Saturday, 28 March 2020

COVID Questions No 4 - What PPE should I wear at the moment and when should I wear it? (Updated 2 April 2020)

This post was originally written on 28th March 2020 and then significantly updated on 2 April 2020 in line with new PHE UK guidance published on that day.

Understandably, there is a lot of confusion and anxiety about the Personal Protective Equipment (PPE) that is needed to minimise the risk of COVID-19 infection being acquired by healthcare professionals.  Guidance is continually changing and the need to to protect ourselves as healthcare professionals in very real.

Different PPE is available for different circumstances and this post will explain what we are advised we should use and when according to the latest Public Health England (PHE) guidance.  Please note that this advice is continually being reviewed and updated.  I will also explore some of the pragmatic ways that we can reduce our infection risk and explain some of the complexities of the PHE guidance.  I will do my best to keep this post up to date but it is essential to look at the most recent guidance from your relevant organisation since decisions about PPE use are also made locally depending on the known prevalence of COVID-19 in specific areas.

There are two main things to understand when using PPE.  The first is what level of risk there is and the other is what level of precaution is advised for that level of risk.

What is the level of risk?

Working in a health care organisation already confers a certain level of risk.  In a time when we are asking people to undertake "social distancing," healthcare workers are going into environments which are probably the most densely populated public buildings at the moment.  These buildings contain the patients and staff in our area most likely to transmit COVID-19 infection.  As such, just turning up to work means that we come into an area where it is difficult to avoid people who put us at some risk.  Every door handle, computer keyboard and telephone is a potential way of catching the infection.

For this reason, most public health organisations have advised staff who are high risk should remove themselves from the workplace altogether.

Those who are physically at work can do a lot to protect themselves and their co-workers.  We should be minimising the number of meetings and restricting the number of people at these meetings as much as possible.  We should be vigilant about hand hygiene at all times, especially when we have used a phone, touched a door handle or other surface such as a computer keyboard.  Any way that we can find to avoid hand contact with surfaces should be adopted.  I now have continuous right shoulder pain and a bruise over my greater trochanter from barging doors open that I would previously have pushed with my hand.

Contact with asymptomatic patients (no fever or cough) is relaitively low-risk but still has the potential for infection.  Not enough is known about COVID-19 to be able to say how possible it is that a completely asymptomatic person might infect another person.  What is known is that in the absence of symptoms, the risk of infection comes primarily from direct contact or high risk procedures.  Someone who is not spreading droplets can transfer infection via surfaces or by having physical contact.

Healthcare workers who are seeing asymptomatic patients can reduce their risk in several ways.  Increasingly patient contacts are being avoided, for the benefit of staff and the public.  Clinic visits are becoming telephone or video consultations.  We are finding that there are opportunities to reduce follow-up and we are getting better at safety-netting rather than arranging a "routine" appointment for a review.

The risk of face-to-face clinical examination is being reduced, for example by avoiding throat examination unless it is necessary, rather than including oropharyngeal examination as a routine part of the assessment.

For face-to-face clinical contact that cannot be avoided, the risk of direct transmission of infection should be removed by good hand hygiene and avoidance of high risk procedures.
Now for the most significant change in the new guidance.  When it is determined that you are dealing with a high level of COVID-19, PHE recommend using mask, gown and gloves for all patient contact or close proximity, whether symptomatic or not.  That decision is made by individual health care providers based on the prevalence of COVID-19 in their patient population.
If a person is working in an area with symptomatic patients but has no direct patient contact and is not within 2 metres (about 6 feet) of patients, PHE recommends that a fluid resistant surgical mask is worn.
Contact and close proximity with symptomatic patients carries the further risk of infection transmission by droplets.  These patients are referred to as hot, but the "hot" patient includes children with a cough as well as febrile patients for this reason.  When having face-to-face contact with a symptomatic child, additional PPE is recommended in the form of:
  • Disposable gloves
  • Disposable moisture resistant apron
  • Moisture resistant mask (surgical mask)
  • Eye protection if there is a risk of splashing of secretions (e.g. from oropharyngeal examination)
The gloves and apron should be put on before approaching the patient and removed after leaving the patient.  PHE now recommends that the surgical mask can continue to be used afterwards.  It is imprtant to avoid contaminating the mask be touching it.

