Chimezie Daniels

Coroner ME Hassell 
Senior Coroner 
Inner North London 
St Pancras Coroner’s Court 
Camley Street 
London N1C 4PP 

 17 September 2021 

Dear Ms Hassell 

Reference Mr Chimezie DANIELS 

Medicines & Healthcare products 
Regulatory Agency 

10 South Colonnade 
Canary Wharf  
London  
E14 4PU 
United Kingdom 

+44 (0) 20 3080 6000

gov.uk/mhra 

I write with reference to your Regulation 28 letter following the inquest into the sad death of Mr 
Chimezie Daniels.  You requested that we take action to prevent similar events of this kind occurring in 
the future.   

I have taken the opportunity to provide supporting information below before providing a response to 
your matters of concern. 

Introduction and regulation of medical devices in the UK 

The Medicines and Healthcare products Regulatory Agency (MHRA) is an executive agency of the 
Department of Health and Social Care and is responsible for the regulation of medical devices, blood 
components for transfusion and medicinal products in the UK.  

The aim of the MHRA Devices Division is to take all reasonable steps to protect the public’s health and 
safeguard the interests of patients, public and users.  We ensure manufacturers of medical devices 
comply with the UK Medical Devices Regulations 2002 to show they meet appropriate standards of 
safety, quality, and performance for as long as a device is in use.  Where possible, we work with a 
range of stakeholders including patients and the public to work towards the promotion of safer medical 
devices and their safe use.   

Manufacturers must demonstrate compliance with the Regulations before a medical device can be 
UKCA or CE marked and placed on the UK market.   Although not mandatory, device manufacturers 
can use designated standards to demonstrate that they are compliant with relevant requirements of the 
Regulations.    

One major area of the MHRA’s responsibilities is to collect, analyse, monitor, and act on information 
relating to safety concerns from a range of data sources including reports of adverse incidents. An 
adverse incident is an event involving a medical device, which produces, or has the potential to 
produce, unwanted effects involving the safety of patients, users, and other persons. These effects 
may arise from shortcomings in the device, its operating instructions, user practice or conditions of 

 use. Adverse incidents may also occur due to patient factors, as not all interventions are suitable for all 
patients and their condition may change over time, requiring a different approach.  

Patient safety is our highest priority and we encourage everyone to report safety concerns to MHRA 
through our Yellow Card scheme.  However, it is mandatory for manufacturers of medical devices to 
report certain incidents to MHRA.  

In general, where an adverse incident occurs the manufacturer of a medical device is responsible for 
carrying out any investigation required and informing MHRA of their findings.  We review their findings 
and actions and will advise on whether additional action is required.  Where necessary we will issue 
safety messages to health and care organisations, patients, and the public.  These types of actions 
help to reduce the risk of similar incidents happening again. 

Incident summary 

The MHRA was informed of the death of Mr Daniels on 26 July 2021 by your Regulation 28 report.  We 
had not previously been notified of the adverse event by the manufacturer, healthcare professionals or 
any other parties involved. 

From the details within your report, Mr Daniels was receiving CPAP therapy when there was a 20-25 
minute interruption to the oxygen supply to the CPAP device.  Although the device alarmed, there was 
some delay in identifying and resolving the cause of the alarm.   

The situation was exacerbated by a number of factors.  There were four other alarms sounding 
simultaneously for four other patients in the bay where Mr Daniels was being nursed, all of which were 
alarming with the same type of alarm.  In addition, the pressure on beds during the pandemic had 
resulted in patients being treated in medical wards. 

Additional information from the minutes of the NHS Homerton University Hospital Board of Directors 
Meeting, 28 July 2021 (published by the Trust on their website) indicates that initially the breathing 
mask was placed on Mr Daniels’ face without the oxygen connection having been plugged into the 
wall.  Although the alarm sounded to alert clinicians to the situation, clinicians were wearing full PPE, 
the environment was loud, and the alarms on the CPAP devices in the ward had been “standardised”, 
so until they looked at the machine it was not possible to identify the reason for the alarm.  The 
clinicians did attempt to reconnect the oxygen tubing but unfortunately did not make a secure 
connection. 

, Head of Legal Services at Homerton 
MHRA were advised on 09 August 2021 by 
University Hospital that the device in question was a Trilogy 202 ventilator manufactured by Philips 
Respironics.  This model is a ventilator for use within a facility which is capable of delivering ventilation 
in a variety of different modes, one of which is CPAP.   

