Alveolar-arterial Oxygen Pressure Difference Research Articles

Can Alveolar-Arterial Oxygen Pressure Difference be used to Diagnose Acute Respiratory Distress Syndrome in Pneumonia Patients?

Alveolar-arterial oxygen pressure difference (P(Aa)O2) can reflect pulmonary ability to exchange oxygen; it shows good correlation with the oxygenation index (OI), which is important in diagnosing acute respiratory distress syndrome (ARDS). This study explored the ability of P(Aa)O2 in diagnosing ARDS in pneumonia patients. Methods We selected patients with community-acquired pneumonia and sepsis in the intensive care unit (ICU) of the People’s Hospital of Qiandongnan Miao and Dong Autonomous Prefecture; we measured P(Aa)O2 and the OI under anoxic conditions upon their admittance to the ICU. We divided the patients into ARDS and non-ARDS groups. We compared the differences in P(Aa)O2 and OI; we analyzed the correlation between P(Aa)O2 and ARDS. To assess the diagnostic ability of P(Aa)O2 for ARDS, we drew the receiver operating characteristic (ROC) curve. Result We found that P(Aa)O2 in the ARDS group was greater than in the non-ARDS group (t = 8.875, P <0.001); the OI in the ARDS group was smaller than in the non-ARDS group (t = –6.956, P <0.001). There was a positive correlation between P(Aa)O2 and ARDS (r = 0.718, P <0.001). The area under the ROC curve for P(Aa)O2 in the diagnosis of ARDS was 0.931 (0.873–0.988); the cutoff value was 214.70 mmHg, the sensitivity was 89.50%, and the specificity was 85.00%. Conclusion We conclude that P(Aa)O2 is a good reference index in diagnosing ARDS

Patients with hemodialysis-induced hypoxemia had a poor prognosis of COVID-19

BackgroundWe experienced that some hemodialysis (HD) patients with coronavirus disease 2019 (COVID-19) exacerbated hypoxemia during HD. Though HD-induced hypoxemia has been reported, there have been no reports of HD-induced hypoxemia in patients with COVID-19 and its effect on prognosis of COVID-19.MethodsEleven HD patients admitted with COVID-19 from August 2020 to April 2021 were classified into the patients whose oxygen demand increased by more than 3 L/min with mask during HD (worsened group, n = 5) and others (not-worsened group, n = 6). The background, laboratory findings, severity of COVID-19 and prognosis were compared between the two groups. In addition, blood gases were measured before and after dialysis among HD patients admitted with COVID-19 on April 2021 (n = 3).ResultsThere were no significant differences in backgrounds, except for a higher proportion of diabetes mellitus in worsened group (p = 0.04). Although laboratory findings were not significantly different on admission day, albumin and LDH levels 7 days after admission were significantly lower and higher in worsened group, respectively (p = 0.03 and < 0.01). The severity of COVID-19 and survival rate were significantly worse in worsened group (p = 0.01 and 0.03). The alveolar-arterial oxygen pressure difference (Aa-DO2) opened during HD in a patient with HD-induced hypoxemia, but did not open in patients without HD-induced hypoxemia.ConclusionsThere is a close relationship among HD-induced hypoxemia and poor prognosis of COVID-19. The HD-induced hypoxemia of patients with COVID-19 may be caused by ventilation/perfusion mismatching.

Effect of transcutaneous electrical acupoint stimulation on pulmonary function and oxidative stress response in lower extremity surgery patients using tourniquet

To investigate the effect of transcutaneous electrical acupoint stimulation (TEAS) on pulmonary function, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content in patients using tourniquet after lower extremity surgery. A total of 40 patients who underwent lower extremity surgery were equally randomized into control group and TEAS group by using a random number table. All patients underwent lumbar epidural anesthesia combined with block anesthesia. The patients in the TEAS group were given TEAS at Zusanli (ST36) and Sanyinjiao (SP6) beginning from 30 min before surgery to the end of surgery, and those in the control group received TEAS at the same acupoints with minimum current intensity. Mean arterial pressure (MAP) and heart rate (HR) were recorded at each time point (T0: pre-surgery /TEAS, T1: 5 min after anesthesia, T2: 1 min before tourniquet-loosening, T3: 1 min after tourniquet-loosening, T4: 5 min after tourniquet-loosening, and T5: 6 h after tourniquet-loosening). Blood samples (4 mL) was collected from the radial artery before TEAS and 6 h after loosening tourniquet for analyzing blood gas parameters as partial pressure of caron dioxide(PCO2), arterial partial pressure of oxygen (PaO2), alveolar partial pressure of oxygen (PAO2), alveolar-arterial oxygen pressure difference (PA-aDO2) and respiratory index (RI) by using a blood gas analyzer, and plasma SOD activity and MDA content were assayed by using xanthine oxidase method and thiobarbituric acid colorimetry method, respectively. Intra-group comparison showed that compared with T0, a significant increase was found in PA-aDO2 and RI at T5 and a significant reduction in PaO2 and PaO2/ PAO2 (a/A) ratio in the control group (P<0.05), and the same changes in the TEAS group (P<0.05) except a/A ratio. Comparison between two groups showed that at T5, both PaO2 and a/A levels were significantly higher in the TEAS group than in the control group (P<0.05), and both PA-aDO2 and RI levels were obviously lower in the TEAS group than in the control group (P<0.05), suggesting an improvement of the pulmonary function after TEAS. At T5, plasma SOD activity was significantly decreased and plasma MDA content was remarkably increased in the control group relevant to T0 (P<0.05), SOD activity was significantly higher in the TEAS group than in the control group (P<0.05), and MDA content was evidently lower in the TEAS group than in the control group (P<0.05), suggesting a reduction of oxidative stress response after TEAS. TEAS at ST36 and SP6 can improve pulmonary function and attenuate oxidative stress response in patients using tourniquet after lower extremity surgery.

