4 Essential Things You Need To Learn About Isolation Gowns

April 16, 2021

Isolation gowns are protective apparel designed to avoid exposure to infectious hazards. It is a part of Personal Protective Equipment (PPE) that has a critical function in the hierarchy of ‘Safety and Health controls’. In a healthcare system, isolation gowns are warranted when engineering and administrative protocols fail to control infectious spread. Due to the COVID-19 pandemic, it has been predicted that medical gowns supply-demand will significantly increase from $1280 million in 2019 to $3,900 million by 2025. The impact of COVID-19 undoubtedly changed the sub-market growth of PPE apparel. Having said that, it is important to know what exactly PPE gowns are — their design variations, interfaces, and critical parameters that must be considered in different healthcare settings. This article will cover everything that you need to know about isolation gowns.

What are isolation gowns?

According to the Food and Drugs Administration (FDA), an isolation gown is defined as, “a gown intended to protect healthcare patients and personnel from transfer of microorganism and body fluids”. In the common marketplace, the term ‘isolation gown’ means the same as, medical gown, operation gown or precautionary gown. However, by FDA standards isolation gown is a sub-type of medical gowns utilized in isolation settings. In this article, we will refer to isolation gown as a general term for all types of PPE apparel. In 2004, a standardized consensus established by the American National Standards Institute/Association of the Advancement of Medical Instrumentation (ANSI/AAMI), classified medical gowns based on the apparel’s barrier performance and level of protection against bodily fluids or infectious pathogens. To understand AAMI classification for fluid barrier performance, it is important to identify critical zones of a gown and how are they related to barrier function. Critical zones are the exposed parts of a healthcare worker with the highest risk of contamination during patient-care activities. It includes the entire front of the gown, and sleeves, excluding the back, cuffs, hems, and bindings. In conclusion, the manufacturer must decide the ‘level’ of the gown based on the barrier function of these critical zones. One type of classification is according to the AAMI guidelines that are based on the ‘level’ of fluid barrier protection, it is elaborated as follow,
  • Level 1: It offers minimum barrier protection therefore preferred in low-risk hospital settings that do not involve surgical or invasive procedures. Mostly used in clinics for basic care, as standard apparel during isolation or, in a basic medical unit.
  • Level 2: It offers low barrier protection mostly used during patient management with a slight risk of contamination. Examples may include when drawing blood, wound dressing, or as a standard gown in an Intensive Care Unit (ICU).
  • Level 3: It offers moderate barrier protection, routinely used in traumatic procedures and when managing bodily fluids under high pressure. For example, during arterial blood draw or IV cannula.
  • Level 4: It offers the highest level of barrier protection therefore, recommended for healthcare workers managing infectious diseases with antibiotic resistance or high-contamination risk. Examples include non-airborne pathogens like Methicillin-resistant Aures (MRSA) or Vancomycin-resistant Enterococcus (VRE).
How one can quantify barrier performance depends on fabric material and standardized tests employed for quality control. Another type of isolation gown classification according to FDA includes,
  • Non-surgical gowns: They are Class I medical devices considered in low-risk settings therefore mostly exempted from regulatory protocols. As a result, these gowns do not require the 510(k) premarket notification from FDA which is an essential quality control measure for safety and efficacy assessment. As the name suggests, non-surgical gowns are not used in surgical procedures, instead, their use in healthcare settings is the same as a level 1 isolation gown.
  • Surgical gowns: These are Class II medical devices that must follow FDA’s regulations and clear the 510(k) premarket notification. It is used during operations to reduce exposure to pathogens, body fluids, and particulate matter. The critical zones include the gown’s front and sleeves only, excluding the cuffs, hems, and bindings. FDA further states that surgical gowns can be used for any risk level that is, levels 1-4.
  • Surgical isolation gown: They are Class II medical devices and require FDA’s 510(k) premarket clearance before its distribution. Compared to traditional gowns (surgical), it has larger critical zones including the gown’s front, back, and seams, and excluding the cuffs, hems, and bindings.
Isolation gowns can be sub-categorized into, sterile and clean medical gowns. Sterile medical gowns are generally preferred for the protection of both healthcare workers and patient when performing invasive procedures. On the other hand, clean gowns are routinely used during patient interaction and in isolation rooms.

What makes an isolation gown a good quality product?

