Methods for evaluating changes in skin condition due to the effects of antimicrobial hand cleansers: two studies comparing a new waterless chlorhexidine gluconate/ethanol-emollient antiseptic preparation with a conventional water-applied product

BACKGROUND

Hand-cleansing products that are milder to the skin of health care personnel are being developed, but the available methodologies to appropriately evaluate these products and quantify differences are not generally being applied in well-controlled studies.

METHODS

Two randomized, blinded, bilateral comparison studies evaluated skin condition during use of 2 antiseptic hand preparation products: a new 1% chlorhexidine gluconate (CHG)/61% wt/wt ethanol antiseptic hand preparation in a unique emollient system for waterless/brushless application and a conventional 4% CHG antimicrobial product that is applied with water and a scrub brush. Trained technicians applied treatments 6 times (for a surgical scrub study) or 24 times (for a personnel handwash study) daily to the hands of healthy volunteers during 5 days of controlled washing. An expert grader evaluated skin for dryness, erythema, and roughness. Subjects completed a self-assessment questionnaire on skin condition. Transepidermal water loss was measured by an evaporimeter, and the skin surface hydration level was measured by an electrical conductance meter.

RESULTS

Fifty-eight subjects were enrolled in the 2 studies and received both treatments. In general, skin treated with the waterless CHG/ethanol product scored significantly (P <.004) better on evaluations of visual dryness and erythema and showed greater improvement in the level of hydration (P <.003). In the health care personnel handwash study, transepidermal water loss was less than that for skin treated with the conventional CHG product (P <.002). Subject assessments showed similar results (total score, P <.007).

CONCLUSIONS

All 3 approaches of expert grader evaluation, subject assessment, and instrumentation were in concordance, demonstrating that the waterless CHG/ethanol product was gentler to skin than the conventional CHG product.

A comparison of peripheral nerve repair using an absorbable tubulization device and conventional suture in primates

Median nerve regeneration was studied in 30 adult primates after repair by microsurgical suture or tubulization with a nonwoven, bioabsorbable, polyglycolic acid device. The two methods were compared electrophysiologically and histologically 6 and 12 months after repair. The electrophysiology included recording of electrically evoked compound action potentials and subsequent determination of threshold, conduction velocity, amplitude, and area above the baseline for each component. Measurements were obtained before nerve transection and at the time of biopsy by stimulating both proximal and distal to the transection site. Analysis of all electrophysiological parameters revealed no statistically significant differences (p less than 0.05) between the two repair techniques. Histopathology included examination of cross sections proximal and distal to the repair sites and longitudinal sections through the coaptation site. End organs (Meissner's and Pacinian corpuscles and muscle) were sectioned to determine the degree of reinnervation. No significant differences between the repair techniques were observed by histological analysis of these sections. These evaluations indicated that the tubulization repair technique produced results comparable to that of the suture technique.

Changes in bacterial flora associated with skin damage on hands of health care personnel

In a prospective observational study of 40 nurses (20 with diagnosed hand irritation and 20 without), nurses with damaged hands did not have higher microbial counts (P = .63), but did have a greater number of colonizing species (means: 3.35 and 2.63, P = .03). Although numbers were small, nurses with damaged hands were significantly more likely to be colonized with Staphylococcus hominis (P = .03). Fifty-nine percent of S hominis isolates from nurses with damaged hands were resistant to methicillin compared with 27% of isolates from those with healthy skin (P = .14). Twenty percent of nurses with damaged hands were colonized with Staphylococcus aureus compared with none of the nurses with normal hands (P = .11). Nurses with damaged hands were also twice as likely to have gram-negative bacteria (P = .20), entercocci (P = .13), and Candida (P = .30) present on the hands. Antimicrobial resistance of the coagulase-negative staphylococcal flora (with the exception of S hominis) did not differ between the 2 groups, nor did a trend toward increasing resistance exist when compared with other studies during the past decade. Skin moisturizers and protectant products were used almost universally by nurses at work, primarily products brought from home. Efforts to improve hand condition are warranted because skin damage can change microbial flora. Such efforts should include assessment or monitoring of hand care practices, formal institutional policy adoption and control of use of skin protectant products or lotions, and prudent use of latex gloves or more widespread use of powder-free and nonlatex products.

Endoscopic carpal tunnel release: a prospective study of complications and surgical experience

A 63-center prospective study of endoscopic carpal tunnel release using the Agee Carpal Tunnel Release System was conducted in 1049 procedures in 988 patients. Prior experience with endoscopic release varied significantly among surgeon participants. Surgeons evaluated the newly redesigned system for blade visibility, blade height, and mechanical function. Data on patient complications were collected at the time of surgery and 3-4 weeks postoperative. The results indicated minimal complications and no confirmed injuries to vessels or nerves; the symptoms from one possible digital nerve injury eventually resolved completely. Surgeons were able to observe the point of entry of the blade into the transverse carpal ligament in 97.5% of procedures. Introduction of the blade assembly into the carpal tunnel was rated easy or adequate in 90.6% of procedures, and blade height was rated adequate in 97.4% of procedures.