The artificial ventilation system is a multi-factor system with some high uncertain risks which should be under controlled by medical risk management of hospitals. The key suggestions for reducing the accidence caused by ventilator are recommented： 1 ） to clarify the risk factor of ventilators, 2 ） to set up management group of ventilators with a clinical engineer who is good at management and quality control of medical equipment on ventilators, 3 ） to develop ventilator clinical practice for safety use, 4 ） to explore the effective risk monitoring and early warning system and mechanism on ventilator application.
目的 监测重症医学科（ICU）呼吸机相关性肺炎（VAP）的发病率，探讨实施干预组合措施对VAP发病率的影响。 方法 对2011年6月1日－2012年5月31日ICU使用呼吸机患者478例为监测对象并按时间先后分为两组，对照组按规范方法进行干预，试验组在规范干预基础上再采取组合干预措施，包括：每日评估患者、用一次性呼吸机螺纹管、用床角量角标识抬高床头、床尾设置黄色警示线、调查手卫生依从性等，统计分析两组VAP发病率。 结果 共监测ICU患者5 937个住院日，使用呼吸机1 510个机械通气日，呼吸机使用率25.43%，发生VAP 60例，VAP发病率为39.74例/1 000机械通气日，其中对照组发生VAP 21例，使用呼吸机343个机械通气日，VAP发病率为61.22例/1 000机械通气日；试验组发生VAP 39例，使用呼吸机1 167个机械通气日，VAP发病率为33.42例/1 000机械通气日，两组发病率差异有统计学意义（χ2=12.702，P=0.000）。 结论 实施干预组合措施可使VAP发病率显著下降，但仍高于国内外大型医院，基层医院还需不断努力控制好VAP的发病率。
Objective To analyze the clinical and etiological characteristics and bacterial susceptibility in patients with ventilator-associated pneumonia (VAP) in Guangzhou area.Methods A retrospective study was conducted on VAP patients in four hospital of Guangzhou from Jan 2004 to Oct 2005.Totally 157 patients were enrolled in this study，whose flora was identified and tested by Kirby Bauer disk diffusion susceptibility test.The univariate analysis method was used to analyze the prognostic parameters.Results The average onset time of VAP was 7.7 days after mechanical ventilation with a mortality rate of 38.2%.The proportion of Gram-negative bacilli，Gram-positive cocci and eumycete was 68.0%，23.4% and 8.7% respectively in 184 isolated strains.The most common pathogens were Pseudomonas aeruginosa (18.5%)，Stenotrophomonas maltophilia (14.1％)，Burkholderia cepacia (10.9%)，Staphylococcus aureus (10.3%) and Acinetobacter baumannii (8.7%).Pseudomonas aeruginosa，Stenotrophomonas maltophilia，and Acinetobacter baumannii were resistant to most common antibacterials such as cephalosporin and imipenem.18 strains oxacillin resistant Staphylococcus aureus，7 strains oxacillin resistant Staphylococcus simulans and one vancomycin resistant Staphylococcus aureus were isolated.Expect for vancomycin，teicoplanin and fusidic acid，the resistance of Gram-positive cocci were above 50% to other 9 antibacterials.Conclusions The antibiotic resistance situation of VAP in Guangzhou is very serious with high mortality.It is important to reinforce the prevention and guidance on the proper treatment of VAP.
Objective To study the clinical feasibility of invasive mechanical ventilation with bilevel positive airway pressure（BiPAP） non-invasive ventilator in the stable patients needing prolonged mechanical ventilation.Methods Eleven patients with respiratory failure admitted in intensive care unit（ICU）of our department，who needed prolonged mechanical ventilation，between Jun 2004 and Nov 2007 were enrolled in the study and followed until death or Jan 2008.The arterial blood gas analysis data，length of stay(LOS)，LOS after changing to BiPAP non-invasive ventilator（Synchrony，Harmony，RESPIRONICS，VPAP III ST-A，RESMED），survival time after discharge(or fulfilled the discharge standards) were reviewed retrospectively.Results The settings of inspiratory pressure，expiratory pressure and respiratory rate of non-invasive ventilation were 21.3 (16-26) cm H2O，4 cm H2O，and 16 min-1，respectively.The LOS (or up to the discharge standard) was (91.5±50.2) days.The LOS (or up to the discharge standard) after changing to BiPAP ventilator was (23.5±12.2) days.The mean survival time after discharge (or up to the discharge standard) was (353.1±296.5) days.Four patients were still alive up to the end of the study.The arterial pH，PaCO2，PaO2，and SaO2 were not significant different before and after changing to BiPAP ventilator.Conclusion The mechanical ventilation with BiPAP non-invasive ventilator via tracheotomy tube is an alternative choice for stable patients needing prolonged mechanical ventilation.
