Patient Safety COVID-19

Patient Safety During COVID-19:

At Anacortes Dermatology patient safety is our number one concern. We have implemented numerous protocols to ensure patient protection:

 

1.) We perform daily high-dose UV-C light and ozone gas sanitization of exam rooms. (See below for efficacy and testing). 

2.) During an average patient appointment, the total volume of air in our exam rooms is treated by a high power UVC light sterilization system (without ozone) approximately 20 times! This is coupled with a 150 watt photocatalytic filter. 

3.) We have specialized medical HEPA air purifiers that filter particles less than 1/20th the size of the COVID-19 virus (SARS-CoV-2).  These are used throughout the clinic, and rapidly filter and exchange the room air every two or three minutes.  All air supplied by our HVAC system is filtered similarly (see below for how rapid this system works).

4.) During the summer months, our exam rooms have negative air pressure and constantly exhaust and replace the room air. Approximately 1000 cubic feet of air is replaced every minute with fresh outside air.

5.) Our provider and staff use Positive Air Pressure Respirators (PAPR’s) and full isolation hoods. This is the highest level of protection other than using a self-contained breathing apparatus (SCBA). Our PAPR's use P100 filters, which block 100% of viral particles from entering breathing air.

6.) All contact surfaces are cleaned with hospital-grade sanitizers between every appointment.

7.) Our social distancing precautions include staggered appointments, with long intervals between patients, and car check-in (patients can wait in their vehicle until we are ready for them). We only evaluate one patient per time slot. Our waiting room is closed for patient protection.

8.) Providers, staff, and their families practice social distancing outside work. When rapid testing for SARS-CoV-2 is more widely available (and reliable), we anticipate testing staff weekly. 

9.) Patients are asked to wear a mask for their appointment, but may be removed during the visit if they desire. 

10.) We follow the regulations and guidelines of the Washington State Department of Health and our professional societies, such as the American Academy of Dermatology and the American College of Mohs Surgery.

 

UV-light and Ozone Gas Sanitization at Anacortes Dermatology

Studies indicate that both UV-light and Ozone are able to inactivate Coronaviruses such as SARS 1, 2.  Our exam rooms are treated with high-dose UV-light and ozone gas (O3), both at the end of the day (with ozone), and continuously during appointments (without ozone).  We have documented this system is highly effective at killing approximately 99.9% of respiratory pathogens in our clinic, even when performed BEFORE the cleaning of surfaces with chemical agents, HEPA air purifiers, and negative pressure air exchange.  

 

In April 2020, we tested our UV-light and ozone systems by placing microbial populations of respiratory bacteria on exam surfaces. Samples were cultured to assess the number of bacteria present before, and after, whole-room UV light and ozone treatment. This is the same method hospitals gauge the effectiveness of cleaning protocols and indicators for the potential presence of virus pathogens such as SARS-CoV-2.  The pictures below demonstrate its’ remarkable effectiveness at killing 99.9% of respiratory bacteria on exam surfaces. Each small dot represents a living bacterial colony. Note the absence of growth in UV-light/ozone treated samples. 

 

 

1.)    Darnell, M., et al. Inactivation of the coronavirus that induces severe acute respiratory syndrome, SARS-CoV. Journal of virologial methods, 2004. 121:p. 85-91

2.)    Zhang et al. Examination of the efficacy of ozone solution disinfectant in inactivating SARS virus. Journal of Disinfection (Chinese), 2004- 01. R187


Whole building air purification to protect from SARS-CoV-2

At Anacortes Dermatology we have a state-of-the-art air purification system to reduce exposure to SARS-CoV-2.  This is accomplished in two steps.  First, 100% of the air circulated through our HVAC system is filtered through an advanced medical-grade HEPA filter with over 170 square feet of surface area.  This filter removes even ultra-fine particles, less than 1/20th the size of the SARS-CoV-2 virus. It effectively eliminates 95% of particles down to 0.003 microns, the smallest particles that exist.  This system can clean the entire volume of air in the building approximately 125 times per day.   We have the same system that was used to help fight the SARS virus outbreak in Asia, and it is the #1 system used in hospitals.  Second, our exam rooms have a stand-alone air filtration system that combines granulated aluminum and carbon filters, along with a medical-grade HEPA filter.  This device removes 99.5% of all ultra-fine particles down to 0.003 microns.  The total air volume in our entire exam room is filtered approximately every 2.5 minutes.  This means during the average appointment, the air in our exam room will have been purified over 12 times!! As you can see from the graph below, starting at time zero (0) with heavily contaminated air, our purifiers rapidly remove particles of all sizes within minutes.  This was verified by two independent particulate meters sitting on the exam chair. They measured everything from ultrafine particles <0.3 microns, to more than 10 microns. 