Fibers are the smallest unit in gown fabrics; therefore, their chemical and physical properties are a critical component for quality assurance. Typically, non-woven, irregularly arranged, and fine fibers have the best barrier performance when designing a high-quality medical gown. Other important parameters to consider when designing an isolation gown includes2,
  • Particle penetration: low absorbing fibers found in synthetic materials like polypropylene result in poor penetration, therefore, reducing the risk of infectious spread.
  • Fiber arrangement: randomly organized non-woven fabrics are ideal technique in gown construction because it significantly reduces fluid transmission. Spunbound/meltblown/spunbound (SMS) technology is the most common technique employed for gown production.
  • Tear resistance: during operations chances of abrasions or tearing is high consequently, increasing infectious spread. As a result, isolation gowns are designed with high tensile strength with an abrasion-resistant material compared to an average cotton cloth. :
  • Compliance: According to one study, there is a strong association between poor PPE compliance and disease spread in a tertiary-care hospital. Certain desirable characteristics that improve compliance to PPE wear include breathability and minimal irritation especially for long-duration wear.
Gown interfaces are as important as the fabric used in PPE gowns. It includes the glove-gown interface which has the highest reported leakage during surgical procedures. In theory, a level 1 barrier protection is essential to reduce infectious spread. However, in the marketplace, the glove-gown interface is not considered a critical zone hence does not offer any barrier protection. As a result, healthcare workers make do by gloving over the cuff instead. The above parameters should be considered by all manufacturers to pass through FDA’s strict regulatory controls. For a consumer, merely looking at the product label that describes its intended use and recognizing AAMI’s level 1-4 is enough to determine the type of gown one should get.

How are isolation gowns made?

Isolation gown fabrics that we see in the marketplace are classified into reusable and disposable gowns. In about 80% of healthcare organizations in the US, disposable gowns are preferred over reusable ones. The type of synthetic fiber used during manufacture depends on whether they need to be disposed of or reused after each use. Disposable isolation gowns used polypropylene fibers and designed with a non-woven technology to allow minimal liquid penetration. The fiber-bonding technology most used is either spunbound or a combination of spunbound-meltblown processes. As a result, the fibers constructed lack the traditional interlocking quality associated with woven fabrics. The final product will then have a high tensile strength while being tear-resistant, flame-resistant, and biocompatible. Reusable gowns are produced with different raw materials and include either 100% cotton, 100% polyester, or a combination of polyester and cotton. The fabrics are arranged in a woven pattern and chemically enhanced with electrostatic properties to repel particulate matter. Reusable gowns can go through 50 or more washing cycles however, exact number of the washing cycle depends on the manufacturer.

Reusable or disposable gowns: What to choose?

The CDC issues guidelines for US healthcare workers on when and what type of PPE should be used in a healthcare setting. In the context of reusable vs disposable gowns, the choice depends on the hospital’s PPE protocol and supply shortage. For most US healthcare units disposable gowns have an 80% market demand, unlike European healthcare institutes that utilize reusable PPE gowns. Despite the tremendous disposable market growth, health organizations recognize the benefits of reusable over disposable gowns. It is a sustainable product, has reduced carbon footprints, and cost-effective in terms of production costs. According to a research study, that compared the effectiveness of disposable vs reusable gowns, it was shown that the latter product showed superior strength in terms of barrier durability and barrier performance, even after several laundering cycles. However, users frequently complain of poor breathability and permeability in reusable gowns. One possible reason could be the multiple washing cycles which must require a durable fabric material ultimately compromising end-users comfort. Organizations must overcome this obstacle if we want to replace disposable gowns on a national level.3 During times of PPE shortages, like the early months of the COVID-19 pandemic, CDC recommended optimization strategies to conserve medical gowns. One of the key strategies was opting for reusable gowns and re-using disposable gowns as last resort options.

The final takeaway

In summary, medical gowns are an integral component during PPE selection. When deciding which type (AAMI level) to wear, one should consider three key factors. The type of anticipated exposure like simple touch, blood-draw, or fluid sprays or, a large volume of high-pressure fluids. Appropriate in a particular healthcare setting, whether a healthcare worker requires fluid-resistance or fluid-proof gowns and, clean or sterile gowns all affect gown selection. Finally, isolation gown must be designed in a way that it fits the healthcare worker. However, many production companies distribute universal size which may affect a gown’s effectiveness in a community of diverse healthcare workers.

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