Fluorescein dye evaluation of glove integrity

Development of an experimental technique to determine the barrier performance of medical gloves when stretched

Protective clothing standards, such as test methods published by ASTM International, play an integral role in ensuring the performance of personal protective equipment. The standard tests are not without limitations and are periodically reviewed and often updated. Some tests may not be reflective of in-use conditions. A new test cell was designed using sanitary fixtures to evaluate the effect of glove stretch on barrier performance using fluorescein solution as the challenge agent for enhanced visualization and fluorometer detection. Domed-shaped and flat screens were developed to permit and limit glove stretch within the test cell. The barrier performance of glove swatches was evaluated for both stretched and unstretched states. Latex, nitrile, and vinyl glove models of various thicknesses were evaluated. The tests were conducted following pressure and time parameters specified in ASTM F903, ASTM F1670, and ASTM F1671. Fluorescein solution movement, which may occur through penetration, was measured using a fluorometer. Glove stretch caused a reduction in glove thickness ranging from 16% to 40%. Overall, 21 sample failures were found (16.7%; n = 126) regardless of test condition. Nitrile gloves provided better barrier efficacy with the lowest failure rates (2.38%; 1 failure out of 42) compared to latex (19.4%; 7 failures out of 36) and vinyl gloves (27.1%; 13 failures out of 48). Differences in failure rates between stretched and unstretched gloves were insignificant; however, the latex material showed a 2.5 times increase in failures when stretched compared to unstretched. The new test apparatus was able to differentiate between the barrier performance of different glove materials. The use of a domed screen allowed the gloves to stretch, a condition that better represents the state of gloves when in use. Analysis of samples collected from the glove surface opposite to the exposure may provide a way to assess chemical permeation in addition to penetration.

Incidence and risk factors for surgical glove perforation in small animal ophthalmic surgery

OBJECTIVE

To determine the incidence of perforation of surgical gloves and identify associated risk factors that contribute to glove perforation in small animal ophthalmic surgery.

STUDY DESIGN

Observational cohort study.

SAMPLE POPULATION

Surgical gloves (n = 2000) collected following 765 small animal ophthalmic procedures.

METHODS

All the gloves were tested for perforation at the end of the procedure using a water leak test. The potential risk factors for glove perforation were recorded, and associations between these risk factors and perforation were explored using univariable (Fisher's exact test) and mixed effect logistic regression analysis. Results were considered significant if P < .05.

RESULTS

Glove perforation was detected in 6% of procedures. Glove perforation was 1.97 (95% CI: 0.98-4.22) times more likely in extraocular than in intraocular surgeries (7.3% vs 3.9%; P = .0462). The incidence of perforations was not statistically different between main and assistant surgeon (P = .86). No significant association was found between the risk of glove perforation and duration of the procedure (P = .13). Perforation of the nondominant hand was 2.6 (95% CI: 1.38-4.98) times more likely than the dominant hand (74% vs 26%; P = .0028). Only 22% of the perforations were detected intraoperatively. Multivariable analysis identified only extraocular surgery as a risk factor for perforations.

CONCLUSIONS

There is a low incidence of glove perforation in small animal ophthalmic surgery, but extra care of the nondominant hand is required, especially during extraocular procedures.

Perforation rates in double latex gloves and protective effects of outer work gloves in a postmortem examination room: A STROBE-compliant study

Medical staff face the risk of exposure to blood-borne infectious agents during postmortem examinations. This study investigated the effectiveness of non-slip work gloves worn over 2 layers of surgical latex gloves (outer and inner gloves) as a means of reducing hand and finger injuries. Complete sets of outer and inner gloves worn during postmortem examinations were collected from participating forensic staff. Latex gloves were categorized into 2 groups based on the users' actions during the examination: the wearing group if the wearer wore their work gloves continuously without interruption, and the taking-off group if the wearer removed them at least once. Perforation rates, locations, and shapes were compared between these groups. Outer-glove perforation occurred significantly more often in the taking-off group (n = 102 pairs) than in the wearing group (n = 91 pairs) (30.4% vs 3.8%, P < .001). Inner-glove perforation occurred at rates of 2.0% and 0.5% (P = .38), respectively. The wearers did not incur hand or finger injuries. Perforation rates were similar between the dominant and non-dominant hands (P = .18). Regarding location, gloves were punctured most frequently at the thumb, followed by the index finger. Most examiners (85.6%) did not notice the perforation when the damage occurred. Therefore, we could not confirm that a specific operation within a set of plural operations affected the rate of perforation. Additionally, we could not prove a relationship between glove perforation and each operation performed with/without work gloves. The perforation appearances varied greatly in shape and size, suggesting multiple causes of perforation. The continuous (i.e., uninterrupted) wear of work gloves during postmortem examinations reduced the incidence of perforations in both latex glove layers and thus reduced the risk of hand and finger injury.