Protective effect of remote ischemic pre-conditioning on patients undergoing cardiac bypass valve replacement surgery: A randomized controlled trial.

Remote ischemic pre-conditioning (RIPC) may have a protective effect on myocardial injury associated with cardiac bypass surgery (CPB). The objective of the present study was to investigate the effect of RIPC on ischemia/reperfusion (I/R) injury and to assess the underlying mechanisms. A total of 241 patients who underwent valve replacement were randomly assigned to receive either RIPC (n=121) or control group (n=120). The primary endpoint was peri-operative myocardial injury (PMI), which was determined by serum Highly sensitive cardiac troponin T (hsTnT). The secondary endpoint was the blood gas indexes, acute lung injury and length of intensive care unit stay, length of hospital stay and major adverse cardiovascular events. The results indicated that in comparison with control group, RIPC treatment reduced the levels of hsTnT at 6 and 24 h post-CPB (P<0.001), as well as the alveolar-arterial oxygen pressure difference and respiratory index after CPB. Furthermore, RIPC reduced the incidence of acute lung injury by 15.3% (54.1% in the control group vs. 41.3% in the RIPC group, P=0.053). It was indicated that RIPC provided myocardial and pulmonary protection during CPB. In addition, the length of the intensive care unit and hospital stay was reduced by RIPC. Mechanistic investigation revealed a reduced content of soluble intercellular adhesion molecule-1, endothelin-1 and malondialdehyde, as well as elevated levels of nitric oxide in the RIPC group compared with those in the control group. This indicated that RIPC protected against I/R injury associated with CPB through reducing the inflammatory response and oxidative damage, as well as improving pulmonary vascular tension. In conclusion, RIPC reduced myocardial and pulmonary injury associated with CPB. This protective effect may be associated with the inhibition of the inflammatory response and oxidative injury. The present study proved the efficiency of this approach in reducing ischemia/reperfusion injury associated with cardiac surgery. Clinical trial registry no. ChiCTR1800015393.

Use of Conventional Ultrafiltration in Patients with Pulmonary Hypertensive Mitral Valve Disease Undergoing Valve Surgery

Adverse effects of cardiopulmonary bypass on blood and lungs are encountered more severelyin pulmonary hypertensive patients undergoing mitral valve surgery. Aim of this study is to identify the favorable effects of conventional ultrafiltration on postoperative pulmonary functions, hemodynamics, morbidity or mortality in pulmonary hypertensive patients undergoing mitral valve surgery. 40 patients with severe pulmonary hypertension who underwent mitral valve surgery were included in study. Patients were divided into two groups according to whether conventional ultrafiltration was applied or not. Demographic data, preoperative transthoracic echocardiography, respiratory functions, complete blood count, biochemical parameters, alterations in pulmonary functions, bleeding, use of inotropic agents and blood products, intubation time, mortality, morbidity, length of intensive care unit and hospital stay, were evaluated. Intubation time (7.97±2.77 vs. 10.12±2.95; p 0.05) and inotropic agents (14 vs. 18; p>0.05) were less than the control group. Increase of pulmonary compliance, cardiac index, oxygen index, decrease of alveolar-arterial oxygen pressure difference and ventilation index were significant in both groups. Hematocrit (28.07±3.18 vs. 26.96±2.51; p>0.05) and white blood cell (13.56±2.37 vs. 13.03±2.51; p>0.05) were higher in the study. No morbidity and mortality were presentin both groups. Conventional ultrafiltration decreased the intubation time, intensive care unit stay, hospital stay, bleeding, use of blood products and inotropic agents. Favorable effects were also detected on pulmonary compliance, cardiac index, oxygen index, alveolar-arterial oxygen pressure difference and ventilation index. Studies with larger patient population, application of conventional and modified ultrafiltration together may give significant results for pulmonary functions.

