The epidemic of the 2019 novel coronavirus (now officially called SARS-CoV-2) has expanded from its place of origin, Wuhan, in China to countries around the world (Lipsitch et al, 2020). SARS-CoV-2 is the virus that causes the disease known as COVID-19. Like other respiratory pathogens, including influenza virus and rhinoviruses, SARS-CoV-2 spreads primarily through droplets of saliva or discharge from the nose when an infected person coughs or sneezes (World Health Organization (WHO), 2020a). The incubation period for COVID-19 is thought to be within 14 days following exposure (Li et al, 2020) but most cases present approximately 4–5 days after exposure (Li et al, 2020).
Based on the evidence available, SARS-CoV-2 is transmitted between people through close contact and droplets, not by airborne transmission, unless the virus becomes aerosolised during a medical procedure, or through coughing and sneezing. The people most at risk of infection are those who are in close contact with a person who has COVID-19 or who care for patients with COVID-19 because of human-to-human transmission (WHO, 2020a; 2020b).
Effective management of COVID-19 by the paramedic should not only centre around prompt recognition and early administration of oxygen, intravenous fluids and transfer to hospital (for the critically ill) as required, but also include infection control, the use of personal protective equipment (PPE) and preventing the spread of the SARS-CoV-2 virus (National Institute for Health and Care Excellence (NICE), 2020).
To help them achieve these aims, paramedics should familiarise themselves with the COVID-19 rapid guideline on managing symptoms in the community published by NICE (2020). This includes information on end-of-life considerations and the approach to tackling the spread of COVID-19 in the community.
The use of PPE is especially important during the COVID-19 pandemic because the virus is spread via person-to-person droplet transmission. Correct use of PPE reduces the risk of a virus such as SARS-CoV-2 spreading by covering up body parts. In addition, PPE protects a person wearing it while minimising the risk to others.
PPE is used in healthcare to reduce the transmission of infectious and/or bloodborne diseases between people and places, with the overall objective of protecting all health personnel, patients and visitors to any healthcare setting (Neo, 2012). The use of PPE is considered the most important strategy for preventing the transmission of infectious diseases in patients and clinical staff such as paramedics. This is based upon the assumption that no patient or clinical worker can be certain they do not carry any infectious disease or pathogen. Specifically, it is important for all clinical staff to assume that all blood and body fluids from patients are potentially infectious.
SARS-CoV-2 infection should be suspected in all cases of respiratory infection until proven otherwise (Public Health England (PHE), 2020a).
NICE (2017) notes that anyone involved in patient care should be: educated about the standard principles of infection prevention and control; and trained in hand decontamination, the use of PPE and the safe use and disposal of sharps. Additionally, NICE states that wherever care is delivered, clinical staff must have appropriate supplies of materials for hand decontamination, sharps containers and PPE available. Moreover, PPE should be used with all patients at all times, regardless of their diagnosis and infection status, and this should include good hand hygiene, the correct level and use of personal protective equipment depending on anticipated exposure, safe injection practices and disposal of sharps.
Gammon et al (2008) performed a comprehensive review of the rates of compliance with PPE. Their review found that compliance with these precautions was suboptimal globally, and that practitioners were selective as to which parts of the precautions they applied to their clinical practice. This was supported by Valim et al (2014), who found that health professionals seem to be selective when supposedly following standard precautions and using PPE. A range of reasons were identified for this: staff were too busy to use PPE; the patient was considered low risk; PPE was uncomfortable to wear; PPE was not available or was difficult to access; PPE negatively affected the practitioner's dexterity; and there was a lack of explicit support from management. However, this study took place prior to the current pandemic and clinical staff now need to wear PPE to protect themselves against this virulent virus.
PPE consists of gloves, gowns, aprons, surgical face masks, protective eyewear and face shields. PPE provides a physical barrier between the user and microorganisms. It prevents microorganisms from contaminating the airways, mucous membranes, skin, clothing, hair and shoes of clinical staff, preventing the potential transmission of microorganisms.
NICE (2017) has indicated that selection of PPE must be based on a thorough assessment of the risk of transmission of microorganisms to and from the patient, and the risk of contamination of a clinician's skin and clothing by a patient's blood, body fluids, secretions and/or excretions. WHO (2020c) highlights that PPE effectiveness depends strongly on adequate and regular supplies, adequate staff training, correct hand hygiene, and appropriate human behaviour. WHO also maintains that PPE use should be based on the risk of exposure (according to the type of activity, for example) and the transmission dynamics of the pathogen (e.g. contact, droplet or aerosol). This is because overuse of PPE will exacerbate supply shortages (WHO, 2020c).
