Objective To explore the expression and effect of heme oxygenase-1 ( HO-1) in ventilator-induced lung injury. Methods Twenty-four New Zealand rabbits were randomly assigned to three groups, ie. a conventional ventilation + PEEP group( C group) , a ventilator-induced lung injury group( VILI group) , and a VILI + HO-1 inducer hemin group( Hm group) .Western blot and immunohistochemistry assay were used to investigate the expression of HO-1 protein. Blood gas analysis, lung wet /dry ratio, lunghistopathology and lung injury score were used to evaluate lung injury. Results HO-1 protein expression significantly increased in the VILI group compared with the C group. HO-1 was found mainly in alveolar epithelial cells and vascular endothelial cells, as well as in alveolar macrophages and neutrophils. Compared with the VILI group, HO-1 protein and PaO2 /FiO2 increased, while lung wet/dry ratio and lung injury score decreased in the Hmgroup significantly( P lt;0. 05) . Conclusion High HO-1 expression can alleviate lung injury from large tidal volume ventilation, implying its protective role in lung pathogenesis.
Objective To evaluate the diagnostic value of soluble triggering receptor expressed on myeloid cells-1 ( sTREM-1 ) in endotracheal aspirate and plasma of patients with ventilator-associated pneumonia ( VAP) . Methods The consentration of sTREM-1 in plasma and endotracheal aspirate, and serum high-sensitivity C-reactive protein ( hs-CRP) were measured by enzyme-linked immunosorbent assay ( ELISA) in 68 patients with VAP ( VAP group) , 50 patients underwent ventilation without VAP ( non-VAP group) , and 50 healthy individuals ( control group) . The sensitivity and specificity of each parameter were calculated. Results In the patients with VAP, sTREM-1 in plasma and endotracheal aspirate before treatment were significantly higher than that in the non-VAP group [ ( 143.62 ±46.82) pg/mL vs. ( 68.56 ±16.24) pg/mL, ( 352.86 ±92.57) pg/mL vs. ( 126.21 ±42.28) pg/mL, Plt;0.05] ; sTREM-1 in plasma and endotracheal aspirate on the 3rd and the 7th day during treatment were significantly decreased ( Plt;0. 05) . By ROC analysis, the cut-off value of sTREM-1 in endotracheal aspirate were 193.64 pg/mL, with sensitivity and specificity of 93.84% and 89.51% respectively. The areas under ROC curve of sTREM-1 in endotracheal aspirate were 0.912. Clinical diagnostic value of sTREM-1 in endotracheal aspirate was better than plasma sTREM-1 and serum hs-CRP ( areas under ROC curve were 0. 768 and 0. 704 respectively) . Conclusions sTREM-1 may be helpful for evaluating the therapeutic effect in patients with VAP. The diagnostic value of sTREM-1 in endotracheal aspirate may be superior to plasma sTREM-1 and serum hs-CRP.
呼吸机相关性肺炎( VAP) 是指患者接受机械通气治疗48 h 后至停用机械通气、拔除人工气道后48 h 内发生的肺实质的感染性炎症。为接受机械通气患者最常见的院内感染。VAP的发生率和病死率由于诊断手段不同, 报道不一。国外报道, VAP 发生率为9% ～70% [ 1] , 病死率高达20% ～71% [ 2, 3] ; 国内医院调查, VAP发生率为48. 5% , 病死率为37. 5% [ 4] 。患者一旦发生VAP, 易造成撤机困难, 并可导致患者在ICU的停留时间及住院时间延长, 增加相关的医疗费用, 严重者可导致患者死亡。因此, VAP的早期预防、早期诊断和治疗就显得非常重要, 本文就近年来VAP 的诊治现状做一概述, 以供同道参考。
Objective To study the influencing factors for duration of mechanical ventilation in chronic obstructive pulmonary disease ( COPD) patients with type II respiratory failure. Methods Twenty-eight cases of mechanical ventilated COPD patients with type II respiratory failure were enrolled from March 2006 to March 2008 in Beijing Shunyi Hospital. They were divided into two groups based on their duration of ventilation: ≤7 d group as group I, and gt; 7 d as group II. Data of heart rate and blood pressure were recorded before the trachea intubation. Clinical data of blood routine, blood gas analysis and serum biochemistry were collected and analyzed. Previous history, smoking history and subsequent complications were also recorded. Results Heart rate in the group II were significantly higher than which in the group I[ ( 121. 50 ±17. 20) /min vs ( 103. 08 ±19. 97) /min, P lt;0. 05] . The incidences of upper gastrointestinal hemorrhage and blood pressure fall immediately after intubation were 63% and 88% respectively in the group II, which were significantly higher than the group I ( 0 and 25% ) . The levels of albumin, pre-albumin, Na+ , PaO2 were ( 29. 06 ±5. 00) g /L, ( 66. 36 ±17. 72) mg/L,( 138. 45 ±4. 74) mmol /L and ( 49. 06 ±20. 11) mm Hg respectively in the group II. While in the group I, those were ( 37. 11 ±2. 73) g /L, ( 127. 70 ±35. 84) mg/L, ( 143. 29 ±3. 42) mmol /L and ( 72. 25 ±38. 69) mm Hg respectively, which showed significant differences compared with the grouop II. The incidence of previous concomitant cerebral infarction showed significant difference between the group I and group II( 33. 33% vs 0) .Conclusion The levels of albumin, pre-albumin, heart rate before the intubation, upper gastrointestinal hemorrhage and blood pressure fall immediately after the intubation are associated with duration of mechanical ventilation and may indicate the prognosis in COPD patients with type II respiratory failure.