Puncture resistance and stiffness of nitrile and latex dental examination gloves

OBJECTIVE

The aim of the current study was to assess the puncture resistance and stiffness of nitrile and latex dental examination gloves.

METHODS

Puncture resistance was measured by employing an adapted version of ASTM F1342-91 using both a 316 stainless steel puncture probe (0.8 mm diameter) and a dental injection needle (0.45 mm diameter) interfaced to a tensile testing apparatus. Glove specimens (12 cm length, 1.5 cm breadth) were removed for modulus (M100) evaluation by assessing the force required to elongate the specimen to 100% of the original length. Glove samples were also aged to investigate whether puncture resistance and M100 values varied with aging at 70 degrees C for 7 days in an air-circulating oven.

RESULTS

The nitrile glove types were assessed to have significantly higher puncture resistance compared with the latex glove type when the steel puncture probe was the pentrometer when using the one way analysis of variance (ANOVA) at the 95% significance level. Interestingly the puncture resistance for the latex glove type was significantly higher (P < 0.001) when a dental injection needle was used as the pentrometer compared with the nitrile glove types. The M100 values were significantly higher for the nitrile glove types for which the stiffness increased when the gloves were aged (P < 0.001).

CONCLUSIONS

The higher stiffness values resulted in increased puncture resistance when the nitrile glove specimens were aged irrespective of the pentrometer type. However, the ability of latex to re-seal itself on puncture may be beneficial when considering the protection potential of each glove type against breaches in cross infection. For clinicians that have experienced an adverse reaction to natural latex gloves, the results of the current study indicate that nitrile gloves are available at reasonable cost and offer the clinician comparable resistance to puncture with latex gloves.

A preliminary report on the incidence of pre-existing pinhole defects in nitrile dental gloves

INTRODUCTION

Examination gloves manufactured from natural latex have been the predominant glove choice to date in dental practice. However, concerns over hypersensitivity have resulted in the use of alternatives such as nitrile gloves. The aim of the current study was to assess the incidence of pre-existing pinhole defects in nitrile examination gloves.

METHODS

Air inflation, followed by water submersion, was used to assess the incidence of pre-existing pinhole defects in five nitrile and two latex glove types. The gloves were filled with a constant volume of air and submerged in 3 litres of water for 10 seconds while being observed for air bubbles which would indicate pinhole defects. The position and number of pinholes were noted for 100 gloves of each type investigated.

RESULTS

The incidence of pre-existing pinholes for latex gloves was 0% for the non-sterile surgical latex glove type and 3% for the powdered latex examination glove type, with pinholes located on the thumb, middle finger and ring finger. Of the nitrile gloves evaluated, three types were assessed to have no pre-existing pinhole defects. One type had a 2% incidence of pre-existing pinhole defects--one pinhole located on the thumb region of the glove and one on the ring finger portion of the glove. The fifth nitrile glove type had one pre-existing pinhole defect located on the middle finger.

SIGNIFICANCE

All glove types examined met the European Standard (EN 455-1) and there was no statistically significant difference between glove types. However, the nitrile gloves generally exhibited less pre-existing pinhole defects than the latex examination gloves.

