Fern Foster

Association of Ambulance Chief Executives
25 Farringdon Street
London
EC4A 4AB

T:

E:

12th August 2024

BY EMAIL:

HM Area of Buckinghamshire
Senior Coroner Crispin Giles Butler

Dear Mr Butler

FERN FOSTER (DECEASED)

I am writing in response to the preventing future deaths report we received at the Association of
Ambulance Chief Executives (AACE) dated 7th June 2024, and I respond as the Director of Operational
Development and Quality Improvement on behalf of the AACE and NASMeD (National Ambulance Service
Medical Directors group). On behalf of AACE and NASMeD, I would also like to extend our sincere
condolences to the family of Fern.

It may be helpful for us to explain that AACE is a private company owned by the English and Welsh NHS
ambulance services. Its purpose is to support its members, UK NHS ambulance services, in the
implementation of national agreed policy and to act as an interface, where appropriate at a national level,
between them and their stakeholders. It is a company owned by NHS organisations and possesses the
intellectual property rights of the Joint Royal Colleges Ambulance Liaison Committee UK ambulance
service clinical practice guidelines (the “JRCALC guidelines”). AACE is not constituted to mandate or
instruct ambulance services however it has national influence via the regular meetings of ambulance chief
executives and chairs along with a network of national specialist sub-groups. NASMeD is one of our
national director groups, and its members are the medical directors of the English and Welsh NHS
ambulance services. The purpose of NASMeD is to improve clinical safety and quality of care by reducing
unwarranted variation, sharing best practice, leading clinical research across the NHS ambulance services
and overseeing the development of the JRCALC clinical practice guidelines.

We note the other relevant organisations named in this PFD report, namely:

 NHS England (NHS Pathways),
 National ambulance resilience unit (NARU)
 National Coding Group (Central Ambulance Team),
 Emergency Call Prioritisation Group (ECPAG)

With regard to your first matter of concern:

The process for triaging and prioritising ambulance attendance to an incident involving the suspected
ingestion of sodium nitrate or sodium nitrite (intentionally or otherwise) does not provide sufficient
opportunity for travel, attendance, conveyance to hospital for emergency treatment and/or provision of
antidote treatment at scene, which may provide the only likely means of prevention of death where
sufficient quantity has been ingested.

The process for triaging and prioritising ambulance attendance is not within the remit of AACE or NASMeD.
The categorisation of 999 calls is overseen at a national level through the NHS England clinical coding
group which reports to Emergency Call Priority Advisory Group (ECPAG). The algorithms for NHS

1

 Pathways and Medical Priority Despatch System (MPDS) are overseen by the owners of the product. In
England currently six ambulance trusts use a system called MPDS and the other four use NHS pathways.

With regards to your second matter of concern:

The carrying by ambulance services of appropriate antidote medication for on-scene administration (such
as Methylene Blue), whilst trialled elsewhere, is not part of regional or national protocol. Swift access to
this in circumstances where sodium nitrate or sodium nitrite ingestion is suspected, and timings mitigate
against survival by the time of arrival at the nearest Emergency Department, could prevent future deaths
in some cases.

Firstly, it must be noted that neither AACE or NASMeD has the authority to mandate the carriage of any
specific drugs, including antidotes, by NHS Ambulance Services. The decision as to which drugs each
ambulance service carries is made by that individual NHS ambulance Trust, authorised by the Medical
Director.

We have considered whether to recommend that ambulance services carry a specific antidote to sodium
nitrate/nitrite poisoning such as methylene blue, and whether to include this in our JRCALC guidance. We
have liaised with a number of our partners and have come to a decision that it is not appropriate to
recommend that all ambulances carry the antidote, nor that all paramedics should be trained in its use or
included in our JRCALC guidance.

We are currently reviewing and updating our overdose and poisoning JRCALC guidance for paramedics,
and we will be including sodium nitrate/nitrite poisoning as an example of a chemical that can be ingested.
The guidance will recommend that paramedics consult the National Poisons Information Service (NPIS)
database (TOXBASE) and where necessary use the NPIS 24-hour, seven-day telephone advice line for
details of the effects of specific substances and advice around possible toxic doses. Where a potentially
or immediately life threatening substance has been taken, rapid conveyance to hospital will be
recommended.

We have liaised with and specifically asked for an expert opinion from the National Poisons Information
Service. The response we received was that there is currently no evidence to recommend the routine
carrying of methylene blue antidote by ambulances. They felt that more studies and evidence is required.
They suggested the approach should be for paramedics to immediately administer 100% O2 and then
rapidly transfer the patient to an emergency department ready to assess and manage the patient.

We are aware of a trial of the use of methylene blue in West Midlands ambulance service by HART
(Hazardous Area Response team) paramedics. These paramedics have received additional training and
respond to incidents including industrial accidents and chemical exposures. HART teams also carry
specialist oximeter devices that are needed to recognise abnormal haemoglobins such as MetHb, which
can occur as a result of sodium nitrate/nitrite poisoning. We are aware that NARU will be convening a
clinical sub group meeting to gather insight into advances in clinical practice for HART paramedics and
share information on clinical practice and that the management of toxicological incidents and subject
matter experts will be invited to contribute to the discussions. The proposed agenda will include the
management of sodium nitrite/nitrate poisoning with the potential role of methylene blue within HART
practice and will include a presentation from West Midlands ambulance service of their experience of using
methylene blue. We anticipate the outcome of this meeting will be fed back to us, so that we can look to
support and improve clinical practice within all ambulance services. One outcome may be to expand the
trials of use of methylene blue by HART paramedics and to gather more evidence of its use. We will also
continue our liaison with NPIS.

