biological oxygen-carrying therapeutics in recent years, in order to provide a certain theoretical basis for further research on the role and clinical application of biological oxygen carrying therapeutic agents. METHODS: The authors searched the relevant articles published from January 2015 to August 2019 in the databases of CNKI, Wanfang and PubMed. The keywords were “blood substitute, hemoglobin oxygen carrier, artificial blood, oxygen-carrying therapeutic agent” in English and Chinese. Types of search literature included original research and reviews. Initially 418 articles were included, and finally 46 eligible articles were classified and reviewed. RESULTS AND CONCLUSION: The biological oxygen-carrying therapeutic agent has a good clinical effect. It can maintain blood osmotic pressure, acid-base balance and blood volume, and also has good oxygen-carrying capacity. It can deliver oxygen to local hypoxic tissue for a long time. It is also easy to store and transport. Biological oxygen-carrying therapeutic agents have been widely used in surgery, which are of great help to expand blood volume and accelerate postoperative recovery. Therefore, the development of biological oxygen-carrying therapeutic agents is of great significance for surgical trauma and resuscitation, hemorrhagic shock, malignant anemia, myocardial infarction and other diseases. It shows a good clinical application prospect.
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Background and Purpose: Hie-symptom is more common in women, with complains of strong cold sensation of fingers and lower limbs during cold weather. From the cyanotic findings of hands and thighs and dark venous blood, blood stasis due to excessive peripheral vein contraction was suspected. Then we studied the changes of sublingual and body surface temperature, venous gas partial pressure in the warm and cold conditions. To examine the role of thermo-dilating effects of nitric oxide (NO), the effects oral administration PDE 5 inhibitor Tadarafil (TDF) were also studied. Subjects and Methods: The subjects were 10 women (31 +- 8.8 yrs) with Hie-symptom and 7 women (26+-3.7 yrs) without Hie-symptom, BMI, blood pressure, heart rate,sublingual and peripheral body surface temperature (hand and lower limb), venous and arterial blood gas partial pressure, and fingertip arterial oxygen saturation were measured. The measurement was carried out at warm indoors (about 23°C) and cold outdoors (about 12°C). Then 10 mg TDF tablet was taken and all measurements were repeated again at the same time on the next day. Results: There was no difference in fingertip arterial blood oxygen saturation in both groups either at indoor or outdoor conditions, and even after taking TDF. In the cold outdoor, the subjects with Hie-symptom, compared to without Hie-symptom, showed significantly lower body surface temperature and venous blood pO2, and increased pCO2. After taking TDF, although sublingual temperature and the decrease in body surface temperature outside the room improved in both groups, the improvement was greater in Hie-symptom. Consideration and Conclusion: Because of normal fingertip arterial blood oxygen saturation, Hie-symptom is not considered to be a disorder of the cardiopulmonary/arterial system. From a significant decrease in peripheral body surface temperature, and peripheral venous blood pO2, and an increase in pCO2 of Hie-symptom in cold outdoors, it is considered that blood stasis by excessive constriction of peripheral veins or arteriovenous anastomosis (AVA) by the cold. The better effects of oral TDF, in Hie-symptom seems to predict the involvement of NO or cGMP in blood stasis.
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RESUMEN La afinidad de la hemoglobina (Hb) por oxigeno (O2) es un factor importante que influye en el transporte de este gas, especialmente en hipoxia y en diferentes enfermedades como anemia o fibrosis quística. En la medición de la afinidad se usa la determinación de la curva de disociación Hb:O2. El método presentado para establecer la curva de disociación Hb:O2 (CDO) simplifica los protocolos normalmente utilizados, ya que elimina el requerimiento del equipo específico para equilibrar la sangre con oxígeno en niveles fijos de presión parcial (PO2). Mediante el uso de ecuaciones matemáticas es posible establecer la cinética de saturación de la hemoglobina (SO2) a valores crecientes de PO2. De igual forma, mediante el método se determinan aspectos típicos de la unión Hb: O2 como la dependencia del pH (coeficiente de Bohr) y el tipo de asociación de la proteína con su ligando mediante el diagrama de Hill. En virtud de la simplificación realizada, el método es aplicable en prácticas de laboratorio en población humana y animal, así como en la investigación de diferentes condiciones experimentales.