Evaluation of Bone Mineral Density by Computed Tomography in Patients with Obstructive Sleep Apnea

Clinical studies have investigated whether obstructive sleep apnea (OSA) can modulate bone metabolism but data are conflicting. Bone mineral density (BMD) measured by dual-energy x-ray absorptiometry is the standard technique for quantifying bone strength but has limitations in overweight patients (body mass index [BMI] ≥ 25 kg/m(2)). The aim of this study was to examine the association between OSA and BMD by examining CT images that allow true volumetric measurements of the bone regardless of BMI. Lumbar vertebrae BMD was evaluated in 234 persons (180 males and 54 females) by CT scan. The method was calibrated by a phantom containing a known concentration of hydroxyapatite. BMD was lower in male patients with severe OSA (apnea-hypopnea index [AHI] ≥ 30/h) than non OSA (AHI < 5; p < 0.05), while OSA and BMD had no association in females. Linear and multiple regression analyses revealed that age (p < 0.0001, β = -0.52), hypertension (p = 0.0068, β = -0.17), and the alveolar-arterial oxygen pressure difference (A-aDO2) (p = 0.012, β = -0.15) in males were associated with BMD, while only age (p < 0.0001, β = -0.68) was associated with BMD in females. Males with severe OSA had a significantly lower BMD than non OSA participants. Age, hypertension, and elevation of A-aDO2 were significant factors for BMD by CT imaging. The usefulness of measuring BMD in OSA patients by CT scanning should be studied in future.

Effectiveness and safety of inhaled granulocyte-macrophage colony-stimulating factor therapy in idiopathic pulmonary alveolar proteinosis

To investigate the effectiveness and safety of inhaled granulocyte-macrophage colony-stimulating factor (GM-CSF) therapy in idiopathic pulmonary alveolar proteinosis (PAP). Ten PAP patients were enrolled, who were hospitalized in the Affiliated Drum Tower Hospital of Nanjing University Medical School from January 2012 to January 2014.All the patients were treated with inhaled GM-CSF therapy, high-dose therapy for 12 weeks, GM-CSF 150 µg twice a day on days 1-7, none for days 8-14, 6 cycles, low-dose therapy for 12 weeks, GM-CSF 150 µg inhaled once a day on days 1-7, none for days 8-14, 6 cycles, and followed-up for one year. Physiologic, serologic and radiologic features of the patients were analyzed. After inhaled therapy, clinical symptoms, oxygenation indexes, pulmonary function of nine patients were improved, and high resolution CT (HRCT) showed ground-glass lesions reduced. After inhaled therapy for 6 months, the average level of arterial oxygen partial pressure (PaO₂) was significantly higher than that before therapy ((75.5 ± 7.0) vs (63.6 ± 8.9) mmHg (1 mmHg=0.133 kPa)), while alveolar-arterial oxygen pressure difference (P(A-a)O₂) was lower than before ((25.1 ± 7.1) vs (41.2 ± 13.5) mmHg) (both P<0.01). Similarly, vital capacity (VC)% predicted, forced vital capacity (FVC)% predicted and carbon monoxide diffusing capacity (DLCO)% predicted all improved after therapy ((77.3 ± 16.6)% vs (63.3 ± 16.6)%), (79.5 ± 17.6)% vs (64.9 ± 17.1)%), (69.4 ± 23.0)% vs (50.0 ± 19.9)%) (all P<0.01). The score of HRCT reduced after therapy for six months (P<0.05). While the levels of serum lactate dehydrogenase (LDH), carcinoembryonic antigen (CEA), CYFRA211 were unchanged. No serious adverse events occurred during observation. Inhaled GM-CSF therapy is safe and effective.

Antigen avoidance tests for diagnosis of chronic hypersensitivity pneumonitis.

Chronic hypersensitivity pneumonitis (HP) is induced by the inhalation of specific antigens. Patients with chronic HP may be able to improve their prognosis by avoiding these antigens. Chronic HP is often difficult to distinguish from idiopathic interstitial pneumonias (IIPs). This study was performed to find out how antigen avoidance tests contribute to the diagnosis of chronic HP. A retrospective analysis was conducted on 265 patients who underwent 2-week antigen avoidance tests between April 2002 and March 2012. The patients were classified into the following categories: acute HP, chronic HP, collagen vascular disease-associated interstitial pneumonia (CVD-IP), lung dominant connective tissue disease (LD-CTD), and IIPs. The following seven clinical parameters were evaluated: vital capacity, alveolar-arterial oxygen pressure difference, Krebs von den Lungen-6, surfactant protein-D, white blood cell count, C-reactive protein, and body temperature. These parameters were compared between the chronic HP group and a control group consisting of CVD-IP, LD-CTD, and IIPs. One-hundred and ninety-six patients with chronic HP and 43 control subjects were evaluated. All clinical parameters improved significantly in the chronic HP group but showed no significant changes in the control group. Four of the parameters changed significantly compared with the control group. Diagnostic criteria established using these data had a sensitivity of 51.0% and a specificity of 80.7%. It was difficult to diagnose chronic HP based solely on 2-week antigen avoidance tests; however, improved clinical parameters among patients supported the diagnosis of HP.