2

 It must also be noted that JRCALC have been named as an interested party into the forthcoming inquest
of another tragic death from sodium nitrate poisoning. We will continue to do everything possible to be
aware of specific poisoning cases and liaise with partners including the coronial system, particularly where
there may be an increased incidence, so that we can continue to review our clinical guidance and consider
the need for changes to our current clinical guidance.

I hope this response has adequately addressed the concerns that you have raised. If you have any further
questions, please do not hesitate to get in touch.

Yours sincerely

Director of Operational Development and Quality Improvement

3

Nitrite Poisoning and Methylene Blue 

NARU Position 

31st of July 2024 

Regulation 28: Report to Prevent Future Deaths 

The  National  Ambulance  Resilience  Unit  (NARU)  received  a  Regulation  28;  Report  to  Prevent 
Future Death from Crispin Giles BUTLER; senior Coroner for the coroner area of Buckinghamshire 
dated 7th June 2024. 

This related to the tragic death of Fern Elizabeth FOSTER on 8th July 2020. Her cause of death is 
 poisoning and a narrative conclusion was reached.  
noted as 

NARU has been named and requested to respond by 2nd August 2024. This is alongside other 
relevant organisations. These are namely:  

•  National Ambulance Service Medical Directors (NASMeD),  
•  Association of Ambulance Chief Executives (AACE),  
•  NHS England (NHS Pathways),  
•  National Coding Group (Central Ambulance Team), 
•  Emergency Call Prioritisation Group (ECPAG) 

NARU is not a legal entity.  NARU is an organisation created through a contractual agreement 
between NHS England and London Ambulance Service (LAS). Prior to April 2024 this contractual 
agreement was held with West Midlands Ambulance Service University NHS Foundation Trust 
(WMASUFT).   

Under that contract, NARU is required to escalate all Regulation 28: Prevention of Future Death 
requests it receives to NHS England for processing and management.  

The Regulation 28; Prevention of Future Death report was received by NARU on 7th June 2024.  

The next step, corporately is for NARU, is to contact the office within our host Trust that deals with 
Regulation 28: Prevention of Future Death requests so they can provide the appropriate response 
on behalf of the organisation and Trust.   This position statement forms part of that submission to 
our host Trust.  

The specific section of the Regulation 28: Prevention of Future Death report was to address the 
second point of the Matters of Concern. 

This was  

‘The  carrying  by  ambulance  services  of  appropriate  antidote  medication  for  on-scene 
administration (such as Methylene Blue), whilst trialled elsewhere, is not part of regional or national 
 ingestion is 
protocol. Swift access to this in circumstances where 
suspected, and timings mitigate against survival by the time of arrival at the nearest Emergency 
Department, could prevent future deaths in some cases.’ 

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 Firstly, it must be noted that NARU has no authority to mandate the carriage of any specific drugs, 
including antidotes, by NHS Ambulance Services. Except for those decided by NHS Resilience 
(EPRR) as part of the Mass Casualty Vehicles (MCV) which are part of the national interoperable 
capabilities for emergency preparedness to major incidents. 

The decision as to which drugs each ambulance service carries is taken by that individual NHS 
ambulance Trust with authorisation from the Executive Medical Director in conjunction with Chief 
Pharmacist. 

The ambulance service medical directors meet regularly within NASMeD to share learning and 
, is a non-voting member of 
practice development. The NARU Medical Advisor; 
NASMeD and regularly attends these meetings. 

The clinical practice of ambulance service paramedics is supported by the Joint Royal Colleges 
Ambulance  Liaison  Committee  (JRCALC)  which  is  hosted  by  AACE.  JRCALC  publish  Clinical 
Practice Guidelines for UK ambulance services. Historically, these guidelines were published in 
hard copy with supplements. Currently they are provided in an App form (JRCALC Plus App) to 
facilitate regular updates. 

Each ambulance Trust can adopt these clinical practice guidelines in totality or modify sections in 
line with their own local practice and clinical governance procedures. This is under the discretion 
of the Executive Medical Director and senior clinicians. 

Whilst not having a statutory role, NARU is keen to facilitate clinical development to benefit patient 
outcomes, particularly in the realm of response to complex and major incidents. NARU do provide 
oversight  for  the  Hazardous  Area  Response  Teams  (HART)  within  each  English  ambulance 
service. These are teams of paramedics with additional training and safe systems of work to allow 
access to deliver patient care in environments that standard paramedics may be unable to access 
due to risk to themselves. This would include incidents with hazardous materials and chemical 
exposure.  Whilst  NARU  can  direct  the  safe  system  of  work,  it  has  no  ability  to  direct  clinical 
practice. The only expectation is that the HART paramedics can deliver the standard skill set within 
JRCLAC clinical practice. However, a number of ambulance Trusts have expanded the skill set of 
their HART paramedics under the discretion of the medical director as they perceive a need for 
an increased level of clinical care to the patients HART may attend. 

The clinical leadership of ambulance service HART therefore represent a useful resource to gain 
insight  into  advances  in  clinical  practice  for  HART  paramedics  and  NARU  holds  intermittent 
Clinical Subgroup meetings to act as a conduit for information sharing on clinical practice. 
The information gained from these meetings can then be fed into NHS Resilience, NASMeD and 
JRCALC. This facilitates cross organisational learning and can be used to improve clinical practice 
within all ambulance services. 