ABSTRACT The affinity of hemoglobin (Hb) for oxygen (O2) is an important factor influencing the transport of this gas especially in hypoxia and in different diseases such as anemia or cystic fibrosis. By the affinity measurement, the determination of the Hb: O2 dissociation curve is used. The presented method to establish the Hb: O2 oxygen dissociation curve (CDO) simplifies the protocols normally used, since it eliminates the requirement of specific equipment to equilibrate blood with oxygen at fixed levels of oxygen pressure (PO2). By using mathematical equations, it is possible to establish the saturation change of hemoglobin (SO2) at increasing oxygen partial pressure. Similarly, the method determines typical aspects of the Hb: O2 binding as the pH dependence (Bohr coefficient) and the association type of protein with its ligand by the Hill diagram. By this simplification, the method is applicable in laboratory practices in human and animal population, as well as in the investigation of different experimental conditions.
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Objective To study the role of partial pressure of oxygen in the treatment of pulmonary hypertension induced by meconium aspiration syndrome. Methods Retrospective analysis was performed on 58 patients with meconium aspirate and pulmonary hypertension from January 1,2007 to December 31,2016, 28 patients in the death group,and 30 patients in the survival group. Blood gas analysis about two groups of children with mechanical ventilation were collected at four different time points:before mechanical ventilation ( 0 h) ,12 hours after mechanical ventilation,24 hours after mechanical ventilation and 72 hours after mechan-ical ventilation. The 80 mmHg(1 mmHg=0. 133 kPa) in blood gas analysis of the partial pressure of oxygen was used as the boundary point to study the effects about different blood oxygen partial pressures on the length of mechanical ventilation time in the survival group. Results Blood gas analysis showed that there were no significant differences in pH,partial pressure of oxygen,HCO3-,and lactic acid before mechanical ventilation in the two groups,but the pH values were significantly higher in the survival group after 12 h, 24 h,and 72 h of mechanical ventilation(t values:-2. 07,-3. 48,-7. 11;P <0. 05). Partial pressure of oxygen were higher in the surviving group at 12 h,24 h,and 72 h than those in the death group(t values-2. 87,-4. 88,-11. 29; P<0. 05). The HCO3-values of the survival group at 12 h,24 h and 72 h were higher than the death group, and the differences were statistically significant ( t values: -3. 90, -5. 60,-5. 76,P<0. 001). The lactic acid of survival group was significantly lower than the death group at 72 h after ventilation (t=5. 12,P<0. 001). Compared with the death group,partial pressure of carbon dioxide in 24 h,72 h decreased significantly in the surviving group(t values:5. 67,7. 60;P<0. 05). In the surviving group,the partial pressure of oxygen was maintained above 80 mmHg in 18 patients and the mechanical venti-lation time was (7. 17 ± 1. 95) d. The partial pressure of oxygen was below 80 mmHg in 12 patients of the surviving group and the mechanical ventilation time was (8. 67 ± 2. 50)d. The difference was statistically sig-nificant(t =12. 02,P <0. 001). Conclusion In the treatment of newborn with pulmonary hypertension caused by meconium aspiration,maintaining a higher pH value and a partial pressure of oxygen higher than 80 mmHg may be beneficial to the recovery of children with pulmonary hypertension.
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Objective To explore the timeliness value of cardiopulmonary resuscitation quality index (CQI) in patients' prognostic evaluation during cardiopulmonary resuscitation (CPR).Methods A prospective descriptive study was conducted.According to whether they got return of spontaneously circulation (ROSC) or not,45 patients receiving CPR were divided into the ROSC group and non-ROSC group.The changes of CQI and partial pressure of end-tidal carbon dioxide (PETCO2) during CPR were collected,and were analyzed to valuate the prognosis of patients.Results The initial,end,and average PETCO2 were statistically different between the ROSC group and the non-ROSC group [7.0(3.6,14.6) vs 7.0(3.6,14.6) mmHg;29.5(19.8,35.9) vs 4.0(2.3,10.2)mmHg;and 22.2(11.8,36.3) vs 4.0(2.5,9.0) mmHg,respectively;P＜0.05],and the end CQI was statistically different between the two groups (59.6±8.9 vs 34.8±5.2,P＜0.05).The CQI differences between the two groups initiated at 11 min after CPR,and stopped at 29 min after CPR.The optimal cut-offpoint of terminal CQI and PETCO2 for prognostic was 33.2 and 16.1 mmHg respectively,and there was a statistically difference in the area under the curve between them (P＜0.05).Conclusions During CPR,both CQI and PETCO2 can be used to evaluate the prognosis,and CQI is more capable of predicting in the late stage of CPR.