Characteristics of serum lipid metabolism in patients with autoimmune pulmonary alveolar proteinosis.

To study the serum lipid panels in consecutive autoimmune pulmonary alveolar proteinosis(APAP)patients and analyze their relationship with anti-granulocyte macrophage-colony stimulating factor(GM-CSF)antibody and other markers. Thirty-two non-diabetic APAP patients were enrolled in the study. Serum lipids of these patients and 100 healthy volunteers were tested after an overnight fasting. Anti-GM-CSF antibody levels were measured with enzyme-linked immunosorbent assay. The correlation of serum lipids with lactate dehydrogenase,carcinoembryonic antigen,pulmonary function,and artery blood gas parameters were analyzed. Total cholesterol and low-density lipoprotein cholesterol levels [(5.54±0.99)and(3.73±0.83)mmol/L respectively] were significantly higher in APAP patients than in healthy volunteers [(5.05±0.97)and(3.17±0.89)mmol/L respectively](all P<0.05). High-density lipoprotein cholesterol(HDL-C)level of the APAP group [(1.10±0.18)mmol/L ]was significantly lower than that of the healthy group(P<0.05). Low-density lipoprotein/HDL and total cholesterol/HDL ratios in the APAP group(3.47±0.90 and 5.14±1.12 respectively)were significantly higher than those in the healthy group[(2.63±0.87)and(4.18±1.12)](all P<0.05). There was no significant difference in triglyceride level between the two groups(P>0.05). HDL-C level was negatively correlated with alveolar-arterial oxygen pressure difference(r=-0.436,P<0.05)and positively correlated with arterial oxygen saturation(r=0.459,P<0.05). None of the lipid markers correlated with serum anti-GM-CSF antibody levels(all P>0.05). APAP patients were likely to suffer from disturbed lipid metabolism,which was correlated with disease severity to some degree. Lipid markers deserved more attention in the management of APAP patients.

Study of the effects of high volume hemofiltration on extra vascular lung water and alveolar-arterial oxygen exchange in patients with septic shock

To explore the effects of high volume hemofiltration (HVHF) on inflammatory factors, extra vascular lung water and alveolar-arterial oxygen exchange in patients with septic shock. The data of 87 patients with septic shock underwent fluid resuscitation admitted to intensive care unit (ICU) of Shandong Provincial Hospital Affiliated to Shandong University were retrospectively analyzed. According to whether HVHF was used or not, all the patients were divided into fluid resuscitation group (n=41) and HVHF group (n=46). The patients in HVHF group received bedside high volume continuous vein-vein hemofiltration for at least 3 days on the basis of fluid resuscitation. The inflammatory factors, indexes of heart function, hemodynamics monitored by pulse-indicated continuous cardiac output (PiCCO), oxygen exchange, the severity of the disease before and after treatment, and 28-day mortality were compared between the two groups. The relationship between extra-vascular lung water index (EVLWI) and alveolar-arterial oxygen pressure difference (P(A-a)DO₂) was analyzed. (1) After treatment, the serum levels of interleukin-6 (IL-6), procalcitonin (PCT), and N-terminal pro-B-type natriuretic peptide (NT(-pro)BNP) in both group were gradually decreased. The IL-6, PCT, and NT(-pro)BNP on the 3rd day after treatment in HVHF group were significantly lower than those in fluid resuscitation group [IL-6 (μg/L): 34.8 ± 15.8 vs. 63.3 ± 21.2, PCT (μg/L): 7.5 ± 6.4 vs. 17.3 ± 11.2, NT(-pro)BNP (μg/L): 561.8 ± 23.7 vs. 584.3 ± 56.7, P<0.05 or P<0.01]. (2) The hemodynamics indexes were improved after treatment in both groups. The levels of intrathoracic blood volume index (ITBVI), EVLWI and pulmonary vascular permeability index (PVPI) on the 3rd day after treatment in HVHF group were significantly lower than those in fluid resuscitation group [ITBVI (mL/m²): 634.2 ± 125.8 vs. 963.8 ± 321.0, EVLWI (mL/kg): 7.5 ± 2.4 vs. 12.3 ± 4.2, PVPI: 2.2 ± 1.2 vs. 4.2 ± 2.0, all P<0.01]. (3) The levels of PA-aDO₂and arterial blood lactic (Lac) were gradually decreased, and oxygenation index (PaO₂/FiO₂) was gradually increased in both groups. Compared with fluid resuscitation group, the P(A-a)DO₂and Lac on the 3rd and the 7th day were significantly declined[P(A-a)DO₂(mmHg, 1 mmHg=0.133 kPa) on the 3rd day: 252.37 ± 29.45 vs. 270.82 ± 38.07, on the 7th day: 181.08 ± 21.81 vs. 221.02 ± 29.13; Lac (mmol/L) on the 3rd day: 3.17 ± 2.03 vs. 4.07 ± 2.43, on the 7th day: 1.95 ± 0.97 vs. 2.45 ± 1.07, P<0.05 or P<0.01], and the PaO₂/FiO₂on the 7th day was significantly elevated (mmHg: 258 ± 41 vs. 178 ± 34, P<0.01). (4) A significant positive correlation was found between EVLWI and P(A-a)DO₂(r=0.693, P=0.001), with the 95% confident interval (95% CI) 0.617-0.773. (5) The condition was improved after treatment in the two groups. The acute physiology and chronic health evaluationII (APACHEII) scores and sepsis-related organ failure assessment (SOFA) scores on the 7th day after treatment in HVHF group were significantly reduced compared with those in fluid resuscitation group (APACHEII score on the 3rd day: 18.2 ± 7.7 vs. 22.4 ± 8.6, on the 7th day: 8.2 ± 3.8 vs. 17.2 ± 6.8; SOFA score on the 3rd day: 13.6 ± 3.4 vs. 15.8 ± 5.0, on the 7th day: 7.6 ± 3.3 vs. 12.8 ± 3.9, P<0.05 or P<0.01). The 28-day mortality in HVHF group was significantly lower than that in fluid resuscitation group [15.22% (7/46) vs. 34.15% (14/41), χ² = 4.242, P=0.038]. HVHF could decrease blood inflammatory factors, and reduce the vaso-permeability and extra vascular lung water with a result of the improvement of the levels of alveolar- arterial oxygen exchange in patients with septic shock and the prognosis at the same time.

