Elizabeth A. McCullough

Methods for determining the barrier efficacy of surgical gowns

BACKGROUND Surgical gowns are worn in the operating room to reduce the incidence of nosocomial wound infections in patients and to prevent the exposure of medical personnel to pathogens in blood and other body fluids from the patient. New test methods have been developed by the American Society for Testing and Materials to identify gowns that provide barriers against liquid and microbes. METHODS This article evaluates the liquid and microbial barrier properties of 13 reusable and disposable gowns and investigates the cumulative effects of laundering and sterilizing on the barrier efficacy of reusable gowns by means of the Impact Penetration (splash) Test, the Synthetic Blood Resistance Test, the Viral Resistance Test, and the Elbow Lean (demonstration) Test. RESULTS Single-layer regular gowns and double-layer fabric reinforced gowns offer different degrees of liquid resistance; that is, they show some resistance to splashes and pooling of liquids on the surface. Gowns reinforced with films, membranes, and coatings are generally liquid-proof, meaning that they resist visible penetration of synthetic blood under pressure. Some of these gowns are also resistant to viral penetration. CONCLUSIONS Hospitals should provide liquid-proof gowns that also offer microbial resistance to their medical personnel for use in high-risk situations in which optimum safety is required. Other gowns may be used when the risk of exposure to body fluids is low. Hospital personnel should determine the type of gown that should be worn in different operating room situations. Any incidents of penetration would indicate that a higher level of protection is required.

Determining temperature ratings for children's cold weather clothing.

This study examined the physical and physiological differences between children and adults that affect body heat generation and losses and then developed a heat loss model for determining the temperature ratings of cold weather clothing designed for use by children of various ages. The thermal insulation values of selected jackets were measured using a heated manikin dressed in two base ensembles, and the temperature ratings were calculated using the model. The results indicated that the type of garments used in the base ensemble had a major effect on jacket ensemble insulation and the predicted comfort temperature. For a given level of insulation, the temperature rating decreased as the wearers age and activity level increased. This is probably because children have a higher surface area per unit mass ratio than adults, and they lose heat faster. However, this effect is partially offset by their higher metabolic rates.

The use of thermal manikins to evaluate clothing and environmental factors

Abstract Life-size, heated manikins are used in a variety of ways to study the human environmental condition. They have been used by many researchers to measure the thermal resistance (insulation) of clothing, sleeping bag systems, bedding systems, and chairs, with the manikin either standing, sitting, walking, or lying down. Standing sweating manikins have been used to measure the evaporative resistance of clothing. Manikins have been used to evaluate the heating, ventilating, and air-conditioning systems (HVAC) in buildings and vehicles by measuring the impact of the environmental conditions on the manikin and by measuring the impact of the manikin on the HVAC systems. Manikins have also been used to measure the effects of fire and heat on protective clothing and the body. Manikin tests have been conducted under steady-state and transient conditions.

Factors affecting the resistance to heat transfer provided by clothing

Abstract 1. 1. This paper discusses the factors that affect the insulation and evaporative resistance provided by clothing. 2. 2. These include: fabric thickness and density, the amount of body surface area covered by garments, the evenness of the distribution of fabrics over the body surface, the increase in surface area for heat loss due to clothing, the looseness or tightness of fit, a persons body position (seated vs standing), body motion and wind.

Quantifying the thermal protection characteristics of outdoor clothing systems.

This paper describes a reliable test method for measuring and comparing the heat-transfer characteristics of outdoor garments and sleeping bags. The procedure involves the use of an electrically heated mannequin located in a climate-controlled chamber. Unlike instruments that evaluate small samples of fabric, the mannequin technique reflects the effects of fabric overlap and garment design, shape, fit, and layering in the measurements. This paper also discusses the textile and human factors that affect the heat exchange between the body and a cold environment.

Liquid Barrier and Thermal Comfort Properties of Surgical Gowns

For many years, protective garments have been worn by surgical personnel to prevent the contamination of the patient from microorganisms. More recently, medical personnel have been concerned about being exposed to diseases from the body fluids of the patient [e.g., hepatitis B (HBV), human immunodeficiency virus (HIV), and acquired immunodeficiency syndrome (AIDS)]. The Association of Operating Room Nurses and testimony at the preliminary hearings of the Occupational Safety and Health Administration have recommended that surgical gowns repel all of the body fluids typically found in the surgical setting (1,2). Consequently, the liquid barrier properties of fabrics used to produce these protective garments need to be measured so that these products can be compared by hospital personnel.

Insulation haracteristics of Outdoor Garments and Fabric Systems

The thermal insulation (clo) values of different combinations of shell fabrics, linings, and filling materials were measured using a guarded hot plate. The same fabric systems were constructed into long and short coats, and an electrically heated manikin was used to measure the insulation provided by each coat worn with a standard set of indoor garments. The type of fabric and/or filling material significantly affected the insulation provided by fabric systems and coat ensem bles. The long coats were significantly warmer than their shorter counterparts, and the sensitivity of garment clo to fabric clo was greater for the long coats than for the short coats. It appears that small differences in the thermal insulation of fabric systems become more important when most of the body is covered with a given fabric system. However, when an outdoor garment covers only part of the body and is worn over garments with less thermal resistance, the garments contribution to total body insulation is lessened.