The next NARU Clinical Subgroup meeting is scheduled for September 2024, though the exact 
date is yet to be confirmed. 

The proposed agenda will include the management of toxicological incidents and subject matter 
experts in the field will be invited to contribute to the discussions. The management of 
poisoning  will  be  discussed  together  with  the  potential  role  of  methylene  blue  within  HART 
practice.  

Part  of  this  discussion  will  include  a  review  of  the  Regulation  28;  Prevention  of  Future  Death 
reports relating to 
 poisonings, together with a presentation from WMASUFT around 
their experience following the introduction of methylene blue into HART practice. 

WMASUFT introduced methylene blue for the treatment of 
poisoning by HART in 
July 2020. This was following a Serious Incident review and Regulation 28; Prevention of Future 
Death report sent to the Trust form a case of nitrite poisoning in 2019. 

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OFFICIAL 

 
 
 
 
 
 
 
 
 
 
 
 
 
 Experience  from  this  project  was  received  by  the  NARU  Medical  Advisor  on  16th  July  2024.  In 
summary, since July 2020 WMASUFT HART have attended 9 cases of suspected 
poisoning. This should be considered in the context of total call volume, representing ~1 in 0.5 
million 999 calls. Of those 9 cases: 

•  4 received methylene blue: 

o  3 received methylene blue at scene and survived to the Emergency Department 
o  1 received methylene blue in the Emergency Department having been conveyed in 
cardiac arrest. They did not respond to treatment and were declared deceased. 

•  5 did not receive methylene blue: 

o  4 were deceased on arrival of the ambulance responders. 
o  1 did not have signs or symptoms of significant nitrite toxicity and had low recording 

of methaemoglobinaemia. 

The  NARU  Clinical  subgroup  will  collate  the  evidence  and  present  a  report  to  NASMeD  for 
consideration.  This  will  be  delivered  in  conjunction  with  guidance  from  subject  matter  experts, 
principally toxicologists from the National Poisons Information Service (NPIS) that can be reviewed 
by NASMeD and AACE representing JRCALC. 

In addition, it should be noted that AACE have approached the NPIS for national expert opinion 
regarding the carriage of methylene blue on ambulances. According to the response received by 
the NARU Medical Advisor on 24th July 2024, this was discussed at the NPIS Clinical Standards 
Group on 4th July 2024. The key part of the response is as follows: 

‘There is currently no evidence to recommend the routine carrying of this antidote by ambulances. 
The evidence from the pilot study was insufficient to change NPIS policy but we are interested in 
the possibility of specialist ambulances carrying it. More studies and evidence are required. 

In most cases, the most useful approach will be for paramedics to immediately administer 100% 
O2 through a NRB mask and then rapidly transfer the patient to an emergency department ready 
to assess and manage the patient.’ 

In view of this opinion the NARU Clinical Subgroup will discuss the potential for wider expansion 
of the WMASUFT trial in a unified format across a number of ambulance Trust HART to gain the 
additional data that would provide evidence to support changes in practice recommendations. This 
would  be  subject  to  agreement  from  the  respective  ambulance  service  Medical  Directors  to 
support their HART units participating. 

This response to the Regulation 28 has been drafted in line with a more detailed clinical response 
written by the NARU Medical Advisor, 
, a Consultant in Emergency Medicine 
and Pre-Hospital Emergency Medicine. This report is attached as Appendix 1 to this response. 

is willing to be contacted should you require any additional information relating to his 

report or this response. 

We wish to express our sincere condolences to the family and friends of Fern for their loss. 

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OFFICIAL 

 
 
 
 
 
 
 
 
 
 
 
 
 Appendix 1 

This  has  been  compiled  by  our  Medical  Advisor, 
FRCS FRCEM DipIMC DipHEPRR 

  MBE  BSc(Hons)  MBChB 

The reference sources for this are from the National Poisons Information Service (NPIS) via the 
Toxbase website and additional open-source literature from the UK and worldwide. 

 Current NARU Position Regarding Methylene Blue  

Methylene blue (methylthioninium chloride) is a recognised treatment for Methaemoglobinaemia 
(MetHb). This is when the iron contained in the haemoglobin molecules changes from Fe2+ to 
Fe3+. This results in a reduced capacity of the haemoglobin in the red blood cells to carry oxygen 
from  the  lungs  to  the  body.  This  is  because  of  two  main  effects  that  result  from  the  change  in 
haemoglobin. Firstly, the MetHb cannot carry oxygen as efficiently as normal Hb. Secondly, the 
MetHb does not release oxygen easily to the tissues. Therefore, this results in the tissues being 
unable to receive oxygen. 

There is a normal low level of MetHb within normal healthy people, usually less than 1%. This 
occurs as a result normal effects on the body. As a result, the body has systems that can convert 
MetHb back to normal Hb via enzymes, though these systems can only cope with a small amount 
of MetHb and will be overwhelmed by significant amounts. 

Therefore,  the  greater  percentage  of  haemoglobin  that  is  methaemoglobin  (MetHb)  the  more 
severe  the  symptoms  and  threat  to  life.  The  effect  of  MetHb  causing  lack  of  oxygen  can  be 
worsened if there are other illnesses that reduce the ability of the body to absorb and distribute 
oxygen. These would include anaemia (low haemoglobin), heart disease and lung disease. 

