Bajaj Tarun Inder, Loh Cecilia, Borgstrom David
Department of Surgery, Bassett Medical Center , Cooperstown, New York.
Surg Infect (Larchmt). 2014 Oct;15(5):544-7. doi: 10.1089/sur.2012.120. Epub 2014 May 21.
Two percent chlorhexidine gluconate (CHG) is used in preparing the skin of surgical patients. In practice, it often is diluted with saline prior to use. Whether this affects efficacy is unknown, as the manufacturer does not address dilution but does recommend scrubbing twice. We attempted to determine whether diluting CHG affects its antiseptic potency and if one scrub is as effective as two.
To test effects of CHG dilution, 60 healthy subjects were recruited and randomized into a dilution group (20%, 40%, 60%, 80%, or 100% CHG) or a control group (saline). One area of one foot of each subject was prepared, and colony-forming units (CFU) were counted at baseline and at 10 min after preparation. In a second study, 60 subjects were again recruited. Based on the previous study, a 50% dilution was applied as the scrub. Colony-forming units were calculated at baseline and after each CHG application.
Baseline CFU did not differ among the dilution groups (p=0.49). Subjects in all dilution groups exhibited nearly a 100% decrease in CFU, whereas the control group exhibited an 80% decrease. These results were statistically significant (p<0.01). In the second study, the CFU values after two scrubs (mean 0.1; range 0-3) were significantly lower than after one scrub (mean 3.6, range 0-100) (p=0.02).
Diluting CHG to a concentration as low as 0.4% does not affect antiseptic efficacy. The manufacturer-recommended two scrubs is superior to one scrub at reducing skin bacterial colony counts.
2%葡萄糖酸氯己定（CHG）用于外科手术患者皮肤的准备。在实际操作中，使用前常常用生理盐水稀释。由于制造商未提及稀释问题，但建议擦洗两次，所以这种稀释是否会影响其疗效尚不清楚。我们试图确定稀释CHG是否会影响其抗菌效力，以及一次擦洗是否与两次擦洗效果相同。
为测试CHG稀释的效果，招募了60名健康受试者，并随机分为稀释组（20%、40%、60%、80%或100%CHG）或对照组（生理盐水）。准备每位受试者一只脚的一个区域，在基线时和准备后10分钟计数菌落形成单位（CFU）。在第二项研究中，再次招募了60名受试者。根据之前的研究，采用50%稀释液进行擦洗。在基线时以及每次使用CHG后计算菌落形成单位。
各稀释组的基线CFU无差异（p = 0.49）。所有稀释组的受试者CFU均下降了近100%，而对照组下降了80%。这些结果具有统计学意义（p < 0.01）。在第二项研究中，两次擦洗后的CFU值（平均0.1；范围0 - 3）显著低于一次擦洗后（平均3.6，范围0 - 100）（p = 0.02）。
将CHG稀释至低至0.4%的浓度不会影响抗菌效果。制造商推荐的两次擦洗在减少皮肤细菌菌落计数方面优于一次擦洗。
