呼吸机管道使用时间对呼吸道细菌定植的影响

目的了解呼吸机管道使用时间对机械通气患者呼吸道细菌定植的影响,为降低呼吸机相关性肺炎采取针对性护理措施提供参考。方法选择使用一次性密闭式双加热呼吸机湿化管道系统机械通气时间超过336h的患者30例,分别于上机72h、168h、240h、336h采集患者咽喉部、下呼吸道分泌物进行细菌培养。结果咽喉部细菌定植以鲍曼不动杆菌为主,其次为杂菌;下呼吸道细菌定植以鲍曼不动杆菌最多,其次为铜绿假单胞菌及真菌。呼吸机管道使用不同时间段呼吸道细菌培养结果比较,差异有统计学意义(P<0.05、P<0.01)。结论机械通气患者随着呼吸机管道使用时间的延长,咽喉部及下呼吸道的细菌培养阳性率显著增加。需依据患者使用的呼吸机管道类型、湿化类型、管道污染情况及基础疾病等选择最佳的呼吸机管道更换时机。     

密闭式呼吸机湿化管道系统细菌培养分析

目的了解机械通气患者呼吸机湿化管道系统细菌定植情况,为湿化管道系统的更换时间及临床护理操作提供参考。方法选择采用密闭式呼吸机湿化管道系统机械通气超过72h以上的患者276例,分别于上机72h、168h、240h、336h、504h、672h采集呼吸机湿化管道系统标本进行细菌培养检测。结果共采集标本数3 271个,分离出病原菌9种541株。其中,呼吸机管道403株,冷凝水124株,湿化罐湿化液14株,均以革兰阴性杆菌为主。不同机械通气时间下,呼吸机管道、冷凝水、湿化罐湿化液细菌培养阳性率比较,差异无统计学意义(均P0.05)。结论采用密闭式呼吸机湿化管道系统,呼吸机管路、湿化罐湿化液的细菌定植量不随着机械通气时间的延长而增加,且湿化液在没有污染的情况下可延长至28d更换1次。     

机械通气湿化罐细菌呼吸管路定植的实验研究

目的 研究机械通气过程中湿化罐细菌是否会随着呼吸机气流定植到呼吸管路其他位置，为保证人工气道安全提供依据。方法随机对30例有创机械通气ICU患者的呼吸机湿化罐内的湿化水、湿化罐出口采样并送细菌培养。建立30个体外模拟机械通气的实验模型，分别种植铜绿假单胞菌或鲍曼不动杆菌到湿化罐的湿化水中，每15个模型种植同一种细菌，并添加肉汤促进细菌繁殖，在种植细菌后第24 h、72 h、168 h分别对湿化罐的湿化水及呼吸机管路的不同位置采样并送细菌培养。结果30组临床样本中，湿化罐内湿化水、湿化罐出口的细菌阳性率分别为46.7%、16.7%。30个体外实验模型中，湿化罐内的细菌大量生长，种菌后24 h、72 h、168 h细菌阳性率差异无统计学意义（P>0.05）；湿化罐出口的细菌阳性率在种菌后24 h达36.7%，72 h达63.3%，168 h达76.7%，差异有统计学意义（P<0.05）；而呼吸机管路的Y型管处及种菌后168 h距湿化罐出口10 cm的细菌培养为阴性。种菌后72 h、168 h，铜绿假单胞菌组在湿化罐出口的细菌浓度高于鲍曼不动杆菌组，差异有统计学意义（均P<0.05）。结论机械通气过程中，湿化罐内的湿化水会存在细菌定植，如果细菌在湿化罐内大量繁殖，细菌可随气流定植到湿化罐出口，不同细菌定植到湿化罐出口的量不同，但细菌不会定植到距湿化罐出口10 cm以上的呼吸管路。     

有创呼吸机管路系统更换时间对VAP发生的影响

目的探讨有创呼吸机管路系统更换时间对呼吸机相关性肺炎发生的影响,为医护人员临床实际操作提供参考。方法将神经内科、神经外科和呼吸科ICU进行有创机械通气的189例患者按入院时间分为对照1组59例,对照2组64例,观察组66例;对照组7d更换1次呼吸机管路,观察组仅在管路肉眼可见明显污染或功能障碍时予以更换。结果观察组和对照1组、2组患者机械通气期间呼吸机相关性肺炎发生率比较,差异无统计学意义(P0.05)。结论管路仅在出现肉眼可见污染或功能障碍时予以更换并不增加VAP发生率,同时可减少患者经济负担和人力、物力资源的消耗。     

