Apr 28 2024 17 mins
The video version of this podcast can be found here:
This video makes reference to guidelines produced by the "National Institute for Health and Care Excellence" in the UK, also referred to as "NICE". Please note that the content on this channel reflects my professional interpretation/summary of the guidance and that I am in no way affiliated with, employed by or funded/sponsored by NICE.
My name is Fernando Florido and I am a General Practitioner in the United Kingdom. In this episode, I go through the concept of Hypertensive Urgency as opposed to Hypertensive Emergency.
I am not giving medical advice; this video is intended for health care professionals; it is only my summary and my interpretation of the guidelines and you must use your clinical judgement.
There is a podcast version of this and other videos that you can access here:
Primary Care guidelines podcast:
· Redcircle: https://redcircle.com/shows/primary-care-guidelines
· Spotify: https://open.spotify.com/show/5BmqS0Ol16oQ7Kr1WYzupK
· Apple podcasts: https://podcasts.apple.com/gb/podcast/primary-care-guidelines/id1608821148
There is a YouTube version of this and other videos that you can access here:
The Practical GP YouTube Channel:
https://youtube.com/@practicalgp?si=ecJGF5QCuMLQ6hrk
The resources consulted can be found here:
Hypertension in adults: diagnosis and management - NICE guideline [NG136]:
· https://www.nice.org.uk/guidance/ng136
The NICE hypertension flowcharts can be found here:
· Website: https://www.nice.org.uk/guidance/ng136/resources/visual-summary-pdf-6899919517
The Clinic BP targets tables can be downloaded here:
· https://1drv.ms/b/s!AiVFJ_Uoigq0mFtrsXeUGOB58DKE?e=J7filE
Worcestershire Acute Hospitals NHS Trust guideline on the Management of Hypertensive crises:
The Worcestershire Acute Hospitals NHS Trust Hypertensive crisis flowchart can be downloaded here:
· https://1drv.ms/b/s!AiVFJ_Uoigq0mRX6no6c5m3ddfEC?e=aPVQ67
NICBH PUBMED
· https://www.ncbi.nlm.nih.gov/books/NBK513351/
Slides MRCP
NEJM article: Acute severe hypertension:
· https://www.nejm.org/doi/full/10.1056/NEJMcp1901117
Approach to HTN urgency in primary care setting
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Transcript
If you are listening to this podcast on YouTube, for a better experience, switch to the video version. The link is in the top right corner of the video and in the episode description.
Hello and welcome, I’m Fernando, a GP in the UK. Today I will touch on a subject which is not really covered by NICE, which is the concept of hypertensive urgency, as opposed to hypertensive emergency. It is an interesting subject which we are going to illustrate with a practical case, so make sure that you stick around till then. For this I have consulted a number of medical publications and guidelines and the links are in the episode description.
Right, so let’s jump into it.
So, let’s start with some definitions.
· Severe hypertension is defined as SBP ≥180mmHg and/or DBP ≥120mmHg
· Hypertensive emergency is defined as severe hypertension associated with evidence of target organ damage.
· Hypertensive urgency is defined as severe hypertension without evidence of ongoing target organ damage. Studies have shown that Hypertensive urgency is two to three times more common than hypertensive emergencies.
We know from the hypertension NICE guideline that for people with a BP of 180/120 or higher we should investigate for target organ damage, that is, we have to differentiate between hypertensive urgency and emergency.
Starting with the history, we should look at possible causes, and non-compliance with antihypertensive drug treatment is the most common precipitating factor. Other possible factors include excess alcohol, anxiety or panic, drugs, either prescribed, over-the-counter, or illicit like cocaine, amphetamines, sympathomimetic agents, nonsteroidal anti-inflammatory drugs, and high-dose steroids.
We will need to consider the past medical history. Systematic reviews have concluded that hypertensive crises occur more often if there is a history of CKD, coronary heart disease, stroke and congestive heart failure and therefore checking whether the patient have these diagnoses is important because they represent both risk factors and consequences of severe hypertension.
In terms of examination, we will ensure that the BP reading is correct, that is, we will take the measurements in both arms making sure that the cuff is the correct size, and take at least two or three readings in the arm with the highest BP.
A study has shown that in up to a third of patients with severe hypertension, the blood pressure falls to less than 180/120 mm Hg after 30 minutes of quiet rest. So, if feasible, we could also try this.
