February 14, 2020

Aortic dissection: are we doing enough?

As a clinical negligence practitioner working within the cardio thoracic negligence team, I was interested to read a report into the diagnosis of aortic dissection by the HSIB (Healthcare Safety Investigation Branch) part of the Department of Health and Social Care.

The aorta is the major artery that carries oxygenated blood around the body, and its wall is made up of three main layers. An aortic dissection is a rare, but life-threatening condition, in which a split develops in the wall of the aorta.

The split causes the blood to flow between the wall’s layers so the flow of blood to the body is reduced. If it is left untreated, the wall can then completely tear resulting in death; timely treatment is essential. Depending upon the type of dissection surgical repair can be performed.

The HSIB’s investigation was triggered by the death of ‘Richard’, a 54-year-old man, following an aortic dissection in which there was a delay of around 4 hours in making the diagnosis.

The catalyst for the investigation – Richard’s case

Richard was a previously fit man who experienced severe sudden onset chest pain whilst in the gym. Although his pain subsequently improved he still felt unwell and, after returning home, he called 111. Richard was taken to the A&E department of his local acute hospital by ambulance. The ambulance paramedics considered that an acute myocardial infarction (heart attack) should be ruled out.

On arrival at the hospital Richard waited 30 minutes for triage where, despite suspicions of a heart attack by the ambulance crew, he was not prioritised as requiring immediate attention.

Richard was seen by an advanced care practitioner (registered nurse) and a second year trainee doctor, but not a consultant. Although initially well on arrival, Richard deteriorated with increased pain, nausea and vomiting. His ECG was normal excluding a heart attack. His blood tests showed a raised level of a blood chemical known as D-Dimer which identifies a risk for dissection.

After three hours in A&E, there was still no clear diagnosis. Richard was eventually referred to the medical team who considered the possibility of an acute aortic dissection and requested an urgent scan. This scan confirmed Richard had an extensive aortic dissection.

There was then a further hour’s wait for the formal report of the scan before Richard was sent by ambulance to the nearest specialist centre for heart and chest surgery but tragically he suffered a cardiac arrest during the journey and died.

How the investigation was conducted

The HSIB was contacted by the Ambulance Trust regarding Richard’s case and the HSIB Chief Investigator authorised a safety investigation. During the investigation important safety issues were considered:

  • The process of diagnosis in the A&E department.
  • The preparation process regarding hospital transfers.
  • The actual transfer itself.

Further details can be seen in the main report.

What went wrong in Richard’s case

The HSIB found a number of concerning facts as a result of their investigation.

There was a lack of awareness of the common symptoms and signs of acute aortic dissection. Furthermore, although the NHS 111 was correct in advising Richard to call an ambulance to go to hospital, he was wrongly advised to take aspirin which can have serious adverse consequences in the case of aortic dissection.

Despite Richard being taken to hospital to rule out a heart attack (in itself a reason to be seen urgently, he still waited over 30 minutes for triage and was then wrongly categorised. During his time in A7E he was not seen by a consultant and there was a delay in escalating his case to the medical team. Who did diagnose his dissection.rise him.

Richard’s x-ray was wrongly interpreted as being normal and then when finally diagnosed he was made to wait a further hour for the formal report of the scan before he could be referred into specialist care. Most concerning of all was that, as the HSIB found, a four hour delay in such cases is not unusual.

Finally, upon being transferred, immediate measures to control blood pressure and heart rate in patients with a diagnosed aortic dissection are recommended. Although these matters were considered before Richard’s transfer, they were ruled out to save the time needed and to avoid the need for a medical escort.

What needs to be done?

The HSIB considered three areas of improvement, to avoid the same event occurring again.

The present hospital triage system does not include aortic pain as a separate underlying cause for chest pain. This should be added to raise awareness of acute aortic dissection as a potential cause.

There should be national evidence-gathering to detect and manage patients with acute aortic dissection who present to A&E departments. This would then lead to a wider strategy to manage non cardiac chest pain.

There is a lack of detailed and accurate data relating to the incidents of aortic dissection and patient outcome in England. If this data were obtained it would help to understand the true scale of the problem and identify where any further intervention may assist.

What is the wider risk of death from acute aortic dissection?

There are approximately 2,500 cases per year in England and around 20% of patients with acute aortic dissection die before reaching any hospital. 50% die before reaching a specialist centre.

Acute aortic dissection is a rare cause of chest pain and many staff in non-specialist hospitals may be unfamiliar with the condition and its presentation. A delay in diagnosis of acute aortic dissection occurs in between 16% - 40% of cases.

It would appear therefore that Richard’s case, although avoidable, is not necessarily a rare occurrence. We hope that the recommendations of the HSIB are taken on board and more will be done to reduce the incidence of missed and delayed diagnosis of this life-threatening condition.

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