Droplets are small but large enough so that they will not bypass a surgical mask.  Essentially they are a projectile, not a vapour and so the risk of infection comes from the droplet travelling in a line from the patient to the clinician, not from the air breathed around the mask.  The size of a droplet causes it to be deposited in the upper airway rather than entering the bronchial tree, which is thought to further reduce its infective risk.  For this reason, filtered masks (FFP) as not required when the level of risk is droplet spread.
Contact with contaminated aerosol carries the additional risk that the infection could be breathed in.  The definition of an aerosol is a small droplet (smaller than 10µm) that is capable of being suspended in the room air and breathed in as far as the lower airways.

The current evidence for what creates a risk of aerosol transmitted infection is the basis for the current PHE guidance on when to use the appropriate PPE for this risk.  The current list is as follows:

Procedures included in the current PHE guidance list of areosol generating procedures (AGP)
  • Intubation, extubation and related procedures e.g. manual ventilation and open suctioning of the respiratory tract (including the upper respiratory tract)*
  • Tracheotomy/tracheostomy procedures (insertion/open suctioning/removal)
  • Bronchoscopy and upper ENT airway procedures that involve suctioning
  • Upper Gastro-intestinal Endoscopy where there is open suctioning of the upper respiratory tract
  • Surgery and post mortem procedures involving high-speed devices
  • Some dental procedures (e.g. high-speed drilling)
  • Non-invasive ventilation (NIV) e.g. Bi-level Positive Airway Pressure Ventilation (BiPAP) and Continuous Positive Airway Pressure Ventilation (CPAP)
  • High Frequency Oscillatory Ventilation (HFOV)
  • Induction of sputum
  • High flow nasal oxygen (HFNO)
Note that the wording of some of the list has changed, presumably in an attempt to be more correct.  I think that it is important to point out that one of the most commonly persormed AGPs could be lost in here.  "Non-invasive ventilation (NIV) e.g. Bi-level Positive Airway Pressure Ventilation (BiPAP) and Continuous Positive Airway Pressure Ventilation (CPAP)" includes use of bag-valve-mask ventilation.  In the current pandemic, if a child has a respiratory arrest you should put on aerosol PPE before providing CPR.

Rather than get caught up in the science of why things are on or off this list, I would say that the list is possibly better named "very high risk procedures."  The list is compiled by experts who have looked at both the available evidence and the hypothetical risk of each.  My personal opinion is that the list is a valid way of determining when best to use each level of PPE.

Any contact with patients who are undergoing such procedures requires aerosol PPE.
  • Filtering face piece (FFP) mask, which should have been fit tested to the clinician previously
  • Eye protection
  • Disposable gown (with full length arms)
  • Disposable gloves
Avoidance of aerosol generating procedures is also recommended where possible.  For example, it has been recommended that HFOT is not used in COVID-19 babies.

Stay safe.  Avoid unnecessary risk.  Clean everything.  Touch nothing you don't have to. Use the appropriate PPE and don't overuse PPE that is in limited supply and will be much needed for the high risk scenarios over the next few weeks.

Edward Snelson

Disclaimer: In the interests of the infographics not being awful, I did none of the drawings myself.  Full credit for the drawings goes to my vey talented daughter Naomi Snelson.  Thanks for the great pictures.

Thursday, 26 March 2020

COVID Questions No 3 - Should I stop examining children's throats?

As increasing evidence comes out of the countries hit worst by the COVID-19 pandemic, there is growing concern about the number of healthcare workers being affected.  A large number of COVID-19 positive tests in Italy (currently about 10%) have been healthcare workers.