Persisting hypoxaemia is an insufficient measure of adverse lung function in very immature infants

BackgroundBronchopulmonary dysplasia (BPD), defined as protracted neonatal hypoxaemia, is considered a risk factor for respiratory disease in adulthood. The relationship between this diagnosis and the actual lung injury appearing in...

Effects of High-Dose Ulinastatin on Inflammatory Response and Pulmonary Function in Patients With Type-A Aortic Dissection After Cardiopulmonary Bypass Under Deep Hypothermic Circulatory Arrest

To investigate effects of high-dose ulinastatin on the release of proinflammatory cytokines and lung injury in patients with aortic dissection after cardiopulmonary bypass (CPB) under deep hypothermic circulatory arrest (DHCA). A prospective, randomized and double-blinded study. A teaching hospital. Thirty-six patients with acute type-A aortic dissection undergoing cardiac surgery using CPB under DHCA. These patients randomly were selected to received total doses of 20,000 units/kg of ulinastatin (n = 18) or 0.9% saline (control, n = 18) at 3 time points (after anesthetic induction, before aortic cross-clamp, and after aortic cross-clamp release). Tumor necrosis factor-alpha, interleukin 6, interleukin 8 and polymorphonuclear neutrophil elastase (PMNE) were measured after anesthetic induction (T0), 30 minutes (T1) after aortic cross-clamp, 3 (T2), 6 (T3) and 9 (T4) hours after weaning from CPB. Except for T1, pulmonary data, such as alveolar-arterial oxygen pressure difference, physiologic deadspace, peak inspiratory pressure, plateau pressure, static compliance and dynamic compliance, were obtained at the same time points. Concentrations of cytokines and PMNE were significantly lower in the ulinastatin group than the control group from T1 to T4, and peaked at T2 between the 2 groups. Compared with the pulmonary data of the control group at T2~T4, postoperative alveolar-arterial oxygen pressure difference, physiologic deadspace, peak inspiratory pressure, and plateau pressure significantly were lower, and static compliance and dynamic compliance higher in the ulinastatin group. Significantly shorter intubation time and intensive care unit stay were found in the ulinastatin group. High-dose ulinastatin attenuates the elevation of cytokines and PMNE, reduces the pulmonary injury and improves the pulmonary function after CPB under DHCA. Consequently, it shortens the time of intubation and intensive care unit stay.

