All specimens were collected using a sterile specimen collection and transport system (BD ESwab system; BD). The swab, which was premoistened in the contained sterile solution included in its packaging, was swiped 10 strokes over a 3-cm × 3-cm region on the right or left side of the posterior aspect of each participant’s neck. All samples were sent immediately after acquisition to the microbiology laboratory for expedient analysis. The microbiologist who performed the plating and evaluation of samples was blinded to the experimental or control nature of each specimen.
Data collected on the study participants included age, sex, and compliance with cleansing protocol (ie, wiped once, twice, or not at all). As noted, power analysis was performed before the start of the trial to ensure adequate power to determine equivalence between the use or nonuse of the CHG wipes. Equivalence between was defined as an absolute difference of zero or one bacterial colony per sample, with each sample at a given time point consisting of 1 mL. A paired Student t-test with α = 0.05 indicated that for the study to achieve 83% power, 16 participants were required, with the contralateral side of each participant’s neck serving as the control site for that participant. Matched-paired Student t-testing was used to determine statistical significance.
Seventeen participants initially consented and were enrolled in the study; however, one participant withdrew before any intervention because of subsequent awareness of an allergy to an ingredient in CHG wipes. Sixteen healthy participants underwent the study protocol and were analyzed. The cohort’s mean age was 37 years. The study population included 10 men and 6 women. All participants reported full adherence to the protocol for self-administration of the CHG wipes at home. All participants were found to have bacterial growth on both the right and left sides of the neck in baseline sampling (median >1,000 colonies/mL on each side).
We then compared these baseline samples (R1 and L1) with samples obtained after CHG wipes were used on the right side (R2) and no intervention was performed on the left side (L2). Thirteen participants had no bacterial growth on the right side of their necks, where they had used CHG, whereas only six participants had no bacterial growth on the control side. The bacterial burdens were reported as the number of colonies per milliliter (Table 1). The mean decrease in bacterial counts from L1 to L2 (control side) was 536 colonies, and the mean decrease from R1 to R2 (interventional side) was 790 colonies; however, this difference between the two sides was not statistically significant (P = 0.059). Five minutes after the surgical scrub was performed on both sides, all patients had zero bacteria isolated from each side of the neck (R3 and L3).
Subjective speciation performed by the lead microbiology director at our institution (S.W.) showed that all patients had coagulase-negative Staphylococcus on both the right and left sides of their necks at the initial time point (R1 and L1). Micrococcus was the second most common species isolated. At the second time point, coagulase-negative Staphylococcus species and Micrococcus were the most common other colonies isolated. A single sample contained gram-negative rods. One plate contained bacillus (Table 2).
Because we noted that some of the L2 samples showed no bacterial growth, we performed a follow-up trial of three control participants to see if these findings could have been attributable to the CHG wipe having been mistakenly used not only on the right side, but partially on the left side of the neck, as well. These participants were sampled at baseline (sample 1) and again the following day (sample 2), without any use of CHG wipes. Then, the necks of these participants were surgically prepared with the standard alcohol and chlorhexidine regimen, allowed to fully dry for 5 minutes, and sampled again (sample 3). All three samples had positive bacterial growth at the first and second sampling time points, and negative growth at the third.
To our knowledge, no prior study has definitively evaluated the effects of preoperative skin cleansing on the cutaneous bacterial burden before spine surgery. Although some studies have examined the potential efficacy of cleansing at home before surgery, multiple studies have demonstrated geographic variation in skin bacterial flora and colony counts.8-13,23,24 We therefore decided to look at the value of preoperative cleansing in posterior cervical spine surgery, where rates of infection as high as 17% or 18% have been reported in the literature.25 Surgeons use numerous methods to decrease the risk of infection in patients perioperatively. Validating the efficacy of these methods will allow the design of optimal protocols that contribute to improved outcomes without undue physical or financial burden on patients.
