呼吸机管道中冷凝水感染时段及常见感染菌分析

Infection Period and Common Bacteria in the Condensate Water in Ventilator Circuits

背景呼吸机的普遍使用导致呼吸机管道的感染率越来越高。冷凝水作为呼吸机管道中最易发生感染的部位不容忽视。目的监测呼吸机管道中冷凝水最易发生感染的时间段及菌群,为冷凝水的管理和临床合理用药提供科学依据。方法选择2014年3月—2014年7月入住锦州市中心医院ICU使用呼吸机时间大于24 h的30例患者,在患者上机后的12、18、24 h时3个时间点分别采集呼吸机管道中的冷凝水进行细菌培养及种类鉴定。结果冷凝水在上机后12、18、24 h时3个时间点细菌感染率分别为13.3%（4例）、93.3%（28例）、100.0%（30例）,3个时间点细菌培养结果比较,差异有统计学意义（χ^2=65.11,P〈0.01）。其中18、24 h时感染率均明显高于12 h时（χ^2=38.57、45.88,P〈0.01）,18 h和24 h时感染率间差异无统计学意义（χ^2=2.07,P〉0.05）。在送检的90例次冷凝水标本中62例次发生感染,共检测出156株病原菌,其中革兰阴性菌占首位（65.4%,102株）,其次为革兰阳性菌（24.4%,38株）,最后是真菌（10.2%,16株）。结论上呼吸机后12-18 h是呼吸机管道中冷凝水最易发生感染的时间段,为了减少感染,护理人员应该在12 h内及时倾倒冷凝水,最迟不超过18 h。临床上应针对感染菌种类合理用药,防止耐药。

Background The rate of bacterial infection caused by the condensate water in ventilator circuits is rising with the common use of mechanical ventilators. Condensate water should not be ignored as the part where bacterial infection is most likely to occur. Objective To investigate the time range when infection was most likely to occur and the common bacteria strains in the condensate water in ventilator circuits. Methods We enrolled 30 patients who were admitted into the ICU of Jinzhou Central Hospital and received mechanical ventilation of more than 24 hours from March 2014 to July 2014. The condensate water in the ventilator circuits was sampled at 12 hours,18 hour and 24 hours after the ventilation began,and the bacteria were cultured and identified. Results The rates of bacterial infection at 12 h,18 h,and 24 h were 13. 3% （4 cases）,93. 3% （28 cases）and 100. 0% （30 cases）,and there were significant differences among the results at the three points（χ2 = 65. 11,P 〈 0. 01）. The infection rates at 18 h and 24 h were significantly higher than 12 h（χ2 = 38. 57,45. 88;P〈0. 01）,while there was no significant difference between 18 h and 24 h（ χ2 = 2. 07,P 〉 0. 05）. Among 90 samples, bacterial infection was found in 62 samples,out of which a total of 156 bacteria strains were identified,with gram - negative bacteria as the primary strain（65. 4% ,102 bacteria strains）,gram - positive bacteria as the secondary strain（24. 4% ,38 bacteria strains）and fungus the third（10. 2% ,16 bacteria strains）. Conclusion Baterial infection in the condensate water of ventilator circuits is most likely to occur between 12 h and 18 h after the ventilation begins. In order to reduce infection,nursing staff should pour out the condensate water before 12 h and no later than 18 h. Rational regimens should be chosen according to the specific bacteria strains.