And, in the history and examination we will look for signs and symptoms of possible end organ damage. So:
· In the eye we will look for symptoms and signs of retinopathy such as blurring or loss of vision, dizziness, retinal haemorrhage, and papilloedema,
· In the CNS we will look for symptoms and signs of hypertensive encephalopathy, intracerebral haemorrhage or ischaemic stroke such as headache, nausea, vomiting, confusion, seizures, visual disturbance, focal deficit, dysphagia, abnormal or loss of sensation, changes in mental status (like agitation or lethargy) and ataxia
· In the aorta we will look for symptoms and signs of aortic dissection such as acute severe back pain or chest pain radiating to the back, unequal peripheral pulse or BP measurements, and diastolic murmur of aortic insufficiency
· In the chest we will look for symptoms and signs of:
o Acute coronary syndrome such as chest pain and shortness of breath and of
o Acute pulmonary oedema such as shortness of breath, elevated JVP, decreased lung sounds, hypoxaemia, tachypnoea and bi-basal crackles and finally
· In the kidneys will look for symptoms and signs of acute kidney injury such as oliguria, haematuria, and proteinuria
If there are any symptoms or signs of target organ damage, we will refer the patient to hospital as an emergency.
It is worth saying too that according to NICE, we should send the patient to hospital too if the patient has suspected phaeochromocytoma based on symptoms, for example, labile or postural hypotension, headache, palpitations, pallor, abdominal pain or diaphoresis.
Otherwise, without concerning symptoms or signs, as we know, we should carry out initial investigations such as:
· UEs, FBC, HbA1c, Lipid profile, and TFTs
· Urine dipstick for blood and protein as well as Albumin Creatinine ratio
· Fundoscopy – and, if unsure, we could consider an urgent optician retinal photography or an ophthalmological assessment
· A Chest X-ray
· An ECG and an
· ECHO if there is evidence of LVH on ECG
Okay, so this is all very good in theory, but let’s put it into practice with a fictitious case:
A 54-year-old Caucasian woman without known hypertension comes to see you for an unrelated problem and you decide to check her BP. Her BP is 200/130 mm Hg. She is otherwise asymptomatic. On examination, funduscopy and the remainder of the examination is normal, including urinalysis.
What should we do next?
First of all, she has no symptoms of concern and no signs of end organ damage, so, assuming that the BP measurement is correct and that there are no other precipitating or risk factors, the next step will be to carry out investigations for end organ damage.
But, in practice, we do not have immediate access to chest x-rays and in some places, ECGs. Even if we can do blood tests and check ACR straightaway, the results wouldn’t be available immediately. Besides, our fundoscopy skills may not be perfect and getting an adequate fundoscopy assessment can also take time. Does this mean that we should always send the patient to the emergency department for a full assessment?
Most of us would probably find a BP of 200/130 quite scary. Our imagination may start thinking of all the possible things that could go wrong: neurological problems, cardiovascular events, retinal haemorrhages and acute kidney injury amongst many others.
In addition, we want to be good doctors, we want to do the best for our patients, we don’t want to get patients’ complaints and even less to be the subject of GMC investigations. But above all, we want to have peace of mind and sleep well at night.
So, what do we do?
And the first thing to say is that we have to do what feels right, it is our clinical judgement, and if it feels right to send the patient to the emergency department for a full screen, then so be it. This would be particularly relevant if we consider the patient to be at high risk because of, for example, other co-morbidities such as CKD, CHD or a previous stroke.
But there may be times when sending the patient to hospital may not be possible, or, perhaps, we will try but the medical team may refuse to accept the patient. What do we do then?
So, for then, let’s consider a few things.
As far as we know, this patient does not have any symptoms or signs of end organ damage.
NICE specifically says that when a patient does not have symptoms or signs indicating same day referral, we should carry out investigations for target organ damage “as soon as possible”. So NICE is asking us to use symptoms and signs, that is, history and examination as the basis for our assessment as to whether the patient needs to be seen in the emergency department or not. What carrying out investigations “as soon as possible” means exactly will be open to interpretation, but we should not take it as having to be done in hospital as an emergency.
Also, although repeated episodes of hypertensive urgency may have long-term complications, the immediate risk of hypertensive urgency is relatively low, and some studies have shown only 1 cardiovascular event per 1,000 patients in the week following the presentation. Therefore, the vast majority of these patients can be safely treated in Primary Care with oral antihypertensives.
Also, in the absence symptoms and signs of acute organ damage, there is limited evidence on benefits of immediate emergency blood and other diagnostic tests. A trial of patients presenting with hypertensive urgency in Primary Care showed that only 5% of ordered tests were abnormal, many of them being simply indicative of poorly controlled chronic hypertension. Consequently, although recommended, for most patients these tests are not needed as an emergency.
Also, most of these patients are likely to suffer from chronic hypertension. We know that many of these patients will have had very high blood-pressure readings for months or even years and we also know that for them the BP needs to be lowered slowly.
Why slowly? This is because perfusion of cardiac, renal, and brain tissue is tightly autoregulated in the body. And what does autoregulation mean?
Autoregulation of organ blood flow refers to physiological adaptations that allow organ perfusion to remain relatively constant across a wide blood-pressure range. For example, in chronic severe hypertension, cerebral blood flow is maintained at similar levels as in normotensive people, but its autoregulatory mechanism allows patients to tolerate higher blood-pressure levels without developing cerebral oedema. However, precisely because of this autoregulation, if the blood pressure is lowered too quickly, these patients are at risk of cerebral hypoperfusion, and this can happen even at higher-than-normal BP levels.