Our study showed no added benefit of using CHG wipes at home before the standard surgical scrub. Home CHG wipes are used with the goal of decreasing SSI rates. The mechanism through which infection rates are thought to be reduced is by decreasing cutaneous bacterial loads. However, our study showed that the use of CHG wipes at home did not decrease the ultimate bacterial burden on the skin after a surgical scrub, compared with control sites that underwent the standard surgical cleansing without home use of CHG wipes. Therefore, one can deduce that CHG wipes do not play a clear role in reducing rates of SSI.
We did observe decreased bacterial counts before the surgical scrub in the regions where the wipes were used, compared with those where the wipes were not used, but the finding was not statistically significant. Furthermore, even though several studies have examined bacterial counts at this stage as their ultimate point of analysis, bacterial burdens at this time are clinically meaningless because the skin has yet to be cleansed thoroughly with standard preparation in the operating room, and thus the bacterial count at this time point does not represent the bacterial count on the skin at the time of incision. We noticed that some participants had no bacterial growth even on the side of the neck that they did not wipe. It is unlikely that they had gathered no bacteria since the time of their shower the previous night. A more likely reason is that they had mistakenly partially wiped the left side of their neck in addition to applying the wipes to the right side of their neck. Our follow-up control trial of three participants supports this claim: When these participants did not use CHG wipes at all, all samples obtained before the surgical scrub were found to be heavily colonized (and after the scrub, all had no bacterial colonization).
Several trials have examined the effects of preoperative cleansing with chlorhexidine with mixed results. Murray et al26 performed a prospective, randomized study examining the effect of CHG cloth treatment at home preoperatively. This industry-sponsored investigation concluded that this cleansing led to decreased bacterial presence preoperatively. However, they reported only the results of samples obtained in the preoperative holding area. Arguably, the bacterial burden after preoperative preparation is of more relevance. Accordingly, a more targeted investigation would be required to determine whether the level equalizes in both groups after a formal scrubbing process because no surgeon routinely operates without a scrub. Murray et al26 also reported a significant increase in side effects (defined as mild itching or dry skin) associated with the chlorhexidine group, compared with the control group (24% versus zero, P < 0.0002). Other studies in plastic surgery have analyzed skin colonization after the use of wipes but before preoperative skin cleansing.27,28 These studies also show decreased bacterial colony counts with no reported differences in SSIs.
Ng et al29 prospectively studied the effect of CHG foot washes on patients before foot and ankle surgery and found reductions in the bacterial burden after washing. They analyzed bacterial flora qualitatively rather than quantitatively, reporting only culture positivity rather than bacterial colony counts. They stated that CHG decreased flora intraoperatively; however, their so-called intraoperative sample was obtained after washing and before the surgical preparation and drape. This sample would be more precisely labeled a preoperative sample. It was obtained approximately 20 minutes after washing, so the decreased bacterial burden in this sample is not surprising. They noted a reduction in bacteria postoperatively in the CHG footbath group; however, this finding was not statistically significant. Further, their methodology included preoperative povidone-iodine skin preparation for all patients. In the foot and ankle literature, Keblish et al11 suggested that chlorhexidine and alcohol preparation is more effective than povidone-iodine preparation. Therefore, preoperative CHG washing in the study by Ng et al29 may have equalized the postoperative results between the groups even further. Additionally, neither researchers nor patients were blinded in that study, which could potentially bias the results.
Arthroplasty literature from a single institution has suggested that infection rates are decreased after preoperative home CHG cleansing.30,31 The cohort data were prospectively collected in a nonrandomized manner. Patient grouping was dependent on compliance with the CHG protocol. All patients were told to do CHG preoperative cleansing. Those who were compliant were placed in the intervention group, whereas the noncompliant patients were placed in the control group. Potential confounding can be seen in the significantly higher numbers of patients who smoked and had coronary artery disease in the control group, compared with the intervention group (P < 0.0001, P < 0.0001). Moreover, the control group also had a higher average body mass index. Assigning patients to groups by their ability to comply with a preoperative protocol may potentially raise larger issues of overall patient compliance. Because of the significantly higher rates of comorbidities in the control group, these factors could likely have contributed to their relatively worse outcomes. Based on these outcomes and theoretic assumptions, economic data would suggest that home CHG cleansing is effective.7,32 However, other economic models based on findings of similar SSI rates regardless of preadmission CHG use suggest the opposing view.33 These evaluations cannot be substantiated without more reliable data as inputs into the economic model.