It is important to emphasise that these statistics will inevitably have at least some bias.  Healthcare workers are much more likely to be tested for COVID-19.  It is a concerning figure nevertheless and it is well known that healthcare environments are inherently risky when it comes to acquiring infection.

There are three main ways to avoid getting infection as a healthcare worker.  The first is to avoid patient contact where possible.  The second is to use appropriate personal protective equipment as per guidance.  The third is to minimise the risk of the clinical encounter.

Over the past few days, there has been a growing discussion amongst frontline clinicians about a radical cultural change in clinical practice.  We have been asking his question:

Should I stop examining children's throats?

Like any such suggestion, the first time the question was asked out loud was probably in a one-to-one conversation in a closed room after checking that the GMC hadn't bugged the place.  Then, as the question was asked more and more, it became quickly apparent that there was a large proportion of frontline clinicians who felt that this was a sensible move in the current situation.

On 25th March 2020 the RCPCH published guidance stating that in the current situation "the oropharynx of children should only be examined if essential."  Never before in my career have I seen such a change in practice go from whispers between colleagues to official college guidance in such a short period of time.  Well done RCPCH!  For the first time since the introduction of FAOMed, you're ahead of us!

While this move is entirely intended to reduce the risk of clinical contact during the COVID-19 pandemic, clinicians will at the very least have questions.  When something is part of our routine and then taken away from us it will cause anxieties.  As acute clinicians, our intuitive thinking relies on a reasonably consistent approach and in most paediatric encounters, we are used to looking in the throat.  So the question is, is it OK to stop doing that routinely?

Here are a few common questions in response to this radical change.

What if I need to know what the focus of infection is?
Good question.  This has always been a hugely subjective issue.  Even before this pandemic, the majority of clinicians and organisations have been trying to encourage self-care for uncomplicated febrile illness in children.  If a clinical confirmation of infection focus was essential, health care organisations would be getting the message out.  "Never give your child fever medicines without seeing a doctor to check what the problem is."  That's not a thing.
A snotty febrile child has an URTI.  URTI does not exclude other infections nor does it exclude sepsis so the redness of the throat should not reassure us if we think a child has another probable diagnosis such as UTI, LRTI or sepsis.
The important question has always been, "does this child have signs of serious bacterial infection or sepsis?"  If the answer is no then the throat exam won't really change things (see below).  If the answer is yes, you're looking for a source and it probably isn't in the throat.

When might I need to examine the throat?
The necessity for this is probably going to be mainly to look for evidence of a significant pathology such as peri-tonsillar abscess.  I would suggest that such a possibility can be all but excluded clinically if a child is well analgesed and is able to eat or drink.
If you do feel that examining the throat is important to do, you must wear eye protection.

Don’t I need to determine if the child has tonsillitis?
Tonsillitis in children can always be treated symptomatically.  The NICE guidance for treating sore throats attempts to direct the clinician toward cases where a symptom benefit from antibiotics is more likely but does not mandate the use of antibiotic in any uncomplicated URTI/ tonsillitis.  The reason there is no mandate is that there is no evidence that in this era in the UK, antibiotics prevent the rare complications of URTI/tonsillitis.
Regardless of clinical findings, the symptom benefit from antibiotics is poor.  The lack of evidence for significant benefit has led the Children's Hospital Melbourne to recommend no prescription of antibiotics in any case apart from high risk children or signs of complicated URTI.
So if the child is low risk (99.9% of children) and has no signs of complications from the infection, the visualisation of the tonsils is non-essential.