Postoperative integrity of veterinary surgical gloves

A multicenter, prospective study was performed to document the incidence of defective gloves postoperatively in veterinary surgery and to correlate defects with a variety of influencing factors. Gloves were collected after surgical procedures performed by the small animal clinical services at two veterinary teaching hospitals and one institution's student surgery laboratories. Gloves were evaluated for defects using electrical resistance testing. The overall incidence of glove defects was 23.3%. Significantly more defects occurred in gloves used for nonsoft-tissue procedures and in gloves worn on the nondominant hand. Eighty-four percent of all defects occurred in procedures lasting >60 minutes. No differences were detected in the brands of gloves used nor among surgeons of different experience levels. The individuals performing the surgery were not able to accurately predict the presence of a defect in their gloves. Surgeons should remain alert for possible glove defects and consider measures such as changing gloves every 60 minutes or double-gloving to minimize potential complications.

Intraoperative glove perforation--single versus double gloving in protection against skin contamination

Surgeons have the highest risk of contact with patients' blood and body fluids, and breaches in gloving material may expose operating room staff to risk of infections. This prospective randomised study was done to assess the effectiveness of the practice of double gloving compared with single gloving in decreasing finger contamination during surgery. In 66 consecutive surgical procedures studied, preoperative skin abrasions were detected on the hands of 17.4% of the surgeons. In the double gloving pattern, 32 glove perforations were observed, of which 22 were in the outer glove and 10 in the inner glove. Only four outer glove perforations had matching inner glove perforations, thus indicating that in 82% of cases when the outer glove is perforated the inner glove will protect the surgeon's hand from contamination. The presence of visible skin contamination was also higher in perforation with the single gloving pattern (42.1%) than with the double gloving pattern (22.7%). An overwhelming majority of glove perforations (83.3%) went unnoticed. Double gloving was accepted by the majority of surgeons, especially with repeated use. It is recommended that double gloves are used routinely in all surgical procedures in view of the significantly higher protection it provides.

Glove barriers to bacterial cross-contamination between hands to food

Human hands are an important source of microbial contamination of foods. However, published data on the effectiveness of handwashing and glove use in a foodservice setting are limited. Bacterial transfer through foodservice quality gloves was quantified using nalidixic acid-resistant Enterobacter aerogenes (a nonpathogenic surrogate with attachment characteristics similar to Salmonella). Five transfer rates were determined: chicken to bare hand, chicken to hand through gloves, bare hand to lettuce, hand to lettuce through gloves (with low inoculum on hands), and hand to lettuce through gloves (with high inoculum on hands). At least 30 observations were made for each percent transfer rate using 30 individual volunteers. The logarithm of percent transfer data were then fit to distributions: chicken to bare hand, normal (0.71, 0.42); chicken to hand through gloves, gamma (5.91, 0.40, -5.00); bare hand to lettuce, logistic (1.16, 0.30); hand to lettuce through gloves (low inoculum), normal (0.35, 0.88); hand to lettuce through gloves (high inoculum), normal (-2.52, 0.61). A 0.01% transfer was observed from food to hands and from hands to food when subjects wore gloves and a 10% transfer was observed without a glove barrier. These results indicate that gloves are permeable to bacteria although transfer from hands to food through a glove barrier was less than without a glove barrier. Our results indicate that gloves may reduce both bacterial transfer from food to the hands of foodservice workers and in subsequent transfer from hands back to food.

Efficacy of protection by latex gloves during orthodontic therapy

The wearing of gloves during orthodontic or dental treatment is generally indicated for reasons of hygiene and protection against infection. This study was aimed at determining the extent and localization of perforations caused by the various orthodontic treatment techniques and interrupting the infection barrier. The impermeability was tested by means of a water retention test according to European standard EN 455, Part 1, performed on 1600 Centramed (Centramed, Koblenz), Tekmedic and SafeEx non-sterile disposable latex gloves (both by Safe Med, Switzerland) and Safe Gan latex gloves with an additional acrylate coating (also by Safe Med). The perforation rate in unused gloves was between 0.5% and 7.5%, rising on average to 11% with increasing use. 36% of the total number of lesions resulted from handling removable appliances, and 57% from handling fixed appliances, especially when replacing arch wires and elastics. Most lesions were in the thumb, index finger and palm region. Only 18% of the defects were noticed by the dentists themselves. The gloves worn by beginners in their first year of postgraduate orthodontic training had about twice as many defects as those worn by qualified orthodontists. When patients with an increased risk of infection are to be treated, additional hand disinfection measures should be taken and 2 pairs of gloves worn in view of the relatively unreliable protection offered by commercially available latex gloves.