Time (minutes)

A word about COVID-19 and “normal” HEPA filters

SARS-CoV-2 is very small, around 80 to 120 nanometers (0.12-0.08 microns). It is believed that the main mode of infection from Coronavirus is via respiratory transmission, where the virus is emitted into the atmosphere on much larger droplets of moisture or saliva, around 12-21 microns. These droplets can dehydrate and shrink to some degree, and remain suspended in the air for eight to fourteen minutes on average, but can persist for hours depending on air movement patterns. The micro-droplets can also adhere to much larger particles such as dust or pollen (15-200 microns).  These particle sizes are effectively captured by even by “normal” HEPA filters, which filter out particles greater than 0.3 microns (100 times larger than our ultra-fine HEPA filters remove).

 

Current data suggests that SARS-CoV-2 is transmitted when a patient coughs, sneezes, talks, or even just breathes normally. Because SARS-CoV-2 is a new virus, the literature is very confusing regarding air purification with HEPA filters. Recent data suggests it's unlikely respiratory droplets less than 1 micron are infectious because nearly all emitted droplets are larger than that size, and the probability that the original hydrated 3-micron drop (which would dehydrate to 1 micron) contains an infectious virus particle is less than 0.01%.3

 

Use of HEPA purifiers to filter infectious pathogens is well documented in Positive Pressure Powered Air Respirators, where the HEPA purifiers have been used to block a variety of viruses.4  Recently scientists have designed systems utilizing HEPA purifiers to protect physicians when intubating patients with COVID-19.5  During the initial SARS outbreak in 2003, HEPA air purifiers were widely used to control infection throughout hospitals in Taiwan.6  Further, HEPA filters can effectively block the particle transmission of Porcine Respiratory Virus (PP-RSV), which is approximately half the size of SARS-CoV-2.7 Use of HEPA filters are recently described as surgical 'best practices' during neurosurgical procedures where negative air pressure is combined with HEPA filters for clean areas.8 Finally, according to the Centers for Disease Control, HEPA filters capture 99.9% of particles (bacteria, fungi, and larger viruses or virus clumps) 0.1-0.3 micrometers in diameter. We feel the predominance of the evidence suggests that HEPA filters are an excellent addition to our clinic and will make it a much safer environment for our patients. This is especially true since our HEPA filters effectively eliminate particles even 1/20th the size of SARS-CoV-2.  

 

3.) Valentyn et al., The airborne lifetime of small speech droblets and their potential importance in SARS-CoV-2 transmission. Proceedings of the National Academy of Sciences, 13 May 2020, htttps://doi.org/19.1973/pnas.2006874117

4.) The microenvironment of Positive Pressure Powered Air Purifying Medical Protective Equipment, Feng et al, Journal Emergency Medicine, May 2020: 37(5):256-257

5.) Lin et al, SWIVEL-HEPA-ETT (SHE)(HE) Methods for safe intubation while managing patients with COVID-19. Emergency Infectious Disease 2004 July:10(7):1187-94

6.) Esswein et al, Environmental and Occupational Health Response to SARS, Taiwan, 2003

7.) Dee et al. Evaluation of systems for reducing the transmission of porcine reproductive and respiratory syndrome virus by aerosol. Canadian Journal of Veterinary Research 2006 Jan 70(1):28-33.

8.) Pandey et al., Minimizing SARS-CoV2 exposure when performing surgical interventions during the covid-19 pandemic. Journal of Neurointerventional Surgery, May 20, 2020, 016161.

 

Comments