Since the SARS-CoV-2 outbreak, PHE (2020b) has provided specific information on the use of PPE in all clinical settings, with particular reference to ambulance staff and paramedics. This guidance signposts all staff to the type of PPE to use. This includes, for practitioners having any direct contact with patients with suspected COVID-19, plastic aprons, fluid-repellent surgical face masks (FRSMs), eye protection and gloves. It further adds that PPE is not required for ambulance drivers of a vehicle with a bulkhead and where social distancing of 2 metres can be maintained (PHE, 2020b).
If ambulance personnel are cleaning a vehicle after and between transportation, WHO (2020c) advocates the use of PPE additional to that mentioned above, including heavy-duty gloves and boots or closed work shoes.
To ensure the safety of prehospital paramedic staff, it could be argued that standard PPE should be used for all patient attendances. However, difficulties arise when patients need interventions that require greater levels of PPE, such as for any aerosol-generating procedures (AGPs).
Donning and doffing zones
The fitting of PPE is pivotal to ensuring optimal protection and working conditions (Loibner et al, 2019.
However, although multilayer gloves and other PPE offer protection, they can limit dexterity. Tasks such as intubation and cannulation can be considerably slower and are more likely to be unsuccessful when practitioners are using PPE (Castle et al, 2009; Loibner et al, 2019). Paramedics should be able to familiarise themselves with PPE and practise various clinical procedures when using it if possible. However, this is not always possible, especially in the current pandemic (Loibner et al 2019; PHE, 2020c).
Paramedics should receive training and guidance on PPE so they can use the correct equipment that is required within their area of practice. The areas with the highest risk include intensive care units, high dependency units and emergency departments and where intubation and cannulation may be required, such as in the prehospital environment (PHE, 2020a; 2020b). These clinical areas are where most AGPs are carried out, such as intubation/extubation, bronchoscopy, tracheostomy, non-invasive ventilation and high-flow nasal oxygen (PHE, 2020a). Some of these procedures may be required in the prehospital environment, although PHE (2020c) mentions only intubation as an AGP that requires additional PPE.
Clinical areas requiring PPE are categorised from low to high risk. A high-risk area is classified as a red zone, moderate risk as amber and low risk as green.
PPE requirements differ according to the level of protection required, with the Health and Safety Executive (HSE) (2020) recommending a face-filtering piece class 3 (FFP3) respirator mask for all AGPs. All clinicians require a fit test for the face mask to ensure it has an adequate seal. If clinical staff fail the fit test, they must use a respiration suit with a hood for protection. The FFP3 respirator filters >99% of airborne microorganisms and other particles, and are consequently used in red zones, along with a face shield/visor and a fluid-resistant, full-sleeved gown and gloves.
Any paramedics working in red zones are required to perform donning and doffing of PPE to minimise the risk of transmission. Donning is the putting on of PPE while doffing is its removal and disposal. Using double rather than single gloves gives additional protection when donning and doffing (Verbeek et al, 2020). Contamination rates with single gloving are 733 particles per 1000 compared with 249 particles per 1000 when double gloved. This is a relative risk (RR) of 0.31, and clearly demonstrates the benefit of wearing two pairs of gloves. Errors in donning and doffing are also a potential source of contamination; in one observational study, training in donning and doffing reduced contamination rates from 467 to 145 particles per 1000 (RR 0.31) (Verbeek et al, 2020).
Amber zones include inpatient areas where there are no identified or confirmed cases of COVID-19 and the use of PPE should depend on a risk assessment (PHE, 2020a). Plastic aprons, gloves and FRSM with a face shield must be used.
In green zones, staff have to follow standard infection-control precautions and maintain social distancing if possible. For patient contact, a plastic apron, gloves and FRSM are required. The rationale for PPE choice should be based upon the risk determined. For example, using an FRSM for an AGP is not viable as it does not provide enough protection; while it offers some protection against the novel SARS virus, it only provides barrier protection from respiratory droplets.
FFP2/N95 respirator masks filter 94–95% of airborne particles so are less effective than the FFP3 respirators but can be used as an acceptable compromise where FFP3 respirators are unavailable (HSE, 2020).
Identifying patient risk and determining the type of zone and therefore the PPE required in the prehospital environment is difficult and paramedics have to rely on information provided by call handlers. This information needs to be specific enough for the presenting crew to make an informed decision as to level of PPE required for that call. Another difficulty will be if the patient's condition changes or if they deteriorate.
Discarding of PPE that is uncomfortable, soiled, damaged and damp is paramount to promote protection and avoid contamination; the maximum duration of PPE use should be according to manufacturer guidelines. PPE should be discarded in an appropriate waste container after use and hand hygiene should be performed before wearing and after taking off PPE.
