THIS WEEK'S ARTICLES
Using Povidone-Iodine in Sinonasal and Oral Cavities
The antiseptic can quickly inactivate coronaviruses, including SARS, MERS and, yes, SARS-CoV-2.
A recent literature review examined the effectiveness of nasal and oral use of povidone-iodine to reduce nosocomial spread of SARS-CoV-2, the virus that causes COVID-19. The authors concluded that using the proper concentrations of povidone-iodine in both the sinonasal and oral cavities can safely and effectively help prevent the spread of coronaviruses in general, and specifically the spread of SARS-CoV-2.
The study, published in the Ear, Nose & Throat Journal, notes that the nasal cavities, nasopharynx, oral cavity and oropharynx can house high viral loads of SARS-CoV-2, which has led to growing interest in decontaminating these areas in patients and healthcare workers to prevent the spread of COVID-19.
That led the authors to examine povidone-iodine for three reasons: its ability to inactivate coronaviruses, its lack of microbial resistance and its long history of clinical use. They reviewed its use in the nasal and oral cavities to test for its safety. Even though in surgical environments its use is episodic, the authors decided to put povidone-iodine through a more rigorous case study to determine if it was safe to use chronically during the pandemic.
The authors say povidone-iodine is effective for both preoperative and chronic nasal decolonization, with no effects on thyroid function, mucociliary clearance or olfaction. "Ciliotoxic effects have been demonstrated at concentrations of 2.5% and above, with safety demonstrated at 1.25% and lower," they add. Povidone-iodine is also used in the oral cavity for surgical disinfection, as well as chronically for dental purposes. Again, the authors say chronic oral use is safe as well, with no evident toxicity, irritation, staining of teeth or change in taste.
They do note concern regarding aspiration of oral povidone-iodine in unconscious patients, which had led to six case reports of aspiration pneumonia in surgical settings. "It is prudent to take care when instilling povidone-iodine in unconscious patients," they say.
All told, the authors say povidone-iodine is safe for nasal use up to 1.25% for five months, and safe for oral use up to 5% for six months. Based on available data, they recommend nasal mucosal decontamination with 0.5 to 2 mL of 1.25% povidone-iodine and oral rinse with up to 10 mL at 2.5% as frequently as needed for decontamination without risk of adverse effects. However, they advise against its use in patients with thyroid disease, pregnant patients and patients receiving radioactive iodine therapy.
For surgical facilities, these findings are instructive, as not only do they reiterate the general safety and effectiveness of povidone-iodine on most patients, but they also indicate that resistance is not an issue due to its effectiveness over long time periods.
COVID-19 Opens Ophthalmologists' Eyes to Povidone-Iodine
The antiseptic can play a variety of roles in protecting providers from the coronavirus.
While much attention was placed on proper handwashing and use of personal protective equipment at the onset of the COVID-19 pandemic, many providers realized the need for additional environmental and administrative protocols — particularly in the realm of ophthalmology.
A recent study in touchOPHTHALMOLOGY notes that the potential use of antiseptics, particularly povidone-iodine, is still being overlooked in eye surgery, despite robust safety and efficacy data that has accumulated. "Due to its ability to protect both patients and healthcare providers alike, [povidone-iodine] utilization, in the form of oral and nasal solutions, should be considered as an additional and expansive step in the standard precautions algorithm," says author Jesse Pelletier, MD, FACS, of Miami-based Ocean Ophthalmology Group.
The issue hits close to home for the ophthalmologist, who notes that Chinese eye surgeons were among the first to recognize COVID-19, as well as some of its earliest casualties. "Now that some of these restrictions have loosened and outpatient clinics/ambulatory surgery centers reopen, ophthalmologists find themselves at the intersection of expanding care, while trying to protect themselves and their patients," explains Dr. Pelletier.
Because COVID-19 is a coronavirus, Dr. Pelletier says the medical community's understanding of coronavirus strains that cause severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) provides the understanding that human-to-human transmission occurs mainly through family members and nosocomial spread. Ophthalmologists are at heightened risk of contracting the virus because of the close, sustained contact they have with patients, high patient volumes and their performance of aerosol-producing procedures. "In order to successfully impede transmission in an outpatient setting, one should not only include appropriate personal protective equipment, but also environmental and administrative protocols," he says.
While it is possible to transmit COVID-19 through ocular exposure, Dr. Pelletier is more concerned with the high activity of the virus in saliva and the nasopharynx, as the upper respiratory tract is specifically susceptible to infection. "The virus can exploit existing secretory pathways in the upper respiratory tract to induce low-level infection that generates virus-laden droplets and aerosols in patients with no overt pathology," he says. "These discoveries have clinical implications reaching beyond the current usage of face masks."