Pharmacological treatment of bacterial infections of the respiratory tract

Bacterial infection of the respiratory tract is amongst the most common presentations to primary and secondary care. In addition to supportive care, the mainstay of pharmacotherapy is antibiotics. Antibiotic treatment of bacterial infections of the respiratory tract needs to consider patient factors such as age, comorbidities, location, previous antibiotic use, microbiological results and allergy. The emergence of multi-drug-resistant bacteria, partly a consequence of inappropriate antibiotic use, has both focussed the need for careful management of bacterial infection and presented a new therapeutic challenge. The choice of antibiotic for respiratory infections needs to be within national guidelines modified by local susceptibility profiles. Bacterial infections of the respiratory tract affect all levels of the airway tree and can be simply classified by their anatomical location, for example, epiglottitis, exacerbations of chronic obstructive pulmonary disease and bronchiectasis and pneumonia. As with all pharmacotherapy, alongside the benefit the potential side effects of the treatment needs to be considered. This is particularly important for the 6-month treatment of tuberculosis, which should only be managed by a specialist. The majority of bacterial infections of the respiratory tract respond well to therapy, but it is important to recognize that this remains a major cause of mortality.     

Pharmacological treatment of bacterial infections of the respiratory tract

Bacterial infection of the respiratory tract is amongst the most common presentations to primary and secondary care. In addition to supportive care, the mainstay of pharmacotherapy is antibiotics. Antibiotic treatment of bacterial infections of the respiratory tract needs to consider patient factors such as age, co-morbidities, location, previous antibiotic use, microbiological results and allergy. The emergence of multi-drug-resistant bacteria, partly a consequence of inappropriate antibiotic use, has both focussed the need for careful management of bacterial infection and presented a new therapeutic challenge. The choice of antibiotic for respiratory infections needs to be within national guidelines modified by local susceptibility profiles. Bacterial infections of the respiratory tract affect all levels of the airway tree and can be simply classified by their anatomical location for example: epiglottitis, exacerbations of chronic obstructive pulmonary disease and bronchiectasis and pneumonia. As with all pharmacotherapy, alongside the benefit the potential side effects of the treatment needs to be considered. This is particularly important for the 6-month treatment of tuberculosis, which should only be managed by a specialist. The majority of bacterial infections of the respiratory tract respond well to therapy, but it is important to recognize that this remains a major cause of mortality.     

Antibiotic treatment of bacterial infections of the respiratory tract

Treatment of bacterial infections of the respiratory tract should allow for factors such as the patient’s history, the treatment situation and the result of any bacteriological diagnosis. Haemophilus influenzae epiglottitis is treated with cefotaxime (a cephalosporin inhibitor of cell wall synthesis) or with chloramphenicol (an inhibitor of bacterial protein synthesis). Exacerbations of chronic bronchitis are treated with broad-spectrum penicillins (inhibitors of cell wall synthesis), tetracyclines or macrolides (both inhibitors of bacterial protein synthesis). Uncomplicated community-acquired pneumonia is treated with penicillins and/or a macrolide. Flucloxacillin (a penicillin resistant to β-lactamase) or vancomycin (a glycopeptide inhibitor of cell wall synthesis) are added if staphylococci are implicated. In severe community-acquired pneumonia of unknown aetiology, a combination of a macrolide and a cephalosporin is indicated. When Staphylococcus aureus is a suspected cause, flucloxacillin or vancomycin is added to the treatment regimen. Pneumonia possibly caused by atypical pathogens, is treated with a macrolide or a tetracycline. If Legionella pneumophila is the suspected causative organism, rifampicin (an inhibitor of bacterial DNA-dependent RNA polymerase) should be used in combination with a macrolide. Hospital-acquired pneumonia is treated with broad-spectrum cephalosporins, anti-pseudomonal penicillins (such as ticarcillin or piperacillin), the monobactam aztreonam or a fluoroquinolone such as ciprofloxacin (an inhibitor of bacterial DNA gyrase). In severe cases gentamicin (an aminoglycoside inhibitor of bacterial protein synthesis) may be used. The treatment of tuberculosis requires specialized knowledge and involves the use of combinations of rifampicin with inhibitors of tubercular mycolic acid synthesis (e.g. isoniazid or pyrazinamide) or with an inhibitor of tubercular arabinosyl transferase (e.g. ethambutol).     

Effect of timing of tracheostomy on changes in bacterial colonisation of the lower respiratory tract in burned children

Objective

The study aims to evaluate the impact of early and late tracheostomy on microbiological changes in the airways in severely burned children.

Materials and methods

Early tracheostomy is sometimes performed within 3 days after the start of mechanical ventilation regular microbiological surveillance of the respiratory tract was done in all patients. From each sputum, tracheobronchial aspirate and bronchoalveolar lavage (BAL), a microscopic slide was made and the material was seeded in a culture medium. The standard culture media used for the growth of respiratory pathogens are blood agar, McConkey agar, VL agar and chocolate agar. The obtained values were statistically analysed.

