Testing of Personal Protective Equipment (PPE)
Condition: Personal Protective Equipment; Heat Stress
MeSH terms: Heat Stress Disorders
Study type: Interventional

Summary: 
      Pandemics and re-emerging diseases put pressure on the health care system to prepare for
      patient care and sample logistics requiring enhanced personnel protective equipment (PPE) for
      health care workers. We generated quantifiable data on ergonomics of PPE applicable in a
      health care setting by defining error rates and physically limiting factors due to
      PPE-induced restrictions. Nineteen study volunteers tested randomly allocated head- or full
      body-ventilated PPE suits equipped with powered-air-purifying-respirators and performed four
      different tests (two laboratory tutorials, a timed test of selective attention and a test
      investigating reaction time, mobility, speed and physical exercise) during 6 working hours at
      22°C on one day and 4 working hours at 28°C on another day. Error rates and physical
      parameters (fluid loss, body temperature, heart rate) were determined and ergonomic-related
      parameters were assessed hourly using questionnaires. Depending on the PPE system the most
      restrictive factors were: reduced dexterity due to multiple glove layers, impaired visibility
      by flexible face shields and back pain related to the respirator of the fully ventilated
      suit. Heat stress and liquid loss were perceived as restrictive at a working temperature of
      28°C but not 22°C.
    

Detailed description: 
      In this randomized study following good clinical practice guidelines nineteen study
      volunteers were recruited to wear one of two different types of randomly allocated PPE suits
      (www.randomizer.at) and to perform four different tests six times at 22°C on one day and four
      times at 28°C on another day in the local core facility clinical research center.

      Study participants Recruiting was based on voluntary registration in response to a public
      announcement. The study was subjected to the local ethical committee review (No. 23-321 ex
      10/11) and all persons gave written informed consent according to the Helsinki Declaration.
      Key lifestyle and medical parameters were documented for every subject. Exclusion criteria
      were pregnancy, latex and polyvinyl chloride allergy, claustrophobia, hypotension, history of
      vein thrombosis, chronic obstructive pulmonary disease, epilepsy, cardiovascular and
      pulmonary diseases, and infectious diseases. Ten male and nine female volunteers were
      recruited, aged between 21 and 38 years with body-mass-indices from 17.2 to 32.5.

      PPE suits Suit A: TychemR F overall whole-body (DuPont de Nemours and Company, 3M, Austria)
      suit including socks with a reusable light hood VersafloTM S-655 (3M, Austria) and an
      external 3M JupiterTM Powered Air Turbo Unit (3M Austria) providing head-only positive
      pressure.

      Suit B: 3MTM JS-series Typ 3 Chemical and Respiratory Protective Suit (CRPS, 3M, Austria)
      with integrated respirator 3M Jupiter JP-ER-03 Powered Air Purifying Turbo (3M, Austria)
      fixed as a rucksack generating whole-suit positive pressure.

      With both suits, Sempercare surgical gloves (Sempermed, powder-free 150; Semperit, Austria)
      as the first layer, Ansell Sol-Vex gloves 37-900 (Ansell, Medical GBU, VWR, Austria) as a
      second layer and white rubber boots were worn. Gloves and boots were sealed to the suit using
      adhesive tape. Tests I and II were performed in a mock-up glove box providing a third layer
      of latex gloves.

      Tests Four tests were repeatedly performed as well as an additional questionnaire on comfort
      and general condition before the tests started and after every four-test-series. Test I
      comprised correct assembly and position of coloured and numbered 2 mL tubes and screwcaps in
      a storage device to test fine motor skills, concentration and error rate. Test II checked the
      same skills in a different approach by pipetting different volumes of coloured water into a
      96-well microliter plate according to a given pattern. Test III "d2 Test of Attention" is a
      timed test of selective attention and a standardized refinement of a visual cancellation. In
      response to the discrimination of similar visual stimuli, the test measures processing speed,
      rule compliance, and quality of performance, allowing estimation of individual attention and
      concentration performance. Test IV investigated reaction time, mobility, speed and physical
      exercise by tapping touch sensors directed by signs on a screen (tapping test by
      talent-systems sportconsulting Gmbh, www.werthner.at). All subjects performed the tests after
      randomisation (www.randomizer.at) of the starting exercise. For example, subject one started
      with test I while subject two started with test II at the same time. After ten minutes
      testing time and a five minute break, subject one carried on with test II and subject two
      with test I. After a five minute break, subject one started with test III while subject two
      performed test IV over a 10 minute period. Again after five minutes break, subject one
      continued with test IV and subject two with test III. Subjects documented their individual
      comfort and general condition in a structured questionnaire before the tests started and
      after every series of tests. All four tests were repeated 6 times at 22°C (6 hours total
      working time) on the first test day and four times at 28°C (4 hours total working time) on
      the second test day. Limiting factors for working conditions were ranked after every series
      from 1 to 10 on the questionnaire whereby ranking 10 was a reason for terminating the study.
      Heart rate (HR) was measured with a wireless heart rate monitor placed below the sternum
      directly on the skin (Garmin Forerunner 305) before and after the test series (data used for
      statistical analysis) and additionally recorded during the test series. Body temperature and
      body weight were measured as well as weight of the respective PPE for calculating dehydration
      and evaluation of heat stress.
    

Intervention name(s): PPE Suit A; PPE Suit B
Intervention type(s): Device; Device
Intervention description(s): In this randomized study following good clinical practice guidelines nineteen study volunteers were recruited to wear one of two different types of randomly allocated PPE suits. Suit A has to be used by randomly selected participants to perform four different tests six times at 22°C on one day and four times at 28°C on another day in the local core facility clinical research center.; Suit B has to be used by randomly selected participants to perform four different tests six times at 22°C on one day and four times at 28°C on another day in the local core facility clinical research center.
Other intervention name(s): Suit A - Tychem F + - 3MTM Mehrwegleichthaube S-655; Suit B -- 3MTM JS-Serie Typ 3 Respiratory Protective Suit
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Keywords: biosafety; outbreaks; clinic; personal protective equipment; ergonomics; error rates