Matters of Concern: 
You have expressed as a matter of concern that the alarms on the device implicated were the same 
regardless of the severity of the alarm scenario (alarm for small leak from mask no different to total 
cessation of oxygen supply), and this is the case for the wider range of CPAP devices used the UK.   

We have considered your request as one to cover ventilators as a whole rather, than limited to models 
which only provide a CPAP function.  To provide a full response to this request, we contacted Philips 
Respironics on 10 August 2021 and asked them to investigate, provide clarification on the reported 
problem and report their findings back to us.  We also asked for a summary of the alarms on the 
Trilogy 202 for all alarm scenarios, how each one sounds, and what message is displayed when they 
are activated. 

 
 
 
 
 
 
 
 
 
 
 
 
 
 Investigation by Philips Respironics 

On 19 August 2021, Philips Respironics provided MHRA with their findings.   

The device was not returned to Philips Respironics for examination, but a copy of the device log was 
received from 
Respironics requested additional information from the healthcare professionals involved. 

 and passed to Philips Respironics for review.  To investigate, Philips 

According to the report from Philips Respironics, Mr Daniels “had been temporarily been taken off the 
Trilogy 202 device to be fed.  When reconnected, the staff forgot to connect the O2 hose to the wall 
outlet. The machine did alarm that insufficient O2 was been delivered to the patient but the staff took 
no note, thinking that the hose had been properly connected.”   

Philips Respironics state that the device alarmed as designed for insufficient oxygen flow and low 
oxygen inlet pressure.  This would include an audible alarm, a warning light and an alarm message 
showing a description of the alarm condition.  No faults were identified with the way the device 
performed.   

Alarms on the Trilogy 202 

Philips Respironics state in the clinical manual provided with the Trilogy 202 that when an alarm 
condition occurs:  
• The alarm LED indicator on the Alarm Indicator/Audio Pause button lights 
• The audible alarm sounds  
• A message appears on the screen describing the type of alarm  
• The remote alarm (if applicable) is activated. 

They have confirmed that there are three levels of alarm on the Trilogy 202.  These are:   

High Priority  

Requires immediate response by the operator.  
The Alarm Indicator/Audio Pause button flashes red. 
A series of beeps sound in the following pattern, which is repeated twice: 3 beeps, 
a pause, and then 2 more beeps. This indicator continues until the cause of the 
alarm is corrected or the audible alarm is paused.  
The alarm pattern is • • •   • •   • • •   • • 
An alarm message is displayed showing a description of the alarm condition 
highlighted in red.    

Medium Priority    Requires prompt response by the operator.  

Low Priority   

The Alarm Indicator/Audio Pause button flashes yellow. 
A series of beeps sound in a 3-beep pattern. This pattern repeats until the cause 
of the alarm is corrected or the audible alarm is paused.  
The alarm pattern is • • • 
An alarm message is displayed showing a description of the alarm condition 
highlighted in yellow.    

Requires operator awareness.  
A solid yellow light appears on the Alarm Indicator/Audio Pause button.  
A series of beeps sound in a 2-beep pattern. This pattern repeats until the cause 
of the alarm is corrected or the audible alarm is paused.   
The alarm pattern is • • 
An alarm message is displayed showing a description of the alarm condition 
highlighted in yellow.    

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 If an alarm is manually reset by the user, the Alarms and Messages screen is removed and the 
Monitoring Screen is re-displayed. If the alarm self-cancels, the Alarms and Messages screen remains 
displayed, but the highlight for the active alarm is removed, the LED is unlit, and the audible alarm 
stops. 

According to the device log provided by 
device alarmed for ‘low oxygen inlet pressure’ (alarm activated 4 separate times), ‘low oxygen flow’ 
(alarm activated 3 separate times), ‘apnea’ (alarm activated 4 separate times), and ‘circuit disconnect’ 
(alarm activated once).  The alarm reset button was pressed but the alarm condition remained and the 
alarms were re-activated by the device.  

, over the period in question (09.11-09.38) the 

The following relevant alarms are taken from the clinician’s manual for the Trilogy 202: 

“Low Oxygen Inlet Pressure  
This is a high priority alarm. It occurs when the oxygen source inlet pressure measures less than 40 
psi. This could be caused by the oxygen source being disconnected from the device, an occlusion in 
the tubing from the oxygen source to the device, or a problem with the oxygen source supply system.” 

“Low Oxygen Flow  
This is a high priority alarm. It occurs when the concentration of oxygen from the device is 10% below 
the FiO2 set point for more than 30 seconds. This could be caused by the oxygen source being 
disconnected from the device, an occlusion in the tubing from the oxygen source to the device, or a 
problem with the output of the oxygen source.” 