Despite the early and sustained focus on handwashing using alcohol-based sanitizers to combat the spread of COVID-19, Dr. Pelletier says the potential use of other antiseptics has been largely overlooked despite robust safety and efficacy data that have accumulated over decades. He specifically stresses the use of povidone-iodine, which is a broad-spectrum, "broadly virucidal" antiseptic with no known resistance and strong antiviral, antifungal and antibacterial properties that can be used safely in the nasal cavity, the sinuses and orally. "A recently developed nasal/oral formulation has been shown to rapidly deactivate SARS-CoV-2 in vitro," he says.
Povidone-iodine is a compelling antiseptic for a variety of purposes, says Dr. Pelletier:
- Dilute povidone-iodine sinonasal rinsing solution has been shown to be a safe and effective ancillary therapy for recalcitrant chronic rhinosinusitis.
- Povidone-iodine gargle and mouthwash, a common practice in Japan, have demonstrated strong bactericidal properties for oral decontamination, outperforming other antiseptics such as chlorhexidine and benzalkonium chloride.
- Rinsing the oropharyngeal tissues with povidone-iodine prior to intubation leads to a lower rate of ventilation-associated pneumonia, suggesting the antiseptic may be an effective protective oropharyngeal hygiene measure for individuals at high risk of exposure to oral and respiratory pathogens.
Ophthalmologists, of course, already utilize alcohols, halogen-based antiseptics or mupirocin in the nares to diminish methicillin-resistant Staphylococcus aureus (MRSA) colonization prior to performing surgeries. Dr. Pelletier calls for these protocols to be expanded with povidone-iodine, especially when preparing patients for aerosol-producing procedures. He adds that providers should consider routinely using povidone-iodine nasal and oral preparations to decrease asymptomatic viral shedding and mitigate disease spread. "It is possible to create safe, effective, and comfortable protocols with repeat dosing of [povidone-iodine], which may decrease the risk of transmission.
"As it is accepted that one washes one's hands prior to donning gloves, so it should be accepted that one decontaminates the oral and nasal tissues prior to donning a mask," says Dr. Pelletier.
Developing a Preoperative Nasal Decolonization Program
How to reduce the bacterial burden and experience successful protocols with your OR team.
Surgical professionals were given a special opportunity to learn about the impact of nasal decolonization on reducing skin flora and surgical site infections from two experts who presented an interactive live AORN Hot Topic Virtual Forum on June 8. "Nasal Decolonization: Who Nose the New Guidelines Best?" was a lively discussion of this important topic with a focus on the new related AORN Guideline for Preoperative Patient Skin Antisepsis.
Speakers Karen deKay, MSN, RN, CNOR, CIC, Perioperative Practice Specialist at AORN, and Deva Rea, MPH, BSN, RN, CIC, Clinical Science Liaison at PDI, focused on navigating risk-based decisions for developing preoperative nasal decolonization programs using the updated AORN Guideline for Preoperative Patient Skin Antisepsis. The purpose of the virtual forum was to remind attendees why decolonization is so significant and how to implement a program at their own surgery facilities. During the forum, attendees learned that many more people carry infection than one would think – and it's not always active. This bacteria can spread to your staff as well as other patients. The goal is to reduce the bacterial burden.
What percentage of patient infection comes from their own bacteria? Karen deKay supplied the eye-opening answer: 80% of S aureus SSIs can be attributed directly from the patient through their nose, skin or hands to the surgery site. Essentially, patients can easily cause their own infection, which is why setting up a program of nasal decolonization that works for your facility and the type of surgery you do is so important.
Certainly, one size does not fit all. As Karen says, "Decolonization is not a one size fits all…. you need to look for protocols within your population and for specific surgeries."
Based on the updated AORN Guideline for Preoperative Patient Skin Antisepsis just released in May (Book publication release in 2022), each location in the country and every surgery center will have different needs and their administrators will want to customize their program.
Community risk factors need to be determined. Karen notes, "It is important to know what is going on in your local community to decide who gets nasal decolonization and who should be considered high risk." She reviewed three strategies to determine what works best for any facility – Universal, Targeted or Blended.
An important recommendation in the AORN Guideline is to plan for interdisciplinary teams, which could include infection preventionists, epidemiologists, pharmacists, perioperative nurses, surgeons, microbiology lab personnel and other stakeholders. This team would determine the best strategy to pursue as well as the resources and training needed, and how to monitor their facility's nasal decolonization program.
Putting the AORN Guidelines into practice was discussed by Deva Rea, MPH, BSN, RN, CIC, Clinical Science Liaison at PDI, who identified how the Profend® Nasal Decolonization Kit fits into the new AORN Guidelines.
Deva defined the elements for successful product implementation and revealed that Profend® swabsticks work for all decolonization strategies, including Universal and Targeted. PDI offers educational support for the healthcare team through onsite/virtual training, an online training module video, as well as a written Profend® Nasal Decolonization Kit IFU. Each facility can plan for its own protocols, and as Deva notes, "The protocol should be formal and written for indefinite reference."