Fitting of PPE is pivotal to optimal protection and working conditions (Loibner et al, 2019), but PPE can restrict the person wearing it and limit their ability to do the task required.
SARS-CoV-2 testing
Until a safe vaccine is found for SARS-CoV-2, the only way to prevent its significant transmission and reduce the numbers of infected people and overall deaths is to have a significant strategy for testing, contact tracing, social distancing and subsequent self-isolation of individuals who have symptoms or who test positive for the virus (Salathé et al, 2020).
Testing is part of an overall policy recommended by WHO (2020b), although testing alone will not stop the spread of the virus. This policy includes; rapid diagnosis and immediate isolation of cases, as well as rigorous tracking and self-isolation of close contacts. However, for this to work, testing needs to be widely available, any barriers to testing need to be limited. Testing facilities should be outside hospitals so as not to add to the burden on already-stretched hospital resources and to avoid transmission to hospital patients and staff.
For this to be effective as part of the overall strategy, the amount of testing and capacity for it need to be dramatically increased. This significantly relies on increasing not only the capacity of testing centres but also the availability of testing equipment so results can be obtained in a timely fashion. Currently, results are generally available within 24 hours, although point-of-care testing where results can be obtained within a matter of minutes is being validated in some countries (Public Health Wales, 2020; Welsh Government, 2020).
To meet the increased worldwide demand for testing, WHO (2020c; 2020d) has set up a COVID-19 supply chain task force to work with private companies in an effort to meet the global demand for testing equipment. This has been replicated by the UK home nation governments to increase the availability of tests and thus the testing capacity of that country.
Widespread testing will help determine the extent of the spread of the virus and give a clearer picture of its exact incidence and distribution. This will assist in determining whether control measures have been effective and, if necessary, identify if these measures need to be reviewed.
Piguillem and Shi (2020) recognised that testing has a threefold benefit especially for health professionals such as paramedics. When a person is known to be infected: it is possible to treat them (even though symptoms can be palliated without a positive test result, e.g. paracetamol can be used for pyrexia); they can be quarantined in a stricter way than the rest of the population to slow the reproduction of the virus; and once the individual has eliminated the virus after a period in quarantine, they can be allowed back to work, which helps to moderate the extent of the recession caused by the virus as well as increasing the capacity of the workforce.
Currently, the SARS-CoV-2 virus is detected via a testing kit where a swab is taken from a person's nose or throat using a long or short swab and chemicals are used to remove proteins, fats and other molecules leaving only the genetic material, the RNA from the virus, behind. The test kit enzymes copy the RNA to DNA, which is amplified to allow virus detection using a polymerase chain reaction (PCR) machine (Green et al, 2020). Fluorescent markers are then used to detect the virus. The PCR test is deemed to be highly sensitive and reliable although it does have some disadvantages; in particular, it relies on capturing and detecting the virus so it could give false-negative results in individuals who have cleared the virus and recovered. This is where antibody testing could help. Green et al (2020) advocate for a combination of testing types at different times to manage the COVID-19 pandemic.
Antibody testing will identify whether a person has had the virus. Many countries are working with scientists to validate antibody tests as a way to find out whether people who test positive for SARS-CoV-2 antibodies are immune to reinfection. This requires a sample of blood, often from a finger prick test. This test can identify if people have been infected with SARS-CoV-2 but cannot distinguish between an active or previous infection. The advantages of such a test is that it is quick, giving results in 15 minutes. However, this technology is new and its accuracy in diagnosing SARS-CoV-2 has yet to be validated to determine accuracy and reliability.
WHO (2020b) continues to review the evidence on antibody testing and, as of 24 April 2020, no study, as yet, has determined whether the presence of antibodies provides immunity from further SARS-CoV-2 infection. Thus, it is currently difficult to confirm immunity to subsequent SARS-CoV-2 infections by identifying the presence of SARS-CoV-2 antibodies. For this reason, WHO (2020b) has warned against countries issuing ‘immunity passports’ as proof against reinfection. It is too early to say whether exposure to SARS-CoV-2 offers protection against further infection (WHO 2020d).
Conclusion
Paramedics have a vital role to play during the current COVID-19 pandemic. Where a thorough risk assessment indicates PPE is required, paramedics should don PPE of the appropriate level before coming within 2 metres of the patient. Doing this will protect the paramedic and help prevent the spread of the virus. As SARS-CoV-2 testing develops, this will facilitate the return to work of any self-isolating staff and help manage the pandemic.