Impaired endothelium-dependent vasodilator response in patients with pulmonary fibrosis

Recent epidemiological evidence indicates an association between cardiovascular diseases and pulmonary fibrosis. The vascular endothelium acts to maintain vascular homeostasis through multiple mechanisms and impaired endothelial function can contribute to the development, progression and clinical expression of atherosclerosis. We consecutively recruited 39 newly-diagnosed chronic interstitial pneumonitis/fibrosis patients without any specific etiology. We assessed endothelium-dependent vasodilator response of patients using digital pulse amplitude tonometry and compared the reactive hyperemia index (RHI) with age-, sex- and body mass index-matched control subjects (n=30). We further investigated the relationships between RHI and clinical characteristics, laboratory cardiovascular risk factors, disease-related factors and circulating levels of inflammatory biomarkers. RHI was significantly lower in patients with chronic interstitial pneumonitis/fibrosis than in control subjects (p=0.02). While circulating levels of total cholesterol, triglycerides, HbA1c and fasting glucose did not differ significantly between groups, patients with chronic interstitial pneumonitis/fibrosis had significantly lower high density lipoprotein levels and higher low density lipoprotein levels as compared with control subjects. Regarding disease-related factors, RHI was significantly associated with the diffusing capacity for carbon monoxide, alveolar-arterial oxygen pressure difference, 6-min walk distance and end-exercise oxygen saturation. Additionally, circulating levels of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 were inversely correlated with RHI. We confirmed a possible link between pulmonary fibrosis and cardiovascular disease by demonstrating an impairment of endothelium-dependent vasodilator response, which was significantly associated with the severity of pulmonary fibrosis and circulating levels of adhesion molecules.

Spectrum of chronic lung disease in a population of newborns with extremely low gestational age

To determine how the ability to oxygenate the blood develops after birth in infants of extremely low gestational age (ELGANs) and to find risk factors for chronic lung disease. A prospective, population-based, cohort study was undertaken in one tertiary-care centre. The alveolar-arterial oxygen pressure difference (AaDO(2)) was monitored. Of 41 survivors, 21 had a period of normal lung function in the first week of life, after which oxygenation deteriorated. Low gestational age and low Apgar score at 5 min were found to be strong and independent predictors of AaDO(2) in the first month of life. Mechanical ventilation did not appear as a risk factor. Lung function at 36 weeks of gestation and duration of oxygen treatment could be better predicted by the severity of lung disease in the first month than by gestational age at birth. Difficulty in oxygenation was a general observation in ELGANs and not only a particular subset. Gestational age and Apgar score were independent predictors of the degree of difficulty over the first month of life. As oxygenation failure often developed after a few days, the process may be possible to treat or prevent once the pathogenesis is known.

Serum level of soluble CX3CL1/fractalkine is elevated in patients with polymyositis and dermatomyositis, which is correlated with disease activity

IntroductionPolymyositis (PM) and dermatomyositis (DM) are chronic inflammatory muscle diseases, in which chemokines are thought to contribute to inflammatory cell migration into muscle. In this study, we retrospectively analyzed the expressions of CX3CL1/fractalkine and its corresponding receptor, CX3CR1, in muscle and lung with interstitial lung disease (ILD) of PM patients and DM patients, and determined the correlation between serum soluble CX3CL1 level and disease activity.MethodsExpressions of CX3CL1 and CX3CR1 in muscle and lung tissue were analyzed by immunohistochemistry. Serum CX3CL1 concentrations were measured by ELISA. For evaluation of patients' disease activity, serum creatinine kinase, manual muscle testing, and the alveolar-arterial oxygen pressure difference were used independently.ResultsCX3CL1 was expressed on infiltrated mononuclear cells and endothelial cells in muscle affected by PM and DM and in lung with ILD, whereas CX3CR1 was expressed on some CD4+ T cells, a majority of CD8+ T cells, and most macrophages in muscle, and on infiltrated mononuclear cells in the lung. Serum soluble CX3CL1 was significantly higher in PM patients and DM patients than in healthy controls. The CX3CL1 level was correlated with serum creatinine kinase and manual muscle testing score. In patients with PM and DM with ILD, serum CX3CL1 was also correlated with alveolar-arterial oxygen pressure difference. Furthermore, CX3CL1 was significantly decreased after conventional treatment.ConclusionsThe interaction between CX3CL1 and CX3CR1 might contribute to the inflammatory cell infiltration into affected muscle and lung with ILD in PM patients and DM patients. Serum CX3CL1 level could be a surrogate marker of disease activity.