The Safety of Using Povidone Iodine for Infection Prevention
New study suggests the method is gaining in popularity as allergic or other adverse reactions rarely occur.
Currently, the two most frequently used agents for nasal decolonization are intranasal mupirocin 2% ointment and chlorhexidine wash. Yet another recent study, however, deems povidone-iodine a safe and effective alternative nasal and oral decolonization agent.
The study, published last summer in Antimicrobial Agents and Chemotherapy, examined approaches to nasal and oral decontamination with povidone-iodine to reduce nosocomial spread of SARS-CoV-2, with a specific focus on its safety when topically applied to the nasal and oral cavity.
The researchers found povidone-iodine can be safely administered for up to five months in the nasal cavity and six months in the oral cavity. "Concentrations less than 2.5% in vitro do not reduce ciliary beat frequency or cause pathological changes in ciliated nasal epithelium, upper respiratory, or mucosal cells," the authors write. "Adverse events with oral use have not been reported in conscious adults or children. Allergy and contact sensitivity is rare."
As for its effectiveness, they write that povidone-iodine is "rapidly virucidal" and inactivates coronaviruses like SARS, MERS and SARS-CoV-2. "Povidone-iodine can safely be used in the nose at concentrations up to 1.25% and in the mouth at concentrations up to 2.5% for up to five months," they write, adding that povidone-iodine rapidly inactivates coronaviruses in as little as 15 seconds.
Nasal and oral decolonization have received heightened attention during the pandemic because, as the authors note, the nasal cavities, nasopharynx, oral cavity and oropharynx typically possess high viral loads.
A Deep Dive Into Using Antiseptics to Fight COVID-19
Literature reviews finds povidone-iodine broadly virucidal.
A recent review of numerous commonly used antiseptics with antiviral properties, including povidone-iodine, Listerine, iota-carrageenan and chlorhexidine, suggested further clinical trials to determine their ultimate effectiveness in mitigating both the progression and transmission of SARS-CoV-2. However, the paper cited numerous studies that indicate povidone-iodine, in particular, is a proven and powerful antiseptic at various concentrations and in numerous clinical scenarios.
The recent study in the Future Medicine journal says povidone-iodine, ethanol and essential oils (Listerine) and a combination of xylitol and iota-carrageenan purified from red marine algae have demonstrated the ability to cut the viral load of SARS-CoV-2 by 3log10 to 4log10 in 15 to 30 seconds in virtro.
Describing povidone-iodine as one of the most common antiseptics available, the authors say it is considered safe to use on the mucosal epithelium at appropriate concentrations, such as a 10% preparation for skin and a 1% preparation for the oral cavity. It cited numerous studies touting povidone-iodine's effectiveness:
- A 0.23% dilution of 7% povidone-iodine mouthwash reduced viral titers of SARS and MERS, similar viruses to SARS-CoV-2, by over 4log10 after a 15-second exposure in vitro.
- In a clinical setting, gargling with a povidone-iodine solution resulted in a 50% drop in respiratory infections caused by pathogens such as Pseudomonas aeruginosa, Staphylococcus aureus and Haemophilus influenzae.
- Specifically against SARS-CoV-2, in vitro testing of povidone-iodine at concentrations ranging from 10% to 0.45% were reported to yield a greater than 4log10 reduction in viral titers after 30 seconds of exposure.
- Povidone-iodine was shown to rapidly inactivate SARS-CoV-2 in vitro at concentrations of 1.5% to 0.5% after a 15-second exposure time with a 3log10 reduction in viral titers.
- An in vivo toxicity study revealed no toxicity concerns with sub-chronic intranasal use of povidone-iodine.
- Povidone-iodine is likely effective both as an oral mouthwash or as a nasal swab or spray. One study reported a decrease in viral load for roughly 50% of patients after a one-minute 15 ml oral rinse of 1% povidone-iodine. Another showed povidone-iodine nasal spray at concentrations of 4.4% and 2.2% did not damage the epithelium of the nasopharynx.
- The authors say nasal povidone-iodine solution was more tolerable than traditional mupirocin as a method of reducing S. aureus preoperatively.
- No allergic reactions to povidone-iodine have been noted, save for a small percentage who may develop low-level skin irritation.
The review says that chlorhexidine, a widely used oral rinse, does not act as quickly as povidone-iodine in reducing viral load in 30 seconds, but it does bind to cell proteins, extending protection. Hydrogen peroxide was said to be less effective than other oral rinses in vitro while raising concerns of cell toxicity. Hypertonic saline, while not directly virucidal, halts replication by increasing hypochlorous acid inside the cell.
"These commercially available products should be further evaluated due to their potential ability to reduce the transmission of SARS-CoV-2 and other viruses that are yet to emerge," the authors conclude.