Objective To investigate the effects of mechanical ventilation( MV) via different tidal volume ( VT) in combination with positive end expiratory pressure( PEEP) on dogs with acute lung injury( ALI) . Methods Dog model of oleic acid-induced ALI was established. And after that animals were randomized into different MV groups ( included low VT group, VT =6 mL/kg; and high VT group, VT =20 mL/kg) and ventilated for 6 h with a PEEP of 10 cmH2O. Arterial blood gas wasmeasured before, during and after ALI model was established ( at 1 h,2 h, 4 h and 6 h during MV) . The albumin concentration in BALF and pathological change of the lung tissue were evaluated in order to determine the lung injury while animals were sacrificed after 6 h MV. Results ALI model was successfully established ( 2. 50 ±0. 80) hours after oleic acid injection. Arterial pH decreased much severer in the low VT group than the high VT group( P lt;0. 01) . PaO2 and SaO2 in ventilation groups decreased after modeling but increased after MV, and PaO2 and SaO2 were significantly higher in the low VT group than the high VT group after 6 h MV( P lt;0. 05) . PaCO2 fluctuated less in the high VT group, while it increased significantly in the low VT group after MV( P lt; 0. 01) . Oxygenation index( PaO2 /FiO2 ) was lowered after modeling( P lt; 0. 01) , decreased to about 190 mm Hg after 1 h MV. And PaO2 /FiO2 in low VT group was significantly higher than the high VT group after 6 h MV( P lt; 0. 05) . BALF albumin concentration and the lung injury score in the low VT group were both significantly lower than the high VT group( both P lt; 0. 05) . Conclusions Ventilation with PEEP could improve the oxygenation of ALI dogs, and low VT ventilation improves the oxygenation better than high VT. Otherwise, low VT could induce hypercapnia and ameliorate lung injury caused by high VT MV.
Objective To evaluate the efficacy and safety of Levofloxacin combined with Cefoperazone/Sulbactam on the patients with ventilator-associated pneumonia ( VAP) . Methods The clinical effect of Levofloxacin combined with Cefoperazone/ Sulbactam on ventilator-associated pneumonia in 58 paitiens with VAP were retrospectively analyzed. Results 26 patients ( 44. 8% ) were cured, 18 patients( 31. 1% ) were marked improved, and 14 patients ( 24. 1% ) were ineffective. The total clinical efficacy rate was 75. 9% . 55 strains of bacteria were isolated, and Gram-negative bacilli were dominant pathogens( 78. 2% ) . The bacterial clearance rate was 78. 2% . The prevalence of adverse reaction was 5. 1% . Conclusion Levofloxacin combined with Cefoperazone/ Sulbactam is effective and safe for patients with VAP.
Objective To analyze the risk factors for ventilator-associated pneumonia( VAP) in adult patients undergoing cardiac surgery with cardiopulmonary bypass ( CPB) . Methods A total of 127 consecutive adult patients who received postoperative ventilation for more than 48 hours between January 2002 and June 2008 in the cardiac surgical intensive care unit( CSICU) were included in this study. The patients were assigned into a VAPgroup( n =64) and a control group( n = 63) . Pre-, intra-, and postoperative factors were collected and analyzed between two groups, and the multivariate analysis( logistic regression)were used to identify the risk factors of VAP. Results The overall incidence of VAP was 5.1%. The mortality of VAP was 28. 1% . Compared to the control group, the patients in the VAP group had longer duration of cardiopulmonary bypass time, ventilation time, more blood products usage and the duration of stay in CSICU( P lt; 0. 001) , higher morbidity of low cardiac output syndrome and tracheotomy( P lt; 0. 01) and higher rate of aortic surgery and mortality( P lt; 0. 05) . The preoperative left ventricular ejection fraction ( LVEF) and postoperative oxygenation index( PaO2 /FiO2 ) were lower in the VAP group than those of the control group( P lt; 0. 001) . Five variables were found to be significantly related to the development of VAP by multivariate analysis: CPB time gt; 120 min( OR = 6. 352, P = 0. 000) ; PaO2 /FiO2 lt; 300 mm Hg( OR =3. 642, P = 0. 017) , transfusion of blood products ≥1500 mL( OR = 5. 083, P = 0. 039) , ventilation time≥5 days( OR = 9. 074, P = 0. 047) and tracheotomy( OR = 19. 899, P = 0. 021) . A total of 102 pathogens were obtained by sputum culture in 64 VAP patients. There were 62( 60. 8% ) cases of gram negative bacilli, 19 cases( 18. 6% ) of gram positive cocci and 21( 20. 6% ) cases of eumycetes. Conclusion This study shows that the cardiopulmonary bypass time, ventilation time, hypoxemia, blood products transfusion and tracheotomy are risk factors most likely associated with VAP development.
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.
呼吸机相关肺炎( VAP) 是指应用机械通气治疗后48 h和停用机械通气拔除人工气道48 h 内发生的肺实质的感染性炎症。VAP 是机械通气治疗中常见的严重并发症。其发生率为9% ～70% [ 1] , 病死率高达20% ～71% [ 2, 3 ] 。依据其发生的时间可分为早发性VAP 和晚发性VAP。早发性VAP: 即气管插管或人工气道建立lt; 5 d 发生者, 约占VAP的1/2, 主要由插管时即定植于呼吸道内的病原体如肺炎链球菌、甲氧西林敏感金黄色葡萄球菌、流感嗜血杆菌等引起。晚发性VAP: 即气管插管或人工气道建立gt;5 d 发生者, 常由肠道革兰阴性细菌如肠杆菌科、不动杆菌属和假单胞菌属细菌所致。采取有效措施预防VAP 的发生, 对于降低病死率, 减少住院时间和医疗费用, 节约医疗资源具有重要的意义。按照随机对照临床试验中的预防措施可总分为非药物性措施与药物性措施。