“Apnea Alarm  
This is a high priority alarm. It occurs when the patient has not triggered a breath within the time 
specified in the apnea alarm setting. The device continues to operate. The alarm will automatically 
terminate when two consecutive patient breaths are detected that meet the apnea alarm time setting.” 

“Circuit Disconnect Alarm  
This is a high priority alarm. It occurs when the breathing circuit is disconnected or has a large leak. 
The device continues to operate. The alarm will automatically terminate when the circuit is reconnected 
or the leak is fixed.”  

The MHRA have asked Philips to comment specifically on the concerns raised around the alarms 
which activate when a face mask is removed being of the same priority level as the alarm for low 
oxygen inlet pressure.  Philips have confirmed this is by design; their rationale is the situation when 
one of these alarms becomes active “would constitute a possible loss of therapy to the patient and 
should be addressed by the clinician with the utmost importance.”   

Philips have confirmed there are a number of alarms which can be set by the user, as well as some 
which are always on.  The ‘always-on’ alarms which would activate if a patient removed their mask are: 
Check Circuit Alarm, Low Inspiratory Pressure Alarm, and Low Expiratory Pressure Alarm.  

There are however also a number of user settable alarms which would also sound if set by the clinician 
if a patient removed their mask (Circuit Disconnect Alarm, Apnea Alarm, Low Vte Alarm, Low Vti 
Alarm, and Low Minute Ventilation Alarm).  To avoid excessive alarms, it is possible for the clinician to 
deactivate these in specific ventilation modes.  Information on how to do this is provided by Philips in 
their clinical manual.  However, it should be noted that deactivating alarms has the potential to 
introduce additional risk as clinicians will not be notified of changes in the patient’s condition.   

Philips have confirmed that the volume of the alarms can be changed by the clinician from loud (92dB) 
to soft (47 dB).  However, they have no evidence to indicate this was done on the device in use at the 
time of the event.   

 
 
 
 
 
 
 
 
 
 
 
 
 In light of this unfortunate event, Philips have offered additional support and training to the site involved 
to increase confidence in the correct setup and use of these devices.  

Review of other incidents 

This model was first CE marked to be placed on the market in the UK in November 2010.  Around 
88,000 have been sold worldwide in the past 3 years alone. 

Information supplied by Philips Respironics states they are aware of 11 reports worldwide of events 
involving alarms which were not acknowledged or addressed during the last 3 years.  Of these, 8 
involved alarms which were not acknowledged by the caregiver, one concerned a device which 
alarmed but was not acted upon as the family were on another floor, one involved a patient who went 
into cardiac arrest before the caregiver acknowledged the alarm, and one involved a patient who 
desaturated before the caregiver acknowledged the alarm.  None of these occurred in the UK and 
none involved failure of the device. 

A search of the MHRA database of reported adverse incidents and corrective actions relating to all 
types of ventilators over the past 5 years has not identified any similar reports where an inability to 
identify the device fault from the audible alarm tone has been reported.   

We are not currently aware of any significant information from other data sources to suggest a wider 
safety concern. 

Actions taken by the MHRA in response to the Matters of Concern 

1.  We reviewed the designated standard available relating to alarms on medical equipment, ‘EN 60601-1-
8:2007+A11:2017 Medical electrical equipment, Part 1-8: General requirements for basic safety and 
essential performance — Collateral Standard: General requirements, tests and guidance for alarm 
systems in medical electrical equipment and medical electrical systems’.  This standard provides 
guidance to medical device manufacturers on requirements for alarm systems, including how the 
alarms should sound to allow users to prioritise action by level of risk involved.  Philips have confirmed 
that they used the international (ISO) version of this standard during the design of their product.  The 
text is the same in both standards.   

2.  Alarm systems on medical electrical equipment have been designed in this internationally recognised 

format across devices for a number of years, with user training and usability taken into account.  It has 
been developed with contributions from clinicians, engineers, and applied psychologists.  Devices 
designed in line with the standard are considered state of the art in this respect. 

3.  Following a review of all available information, a change in design of all audible alarm severity levels 
would likely introduce new risks and/or increase the risk of confusion on prioritisation.  Use of the 
designated standard in the design of alarm systems is an acceptable method of minimising the risk 
associated with alarm conditions.  User training and manufacturer guidance in the instructions for use 
are used to mitigate residual risks. 