The harmful clinical effects are related to the percentage of MetHb within the bloodstream. The 
higher the percentage, the more serious the effects. 
The exact percentage that clinical signs and symptoms develop does have a degree of variation 
between patients and a summary of the published guidance below highlights the different  

Percentage 
MetHb 
<10% 
10-20% 

20-30% 

30-50% 

50-70% 

70% 

Patient Appearance 

Clinical Symptoms  

Normal 
Slight Cyanosis (blue 
tinge to skin) 
Cyanosis and chocolate 
brown blood when 
sampled 
Profound cyanosis 

No symptoms 
Mild symptoms, slight shortness of breath, mild 
headache 
Anxiety, headache, lightheaded, slight 
increased pulse rate 

Confusion, fast pulse and breathing rate, low 
blood pressure 
Unresponsive (coma) or seizures, abnormal 
heart rhythms, slowing of breathing 
Death 

The clinical appearance of the patient; blue grey skin discolouration is useful but does not equate 
accurately  to  MetHb  levels.  The  recognition  of  cyanosis,  blue  tinged  skin,  in  patients  with 
pigmented skin can be challenging. 
However, the combination of cyanosis and ‘chocolate brown blood, seen when a patient has an 
intravenous cannula inserted can be used to suggest the level of MetHb is over 15-20%. 

In addition to the lack of oxygen (hypoxia) high levels of MetHb cause acidosis and breakdown of 
the red blood cells leading to further harm. 

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 Diagnosis of Methaemoglobinaemia 

Recognition of MetHb levels is best assessed by a blood test to accurately measure the MetHb 
level. This is easily done in hospital on blood gas analysers. This equipment is expensive in initial 
cost and maintenance. Therefore, these are not commonly carried in the prehospital environment. 
However, a few air ambulance critical care teams carry small mobile versions of this equipment, 
though again they are costly to buy and maintain. 

Waveform oxygen saturation monitors are carried on all front-line vehicles. These use red-infrared 
spectroscopy to give an estimate of how much oxygenated and deoxygenated Hb is in the blood 
stream of the patient. In normal health the level of oxygenated would be over 95%. Though in 
those  with  chronic  lung  disease  and  some  other  conditions  a  level  of  88%-92%  might  be 
acceptable and tolerated by the patient. These normal oxygen saturation probes are not designed 
to monitor MetHb.  In fact, abnormal types of haemoglobin such as MetHb can confuse a standard 
pulse oximeter and result in inaccurate readings of oxygenated haemoglobin. Characteristically 
MetHb  gives  an  artificial  reading  of  ~85%  (82-87%)  regardless  of  whether  the  true  level  of 
oxygenated is higher or lower. Therefore, it can significantly underestimate the low level of oxygen 
the patient is experiencing. 

Specialist  oximeter  devices  that  can  recognise  abnormal  haemoglobins  such  as  MetHb  are 
available. However, these are significantly more expensive than standard saturation monitors. 
These specialist monitors are carried by the ambulance service Hazardous Area Response Teams 
(HART). These monitors are carried by these specialist ambulance response teams due to the 
incidents they are responded to which includes industrial accidents and chemical exposures. 

The exact level of MetHb accurately measured by these monitors is variable and there is some 
data to suggest that levels over 15-20% become less accurate. 

Therefore,  using  a  combination  of  the  following  it  is  possible  to  make  an  appreciation  of  the 
likelihood  of  MetHb  and  approximation  of  the  level  of  MetHb.  Though  this  would  be  more 
challenging  if  other  problems  coexisted  with  the  MetHb.  Several  other  toxins  and  medical 
conditions can create a similar pattern of clinical signs and symptoms. 
The factors would include: 

•  Likelihood of MetHb due to circumstances patient is found in; such as known ingestion of 

toxin likely to cause MetHb. 

•  Cyanosis and chocolate brown blood 
•  Clinical signs and symptoms suggestive of significant MetHb levels 
•  Oximetry readings confirming MetHb >10% 

. 
Causes of Methaemoglobinaemia 

A pathological increase in methaemoglobin levels can occur from a number of factors including 
genetic  predisposition  or  drug  related.  Within  hospital  this  is  most  commonly  related  to  the 
administration  of  certain  types  of  drugs  as  part  of  patient  care,  notably  specific  types  of  local 
anaesthetic.  From  a  prehospital  perspective  the  most  common  cause  is  ingestions  of  toxins, 
notably ingestion of 
 or 
 as a form of suicide 
There has been an increase in intentional ingestion of 
since 2015, with a peak in 2019, though these tend to be clustered. The role of online discussion 
groups and ordering of the substances is recognised in the literature as contributing to these peaks 
of incidence. 

. This may be accidental or intentional.  

 and 

One of the key factors in the management of these deliberate suicide attempts is the fact that often 
very large quantities are ingested in comparison to accidental exposures. This results in very rapid 
high levels of MetHb making the fatality rate higher. 

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 Treatment of Methaemoglobinaemia 

The requirement for treatment of MetHb is guided by the severity of symptoms and percentage 
MetHb within the bloodstream. As previously described these are related, however symptoms of 
low  levels  of  oxygen  being  delivered  to  the  tissues  are  the  key  determinant  of  requirement  for 
treatment. 

The  principal  component  of  treatment  is  to  maximise  delivery  of  oxygen  to  the  tissues  by 
increasing the oxygen levels within the bloodstream. This can be achieved in several ways but 
key treatment for severe MetHb is to use medication to shift the iron within the haemoglobin from 
Fe3+ back to the normal Fe2+, thus improving the oxygen delivery to the tissues. 