Therefore, although our wish may be to see a substantial drop in BP quickly, with no end organ damage, the BP should be lowered gradually, over a period of days to avoid hypotension, syncope, myocardial ischaemia and acute kidney injury which are commonly associated with, for example, the administration of sublingual nifedipine which is no longer widely advocated precisely for that reason.
Limited data suggest that hypertensive patients recover normal autoregulatory responses within weeks after treatment initiation.
Right, so, we have decided that this patient does not necessarily need to attend A&E so we will arrange investigations for end organ damage as soon as possible which, in Primary Care could be blood tests and ACR within 24 hours with available results generally within 48 hours. The availability of ECGs and CXRs may vary from practice to practice but, as long as there are no concerning symptoms, doing them within a few days may be acceptable. Equally, if we do not feel confident about our fundoscopy examination, we could arrange retinal photographs via an optometrist or arrange an alternative ophthalmological assessment, also within a number of days.
Now that we have arranged the investigations, and we have reassured ourselves that we do not need to send the patient to hospital, what do we actually do with the patient?
If the patient is known to have hypertension and the severe hypertension is secondary to, for example, non-compliance with medication, then it is easy. We will restart the medication counselling and monitoring the patient accordingly.
However, for those without a previous diagnosis of hypertension, NICE says that, as long as there are no symptoms or signs of end organ damage, we will confirm the diagnosis by either repeating the BP within 7 day or by reviewing the HBPM or ABPM results also within seven days, and then treat them if the diagnosis of hypertension is confirmed.
But I know that some of you will be thinking: really? Are we really going to let a patient go home for up to a week with a BP of 200/130 just like that?
Well, NICE says “review the BP within 7 days”, so this could mean reviewing the patient much more quickly, for example within 1 or 2 days. But I know that whilst this may be an appropriate management strategy for many patients, for others we, as doctors, would feel happier if we could do something sooner.
And this may also be a fair approach. In fact, although not advocated by NICE, there are other guidelines that recommend starting hypertensive medication straightaway in these situations, for example, the current guideline on the management of hypertensive crises by Worcestershire Acute Hospitals NHS Trust.
So, if you are worried enough to want to start medication straightaway, you could be justified doing just that, even if that means deviating from the NICE guideline.
And the next question is, how should this patient be treated?
Medical publications state that there is little evidence addressing directly what specific agent is best to use in the case of hypertensive urgency, that is a BP of 180/120 or higher without evidence of end organ damage.
This patient is Caucasian and she is under 55 years of age, so according to NICE, we should start her on an ACEI or an ARB.
But this is where some of the guidelines also differ. For example, some guidelines recommend starting what they call “rapid” antihypertensive agents. For example, the Worcestershire guideline advocates starting a 10 to 20 mg daily dose of oral slow release nifedipine if the patient is not on a calcium channel blocker because it can be titrated up as required and it has a faster onset of action compared to amlodipine. When switching to amlodipine, they also recommend an overlap of 1-2 days, during which a patient can receive both Nifedipine and Amlodipine, to allow for the latter to reach adequate therapeutic levels before stopping nifedipine. To minimise the risk of cerebral hypoperfusion, an initial BP target of 160/100 within 6 to 24 hours is generally recommended.
After that, in general, once the hypertensive urgency has been addressed, the treatment options should be guided by NICE recommendations.
Worcestershire Acute Hospitals NHS Trust has created a simple flow chart which you will be able to find in the episode description.
Let’s have a look at it.
So, if the patient has severe hypertension, we will ask ourselves if there is evidence of end organ damage. If the answer is yes, then we will treat this as a hypertensive emergency, we will admit the patient and consider lowering the BP with IV medication.
If on the other hand, there is no evidence of end organ damage, then we will treat it as a hypertensive urgency that may not need admission and may be treated with oral medication. This could be nifedipine slow release orally or simply restarting usual antihypertensive medication in the case of non-compliance.
In summary, we must distinguish hypertensive emergency from hypertensive urgency. Short-term risk for serious cardiovascular events is minimal with hypertensive urgency and most of these patients can be safely treated in the Primary Care. Referral to the Emergency Department, aggressive BP reduction, and immediate diagnostic tests are generally unwarranted unless we have specific concerns. BP control is best achieved with the initiation or adjustment of long-acting oral antihypertensive medications although more rapid agents such as oral slow release nifedipine can be used if a faster onset of action is necessary. We should also consider and address any other possible precipitating factors.
Right, so this is it, a review of hypertensive urgencies.
We have come to the end of this episode. Remember that this is not medical advice and it is only my summary and my interpretation of the guidelines. You must always use your clinical judgement.
Thank you for listening and goodbye.