Daily inpatient decontamination regimens have also been examined in large inpatient populations. Bode et al34 enrolled Staphylococcus aureus carriers across a variety of inpatient medicine and surgical wards from 2005 to 2007 in a randomized controlled trial (RCT) to assess the benefit of repetitive nasal mupirocin administration and CHG skin cleansing. They concluded that the decolonization protocols reduced S aureus infections among inpatients.34 A similar finding was reported in a study analyzing daily bathing of patients in intensive care units.35 These findings suggest that peri-incisional decolonization protocols—not before the routine cleansing that occurs in the operating room, but instead postoperatively, before the wound has healed—could possibly be beneficial for hospitalized surgical patients.
Rotter et al17 reached opposing conclusions, stating that preoperative chlorhexidine bathing did not decrease bacterial burdens or the rate of SSI. They performed a prospective randomized double-blinded, multicenter trial of 2,813 patients across multiple European countries. They reported similar rates of SSI at 21 days and found no difference in culture data between the patients who bathed twice preoperatively with a specific detergent that included chlorhexidine and the patients who used the detergent without it. These patients were from several surgical specialties, including general surgery, orthopaedic surgery, and vascular surgery. The authors of the study acknowledged that these specialties had varying infection rates, with some procedures in the trial having four times the infection rates of others. Wound infections were noted by a nurse or surgeon in the hospital. The authors stated that an attempt was made to contact each patient up to 21 days postoperatively, which may be insufficient to track infections comprehensively in joint arthroplasty and spine surgery patients. In addition, of the 70 infections they encountered, only 25 had bacterial culture results, which provides insufficient power to detect differences in bacterial results. These results were qualitative, not quantitative, and the methods of microbiologic sampling and processing were not standardized across sites. Furthermore, the use of antibiotic and infection prophylaxis varied. Only 12% of patients in the trial received preoperative antibiotics, which may have confounded the results. Two other meta-analyses, including a recent Cochrane review, have not been able to show a definitive benefit of preoperative CHG cleansing at home.36,37 The Cochrane meta-analysis reviewed 7 RCTs, whereas the other meta-analysis reviewed 16 trials, of which 8 were RCTs.36
Our study has limitations. We analyzed bacterial counts and culture results as our primary outcomes, rather than analyzing rates of SSI. The proposed mechanism of action of CHG wipes is through cutaneous bacterial reduction, rather than systemic therapy. If CHG wipes do not decrease the bacterial burden, one can logically infer that the use of these wipes cannot directly lead to a decrease in SSIs. Although we had a relatively small sample size, the study was adequately powered to determine statistical equivalence between groups. The decreased bacterial count in the control region before the surgical scrub, compared with the baseline count in that region, was likely attributable to mistaken partial wiping of that side of the neck. Measurement at this time point was not clinically relevant, and the final bacterial counts all ultimately decreased to zero regardless of whether the preoperative home cleansing occurred. Our prospective, case-controlled cohort design allowed for a feasible and efficient way to compare bacterial burdens after an intervention. However, prospective RCTs of patients undergoing spine surgery, rather than healthy volunteers, will be needed to validate these findings.
The main purpose of this study was to assess bacterial growth after drying of the alcohol and chlorhexidine preparation that would be used immediately before skin incision. All samples at this time point exhibited zero bacterial growth, supporting the conclusion that CHG wipe use at home adds no additional benefit to the standard procedure.