ObjectiveTo analyze the clinical characteristics and pathogenesis in patients with chronic obstructive pulmonary disease (COPD) with ventilator-associated pneumonia (VAP). MethodsNinety-two patients with VAP who underwent mechanical ventilation via tracheal incubation due to COPD and respiratory failure were recruited in the study.The clinical characteristics,bacterial culture and antibiotics sensitivity of specimen from tracheal secretion and bronchoalveolar lavage fluid were retrospectively analyzed. ResultsThe main pathogenic bacteria in the patients with COPD with VAP were as following,ie. Ainetobacter baumanii(24.1%),Pseudomonas aeruginosa (17.6%),Klebsiella spp (15.9%),Methicillin-resistant Staphylococcus aureus(14.7%),and Escherichia coli(10.6%) in which Gram negative bacteria were predominant. When compared with the patients who received antibiotics before mechanical ventilation,the mortality in the patients who did not receive antibiotics before mechanical ventilation was significantly lower (17.9% vs. 40.6%,P<0.01). The patients who received de-escalation antibiotics therapy had lower mortality than those who received escalation antibiotics therapy(19.3% vs. 57.1%,P<0.01). There was no significant difference in mortality between the patients who suffered from VAP less or more than 4 days after mechanical ventilation (54.8% vs. 45.2%,P>0.05). ConclusionsHigh drug resistant rate is observed in patients with COPD and VAP especially in those patients who using antibiotic before mechanical ventilation. De-escalation antibiotics therapy can lower the mortality. The mortality rate is not significant different between early-onset and late-onset VAP in patients with COPD.
Objective To observe the effects of mechanical stretch on cytokines release from alveolar macrophages( AMs) and the expression of macrophage inflammatory protein-2( MIP-2) induced by lipopolysaccharide( LPS) . Methods AMs were divided into the following groups: ①AMs were subjected to 20% elongation by Flexercell 4000T cell stress system for 24 hours and the supernatant was collected to detect the levels of TNF-α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, IFN-γ, macrophage inflammatory protein-1α( MIP-1α) , MIP-2, monocyte chemoattractant protein-1( MCP-1) , granulocyte /macrophage colony stimulating factors( GM-CSF) , interferon inducible protein-10( IP-10) , regulated on activation in normal T-cell expressed and secreted( Rantes) and keratinocyte chemoattractant( KC) , by using LiquiChip system. ② AMs were subjected to 5% , 10% , 15% and 20% elongation for 24 hours and the supernatant was collected to detect the levels of MIP-2. ③AMs were subjected to 20% elongation and MIP-2 in supernatant was detected 1, 3,6, 12, and 24 hours later. ④ AMs were subjected to 20% elongation and/ or LPS at a concentration of 10 ng/mL, and MIP-2 in supernatant was detected 24 hours later. Unstretched AMs were used as control in all kind of test. Results ①The levels of IL-1β, IL-6,MIP-2, MCP-1, IFN-γand IP-10 secreted by stretched AMs were 8. 7, 4. 3, 38. 6, 4. 8, 14. 2 and 5. 0 times those of the control group( all P lt; 0. 001) . ② The levels of MIP-2 secreted by AMs subjected to 10% , 15% and 20% elongation were ( 480. 5 ±93. 1) pg /mL,( 806. 3 ±225. 9) pg/mL and ( 1335. 7 ±18. 5) pg/mL respectively, all significantly higher than those oft he control group [ ( 34. 6 ±11. 4) pg/mL, all P lt;0. 001] . ③ Three hours after the stimulation of stretch the level of MIP-2 began to increase gradually. And 6, 12, and 24 hours after the stimulation the levels of MIP-2 secreted by the AMs were ( 819. 4 ±147. 5) pg/mL, ( 1287. 6 ±380 ±3 ) pg/mL and ( 1455. 9 ±436. 7) pg/mLrespectively, all significantly higher than those of the control group[ ( 33. 4 ±10. 2) pg/mL, all P lt; 0. 001] . ④When the AMs were stimulated individually by LPS( 10 ng /mL) or mechanical stretch ( 20% ) , the levels of MIP-2 increased to ( 1026. 3 ±339. 5 ) pg/mL and ( 1335. 7 ±318. 5 ) pg/mL respectively( both P lt; 0. 001) . When the AMs were costimulated by LPS and mechanical stretch, the level of MIP-2 increased to ( 2275. 3 ±492. 1) pg/mL, implicating a synergistic effect between mechanical stretch and LPS ( F = 121. 983, P lt; 0. 001) . Conclusions Mechanical stretch activates AMs to produce multiple inflammatory cytokines and induce AMs to secret MIP-2 in a strength- and time-dependent manner.Mechanical stretch also has synergistic effect with LPS in inducing MIP-2 release, which might play an important role in the development of ventilator-induced lung injury.