Results

In the observed period, a total of 68 children underwent mechanical ventilation in our department. A total of 31 (45.59%) children had undergone surgical tracheostomy (18 patients with early tracheostomy and 13 patients with late tracheostomy). The most common bacterium isolated from the lower respiratory tract in patients with early and late tracheostomy was Acinetobacter baumannii (31.53% resp. 44.30% of all bacterial strains).In patients with early tracheostomy, the ratio of G+/G− during the 6–7th day of mechanical ventilation was 1.29:1 and during the 8–10th day, 1:1.43. In patients with late tracheostomy the G+/G− ratio was 1:2.25 and during the 8–10th day, 1:2.25. There was not any statistically significant deviation in the G+/G− ratio in patients with early and late tracheostomy in any of the monitored periods.

Conclusion

The main reasons for performing early tracheostomy are: extent, localisation and depth of the burn. Difficult weaning in an uncooperative patient, failure of extubation with subsequent reintubation and other complications may be an indication for late tracheostomy.The study confirms that the use of appropriately indicated early tracheostomy provides a microbiological benefit for burned children.     

Effect of surgical delay on bacterial colonization in proximal humeral fractures

Postoperative infection is a severe complication after proximal humeral fracture surgical treatment. The aim of this study was to determine if the surgical delay could modify the number and type of bacteria on the surgical site. A two stages study was set up. In the first stage the effect of delay was simulated in 20 patients affected by proximal humeral fracture treated conservatively. In a second stage, the effect of delay was measured in 20 patients that underwent surgery. In stage 1, three skin culture swabs were taken in correspondence of the deltopectoral approach, the day of the fracture (day 0), the day after (day 1), and five days after fracture (day 5). In stage 2, skin swab cultures were taken the day of trauma and immediately before surgery and cultured on various media suitable for aerobic and anaerobic bacteria. The number of bacteria increased over the course of the study, from day 0 to day 5, both considering the total number of colony‐forming units and individual species of pathogen bacteria. The second stage of the study confirmed these data. An increasing number of bacteria was observed in patients that underwent surgery later than 2 days from trauma. The delay of surgery increased bacterial colonization of the skin in the deltopectoral approach area including common pathogenic bacteria such as Staphylococcus aureus, coagulase‐negative staphylococci and Propionibacterium acnes. This might justify the correlation between delay to surgery and risk of infection. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:942–948, 2016.     

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现代腹部外科治疗的病种越来越复杂，难度也越来越高。因此，呼吸道感染成为腹部外科重危病人的主要并发症之一，也是重危病人死亡的主要原因之一。腹部外科围手术期肺部感染与普通内科病人的肺部感染在诊断和治疗上有一定共性，但亦有其独特的个性，特别是在明确诊断和经验治疗方面还存在着一定的争议。外科医生在听取呼吸     

Endotracheal tubes coated with antiseptics decrease bacterial colonization of the ventilator circuits, lungs, and endotracheal tube

BACKGROUND: Formation of a bacterial biofilm within the endotracheal tube (ETT) after tracheal intubation is rapid and represents a ready source of lung bacterial colonization. The authors investigated bacterial colonization of the ventilator circuit, the ETT, and the lungs when the ETT was coated with silver-sulfadiazine and chlorhexidine in polyurethane, using no bacterial/viral filter attached to the ETT. METHODS: Sixteen sheep were randomized into two groups. Eight sheep were intubated with a standard ETT (control group), and eight were intubated with a coated ETT (study group). Animals were mechanically ventilated for 24 h. At autopsy, the authors sampled the trachea, bronchi, lobar parenchyma, and ETT for quantitative bacterial cultures. Qualitative bacterial cultures were obtained from the filter, humidifier, inspiratory and expiratory lines, and water trap. ETTs were analyzed with light microscopy, scanning electron microscopy, and laser scanning confocal microscopy. RESULTS: In the control group, all eight ETTs were heavily colonized (10(5)-10(8) colony-forming units [cfu]/g), forming a thick biofilm. The ventilator circuit was always colonized. Pathogenic bacteria colonized the trachea and the lungs in five of eight sheep (up to 10(9) cfu/g). In the study group, seven of eight ETTs and their ventilator circuits showed no growth, with absence of a biofilm; one ETT and the respective ventilator circuit showed low bacterial growth (10(3)-10(4) cfu/g). The trachea was colonized in three sheep, although lungs and bronchi showed no bacterial growth, except for one bronchus in one sheep. CONCLUSIONS: Coated ETTs induced a nonsignificant reduction of the tracheal colonization, eliminated (seven of eight) or reduced (one of eight) bacterial colonization of the ETT and ventilator circuits, and prevented lung bacterial colonization.     