There is a paucity of level I data supporting the efficacy of preadmission chlorhexidine cleansing despite its widespread use. Even if preadmission chlorhexidine cleansing decreases the cutaneous bacterial burden, patients become contaminated with a plethora of bacteria en route to the sterile operating room. This contamination occurs in the patients’ homes, in transportation vehicles, and even in preoperative holding areas. One could argue that the financial cost of using chlorhexidine wipes at home is minimal and that their use has few negatives. However, if a regimen, no matter how inexpensive, does not add a scientifically proven benefit, one cannot easily argue for its widespread use. Surgeons often use techniques based on personal preference or dogma rather than scientific evidence. Evidence has disproven the benefits of several trends, such as soap irrigation, high-pressure irrigation, urgent surgical débridement of open fractures within 6 hours, and even widespread home use of antibacterial soap.38-40 This study reinforces the concept that thorough skin preparation, consisting of cleansing with alcohol followed by two sequential cleansings with chlorhexidine paint solution, allowed to dry at least 1 minute between applications, is essential in decreasing the bacterial load and minimizing infection rates after posterior cervical surgery.3 Continued attention to the efficacy of interventions is warranted to focus efforts on the truly beneficial strategies.
Supplemental home chlorhexidine use is not without long-term population-based risk. Chlorhexidine currently has tremendous bactericidal capability (as does mupirocin for nasal mucosa S aureus). With its increasingly widespread use in the community setting, consideration should be paid toward minimizing the risk of bacterial resistance.34
Because of the morbidity, mortality, and cost of SSIs, continued efforts must be focused on optimizing protocols to decrease the risk of infection. We have shown that although skin cleansing may decrease the bacterial burden preoperatively, this effect becomes irrelevant after the chlorhexidine preparation is performed in the operating room. Therefore, the use of CHG wipes at home may not offer any additional benefit over the current standard preoperative surgical scrub. Patients and physicians could focus on the methods that have been shown to decrease bacterial counts and SSIs, without the need to expend time and resources to have patients perform preoperative skin cleansing at home.
Evidence-based Medicine: Levels of evidence are described in the table of contents. In this article, references 6, 14, 15, and 38 are level I studies. Reference 8 is a level II study. References 4 and 22 are level III studies. References 2, 3, and 32 are level IV studies. References 1 and 40 are level V expert opinion.
References printed in bold type are those published within the past 5 years.
1. Vitale MG, Riedel MD, Glotzbecker MP, et al.: Building consensus: Development of a Best Practice Guideline (BPG) for surgical site infection
) prevention in high-risk pediatric spine surgery. J Pediatr Orthop 2013;33(5):471-478.23752142
2. Savage JW, Anderson PA: An update on modifiable factors to reduce the risk of surgical site infections. Spine J 2013;13(9):1017-1029.23711958
3. Pahys JM, Pahys JR, Cho SK, et al.: Methods to decrease postoperative infections following posterior cervical
spine surgery. J Bone Joint Surg Am 2013;95(6):549-554.23515990
4. Glotzbecker MP, Riedel MD, Vitale MG, et al.: What’s the evidence? Systematic literature review of risk factors and preventive strategies for surgical site infection
following pediatric spine surgery. J Pediatr Orthop 2013;33(5):479-487.23752143