Objective To explore the efficacy of continuous lateral rotation therapy ( CLRT) for the prevention of ventilator associated pneumonia ( VAP) . Methods Database of Medline and SinoMed were searched. Randomized and controlled trials assessing the efficacy of CLRT vs. placebo or conventional treatment for the prevention of VAP were included. Data were extracted on study population, exclusion and inclusion criteria, diagnostic criteria of VAP, incidence of VAP, ICU mortality, ICU length of stay, andduration of mechanical ventilation. The VAP incidence and mortality were extracted as dichotomous variables and the other parameters were extracted as continuous variables. The pooled analyses of VAP incidence and mortality were performed by using Review Manager 5. 0 software. The heterogeneity was analyzed by thestatistic I2 . Results A total of 5 clinical trials met the inclusion criteria. CLRT could reduce the incidence of VAP ( OR=0. 50,95% CI 0. 32-0. 78) , and the heterogeneity was not statistically significant. The impact of CLRT on the ICU mortality was insignificant. The ICU length of stay and duration of mechanical ventilationwere not significantly different between CLRT and control groups. Conclusion CLRT is beneficial for the prevention of VAP, whereas its impacts on other clinical outcomes such as the ICU mortality, ICU length of stay, and duration of mechanical ventilation require further investigations.
ObjectiveTo carry out targeted surveillance on ventilator-associated pneumonia (VAP) newly defined by the Centers for Disease Control and Prevention of the United States in 2013, and to understand its applicability and influence on the prognosis, and infection rate and risk factors of the disease. MethodsTargeted surveillance was carried out on all patients receiving mechanical ventilation in the general ICU of our hospital between January and December 2014. VAP infection rate was studied, and patients were divided into groups based on the development of the disease. SPSS 18.0 was used for statistical analysis of the prognostic indicators. ResultsA total of 885 patients received mechanical ventilation and were monitored, 31 of whom had VAP. The VAP case infection rate was 3.5% and its daily infection rate was 3.9‰. The results of multiple factors regression analysis showed that age (OR=1.025, P=0.025) and combining other types of hospital infection (OR=4.874, P<0.001) were independent risk factors for the development of VAP. VAP was the independent risk factor for both length of stay in the ICU and length of mechanical ventilation (P<0.001), but it was not the independent risk factor for mortality in the ICU (P=0.515). ConclusionThe applicability of the newly defined ventilator-associated pneumonia may be under restrictions in developing countries. It may influence the outcomes of patients by prolonging the length of stay in ICU and the length of mechanical ventilation.
Objective To study the advantages of heat and moisture exchangers compared with heated humidifiers in reducing the incidence of ventilator-associated pneumonia ( VAP) . Methods We searched PubMed as well as reference lists from publications to collect randomized controlled trials which comparing heat and moisture exchangers with heated humidifiers in preventing VAP for mechanically ventilated patients. Meta-analysis was performed using software Review Manager 5. 0. Results Fifteen randomized controlled trials were included. There was no difference in incidence of VAP among the patients managed with moisture exchangers or heated humidifiers ( OR1. 18, 95% CI [ 0. 96, 1. 44] ) . The subgroup of patients using moisture exchangers had lower VAP incidence compared with those using heated humidifiers without heated wire circuits ( OR 1. 39, 95% CI [ 1. 08, 1. 79] ) . There were no differences between the compared groups in mortality, length of intensive care unit stay, or duration of mechanical ventilation. Conclusion The available evidence indicates that moisture exchangers are superior to heated humidifiers without heated wire circuits, and not to heated humidifiers with heated wire circuits to prevent VAP.
Since 2016, the guidelines for the management of adults with hospital-acquired pneumonia (HAP) / ventilator-associated pneumonia (VAP) have been updated in the United States, Europe, and China, respectively. The differences among these guidelines are demonstrated in this paper. The definition of VAP, how to evaluate the effect of anti-infection therapy, and the prevention strategy are controversial. The consensuses contain diagnostic value of respiratory secretions achieved by noninvasive way for VAP and shorter anti-infection course for VAP. Importantly, pathogenic spectrum for HAP in China is different from others, which is essential for clinical practice.