The effects of joint administration of 6% hydroxyethyl starch 130/0.4 and high-volume hemofiltration on patients with acute lung injury and acute kidney injury

To evaluate the effects of administration of 6% hydroxyethyl starch (6% HES 130/0.4, voluven) in combination with high volume hemofiltration (HVHF) in patients with ALI and AKI. One hundred and eight patients with acute lung injury (ALI) and acute kidney injury (AKI) were enrolled from Department of Intensive Care Unit (ICU) of the provincial Hospital Affiliated to Shandong University between August 2006 and May 2011. The patients were randomly divided into two groups A (n = 68) and B (n = 40) to receive voluven (i.v., for volume resuscitation) and voluven+HVHF for 72 hours. The arterial blood lactate concentration (Lac), high sensitivity C-reactive protein (hs-CRP) serum concentration, pulmonary function index alveolar-arterial oxygen pressure difference [P(A-a)DO2] and oxygenation index (OI), as well as kidney function index serum cystatin C (Cyst C) and serum creatinine clearance rate (CCr) were measured at the time of admission and 72 hours after the treatment for statistical analysis. In comparison with group A, group B had significantly (all P < 0.01) lower mean value in the level of arterial Lac (mmol/L: 1.7 ± 0.7 vs. 2.7 ± 1.5), serum hs-CRP (mg/L: 35.8 ± 18.8 vs. 99.5 ± 20.4), P(A-a)DO2 (mm Hg, 1 mm Hg=0.133 kPa: 115.5 ± 23.1 vs. 155.4 ± 27.4), Cyst C (mg/L: 2.06 ± 1.12 vs. 3.95 ± 2.06) and significantly higher (both P < 0.01) mean value of OI (mm Hg: 295.2 ± 38.8 vs. 239.5 ± 32.7) and CCr (ml/min: 108.71 ± 31.33 vs. 90.21 ± 30.35) 72 hours after treatment. The mortality rate of group B was significantly lower than group A [10.00%(4/40) vs. 29.41%(20/68), P < 0.05] 7 days after the admission. 6% HES 130/0.4 in combination with HVHF could improve the lung and kidney function of the patients with ALI and AKI, prevent the development of multiple organ dysfunction syndrome (MODS), therefore improve the survival rate of these patients.

Effect of Subzero-Balanced Ultrafiltration on Lung Gas Exchange Capacity after Cardiopulmonary Bypass in Adult Patients with Heart Valve Disease

This study was conducted to evaluate the effect of a new ultrafiltration technique--the subzero-balanced ultrafiltration (SBUF)--on lung gas exchange capacity after cardiopulmonary bypass (CPB) in adult patients with heart valve disease. Attenuation of lung gas exchange capacity is one of the most common manifestations of an inflammatory response after CPB. Ninety-four patients who required CPB for cardiac surgery were randomized into 2 groups according to whether they received SBUF. Gas exchange capacity expressed as the oxygen index (OI), the respiratory index (RI), and the alveolar-arterial oxygen pressure difference (P(A-a)O2) were measured after intubation (T1), at the termination of CPB (T2), on admission to the intensive care unit (ICU) (T3), at postoperative hour 6 (T4), and at postoperative hour 12 (T5). There were no significant differences in gas exchange capacity between the 2 groups at T1, T4, and T5. CPB produced significant changes in OI, RI, and P(A-a)O2 in the control group, whereas these changes were not significantly different in the study group. The OI in the study group was significantly higher at T2, and RI and P(A-a)O2 were significantly lower at T2 and T3. In the study group, the intubation time was shorter, and the transfusion volume within 24 hours postoperatively was less. The 2 groups were comparable with respect to the incidence of respiratory complications, length of stay in the ICU, duration of hospital stay, need for infusions of inotropic agents, and drainage volumes within 24 hours postoperatively. SBUF during CPB can produce an immediate improvement in lung gas exchange capacity, which may effectively minimize pulmonary dysfunction in adult patients undergoing cardiac surgery.

Effects of high-volume hemofiltration on alveolar-arterial oxygen exchange in patients with refractory septic shock.

High-volume hemofiltration (HVHF) is technically possible in severe acute pancreatitis (SAP) patients complicated with multiple organ dysfunction syndrome (MODS). Continuous HVHF is expected to become a beneficial adjunct therapy for SAP complicated with MODS. In this study, we aimed to explore the effects of fluid resuscitation and HVHF on alveolar-arterial oxygen exchange, the Acute Physiology and Chronic Health Evaluation II (APACHE II) score in patients with refractory septic shock. A total of 89 refractory septic shock patients, who were admitted to ICU, the Provincial Hospital affiliated to Shandong University from August 2006 to December 2009, were enrolled in this retrospective study. The patients were randomly divided into two groups: fluid resuscitation (group A, n=41), and fluid resuscitation plus high-volume hemofiltration (group B, n=48). The levels of O2 content of central venous blood (CcvO2), arterial oxygen content (CaO2), alveolar-arterial oxygen pressure difference P(A-a)DO2, ratio of arterial oxygen pressure/alveolar oxygen pressure (PaO2/PaO2), respiratory index (RI) and oxygenation index (OI) were determined. The oxygen exchange levels of the two groups were examined based on the arterial blood gas analysis at different times (0, 24, 72 hours and 7 days of treatment) in the two groups. The APACHE II score was calculated before and after 7-day treatment in the two groups. The levels of CcvO2, CaO2 on day 7 in group A were significantly lower than those in group B (CcvO2: 0.60±0.24 vs. 0.72±0.28, P<0.05; CaO2: 0.84±0.43 vs. 0.94±0.46, P<0.05). The level of oxygen extraction rate (O2ER) in group A on the 7th day was significantly higher than that in group B (28.7±2.4 vs. 21.7±3.4, P<0.01). The levels of P(A-a)DO2 and RI in group B on the 7th day were significantly lower than those in group A. The levels of PaO2/PaO2 and OI in group B on 7th day were significantly higher than those in group A (P<0.05 or P<0.01). The APACHE II score in the two groups reduced gradually after 7-day treatment, and the APACHE II score on the 7th day in group B was significantly lower than that in group A (8.2±3.8 vs. 17.2±6.8, P<0.01). HVHF combined with fluid resuscitation can improve alveolar-arterial-oxygen exchange, decrease the APACHE II score in patients with refractory septic shock, and thus it increases the survival rate of patients.