5. Byrne DJ, Phillips G, Napier A, Cuschieri A: The effect of whole body disinfection on intraoperative wound contamination. J Hosp Infect 1991;18(2):145-148.1678760
6. Zdeblick TA, Lederman MM, Jacobs MR, Marcus RE: Preoperative use of povidone-iodine: A prospective, randomized study. Clin Orthop Relat Res 1986;213:211-215.3536248
7. Bailey RR, Stuckey DR, Norman BA, et al.: Economic value of dispensing home-based preoperative chlorhexidine
bathing cloths to prevent surgical site infection
. Infect Control Hosp Epidemiol 2011;32(5):465-471.21515977
8. Graling PR, Vasaly FW: Effectiveness of 2% CHG cloth bathing for reducing surgical site infections. AORN J 2013;97(5):547-551.23622827
9. Dixon JM, Carver RL: Daily chlorohexidine gluconate bathing with impregnated cloths results in statistically significant reduction in central line-associated bloodstream infections. Am J Infect Control 2010;38(10):817-821.21093698
10. Bleasdale SC, Trick WE, Gonzalez IM, Lyles RD, Hayden MK, Weinstein RA: Effectiveness of chlorhexidine
bathing to reduce catheter-associated bloodstream infections in medical intensive care unit patients. Arch Intern Med 2007;167(19):2073-2079.17954801
11. Keblish DJ, Zurakowski D, Wilson MG, Chiodo CP: Preoperative skin preparation of the foot and ankle: Bristles and alcohol are better. J Bone Joint Surg Am 2005;87(5):986-992.15866960
12. Tanner J, Gould D, Jenkins P, Hilliam R, Mistry N, Walsh S: A fresh look at preoperative body washing. J Infect Prev 2012;13(1):11-15.22448182
13. Bergman BR, Seeberg S: A bacteriological evaluation of a programme for preoperative total body-washing with chlorhexidine
gluconate performed by patients undergoing orthopaedic surgery. Arch Orthop Trauma Surg 1979;94(1):59-62.485793
14. Edmiston CE Jr, Lee CJ, Krepel CJ, et al.: Evidence for a standardized preadmission showering regimen to achieve maximal antiseptic skin surface concentrations of chlorhexidine
gluconate, 4%, in surgical patients. JAMA Surg 2015;150(11):1027-1033.26308490
15. Edmiston CE Jr, Krepel CJ, Edmiston SE, et al.: Empowering the surgical patient: A randomized, prospective analysis of an innovative strategy for improving patient compliance with preadmission showering protocol. J Am Coll Surg 2014;219(2):256-264.24880956
16. Edmiston CE Jr, Krepel CJ, Seabrook GR, Lewis BD, Brown KR, Towne JB: Preoperative shower revisited: Can high topical antiseptic levels be achieved on the skin surface before surgical admission? J Am Coll Surg 2008;207(2):233-239.18656052
17. Rotter ML, Larsen SO, Cooke EM, et al.; The European Working Party on Control of Hospital Infections: A comparison of the effects of preoperative whole-body bathing with detergent alone and with detergent containing chlorhexidine
gluconate on the frequency of wound infections after clean surgery. J Hosp Infect 1988;11(4):310-320.2899582
18. Eiselt D: Presurgical skin preparation with a novel 2% chlorhexidine
gluconate cloth reduces rates of surgical site infection
in orthopaedic surgical patients. Orthop Nurs 2009;28(3):141-145.19494763
19. Leigh DA, Stronge JL, Marriner J, Sedgwick J: Total body bathing with ‘Hibiscrub’ (chlorhexidine
) in surgical patients: A controlled trial. J Hosp Infect 1983;4(3):229-235.6195235
20. Ayliffe GA, Noy MF, Babb JR, Davies JG, Jackson J: A comparison of pre-operative bathing with chlorhexidine
-detergent and non-medicated soap in the prevention of wound infection. J Hosp Infect 1983;4(3):237-244.6195236
21. Garibaldi RA, Skolnick D, Lerer T, et al.: The impact of preoperative skin disinfection on preventing intraoperative wound contamination. Infect Control Hosp Epidemiol 1988;9(3):109-113.3351267