4.  We are engaging with the Association of Respiratory Nurse Specialists to explore how the current 
training programme addresses the issue of audible alarm prioritisation, and whether there may be 
more actions for the health care system to take to mitigate the risk.  We are also engaging with the 
Royal College of Anaesthetists and Association of Anaesthetists for their input into how this issue can 
be addressed. 

5.  The MHRA has also requested information from NHS Improvement’s database of patient safety 

incidents in England; the Learn from Patient Safety Events Service (LPSE) 

 
 
 
 
 
 
 
 
 
 
 
 
 
 https://www.england.nhs.uk/patient-safety/patient-safety-incident-management-system, to identify 
whether they are aware of any pattern in similar reported events.  We expect a response shortly. 

This information will inform whether any further action is required. 

Conclusion 

The audible alarm system in the Philips Trilogy 202 device is based on an internationally recognised 
and well-established standard.  There is currently no evidence to indicate a wider safety concern.  
Therefore, based on the information currently available to us, MHRA do not intend to take further 
action beyond that detailed above.  However, we will review our position should evidence obtained 
during our ongoing engagement with stakeholders and monitoring of safety concerns suggest that 
further action is required.   

Yours sincerely 

Dr 
Chief Safety Officer, MHRA

National Medical Director  
NHS England & NHS Improvement and 
Interim Chief Executive,  
NHS Improvement  
Skipton House 
80 London Road 
London 
SE1 6LH 

9th September 2021 

Coroner M E Hassell  
Senior Coroner  
Inner North London  
St Pancras Coroner’s Court  
Camley Street  
London  
N1C 4PP  

 Dear Ms Hassell, 

Re: Regulation 28 Report to Prevent Future Deaths – Chimezie DANIELS who 
sadly died 26 January 2021  

Thank you for your Regulation 28 Report dated 16 August 2021 concerning the 
death of Chimezie Daniels on 26 January 2021. Firstly, I would like to express my 
deep condolences to Chimezie Daniel’s family.  

The regulation 28 report concludes Chimezie’s death was a result of SARS CoV-2 
infection and pulmonary sarcoidosis.  

Following the inquest you raised concerns in your Regulation 28 Report to NHS 
England regarding  

•  At inquest, I heard that on most CPAP machines, the alarm that sounds for a 
very small leak from the mask is no different from the alarm that sounds for 
total cessation in oxygen supply.  

•  Clinicians told me that it would be much more helpful if very serious matters 
were denoted by an urgent alarm, and less serious matters in another way.  

•  When the alarm on Mr Daniels’ machine sounded, there were four other 

alarms sounding simultaneously for the four other patients in the bay where 
he was being nursed. This gave the determination of the cause of his low 
oxygen saturations an added complexity, particularly at a time in the 
pandemic when there was so much pressure on beds that CPAP patients 
were being nursed on medical wards rather than in the high dependency unit.  
I appreciate that there will not always be an intention to connect to an oxygen 
supply. Nevertheless, I am sure that further consideration can be given to the 
issue that the inquest touching Mr Daniels’ death has highlighted.  

• 

The national patient safety team at NHSEI have provided me with a response below.  

NHS England and NHS Improvement 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 The main area of concern that you raised within the Preventing Future Deaths report 
relates to the alarm sound and whether there should be a different sound for ‘serious 
matters’. This will require a change in the design of the associated medical devices 
which would fall into the remit of the Medicines and Healthcare products Regulatory 
Agency (MHRA).  

The national patient safety team have worked with two national professional 
organisations on general safety concerns relating to non-invasive ventilation/CPAP.  

•  The national patient safety team worked closely with the British Thoracic 
Society during the development of their recently published guidance on 
Respiratory Support Units to ensure that several key safety issues were 
addressed in the guidance.  This included recommendations that ‘local 
protocols should be in place to detect disconnection from CPAP and NIV and 
will include disconnection alarms on machines and defining the protocols for 
the frequency of nursing review especially for patient nursed in side rooms’ 
and ‘all machines should, at a minimum, have a disconnection alarm … where 
patients are nursed in side rooms, the alarm should be audible from outside 
the room.’ The BTS guidance also includes a checklist which provides an 
additional safety intervention and includes checking alarms and that the 
device is actually attached to oxygen. 

•  The national patient safety team continues to work with the Faculty for 

Intensive Care Medicine to develop guidance on the setting up of breathing 
circuits and we will engage with them to include guidance on disconnection 
alarms to ensure staff are aware of what each alarm may be indicating and 
the relative urgency to respond to an alarm. 

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

Yours sincerely, 

National Medical Director  
NHS England & NHS Improvement and  
Interim Chief Executive,  
NHS Improvement