Effect of ipratropium bromide aerosol on respiratory function in patients under ventilator treatment

Twenty patients, 36-78 years old, with a history of chronic obstructive lung disease, and immediately after operation mostly for cardiac disease, were treated with ipratropium bromide (IB, 15 cases) or placebo (5 cases). A metered dose inhaler with a new adapter was used during postoperative ventilator treatment. In the IB group the heart rate did not change, but the inspiratory resistance decreased and the arterial oxygen tension increased. This is considered to indicate an effect not only on large but also on small airways, or an improvement of the ventilation/perfusion relationship. The investigation also demonstrated the practical usefulness of the new adapter.     

Effect of antibiotics on Oxalobacter formigenes colonization of human gastrointestinal tract

BACKGROUND AND PURPOSE: Oxalobacter formigenes is a bacterium residing in the human gastrointestinal tract that degrades oxalate and reduces its availability for absorption. This bacterium is assumed to be antibiotic sensitive, and repeated antibiotic therapies could eradicate it. The aim of the present study was to determine the differences in the colonization by O. formigenes of individuals who had been on antibiotics for at least 5 days at the time of sample collection and individuals who had not taken antibiotics for at least 3 months. PATIENTS AND METHODS: Stool samples were collected from 80 individuals without stone disease (35 with and 45 without antibiotic consumption) and 100 patients with stone disease (20 with and 80 without antibiotic consumption). Oxalobacter formigenes was detected by a polymerase chain reaction-based method, and the presence/absence of O. formigenes was correlated with urinary oxalate concentrations. RESULTS: Lower percentages of individuals without stone disease and with stone disease who were consuming antibiotics had O. formigenes colonization than individuals without antibiotic consumption. Urinary oxalate concentrations were higher in the individuals without O. formigenes than in colonized individuals. CONCLUSION: Our observations confirm a direct association between antibiotic consumption and absence of O. formigenes. Absence of intestinal O. formigenes could represent a pathogenic factor in calcium oxalate urolithiasis when antibiotics are prescribed generously.     

细菌生物膜对尿管相关性尿路感染的影响

目的 探讨细菌生物膜对留置尿管相关性尿路感染的影响。方法 对留置尿管不同时间的43例患者，于撤除尿管时行尿液细菌培养，并采用阿利新蓝-刚果红联合染色和扫描电镜观察尿管细菌生物膜形成情况，分析尿管细菌生物膜形成与尿管细菌培养及抗生素应用情况的关系。结果 留置尿管患者尿管细菌生物膜阳性率，3d组为0（0／4），1周组33．3％（4／12），2周组71．4％（10／14），4周组100．0％（13／13）。应用抗生素组60．6％（20／33），未用抗生素组70．0％（7／10），2组差异无统计学意义，P〉0．05。结论 细菌生物膜形成是留置尿管相关性尿路感染的重要致病因素，抗生素预防治疗效果不明显。缩短尿管留置时间，采用封闭式引流等仍是尿路感染主要的防治方法。     

重症监护病房下呼吸道感染或定植嗜麦芽窄食单胞菌患者48例分析

目的分析ICU患者下呼吸道检出嗜麦芽窄食单胞菌的常见因素，探讨嗜麦芽窄食单胞菌的定植、感染及其转归。方法将笔者单位ICU 2004年1月-2005年12月收治的48例痰培养有嗜麦芽窄食单胞菌生长的患者进行定植或感染的初步诊断后，回顾性分析比较其在院内采取的各项措施、病情发展等，并对嗜麦芽窄食单胞菌进行体外药物敏感试验，将敏感药物用于上述48例患者的治疗。结果48例患者中嗜麦芽窄食单胞菌感染者32例、定植者16例。气管插管时间较长、使用碳青霉烯类抗生素或糖皮质激素的时间较长、合并低蛋白血症、急性生理功能和慢性健康状况Ⅱ评分较高（〉15分者占87．5％）均与下呼吸道感染嗜麦芽窄食单胞菌明显相关。与定植者相比，下呼吸道感染嗜麦芽窄食单胞菌易发展为重症肺炎，伴发呼吸功能衰竭（感染者中有84．4％，定植者中有31．3％），且体外敏感的抗菌药物对其临床治疗效果欠佳。嗜麦芽窄食单胞菌主要对新型氟喹诺酮类药物莫西沙星、左氧氟沙星敏感率高，分别为83．3％和75．0％；对常用的第三代头孢菌素及碳青霉烯类抗生素耐药率达80％左右。结论对ICU患者缩短气管插管时间、合理使用抗菌药物、增强机体免疫功能等，有利于防治下呼吸道感染嗜麦芽窄食单胞菌。     

呼吸机管道更换频次对VAP影响的研究进展

综述呼吸机管道更换频次对VAP的影响,从单一角度(呼吸管道污染情况或VAP的发生率)分析呼吸机管道更换频次的利弊。指出在临床实践中,应结合管道污染情况和VAP的发生率综合分析,以寻求最佳的呼吸机管道更换频次。