22. Bebko SP, Green DM, Awad SS: Effect of a preoperative decontamination protocol on surgical site infections in patients undergoing elective orthopedic surgery with hardware implantation. JAMA Surg 2015;150(5):390-395.25738898
23. Montes LF, Wilborn WH: Anatomical location of normal skin flora. Arch Dermatol 1970;101(2):145-159.5413252
24. Bibel DJ, Lovell DJ: Skin flora maps: A tool in the study of cutaneous ecology. J Invest Dermatol 1976;67(2):265-269.950492
25. Barnes M, Liew S: The incidence of infection after posterior cervical
spine surgery: A 10 year review. Global Spine J 2012;2(1):3-6.24353939
26. Murray MR, Saltzman MD, Gryzlo SM, Terry MA, Woodward CC, Nuber GW: Efficacy of preoperative home use of 2% chlorhexidine
gluconate cloth before shoulder surgery. J Shoulder Elbow Surg 2011;20(6):928-933.21612945
27. Veiga DF, Damasceno CA, Veiga Filho J, et al.: Influence of povidone-iodine preoperative showers on skin colonization in elective plastic surgery procedures. Plast Reconstr Surg 2008;121(1):115-118, discussion 119-120.18176213
28. Veiga DF, Damasceno CA, Veiga-Filho J, et al.: Randomized controlled trial of the effectiveness of chlorhexidine
showers before elective plastic surgical procedures. Infect Control Hosp Epidemiol 2009;30(1):77-79.19046051
29. Ng AB, Adeyemo FO, Samarji R: Preoperative footbaths reduce bacterial colonization of the foot. Foot Ankle Int 2009;30(9):860-864.19755070
30. Johnson AJ, Daley JA, Zywiel MG, Delanois RE, Mont MA: Preoperative chlorhexidine
preparation and the incidence of surgical site infections after hip arthroplasty. J Arthroplasty 2010;25(6 suppl):98-102.20570089
31. Zywiel MG, Daley JA, Delanois RE, Naziri Q, Johnson AJ, Mont MA: Advance pre-operative chlorhexidine
reduces the incidence of surgical site infections in knee arthroplasty. Int Orthop 2011;35(7):1001-1006.20563806
32. Kapadia BH, Johnson AJ, Issa K, Mont MA: Economic evaluation of chlorhexidine
cloths on healthcare costs due to surgical site infections following total knee arthroplasty. J Arthroplasty 2013;28(7):1061-1065.23540539
33. Lynch W, Davey PG, Malek M, Byrne DJ, Napier A: Cost-effectiveness analysis of the use of chlorhexidine
detergent in preoperative whole-body disinfection in wound infection prophylaxis. J Hosp Infect 1992;21(3):179-191.1353510
34. Bode LG, Kluytmans JA, Wertheim HF, et al.: Preventing surgical-site infections in nasal carriers of Staphylococcus aureus
. N Engl J Med 2010;362(1):9-17.20054045
35. Climo MW, Sepkowitz KA, Zuccotti G, et al.: The effect of daily bathing with chlorhexidine
on the acquisition of methicillin-resistant Staphylococcus aureus
, vancomycin-resistant Enterococcus
, and healthcare-associated bloodstream infections: Results of a quasi-experimental multicenter trial. Crit Care Med 2009;37(6):1858-1865.19384220
36. Webster J, Osborne S: Preoperative bathing or showering with skin antiseptics to prevent surgical site infection
. Cochrane Database Syst Rev 2007;2:CD004985.17443562
37. Chlebicki MP, Safdar N, O’Horo JC, Maki DG: Preoperative chlorhexidine
shower or bath for prevention of surgical site infection
: A meta-analysis. Am J Infect Control 2013;41(2):167-173.22722008
38. Bhandari M, Jeray KJ, Petrisor BA, et al.; FLOW Investigators: A trial of wound irrigation in the initial management of open fracture wounds. N Engl J Med 2015;373(27):2629-2641.26448371
39. Schenker ML, Yannascoli S, Baldwin KD, Ahn J, Mehta S: Does timing to operative debridement affect infectious complications in open long-bone fractures? A systematic review. J Bone Joint Surg Am 2012;94(12):1057-1064.22572980
Keywords:© 2017 The Author(s). Published by Wolters Kluwer Health, Inc., on behalf of the American Academy of Orthopaedic Surgeons.
cervical; chlorhexidine; surgical site infection; SSI