Episode 36: COVID-19

PHEMCAST

https://phemcast.co.uk/wp-content/uploads/2020/05/covid-02-05-2020-18.41.mp3

Case definition

Current case definition for COVID-19 can be accessed here.

Risk stratification

This is the Emergency Medicine Specialty guide we discussed in the podcast, which includes use of the NEWS and 40 step test (edit: since recording the podcast yesterday (!) we’ve been made aware of the Sit to Stand test). Here is a review of both if you’d like to read more.

PPE

As at May 1st, the advice from PHE is ‘There is currently sustained transmission of COVID-19 throughout the UK as defined by the four nations Public Health experts, therefore there is an increased likelihood of any patient having coronavirus infection. Therefore, whilst in this phase all patient contacts require level 2 PPE in accordance with Table 4‘: T4_poster_Recommended_PPE_additional_considerations_of_COVID-19

Level 2:

• disposable gloves
• disposable apron
• fluid repellent surgical mask
• eye protection (if risk of splashing)

Level 3:

• disposable gloves
• fluid repellent coveralls/long sleeved apron/gown
• FFP3* or powered respirator hood
• eye protection

*Where an FFP3 mask with a non-shrouded valve is worn, it should be accompanied by a full-face visor. If a visor is not available, then a risk assessment should be carried out regarding the risk of splash to the valve. If a large splash (as opposed to droplets) does occur, then the FFP3 mask should be replaced immediately.

There are a number of PHE PPE videos available, this is the one describing donning and doffing Level 2.

From PHE Guidance for ambulance trusts: Where AGPs such as intubation are performed, PPE guidance set out for AGPs (section 8.1) should be followed (disposable fluid repellent coveralls may be used in place of long-sleeved disposable gowns). For any direct patient care of patient known to meet the case definition for a possible case, plastic apron, FRSMs, eye protection and gloves should be used. Where it is impractical to ascertain case status of individual patients prior to care, use of PPE including aprons, gloves, FRSM and eye protection should be subject to risk assessment according to local context. PPE is not required for ambulance drivers of a vehicle with a bulkhead and those otherwise able to maintain social distancing of 2 metres. If the vehicle does not have a bulkhead then use of a FRSM is indicated for the driver (additional PPE would be as for other staff if providing direct care).

For the coverall-type Level 3 PPE most commonly being used by ambulance clinicians, have a look at these two guidelines on donning and doffing.

Aerosol generating procedures

Reference available here.

Aerosols are produced when an air current moves across the surface of a film of liquid; the greater the force of the air the smaller the particles that are produced. Aerosol generating procedures (AGPs) are defined as any medical and patient care procedure that results in the production of airborne particles (aerosols). AGPs can produce airborne particles <5 micrometres (μm) in size which can remain suspended in the air, travel over a distance and may cause infection if they are inhaled. Therefore AGPs create the potential for airborne transmission of infections that may otherwise only be transmissible by the droplet route.

The most recent assessment by WHO (2014) states that there is only consistent evidence that there is an increased risk of transmission for the following procedures: tracheal intubation, tracheotomy procedure, non-invasive ventilation, and manual ventilation before intubation as AGPs. This evaluation is based on a systematic review by Tran et al. whose review included 10 studies (5 case-control; 5 cohort), all of which investigated transmission of SARS from patients to healthcare workers in intensive care or other healthcare settings during the 2002-2003 SARS outbreaks.

Cardiac arrest

From PHE:

First person attending scene

• In order to minimise any delay attending a time critical cardiac arrest, it is acceptable for the first person to enter the scene wearing level 2 PPE (fluid repellent surgical mask, apron, gloves and eye protection). Where trained and equipped to use level 3 PPE, this may be used where it will not cause a delay
• commence resuscitation where this is indicated by local clinical guidance. If resuscitation is not commenced, or is terminated before the arrival of other resources, provide an early sitrep to reduce the number of responders who need to enter the scene
• do not place your face near the patient to assess breathing
• where available, place a surgical mask or oxygen mask on the patients face
• commence chest compressions, attach the defibrillator and defibrillate if indicated. None of these tasks are considered aerosol generating procedures (AGPs)
• do not progress to airway management or ventilation
• if not already available on-scene, request back up from a level 3 PPE trained response

Subsequent attendance at scene of responder(s) trained and equipped to use level 3 PPE

• don level 3 PPE
• enter scene and determine whether the resuscitation should be continued according to local clinical guidance.
• if resuscitation is to be continued, take over patient management from any responder wearing level 2 PPE
• all responders wearing level 2 PPE are to leave the scene (more than 2m away from the patient) prior to the commencement of any airway management, ventilation or other AGPs. Responders may later re-enter if trained and equipped to wear level 3 PPE
• level 3 PPE responders to continue the resuscitation, including airway management and ventilation

Anyone who is not trained or does not have access to level 3 PPE must then withdraw from the scene.

From the Resuscitation Council:

Click here for more from the Resus Council on COVID-19.

Just before you go … something to make you smile! (thankfully the music department at Plymouth Uni have got the tech to make me sound like I can actually sing!!!)

References

For more on the growing evidence base around COVID-19, please have a read of this blog from our colleague, and Defence Professor of Emergency Medicine, Jason Smith.

World Health Organization. Infection prevention and control of epidemic and pandemic-prone acute respiratory infections in health care. WHO guidelines. https://www.who.int/csr/bioriskreduction/infection_control/publication/en/ (2014).

Tran K, Cimon K, Severn M, et al. Aerosol generating procedures (AGP) and risk of transmission of acute respiratory diseases (ARD): A systematic review. PloS One 2012; 7. Conference Abstract.

https://www.gov.uk/government/publications/covid-19-guidance-for-ambulance-trusts/covid-19-guidance-for-ambulance-trusts#patient-assessment

Tim Cook PPE review: https://onlinelibrary.wiley.com/doi/epdf/10.1111/anae.15071

Health Service Journal: Exclusive: deaths of NHS staff from covid-19 analysed

Considering transmission from staff uniforms:

Infection Control and Hospital Epidemiology. Volume 31, Issue 5 May 2010 , pp. 560-561. Coronavirus Survival on Healthcare Personal Protective Equipment. Lisa Casanova (a1), William A. Rutala (a2), David J. Weber (a2) and Mark D. Sobsey (a1). DOI: https://doi.org/10.1086/652452

PLoS One. 2011; 6(11): e27932. Survival of Influenza A(H1N1) on Materials Found in Households: Implications for Infection Control. Jane S. Greatorex, 1 Paul Digard, 2 Martin D. Curran, 1 Robert Moynihan, 2 Harrison Wensley, 2 Tim Wreghitt, 1 Harsha Varsani, 1 Fayna Garcia, 1 Joanne Enstone, 3 and Jonathan S. Nguyen-Van-Tam 3 , 4 , * https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3222642/

Acute myocardial injury in COVID

https://www.nice.org.uk/guidance/ng171/resources/acute-myocardial-injury-algorithm-pdf-8717541373

https://www.nice.org.uk/guidance/ng171/chapter/3-Diagnosing-acute-myocardial-injury-in-patients-with-suspected-or-confirmed-COVID-19

See also: Clinical guide for the management of critical care for adults with COVID-19 during the coronavirus pandemic