Complete history and guide to choosing surgical gloves

The evolution of protective operating room attire paralleled the development of aseptic techniques in the latter half of the 19th century. Rubber surgical gloves were introduced not to protect the patient, but to protect the wearer's hands from the harsh, irritating antiseptic solutions and soaks of the 1870s and 1880s. In the late 1890s, Dr. William Halsted, chief of surgery at Johns Hopkins, popularized the use of gloves to protect patients from the bacteria present on ungloved hands. Disposable latex gloves, which were first introduced around 1958, were a welcome innovation that saved countless hours of daily glove reprocessing, repairing and sterilizing. Today, the universal use of disposable medical gloves is well established.

The evolution of protective operating room attire paralleled the development of aseptic techniques in the latter half of the 19th century. Rubber surgical gloves were introduced not to protect the patient, but to protect the wearer's hands from the harsh, irritating antiseptic solutions and soaks of the 1870s and 1880s. In the late 1890s, Dr. William Halsted, chief of surgery at Johns Hopkins, popularized the use of gloves to protect patients from the bacteria present on ungloved hands.¹ Disposable latex gloves, which were first introduced around 1958, were a welcome innovation that saved countless hours of daily glove reprocessing, repairing and sterilizing. Today, the universal use of disposable medical gloves is well established.

Glove Regulations
The FDA places medical devices into one of three regulatory classes as required by the Federal Food, Drug and Cosmetics Act. The class of a device determines the level of regulatory control that applies to it. Medical gloves currently are in Class I. The FDA is considering reclassifying medical gloves from Class I to Class II, subjecting them to additional testing and controls. This would include limiting powder and protein, labeling the actual levels of powder and protein and expiration dating.

Surgical glove manufacturers also are required to meet the Current Good Manufacturing Practices (CGMP) regulation for medical devices (21 CFR 820), which includes establishing and maintaining control procedures to ensure that the gloves' specified design requirements consistently are met.

The minimum standards for surgical gloves that must be met are listed in the American Society for Testing and Materials' (ASTM) "Standard Specification for Rubber Surgical Gloves" (D3577). This standard describes requirements for sterility, freedom from holes, physical dimensions and property characteristics and recommended maximum protein and powder limits. Other optional tests can provide further information on how the gloves will perform.

Surgical Glove Minimum Performance and Physical Requirements (ASTM D3577)
Length: Glove length is measured from the tip of the middle finger to the wrist cuff and, for surgical gloves, may range from 12 inches to 15 inches (305 to 381mm). The ASTM standard represents the minimum length required. Longer gloves may be needed for specific fields, such as obstetrics or special purposes. Decisions about length should be based on the type of procedure, the probability of splash and the depth of immersion. Lengths may vary among manufacturers, so users should verify that the cuffs are long enough to fit snugly over a surgical gown and provide a continuous barrier from hand to arm.

Size: Size is determined by the circumference of the palm at its widest point and reflects a range rather than a fixed dimension. Surgical gloves usually come in whole and half sizes, ranging from size 5.5 to 9 and may vary in fit based on the manufacturer. Size does matter. If a glove is too large, dexterity can be affected; if it is too small, it can cause hand fatigue.

Thickness or Gauge: Surgical gloves must be at least .10mm thick as measured at the finger, palm and cuff. If the polymer film has not coated the glove formers evenly, greater variations in thickness may occur at different parts of the glove.

Acceptable Quality Level (AQL): This typically refers to the barrier protection confidence level. A lower AQL represents a higher quality product, i.e., a manufacturing process with fewer allowable defects. For purposes of sampling inspection, the AQL is used by manufacturers to identify the maximum number of allowable defects (pinholes) per hundred units. All gloves must be statistically sampled to verify the attainment of specific AQLs. Suppliers should be asked about their manufacturing process's average AQL.

Tensile Strength: Tensile strength involves how much force, in megapascals (MPa), is required to stretch a glove sample until it breaks. Higher numbers indicate a stronger glove film.

Ultimate Elongation: This measures how far, as a percentage of the original sample length, the glove stretches before it breaks. For example, if a 1 inch sample stretches to 9 inches before it breaks, the elongation is 800 percent. Higher numbers indicate a stronger glove film.