Simple measures such as administering high flow oxygen will help maximise the oxygen carrying 
capacity within the normal haemoglobin, and to a small degree encourages the shift from Fe3+ 
back to Fe2+. Therefore, high flow oxygen should form a key part of the clinical response. 

The dosing of methylene blue is guided by clinical presentation and MetHb levels. Hence the ability 
to gain accurate MetHb levels is very useful in directing treatment.  

The dosing guide from Toxbase is as follows: 

•  Severe Life-threatening Cases 

o  2mg/kg in 100ml 5% glucose over 5 minutes 

•  MetHb concentration > 45% 

o  2mg/kg in 100ml 5% glucose over 5 minutes 

•  MetHb concentration 30-45% 

o  1mg/kg in 100ml 5% glucose over 5 minutes 
•  MetHb concentration < 30% with hypoxic symptoms 
o  1mg/kg in 100ml 5% glucose over 5 minutes 

•  MetHb < 30% without hypoxic symptoms 

o  Repeat  MetHb  level  at  30  minutes  and  administer  1mg/kg  in  100ml  5%  glucose 
over 5 minutes if MetHb level does not reduce or if hypoxic symptoms develop. 

It  should  be  noted  that  5%  glucose  is  not  part  of  standard  ambulance  fluid  protocols  and  if  an 
infusion is to be given over 5 minutes this should ideally be delivered by a syringe driver or fluid 
infuser which is not standard paramedic equipment. 

The patient may also present with other signs and symptoms caused by the severe MetHb. These 
could include hypotension (low blood pressure) and seizures. 

The first line response to hypotension would be a fluid bolus which is within the paramedic skill 
set. 

A single, brief seizure does not require treatment, but frequent or prolonged seizures should be 
treated with benzodiazepines, which are within the paramedic skill set. 

Methylene blue is part of antidotes carried in all Emergency Departments when incidents of MetHb 
occur,  albeit  on  an  infrequent  basis.  Plus,  some  medications  used  in  hospital  can  precipitate 
MetHb formation. 

Side Effects of Methylene Blue 

Methylene blue is not without side effects. Severe allergic reactions appear uncommon, but this 
medication is rarely used to the true incidence is difficult to predict. Relatively common symptoms 
are  headache,  nausea  and  vomiting.  Though  these  symptoms  should  be  considered  relatively 

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OFFICIAL 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 insignificant  in  the  context  of  the  sever  symptoms  of 
toxicity. 

  poisoning  and  the  severity  of  this 

One potentially significant side effect is that methylene blue may precipitate serotonin syndrome. 
Serotonin  syndrome  is  when  medications  interact  and  cause  the  release  of  large  amounts  of 
serotonin within the body. Serotonin is naturally occurring chemical that transmits signals in the 
nervous system. The symptoms of serotonin syndrome range from mild to life-threatening. 

These  symptoms  include  tachycardia  (fast  pulse),  hypertension  (high  blood  pressure),  flushed 
skin and hyperthermia (high temperature). There is also commonly agitation, tremor, increased 
muscle tone. This syndrome can not effectively be treated by paramedics. 

The  exact  incidence  of  serotonin  syndrome  in  those  treated  with  methylene  blue  for 
poisoning  is  unknown,  however  the  cases  that  are  reported  in  the  literature  are  very  severe. 
Though that may be due to the fact that only significant cases would gain publication in a peer-
reviewed journal. NPIS might be able to give us additional information. 

Serotonin syndrome usually occurs in those patients taking selective serotonin reuptake inhibitors. 
This is either because of taking excess amounts in overdose or when another medication is given 
that precipitates it. These are medications are very common in the management of mental health 
patients, so there is an increased likelihood the patient group taking 
 as a method of self-
harm will be taking them. So, whilst this risk may be acceptable in those with proven MetHb it may 
not be without confirmation. 

Carriage of Methylene Blue by Ambulance Service 

Firstly,  it  is  not  for  NARU  to  mandate  what  is  carried  on  frontline  ambulance.  This  would  be  a 
decision for each individual ambulance Trust and be guided by JRCALC and NASMeD. However, 
given the role of HART in Individual Chemical Exposure (ICE) incidents we ae keen to understand 
the magnitude of the situation and collaborate with experts to scope the potential benefits of this 
antidote being available. Though it should be recognised a HART response would not be available 
in a timely fashion across England to prevent deaths even if methylene blue were carried by every 
HART unit. 

The use of methylene blue by paramedics would require significant support as it is not within the 
list  of  Schedule  17  medications  under  the  Human  Medicines  Regulations  2012.  Therefore,  a 
Patient Group Directive (PGD) or verbal order from a prescribing clinician would be required for 
them to administer it. This would be in addition to a training package. 

The dose required is 1-2mg/kg body weight and this is given in a glucose solution. 

The dose required to treat a large adult (100kg) would be 100-200mg. This is a significant amount 
that  will  require  storage  within  the  ambulance.  Given  space  is  limited,  we  might  be  faced  with 
decisions as to what would be removed from the ambulance to make room for the methylene blue. 
Therefore, needing to prioritise the medications carried. 

As previously discussed the additional 5% glucose 100ml bags and potentially an infusion pump 
would be significant additional equipment costs and training burden. 