Glove perforation during surgical extraction of wisdom teeth

OBJECTIVE

This study investigated the incidence of sterile surgical glove perforation during hospital-based surgical extractions of wisdom teeth performed with patients under general anesthesia.

STUDY DESIGN

A total of 104 consecutive patients (420 gloves) were studied prospectively. A standardized water inflation technique was used.

RESULTS

The operative perforation rate was 8.6%, or 4.3% per surgeon per operative side. The individual glove perforation rate was 2.1% per operation. Over 55% of perforations were not noticed at the time of surgery. There were no skin-penetrating injuries or visible contamination with body fluids. The perforation rate was the same with drill and chisel.

CONCLUSIONS

The incidence of glove perforation is lower than previously reported. The surgical extraction of wisdom teeth carries a relatively low yet still significant risk with regard to exposure to bloodborne cross-infection. We recommend that high-quality surgical gloves be used and that universal precautions be adhered to.

Loss of glove integrity during emergency department procedures

STUDY OBJECTIVE

We sought to assess the loss of integrity of the latex-glove barrier during use in the ED setting.

METHODS

We conducted a prospective observational study in an urban ED and Level I trauma center. Procedures performed by ED health care workers (HCWs) were directly observed, timed, and categorized. The gloves used by the HCWs were collected and subjected to the standard US Food and Drug Administration leak test.

RESULTS

Ninety-nine (7.9%) of 1,254 pairs of gloves used for observed procedures leaked, compared with 2 of 200 unworn control pairs (1.0%) and 12 of 300 pairs that were worn but not used (4.0%). Leak rates varied by manufacturer and were higher for gloves worn 20 minutes or longer (13.7%, P = .015), used for four or more procedures (50%, P < .01), or used for critical care procedures (23.5%, P < .01). Sixty-six of an additional 325 pairs of gloves collected from unobserved critical care procedures (20.3%) leaked.

CONCLUSION

Loss of glove integrity occurs during the performance of ED procedures, subjecting the HCW to possible infectious-fluid exposure. Risk of glove perforation increases with duration of wear, number of procedures performed, and the performance of critical care procedures.

The permeability of dental gloves following exposure to certain dental materials

OBJECTIVES

This investigation sought to study the permeability of three commonly used clinical gloves when exposed to chemical agents.

METHODS

A total of 35 gloves of each type were selected at random and were assigned to one of seven equally sized treatment groups. The effective barrier properties were investigated following treatment for 15 min with one of: acid etchant, Trim, cavity varnish, Hibiscrub, Hydrex and Vitremer using a dye permeability test. Following the chemical insult a 0.02% solution of erythrosine dye was introduced into each glove and the outer glove surface was washed with 10 ml of distilled water at intervals of 30, 60, 90 and 120 min. The percentage absorption of the collected washings, at 530 nm, was determined using a spectrophotometer. The results were compared with those values obtained from untreated gloves.

RESULTS

Acid etchant and Hydrex had little effect on any of the gloves. Trim caused an increase in permeability of the vinyl gloves but had little or no effect upon those made of latex. Cavity varnish increased the permeability of both Biogel D and Tru-Touch but had no effect on Featherlite. The integrity of the latex gloves was diminished by Hibiscrub but little effect was observed in the case of the vinyl based glove. The permeability of all three gloves was increased by exposure to Vitremer liquid.

CONCLUSIONS

Manufacturers should provide details of potential glove chemical interactions to assist dentists in glove selection.

Structural features of latex gloves in dental practice

The aim of this study was to define from a morpho-structural point of view, using scanning electron microscopy, the features of various types of disposable latex gloves commonly used in Italian dental practice (Biogel D, Trend, Pagni, J&J, Latechnics, Pehasoft, Bantex). None of the brands examined was free from morphological flaws; however, while in some of these only slight depressions were found (Biogel D, Trend), in others (Latechnics, Bantex) there was a marked lack of homogeneity in the latex structure or real holes (Pehasoft). This study emphasizes the current difficulties faced by dentists in the search for safe working conditions.