Stress at 500 Percent Elongation: Also known as modulus, this measures how much force, in MPas, is required to stretch a glove sample to twice its length. This is a measure of comfort; lower numbers reflect a softer, typically more comfortable glove. Surgical gloves are a very personal part of protective clothing that can directly affect a clinician's ability to practice his or her craft. Comfort is dependent on proper fit, the glove materials' modulus and, to some extent, the glove's thickness.

Donning Lubricants
Powdered surgical gloves currently have an ASTM-recommended powder limit of 20mg/dm2. Gloves labeled as "powder-free" are required by the FDA to have 2mg or less of total particulate per glove.

New technologies in glove manufacturing are emerging and various polymer coatings inside the gloves are eliminating or minimizing the need for powders. Historically, powder has been used to facilitate the release of gloves from formers during the manufacturing process and to aid in donning. Polymer coatings in combination with chemical lubricants are often applied to the glove surface to provide optimum wet and dry donning capabilities.

A majority of the coated surgical gloves on the market are manufactured by applying polymer coatings to the inner glove surface. This is followed by post-forming processes such as chlorination and lubrication. The chlorination process oxidizes the outer rubber surface to reduce the surface tackiness and also removes most of the powders deposited on the outer glove surfaces.

Polymer coatings appropriate for medical gloves must possess certain key characteristics. To provide a high-quality glove on a consistent basis, it is critical that a polymer coating is designed and engineered to meet all of these requirements:

Protein Levels
Currently, the only protein level label claim for natural rubber latex gloves that manufacturers can make is using the ASTM D5712 "Standard Test Method for the Analysis of Aqueous Extractable Protein in Natural Rubber and its Products" (the modified Lowry Method). The lowest allowable claim is "These Latex Gloves Contain 50 Micrograms or Less of Total Water Extractable Protein Per Gram," due to the insensitivity of the modified Lowry assay below that level.

Not all natural rubber latex proteins are allergens. Therefore, allergen levels may be of greater clinical significance than total protein levels. Ask your supplier for allergen testing results.

Factors Compromising Barrier Properties
Glove degradation is characterized by either a glove that feels too soft and tears easily or is too hard and brittle or crumbling. Medical gloves must be stored appropriately to maintain their strength and barrier properties. Do not store gloves near heaters, air conditioners, sterilizers, x-ray units or in areas exposed to ultraviolet light, sunlight or fluorescent light. Any of these factors can degrade the glove polymers. Additionally, stock should be rotated so that older gloves are used first.

Only water-based lotions or moisturizers are compatible under natural rubber latex gloves. Appropriate use of lotions and moisturizers is an integral component of an effective hand care regime, but products that contain mineral oil or petroleum or lanolin are not recommended for use under natural rubber latex gloves. If you are not certain of a product's content, check with the hand care product's manufacturer and request compatibility testing results.

The FDA also is considering requiring expiration dating on medical glove packages. A two-year expiration date would be assigned initially based on acceptable accelerated aging resistance data (e.g., stored seven days at 70 degrees Celsius). Longer expiration dates could be assigned if the manufacturer has real-time aging testing data to demonstrate the continued stability of the gloves' strength and barrier properties.

Appropriate Use of Gloves
Scrubbing is an important first step in preparing for a surgical procedure not only from the standpoint of asepsis, but also because any foreign debris or material on your hands that comes in contact with the glove may compromise its ability to provide barrier protection. Wearing rings or any other type of jewelry may cause holes or tears and may puncture or weaken the glove. Fingernails should be short and well manicured. Even if long fingernails don't rip through the cuff when donning the glove, they cause significant additional stress at the fingertips of that glove, possibly compromising the barrier.

During a surgical procedure, when the surgical team's hands come in contact with instruments, sharps and needles, it's very important to periodically inspect your hands to see if the glove has a tear or pinhole. Additionally, because of the "fatigue factor" of the polymer film, clinical consensus guidelines recommend changing surgical gloves every hour, and more frequently if they have contact with significant quantities of blood, fats and other body fluids.²

The AORN's "Recommended Practices for Maintaining a Sterile Field" indicates that double gloving may be needed for some procedures (according to a facility's policies and procedures).³ In one study involving surgeons and first assistants, the overall glove failure rate was 51 percent when a single pair of gloves was worn. The longer the gloves were worn, the greater the failure rate. Adding a second pair of gloves decreased the failure rate to 7 percent. In this study, failure was defined as blood contamination of the fingers.⁴

