关于负压隔离病房可以使用循环风的讨论——国标《医院洁净护理与隔离单元技术标准》编制组系列探讨问题之二
Discussion on using of recirculating air in negative pressure isolation ward: Part 2 of the series of research practice of national standard Technical code on clean nursing and isolation unit
摘要：
认为用全新风不是负压隔离病房的必要条件，一些国外标准也指明有高效过滤器时，可以使用回风。排风采用国产C类高效过滤器且保证边框无泄漏时，滤菌效率达99.999 997%。病人一个喷嚏最多产生30万个/min菌粒，对于12 h-1换气的病房，1 h打5个喷嚏，采用循环风时平均有0.34×10-4个/L微粒送入室内，和病人所在氛围中菌浓相比可视为0，故可使用循环风。从国外几个标准看，只要通过高效过滤器，允许使用室内自循环风。
Abstract：
It is considered that the full outdoor air system is unnecessary in negative pressure isolation ward, while some foreign standards also support that the recirculating air is utilizable when there are high efficiency particulate air (HEPA) filters. Taking class C HEPA filter for example (bacteria filtration efficiency reaches 99.999 997%), if a sneeze produces up to 300 000 bacterial particles per minute and a patient sneezes five times per hour in the ward with air exchange rate of 12 h-1, there are 0.34×10-4 particles/L being transferred to the room when using recirculating air. However, compared with the concentration of bacteria in the patients environment, it can be neglected. In addition, according to several foreign standards, the indoor recirculating air is also allowed after it passes through high efficiency filters.
Keywords:negativepressureisolationward,highefficiencyparticulateair(HEPA)filter,recirculatingair,fulloutdoorair,totalexhaustair