Health care workers must always wear a complete set of protective equipment to shield themselves and their patients from disease. One of these pieces of equipment is isolation gowns.

Different medical gowns are used for specific situations where essential protective equipment or better protection is needed. All medical-quality isolation gowns must go through a series of tests to meet the standards set by AAMI.

What are Isolation Gowns?

Medical isolation gowns are personal protective equipment used by health care workers. These gowns can come in different varieties for specific health care settings like for surgeries and operating room use.

This protective equipment serves as a barrier for the host against possible infection when they contact infected solid or liquid material, like respiratory droplets. Medical isolation gowns are also helpful when facing vulnerable and immunocompromised patients, as these gowns bar germs from being exposed to these patients.

There are critical zones found in surgical gowns. These critical zones are where direct contact with possible infectious material like bodily fluid is most likely to land. These are on the sleeves and centre of the gown.

For these gowns to effectively protect the user, the wearer must tie them correctly. When they’re soiled or the user must leave the area, they must take the gown off, dispose of it, and immediately wash their hands afterwards.

What is the difference between Medical Gowns Level 1, 2, 3, and 4?

There are different gowns appropriate for specific medical settings, as some settings may require better protection, and some are for simple health set-ups.

Four levels of AAMI ratings for medical isolation gowns are set, largely dependent on their ability to be barriers against fluids, blood-borne pathogens, and viruses.

The lowest medical gown level, level 1, provides the lowest barrier protection. It only has a minimal level of protection against fluids. Due to this, its use is restricted to settings where there is minimal risk of fluid exposure. These gowns are for daily patient care, visitors, routine check-ups, and the like.

Level 2 provides a low level of protection from fluids. It protects the wearer from infection through splatter or soaking. Unlike the previous level, health workers use these inside the intensive care unit or the pathology lab. Health care workers also wear this protective medical gown when suturing or drawing blood.

Level 3 are medical gowns for moderate-risk situations of liquid penetration. Compared to the former level, it bars a more significant amount of splatter from infecting the wearer. Health workers wear this gown for most surgical procedures in the emergency room. They may also wear this when inserting intravenous lines or drawing blood from an artery.

Level 4 isolation gowns offer the highest level of barrier protection against blood-borne pathogens, fluids, and viruses. It can prevent all kinds of fluid and viral infiltration for up to an hour. These are best suited for lengthy, arduous procedures that expose the wearer to blood and non-airborne diseases, like surgeries.

What is the ANSI/AAMI standards for surgical gowns?

AAMI, known as the Association for the Advancement of Medical Instrumentation, creates standards for medical-device and supply companies to guarantee a global norm.

AAMI created the four levels of gowns for barrier performance after conducting several standardized tests on all.

One of these tests was to measure water penetration by impact and how fabrics resist it. This is the AATCC 42-2017 test. The AAMI level 1 resulted in this test with less than or equal to 4.5 grams of water impact. Both levels 2 and 3 resulted in a spray impact of less than 1.0 grams.

The AATC 127-2017 test records water penetration into the fabric under hydrostatic pressure and its resistance. Levels 2 and 3 resulted in hydrostatic pressure of less than 20 and 50 cm, respectively.

ASTM F1670-17 tests the infiltration of synthetic blood under continuous liquid and how elements found in protective clothing resist it.

Lastly, ASTM F1671-13 uses a surrogate microbe to test the penetration of blood-borne pathogens to the materials under continuous liquid contact. If there is no virus at the end of the test, the isolation gown passes this test. Level 4, the highest AAMI level of isolation gowns, pass this test.

Conclusion

Health workers must wear specific isolation drapes in particular situations, from basic care to trauma room cases to surgeries. It is dictated into levels by the AAMI fluid barrier standards once they go through the specific liquid and viral penetration tests. It is best for health care workers to wear the correct isolation gown to protect themselves from infection of diseases.