Should I therefore prescribe antibiotics empirically?
In the interests of openness and honesty, I need to say first that the RCPCH does advocate this.  There is a reminder that under the age of three years old, FeverPAIN should not be used.  Over the age of three, it is proposed that in the current climate we prescribe antibiotics as follows.
"If using the feverpain scoring system to decide if antibiotics are indicated (validated in children 3 years and older), we suggest that a pragmatic approach is adopted, and automatically starting with a score of 2 in lieu of an examination seems reasonable. 
Children with a total feverpain score or 4 or 5 should be prescribed antibiotics (we suggest children with a score of 3 or less receive safety netting advice alone)"

I'm going to stick my neck out and suggest that this approach is wrong, for the following reasons:

  1. First and foremost, it contradicts the public health approach to containing the COVID-19 pandemic.  People are being told that if they have a fever without signs of something that looks like a serious illness (difficulty breathing, poorly responsive etc.) they should stay at home, self-medicate and not seek a face to face clinical contact.  This is for their benefit, to protect the health service and to reduce the spread of COVID-19.  Lowering a threshold for prescribing antibiotics for sore throat at this time goes against that move.
  2. Secondly, the RCPCH has misquoted the NICE guidance.  In their speediness to protect clinicians from unnecessary risk, they have missed a word.  Just the one but it the word from the guidance that frequently goes unnoticed.  That word is consider.  It doesn't say give antibiotics for a FeverPAIN score above 4.  It says consider.  I consider that question every time and in most cases the answer is "The likelihood of benefit from antibiotics does not justify the risks."  

I feel (personal opinion) that since there is no mandate to treat low risk children who have no signs of complications of their URTI/tonsillitis, we should default to not prescribing antibiotics in these cases.  To lower our threshold for prescribing instead of raising it at this time of such a high risk clinical environment feels wrong.  It seems contrary to the need to protect children and their carers from the risks of a visit to a GP or hospital and it feels contrary to the drive to reduce the number of people bringing COVID-19 with them to those places.

Again, huge respect to the RCPCH for cutting through the red tape and rapidly producing guidance to protect healthcare workers.  Whenever something is done in that sort of timeframe, it is likely that detail gets missed.  That's where we come in.  We notice the typos and consider the implications.  We ask questions that deserve answers after the fact in lieu of the consultation period that couldn't happen due to the timescale needed.

Edward Snelosn

Wednesday, 25 March 2020

COVID questions No 2 - What PPE do I need to give a nebuliser to a child?

Healthcare workers are rightly concerned about their own health and want to avoid catching COVID-19.  Wearing the right personal protective equipment (PPE) for each patient and procedure is part of how we are going to minimise our risk of infection.

At the same time, many places have experienced shortages of PPE, especially the availability of filtering face piece protection (FFP) masks.  It is therefore important that we don't overuse PPE during this COVID-19 pandemic.  I will cover the issue of what the recommended level of PPE is and why in a post in the near future.  In this post I'm going to explore the answer to a very specific issue that has caused a great deal of discussion in the past few days.

Should I be wearing an FFP mask when giving a nebuliser to a child?

In order to answer that question, I'll need to answer a few other questions first.  The issue of level of PPE recommended by Public Health England (PHE) is said to be related to whether the patient contact involves an aerosol generating procedure, droplets or neither.

What is the difference between a droplet or an aerosol?

Essentially the difference is size.  An aerosol is defined as a droplet <10µm in diameter.  The significance of this is that it is large enough to carry a virus but small enough to bypass a standard droplet resistant mask (surgical mask) and enter the respiratory tract.

Is a nebuliser an aerosol generating procedure?

A nebuliser is not an AGP within the definition that is pertinent to this issue.  A nebuliser mask does create aerosol but the aerosol is water and drug only. (unless you are doing it very wrong indeed!  Don't get the child to spit in the chamber before you turn it on.)  The mist that you see coming out the side is not contaminated with virus.

The science of what happens next is that any aerosol from the nebuliser that comes in contact with the respiratory tract sticks where it lands.  If the child coughs, what comes out is droplets, for which a standard surgical mask is protective.

There is good evidence that nebulisers do not create a high risk of infection to health care workers.

Why is high flow oxygen therapy (HFOT) on the list of aerosol generating procedures then?