Some surgeons chose not to participate in the study, citing loss of dexterity with two pairs of gloves and claiming the second pair was unnecessary. The results of this study demonstrate that double gloving has benefits. Based on the data obtained, the authors recommend double gloving during procedures in which a patient is known or suspected to be infected with a transmissible virus and for major procedures lasting more than two hours or with a blood loss of more than 100mL.⁵

Glove Hydration, Conductivity and Permeation
Glove hydration may be a concern for surgeons when they are using electrocautery devices. Electrocautery surgery is performed with a small probe that houses an electric current that cauterizes (burns or destroys) the tissue. Body fluids that may hydrate the surgeon's gloves during electrocautery surgery can act as a conduit for the flow of electricity through the gloves. There currently are no requirements or standard test methods for measuring the hydration rate of natural rubber latex products. As a glove hydrates, it may lose its resistivity, becoming more conductive over time. Surgical gloves are not designed to insulate against electrical shock. It is extremely important that the equipment used for electrocautery surgery be properly set up to prevent burns on the patient's skin and also to protect the surgeon performing the cauterization.

Some research has hypothesized that as a glove hydrates, it may be more permeable to pathogens. If this were true, gloves would fail the ASTM F1671 "Standard Test Method for Resistance of Materials Used in Protective Clothing to Penetration by Bloodborne Pathogens Using Phi-x174 Bacteriophage as a Test System." This method keeps the glove film in contact with a suspension of a microbe smaller than many viruses for a total of 60 minutes. The film is then tested to see if any bacteriophage penetrated the glove film. Gloves from Cardinal Health, for example, have been tested and passed using this method. In fact, in one internal study, the bacteriophage suspension was held within Cardinal Health gloves for four hours without permeation. Ask your glove supplier if they evaluate their products with this test method.

Your Surgical Glove Manufacturer
Gloves are the single most important product purchased to protect staff and patients. It's likely that your facility uses more gloves than any other supply. When you consider all the hands you need to cover and all the possible glove choices, choosing the right gloves for the right reasons can be a complex decision. Clinical requirements need to be appropriately balanced with cost-management efforts and maximizing value.

Know who you're buying your surgical gloves from and what they can do for your organization beyond simply providing a product. For example, ask your manufacturer if they have a comprehensive program for medical glove standardization and utilization that can be tailored to meet your specific needs. Some manufacturers have programs that can analyze exactly how and where you are spending your glove dollars by examining utilization patterns and providing industry benchmarks for comparisons. The manufacturer then works with you to design a plan for optimal glove choices, standardizing your glove usage by defining the appropriate gloves by clinical procedure and job function.

While the manufacturers of surgical gloves are required to comply with Current Good Manufacturing Practices (CGMP), verifying they are ISO 9001/9002 certified provides you with additional assurance that they have rigorous design control, documentation and process control in place.

The FDA randomly inspects glove shipments coming into this country and tests them for pinholes. If a manufacturer's shipment fails this test, they are put on FDA detention and the product cannot be sold. Ask your manufacturer about their demonstrated track record of quality. Are they now or have they ever been on any level of FDA detention? If so, this calls into question not only the product quality (e.g., your assurance of barrier protection), but also the manufacturer's ability to consistently provide the level of service and amount of product your organization needs.

Important Choices
Currently in the United States alone, an estimated 27 million surgical procedures are performed each year⁶. Surgical gloves are an important part of a clinician's personal protective equipment and are highly regulated medical devices. Awareness of key design and manufacturing factors can help you select the right gloves for the right reasons.

¹Atkinson, L.J., Berry and Kohn's Operating Room Technique, 7th Ed., Mosby-Year Book, Inc. 1992.
²"Glove Use for Healthcare Providers: Hand Covering and Barrier Protection," APIC Information Brochure, 2000.
³"Recommended Practices for Maintaining a Sterile Field," in Standards, Recommended Practices, and Guidelines. Denver: Association of Operating Room Nurses, Inc., 1999, 317-322.
⁴Quebbeman, E.J., et al, "Double Gloving: Protecting Surgeons from Blood Contamination in the Operating Room," Arch Surg 127 (Feb 1992): 213-217.
⁵Ibid.
⁶Centers for Disease Control and Prevention (CDC) Hospital Infections Program Advisory Committee, "Guideline for Prevention of Surgical Site Infection," 1999.