The cost of a full treatment regime for a 100kg adult would be £600 to £1,500 depending on which 
brand were carried. Whilst this sum is insignificant for an individual life saved, if taken in the context 
of that amount for every frontline ambulance in England, that is a substantial outlay.  

There  are  at  least  two  variants  of  the  product  used  within  UK  practice.  Each  would  require  an 
individual  PGD  to  allow  paramedic  administration.  It  is  not  that  common  a  medication  and  we 
would need to understand the production rate and supply chain flow. If this is a rate limiting step 

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 this could have unforeseen consequences if the supply is directed to prehospital providers in large 
quantities to the detriment of hospital supply. 

This then needs to be balanced against the shelf-life of the product plus the frequency of use. 
Particularly in the current health economic climate. This will vary according to exact product, but 
the shelf life appears to be relatively short. (In my Emergency Department we recently received 
additional stock of methylene blue as we had a cluster of 
 poisoning presentations. This stock 
had a shelf life of 8-months. 

This all impacts on cost and frequency of use. This will be predicated on the incidence, which is 
not well defined. 

Therefore, the overall cost burden of equipping every ambulance in the UK with methylene blue 
is likely to be very high and potentially prohibitive in the current financial situation. That is before 
we consider the storage space required and the training burden. 

I also note the recent response from the NPIS Clinical Standards Group that is not supportive of 
the carriage of methylene blue on every ambulance. They remain to be convinced of the need for 
HART  to  carry  this  until  further  evidence  is  provided.  The  preliminary  data  below,  from  the 
WMASUFT trial has been shared with them. 

Following the Prevention of Future Deaths report issued to WMASUFT in 2020 they embarked on 
carrying methylene blue in HART as a trial. I have recently received the interim report which gives 
4 uses in the 9 cases attended over 4 years. This is equivalent to one case for every 0.5 million 
999 calls. So, whilst the incidence of 
poisoning is increasing it is still a very rare occurrence 
for front line ambulance responders. Methylene blue was administered in four of the nine cases. 
Three of these uses seem to be of benefit with survival to the ED. 

One further administration was given in ED when the patient was conveyed in cardiac arrest and 
the ED stock of methylene blue could not be accessed rapidly, they did not manage to resuscitate 
this patient and the patient unfortunately died.  

In the 5 cases when methylene blue was not administered, 4 were obviously deceased on arrival 
of the first attending ambulance crew.  

  ingestion  and  had  mild,  rather  non-
In  the  remaining  case,  the  patient  gave  a  history  of 
specific  symptoms  and  MetHb  waveform  showed  a  non-toxic  level.  So,  administration  was 
appropriately withheld, and the patient conveyed to ED for formal assessment including accurate 
MetHb levels through blood testing. 

The subject of antidotes carried by HART is on the list for discussion at a Clinical Subgroup. The 
advice from this group will be guided by subject matter experts in toxicology and prehospital care. 
Methylene blue and the detection and management of methaemoglobinaemia will be one of the 
topics covered.  Until we understand the frequency, potential benefits and costs we will not be 
able to provide guidance to HART. This could be part of a wider trail across a number of HART 
units to collate more data on patient benefits. 

However, it is still essential it is appreciated that we cannot mandate carriage of any medication, 
neither  on  every  frontline  ambulance,  nor  even  enforce  the  carriage  by  every  HART  unit.  This 
would be dependant on the agreement of the respective ambulance service medical directors for 
each HART unit.  

Unfortunately, even if carriage by HART is accepted and rolled out this may not prevent every 
future death from nitrite-nitrate ingestion due to dose taken and time for HART to attend.  

The  decision  as  to  whether  to  wait  for  HART  or  transfer  the  patient  to  the  nearest  Emergency 
Department, where the treatment is available, would need to be made on a case-by-case basis. It 
would be potentially detrimental if an ambulance crew were to wait at scene for the arrival of HART 

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OFFICIAL 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 with the antidote when this could be achieved in a timelier way by rapid conveyance to the nearest 
ED which will have the antidote. 

Incidence of 

 Poisonings 

A factor in our decision making will be the incidence of 
 poisoning. This is challenging 
to ascertain with accuracy within the UK. A recent literature review by Tusiewicz et al (Toxics 2023: 
11,  832)  demonstrated  a  significant  increase  in  suicide  attempts  and  deaths  through 
ingestion from 2015, peaking in 2020 across the world. This is reinforced by an Australasian study 
relating to 
 suicides by Stephenson et al (Forensic Science, Medicine and Pathology 
2022: 18: 311-318). This review demonstrated 10 deaths between 2000-2019, these only began 
in 2017 with a steep increase to 2019. Many of the recent increase in cases are linked to ability to 
purchase on-line 
 to commit suicide. 
Arguably, if considering the broader scope of preventing deaths then the ability to purchase 

 or websites advocating 

 online should also be part of the solution alongside the availability of antidotes. I am aware 

this subject is part of another Regulation 28: Prevention of Future Death report. 

There  is  undoubtedly  an  increase  in 
resulted  in  several  Regulation  28:  Prevention  of  Future  Death  reports  relating  to 
poisoning.  However,  those  are  often  sent  to  different  responsible  bodies  by  each  Coroner,  so 
neither NARU nor NHSE may be sighted on them all. 
from NHSE EPRR and I have 
reviewed the open access judiciary website to aim to collate all the cases. Though I am not sure 
if additional information may be available via the Chief Coroner or via National CBRN centre. 

ingestion  over  the  recent  years.  This  has 

The coronial information will give the context of those who have died as a result. In addition, we 
will require the incidence of 
poisonings attending the ED. The NPIS actively attempt 
to gain data on these cases, and they request they are contacted if any cases present. This is to 
not only to provide support to the clinical care but facilitate audit and follow up. Therefore, they are 
likely to have reasonably accurate date on those that have not died at scene. 