Use of a latex cover sheath for transesophageal echocardiography (TEE) instead of regular disinfection of the echoscope?

Better visualization of cardiac structures is an advantage of transesophageal echocardiography (TEE). Because of this, the transesophageal approach is an essential window in the assessment of various cardiovascular disorders. Quick consecutive access to this instrument should not be delayed by time-consuming cleansing procedures of the probe. In this study we used a sterile latex condom in routine TEE examinations as a barrier to contamination of the echoscope, observing practical use and the incidence of perforations. Defects were detected after the procedure by visual inspection and by an airtightness test. Maneuvers or situations associated with an increased likelihood of injury were checked for. In 180 studies a total of 168 patients were consecutively examined; insertion was feasible in all but one case (99.5%). We found 8 of 181 (4.4%) sheaths defective following the procedure. Visual inspection was less sensitive (only 3 of 8) for finding defects than an airtightness test (8 times). Teeth in situ and/or a bite guard are the only sharp edges during insertion and removing the probe; these seem to be the main risk factors in latex perforation. Application of a cover sheath for each examination saves approximately two-thirds of the time otherwise necessary for a cleansing bath, and easy handling of cover sheaths for TEE make them an alternative to regular disinfection in general. For reasons of safety we recommend checking each used cover sheath after examination for holes so as not to jeopardize the following patient by the possible spread of germs from contaminated probes. Not only visual inspection but also a second method, for example, an airtightness test, is mandatory.

Australian Dental Research Fund Trebitsch Scholarship. An assessment of the permeability of dental protective gloves

Several overseas studies have documented the presence of defects in unused latex and vinyl gloves. Since such defects compromise the barrier protection afforded by gloves, information regarding the frequency and site of defects which occur during manufacture is of direct clinical relevance. This study utilized a four-stage testing procedure to evaluate defects in 13 brands of gloves which are used commonly in dental practice in Australia. Macropores in unused gloves were a significant problem, with 10 brands containing 1 per cent or more defective gloves. In addition, variations in electrical conducitivity, signifying microporosity or inconsistencies in thickness, were also observed. These findings indicate that there is room to improve further the quality of protective gloves.

Effectiveness of handwashing agents in eliminating Staphylococcus aureus from gloved hands

The recent emphasis on gloving has resulted in accounts of healthcare workers washing gloves instead of changing them. This study evaluated the efficacy of soap and three germicidal agents in decontaminating latex and vinyl medical gloves that were experimentally contaminated with Staphylococcus aureus. Gloves were tested for perforations before and after the glove-washing procedure. Results of this study demonstrated that contamination was reduced from the glove surfaces. Although the routine washing of gloved hands cannot be recommended, it may be carried out under limited circumstances.

Use of non-sterile gloves in clinical practice

This paper reviews the use of non-sterile gloves in dental practice. It is now considered to be normal practice to wear gloves for all dental procedures and although there is considerable controversy regarding patterns of glove use, there is increasing evidence to the effect that single patient use is indicated. Careful use of gloves and proper hand care are key components to effective cross-infection control in clinical practice.

Blood exposure in single versus double gloving during pelvic surgery

In light of continued reports suggesting the inadequacy of surgical gloves as sterile barriers, as well as an increasing number of reports describing intraoperative cross infections, a prospective study was performed comparing the presence of visible blood on the hands of surgeons wearing single or double gloves during 45 consecutive major obstetric and gynecologic operations. Single-gloved hands revealed the presence of visible blood in 38% of cases (n = 42) whereas visible blood was noted in only 2% of double-gloved hands (n = 48) (p less than 0.001). These results demonstrate that the sterile barrier between surgeon and patient was compromised intraoperatively and that particles the size of red blood cells were able to cross this barrier. In addition, these data suggest single gloving may be less than optimal in maintaining a sterile barrier, as well as strongly suggesting that double gloving can improve the integrity of the patient-surgeon sterile barrier during pelvic surgery.