That is an excellent question and one that I asked when I saw the list.  The answer is that the list is probably badly named.  In reality the list is made up of a combination of AGPs, high risk procedures and procedures that may be high risk but this is as yet uncertain.  HFOT is much closer to nebulised therapy than it is to bag-valve-mask ventilation or CPAP so it may be low risk.  As a relatively new therapy, it is a sensible precaution to treat it as high risk procedure.  However it is probably misleading to call HFOT an AGP.

So here's the bottom line:

As a final note, metered dose via spacer is at least as effective and often preferable.

Keep sending your COVID-19 questions.

Edward Snelson

Monday, 23 March 2020

COVID Questions: No 1 - Should clinicians recommend the use of ibuprofen in a child with suspected COVID-19 infection?

As the COVID-19 pandemic gains momentum, we're all going to find ourselves either much busier or stuck at home.  Over the next few weeks I intend to publish a series of short articles for the FOAMed community, to provide some coffee break sized learning for clinicians on the front line.  If you have any COVID questions of your own, please send them to me.

These posts will not be heavily referenced, if at all.  We are in the very early stages of gathering evidence and the risk with early evidence is that it can be very misleading for various reasons.  Much of what is coming out from this crisis is a renaissance of pragmatism.  That pragmatism is born out of necessity but is based in the common sense and experience of the clinicians who look after children.  Together we can figure out what's truly important and cut through the evidence, without ignoring it.

The first question is: Should we recommend the use of ibuprofen for symptomatic relief in a child with a respiratory tract infection?

France's health minister, Olivier Véran created a great deal of anxiety for both clinicians and the public when he said that people should avoid using ibuprofen because it may make COVID-19 infection worse.  This prompted a variety of responses from organisations around the world.  Some recommended against using ibuprofen and some stating that there was no evidence that it made COVID-19 infection worse.

Why was there such a disparity of recommendations?  The answer is that your view will depend on your perspective.

Is there a possibility that ibuprofen could make COVID-19 infection worse?  Yes.  There is a hypothetical risk because the anti-inflammatory properties of ibuprofen include some elements of the immune response.

Is there any evidence that this biochemical effect has any clinical effect?  No.  There is no clinical evidence that ibuprofen actually makes COVID-19 infection worse.

So with a hypothetical harm and no evidence that it is real, what should you recommend?  That depends on whether you think that being able to take ibuprofen is important.  If not, then you may as well avoid it.  I would argue that there are plenty of reasons to think that avoiding the use of ibuprofen is harmful in children with respiratory tract infection.

It is arguable that the single greatest risk of avoiding Ibuprofen is the unnecessary exposure to infection.

Children with uncomplicated respiratory tract infections are best managed symptomatically.  Although parents often seek a clinical assessment, this rarely adds anything other than reassurance in the child who has no respiratory distress, signs of sepsis or dehydration.  In normal circumstances, the clinical assessment itself is low risk.  These times are not normal circumstances.  Any healthcare setting is currently extremely high risk for acquiring COVID-19 infection, so anything that brings you to the doors of a hospital or community clinical environment is itself dangerous.

It therefore follows that anything that avoids this attendance is protective.  Analgesia is a good way of helping a child with a respiratory tract infection to feel well and behave in a way that lets the parent know that they are not dangerously unwell.  It is also a good way to give the child the best possible chance of hydrating orally, by resolving their sore throat, sore ear or general malaise.

It is interesting that the initial flurry of recommendations against the use of ibuprofen was followed by a steady stream of statements that there was no evidence for such avoidance and a series of retractions and clarifications.  I think that the about turn was brought about by an alliance of evidence based medicine purists and front-line pragmatists who recognised that symptomatic relief is under-rated and has a genuinely important role in these times.

Even if you have genuine anxieties about the use of ibuprofen in children with potential COVID-19 infection, I would suggest the following principle:
While avoiding ibuprofen may feel safe, my opinion is that ibuprofen may be useful as a way to keep children and the adults who care for them safe by avoiding uneccessary clinical contact.

Edward Snelson