Future Direction 

The  forthcoming  NARU  Clinical  Subgroup  in  September  has 
  poisoning  on  the  agenda 
alongside  other  toxicological  matters.  We  will  review  the  evidence  from  the  WMASUFT  trial 
alongside the proposed project from YAS. Ideally, we should create a unified trial across several 
ambulance Trust HART units to collate data from across the country. 

A review of all the previous Regulation 28; Prevention of Future Death Reports can assist us. 
I  will  be  meeting  with  NASMeD  and  JRCALC  on  31st  July  to  discuss  a  forthcoming  Coroner’s 
inquest on another nitrite poisoning where JRCALC have been named as an Interested Party. 

In conclusion I would like to express my deepest sympathies to the family of Fern for their loss. In 
addition, my sincere condolences to all other families who have experienced the tragedy of family 
member suicide due to a 

 ingestion. 

Sincerely, 

[Ends] 

MBE BSc(Hons) MBChB FRCS FRCEM DipIMC DipHEPRR 

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OFFICIAL

Mr Crispin Giles Butler 
HM Senior Coroner 
Buckinghamshire Coroner’s Service 
29 Windsor End 
Beaconsfield 
HP9 2JJ  

National Medical Director  
NHS England  
Wellington House 
133-155 Waterloo Road  
London 
SE1 8UG 

29/07/2024  

Dear Coroner, 

Re: Regulation 28 Report to Prevent Future Deaths – Fern Elisabeth Foster 
who died on 8 July 2020  

Thank you for your Report to Prevent Future Deaths (hereafter “Report”) dated 7 June 
2024  concerning  the  death  of  Fern  Elisabeth  Foster  on  8  July 2020.  In  advance  of 
responding to the specific concerns raised in your Report, I would like to express my 
deep condolences to Fern’s family and loved ones. NHS England are keen to assure 
the  family  and  the  Coroner  that  the  concerns  raised  about  Fern’s  care  have  been 
listened to and reflected upon.   

Your  first  concern  relates  to  the  process  for  triaging  and  prioritising  ambulance 
attendance to an incident involving 
, 
and that this does not provide sufficient opportunity for emergency treatment.  

Assessment and prioritisation of cases usually occurs in Urgent and Emergency Care 
(UEC) settings; in this instance the 999 ambulance service. The prioritisation of cases 
by  ambulance  services  is  managed  through  NHS  England’s  Emergency  Call 
Prioritisation  Advisory  Group  (ECPAG).  This  group  has  membership  from  the 
Association  of  Ambulance  Chief  Executives,  National  Ambulance  Service  Medical 
Directors and wider clinical stakeholders, along with the in-house UEC triage product 
(NHS  Pathways)  clinical  leadership.  The  group  reviews  data,  trends  and  clinical 
evidence  (including  NHS  Pathways  data)  provided  from  the  ambulance  Clinical 
Reference Group (CRG) to determine the case-mix in the ambulance categories. The 
NHS Pathways product is then built against these standards, and alignment to these 
standards,  and  other clinical  guidance,  is assured  by  the  National Clinical Advisory 
Group (NCAG) hosted by the Academy of Medical Royal Colleges (AoMRC). 

Overdoses,  whether  intentional  or  accidental,  can  be  challenging  cases  to  assess 
remotely;  many  different  substances,  medicines,  doses  and  combinations  are 
possible.  This  poses  challenges  to  classify  and appraise  the  relative  lethality  of  the 
substances involved and balance this risk against the symptoms and circumstances 
at the time of the call. Where an overdose has occurred, and in the absence of signs 
or  symptoms  indicating  an  immediate  life-threat  (reduced  consciousness  level, 
breathlessness or shock, for example), the lowest disposition that can be reached is 
a Category 3 ambulance response. A higher response will be reached where there are 
symptoms indicating an immediate life threat. 

                                                                                                                       
 
 
 
 
 
 
 
  
 
 
 
 
 
  
 NHS England issued communications to ambulance services and NHS 111 providers 
in 2019 and 2021 in respect of managing overdose cases, and in November 2023 an 
updated version was issued instructing that any case reaching a Category 3 response 
should  have  further  clinical  assessment  within  a  set  timeframe,  or  else  be 
automatically upgraded to a Category 2 response. Further details are set out below. 

“High risk” vs “low risk” substances 

The objective of further remote clinical assessment is to determine the likely threat to 
the patient by gathering the clinical information about the substance(s) ingested and 
their quantities. Clinicians using specific modules of the NHS Pathways product are 
recommended to use TOXBASE® to support their assessment. 

TOXBASE is the clinical toxicology database of the UK National Poisons Information 
Service that clinicians have access to, to help support clinical decision making when 
excess medications have been ingested. 

Health advisors are not clinically trained. Their training ensures an understanding of 
the limits to their scope of practice so that they seek supervisory, or clinical, support 
where  appropriate.  This  includes  instances  where  medical  information,  such  as 
medication names, are volunteered during the assessment and they are not expected 
to understand or identify medication names or drug classifications. 

