London team helps source important PPE gear

A team of chemical engineers at Imperial College London has sourced important equipment to help surgeons perform high-risk surgical operations.

The reusable personal protective equipment, known as powered air-purifying respirators, or PAPRs, are personal respirators that filter the air, removing hazardous fine particles such as those produced by the COVID-19 disease.

The equipment has been tested and successfully used for risky surgical operations by several National Health Service hospitals in London, including hospitals run by Imperial College NHS Trust, Guy's and St Thomas' NHS Foundation Trust, as well as University Hospital Lewisham, and University College Hospital.

The novel coronavirus that causes the COVID-19 respiratory disease has caused many patients to be admitted to intensive care as a consequence of viral pneumonia and respiratory distress syndrome.

Many of these patients require tracheostomies－where a tube is placed into the patient's trachea or windpipe. Early reports from the pandemic revealed that surgeons were susceptible to contracting the infection during these procedures.

The PAPRs project was started after Professor Neil Tolley, who leads a team of surgeons in the Ear, Nose and Throat division at Imperial College NHS Trust, sought assistance from colleagues at the Department of Chemical Engineering, for advice on a form of enhanced PPE.

Song Qilei, a lecturer in the Department of Chemical Engineering who is also the coordinator of the project, and his team sourced several commercially available PAPRs and respiratory hoods from a variety of UK suppliers and assembled a few prototypes in a week.

After a quick screening and evaluation process, the team chose the TECMEN PAPRs with P3-level high-efficiency particulate air (HEPA) filters from the UK distributor Weldfast UK.

Song then contacted the manufacturer of TECMEN PAPRs, Nanjing TECMEN Electronics in Nanjing China and the company donated more than 10 sets of upgraded TECMEN TM-H2 PAPR systems and reusable hoods.

The PAPR system when combined with a protective hood covers the wearer's face, eyes, skin, and neck, to prevent contamination from infectious aerosol particles. It offers surgeons a good field of vision and can allow medical staff to breathe clean, filtered air for up to nine hours.

It has proven particularly useful for medics during throat surgeries.

Tolley said: "The PAPRs have been a game changer as they have facilitated a change in the management of ENT emergencies and have permitted us to recommence airway and emergency surgery to pre-COVID principles, and ultimately minimized risk for medical staff permitting us to perform more potentially high-risk procedures."

Song said: "The coronavirus disease pandemic is the greatest global healthcare challenge and frontline healthcare workers are still risking their health and lives to fight against the coronavirus and save patients. We've brought together expertise from scientists, engineers, medical staff and industry from the UK and China, to develop this system to protect frontline healthcare workers while they treat patients."

Song and his colleagues at Imperial also got in touch with frontline doctors in Wuhan, China, who have been sharing their clinical experiences and knowledge with the hospital staff, as well as experience in using the equipment.