Effects of fluid resuscitation and hemofiltration on Alveolar-arterial oxygen pressure exchange

Objective To evaluate the effects of fluid resuscitation and large-volume hemofiltration (HVHF) on the Alveolar-arterial oxygen exchange in patients with refractory septic shock. Method A total of 89 intensive care patients with refractory septic shock treated with fluid resuscitation and/or HVHF were enrolled between August 2006 and December 2009. All the patients were randomly divided into two groups. In group A, patients were treated with fluid resuscitation, n = 41 cases) and in group B, patients were treated with large-volume hemofiltration and fluid resuscitation, n =48). The O2 content of central venous blood(CcvO2), arterial oxygen content (CaO2), Alveolar-arterial oxygen pressure difference (P(A-a)DO2), the ratio of arterial oxygen pressure/alveolar oxygen pressure (PaO2/PAO2), respiratory index (RI) and oxygenation index (OI) were checked. The levels of oxygen exchange in two groups were detected by arterial blood gas analysis before treatnent, 24 hour, 72 hour and 7 days after treatment. The APACHE Ⅱ scores in patients with refractory septic shock were measured before and the 7th day after treatment with HVHF and/or fluid resuscitation respectively. Data were analyzed by using t -test and chi-square test to compare the differences and ratio between two groups and were expressed in mean ± standard deviation, and the analysis of variance was done with SPSS version 12.0 software. Results ① The differences in CcvO2 and CaO2 between two groups were[(0.60±0.24) vs. (0.72±-0.28), P ＜0.05 and (0.84±0.43) vs. (0.94±0.46), P ＜0.05]; and the oxygen extraction rates (O2ER) were significantly different between two groups [(28.7±2.4) vs. (21.7±3.4), P<0.01];② The levels of P(A-a)DO2、ratio of PaO2/PAO2、RI and OI in group B were reduced more significantly than in group A (P<0.05 or P<0.01);③The APACHE Ⅱ scores in both groups were gradually reduced after treatment for 7 days, and the APACHE Ⅱscore in group B on the 7th day of treatment were lower than that in group A[(17.2 ± 6.8) vs. (8.2 ± 3.8), P ＜ 0.01]. Conclusions Fluid resuscitation and HVHF could improve alveolar-arterial-oxygen exchange in patients with refractory septic shock, and at the same time decreased the APACHE Ⅱ scores, improving the survival rate of patients. Key words: Fluid resuscitation; High-volume hemofiltration(HVHF); Septic shock; Oxygen extraction rate (O2ER); Alveolar-arterial-oxygen exchange; Ratio of PaO2/PAO2; Respiratory index (RI); Oxygenation index (OI); Acute physiology and chronic health evaluation Ⅱ(APACHEⅡ)

Chronic thromboembolic pulmonary hypertension as a cause of dyspnoea in an older patient with a complex history

A full diagnostic work-up for patients with pulmonary hypertension (PH) is vital. Classification and diagnosis of the underlying cause is important to ensure optimal management, but may be complicated by overlapping signs and symptoms. This case study describes how a full work-up identified chronic thromboembolic PH (CTEPH) as the cause of dyspnoea in a 68-yr-old male with a history of pulmonary embolism and an original diagnosis of chronic obstructive pulmonary disease. Key indicators included decreased tricuspid annular plane systolic excursion, increased Tei index and elevated systolic pulmonary artery pressure. Multi-slice spiral chest computed tomography and pulmonary angiography showed severe chronic thromboembolic pulmonary disease, both centrally and distally. Diffusing capacity of the lung for carbon monoxide was reduced and blood gas analysis revealed a wide alveolar-arterial oxygen pressure difference, which is typical of CTEPH. The patient was eligible for pulmonary endarterectomy according to established criteria. Residual PH after surgery was successfully managed with bosentan.