Enabling  prioritisation  of  cases  for  clinical  assessment,  and/or  automatic 
upgrade 

To support NHS England’s 2019 communication and enable services to identify these 
Category 3 cases to clinicians for priority assessment,  NHS Pathways developed a 
specific  disposition  code  ‘Dx0124  Emergency  Ambulance  Response  for  Risk  of 
Suicide (Category 3)’ in April 2019. This code facilitates improved visibility of overdose 
or  suicide  attempt  cases  within  the  ambulance  dispatch  queue.  These  actions,  to 
develop and deploy this disposition code, were ratified by the former NHS Pathways 
National Clinical Governance Group (NCGG) in February 2019 (this group has been 
superseded  by  NCAG). This was  also approved  by  NHS  England’s ECPAG on 3rd 
July 2019. It was deployed to all service users as part of Release 18 in October 2019. 

In April 2021, NHS England and Improvement, in conjunction with the Association of 
Ambulance Chief Executives (AACE), published a new operational procedure for all 
ambulance  services  in  England  entitled,  “Category  3/  999  Overdose  and  Suicidal 
Ideation  Calls;  Initial  Assessment  of  Lethality/Toxicity  Principles  Document”.  This 
document  followed  a  detailed  review  that  had  been  undertaken  to  consider  agreed 
ambulance control room processes, to ensure that suicidal patients receive the correct 
clinical response. This review had also been the catalyst for NHS England contacting 
all ambulance and NHS 111 services in early 2019 as described above. In this 2021 
document, NHS England set out that, where an overdose is declared, a further clinical 
intervention should take place within 30 minutes and/or the case will be automatically 
upgraded if this does not occur within 40 minutes. In October 2023, a review of this 
document  was  completed  by ECPAG  and  the  National Ambulance  Service  Medical 

 
 
 
 
 
 Director’s Group (NASMeD, Association of Ambulance Chief Executives) to ensure it 
remains  fit  for  purpose.  The  view  from  the  Ambulance  Response  Programme 
Implementation  Group  at  NHS  England,  supported  by  NASMeD,  was  that  cases 
involving suicidal ideation (including overdoses) are often multi-factorial and therefore 
too complex for Health Advisors to apply a definitive disposition without assessment 
by a clinician. Instead, they require an urgent  remote clinical risk assessment in the 
absence  of  priority  airway,  breathing  or  circulation  symptoms  during  triage.  This 
means  that  for  those  cases  which  do  not  automatically  result  in  a  Category  1  or  2 
emergency  ambulance  response,  an  urgent  remote  clinical  assessment  will  take 
place,  pending  which  the  case  will  be  dealt  with  as  a  Category  3  emergency 
ambulance  response.  If,  however,  on  review  the  clinical  view  is  that,  given  the 
individual factors of the case this should be upgraded to a Category 1 or 2 emergency 
ambulance response, this is done without delay. 

NHS Pathways consulted with their Clinical Stakeholder Group (CSG) in November 
2021 and March 2022 to discuss the challenges of dealing with overdose calls. The 
consensus  was  that  Health  Advisors are  not  best  suited  to  dealing  with  medication 
complexities,  such  as  medication  names,  staggered  overdoses,  involvement  of 
recreational drugs, interaction of other medications and other patient specific factors. 
The consensus was that clinical reasoning was required with the use of  TOXBASE, 
and that the current process was most suitable.  

In addition to the core telephony product, NHS Pathways also provides a telephone 
consultation tool called Pathways Clinical Consultation Support System (PaCCS). This 
is for use by experienced clinicians and comprises a suite of clinical templates based 
on  existing  NHS  Pathways  clinical  content. These  templates  are presented  in  a  list 
format which provides the user with a less prescriptive tool, lending itself more to a 
consultation-led assessment rather than triage. Within each clinical template, there is 
additional supporting information and links to approved websites that can be viewed if 
required by the user. In November 2021, as a result of learning from another case, 
NHS  Pathways  enhanced  the  toxic  ingestion  template  in  PaCCS  to  ensure  clinical 
users were given clear and concise information to access TOXBASE, and they were 
also provided with the web link to do so. 

Should national guidance or standards be amended such that toxic substances, where 
identified,  impact  on  ambulance  categorisation  or  disposition,  NHS  England  would 
align the NHS Pathways product accordingly. 

Your second concern relates to the fact that it is not regional or national protocol for 
ambulance services to carry antidote medication for on-scene administration.  

The carrying of specific medications by ambulance services is an operational issue 
and is up to individual ambulance trusts; NHS England does not mandate such issues.    

NHS  England  is  aware  of  a  small  number  of  ambulance  specialist  units  who  carry 
. This antidote is carried by specialist clinical teams for administration 

 
 
 
 
 
 
 , which can 
in cases of 
be measured through an exhaled breath monitor. Clinical feedback suggests it is likely 
that 
would not be used except for severe cases or where there is a 
long journey time to definitive care. 

I  would  also  like  to  provide  further  assurances  on  the  national  NHS  England  work 
taking  place around  the  Reports  to  Prevent Future  Deaths.  All  reports received  are 
discussed  by  the  Regulation  28  Working  Group,  comprising  Regional  Medical 
Directors,  and  other  clinical  and  quality  colleagues  from  across  the  regions.  This 
ensures that key learnings and insights around events, such as the sad death of Fern, 
are shared across the NHS at both a national and regional level and helps us to pay 
close attention to any emerging trends that may require further review and action.   

Thank you for bringing these important patient safety issues to my attention and please 
do not hesitate to contact me should you need any further information.  

Yours sincerely,  

National Medical Director