We’re back and this time, we’re turning the tables around and offering some tips and tricks to the youth!

Mohammed is joined by Barry and Karl, and they have gone back to school to re-live the trauma of final med exams while exploring hypertensive emergencies.
Those three need to be kept in check, so thankfully our Adult in the Room Dr Emer Kidney is on the case!
Dr Una Kennedy joins us again and sits down with Deirdre for a chat about looking after our wellbeing around exam time.

Callum is back with another great instalment of The Echo Chamber, where he chats with a future star of EM, Natalie Krakoski.

Right, let’s get to it!

Hypertensive Emergencies

Hypertension is a common referral to the ED. The most important role for the ED physician is to out-rule a hypertensive emergency.

Definitions

A hypertensive emergency is defined as a marked elevation in blood pressure associated with end-organ damage.
This may be indicated by a diastolic BP >125mmHg or hypertension with end-organ dysfunction.
What do we mean by end-organ dysfunction?
- Hypertensive encephalopathy
- Intracranial haemorrhage
- Myocardial ischaemia/infarction
- Aortic dissection
- Acute heart failure
- Eclampsia
- Acute renal failure

Causes

Essential hypertension (most cases)
Secondary causes

Drugs
- Cocaine
- Amphetamines
CNS
- Ischaemic or haemorrhagic stroke
Endocrinopathies
- Hyperaldosteronism
- Cushing’s syndrome
- Hyperthyroidism
- Phaeochromocytoma
Cardiac
- Ischaemia
Renovascular
- Renal artery stenosis
Aortic dissection
Non-compliance with anti-hypertensives

Investigations

Blood pressure!
Urinalysis - haematuria, proteinuria
Beta HCG (pre-eclampsia, eclampsia)
CXR
- Pulmonary oedema,
- Widened mediastinum
- Cardiomegaly
ECG
- Left ventricular hypertrophy
- Ischaemia
Bloods
- FBC and blood film
  - Microangiopathic haemolytic anaemia
- Routine clinical chemistry (renal profile)
  - Glomerulonephritis
  - Nephrotic syndrome

Specific aetiologies need specific investigations!

CT Brain
- Haemorrhage
- Encephalopathy
  - PRES (Posterior Reversible Encephalopathy Syndrome)
- Oedema (but MRI is more sensitive!)

POCUS in Hypertension

Lungs
- Pulmonary oedema
Heart
- Pericardial effusion
- Dissection flap
- Apical four chamber and suprasternal views needed
Aorta
- Dissection flap
Renal arteries (if proficient!)
Eyes
- Papilloedema

Management

The management of hypertension in the emergency department is somewhat controversial but here are the key take-home points. Firstly, don’t drop the blood pressure by too much too quickly. Aim for a reduction in blood pressure of 10-20% in the first hour. Beware of goose-chasing though. Don’t go chasing an arbitrary endpoint otherwise you risk causing harm to the patient!

If you remember nothing else as emergency medicine colleagues, medical students, interns or otherwise

DON’T USE AMLODIPINE!!!

Onset of action 6-12 hours
Tendency to prescribe another agent or another dose when it doesn’t work quickly which leads to dose stacking
Subsequent drastic reduction in blood pressure can cause huge harm including the possibility of a stroke

Bottom line: Do not treat hypertension in the emergency department in the absence of end-organ dysfunction - aim for slow reduction with the patient’s GP

Buuuuttttt….. that’s a lot of “Don’ts”, let’s move on to the “Do’s,” shall we?

Labetalol

Agent of choice
Beta-blocker, with selective alpha blocking properties

GTN

Venodilation vs arterial dilatation
Rapid onset and offset
Increases coronary flow - excellent in cardiac ischaemia and also commonly used in stroke with hypertension
May cause tachycardia

Sodium Nitroprusside

Short half-life (1-2 minutes)
Arterial dilatation vs venous
Rapid onset and offset
Adverse outcomes
- Cyanide toxicity
- Tachycardia
- Coronary steal syndrome - promotes myocardial ischaemia
- Can increase intracranial pressure

Phentolamine

Alpha blocker
Catecholamine-induced hypertension

Phaeochromocytoma

Ah the wonderful phaeochromocytoma… a solid option for every MCQ answer. But in truth, what is it?

A phaeochromocytoma is a tumour of the adrenal glands. In 85-90% of cases, these tumours are benign in nature.

Epidemiology

Usually affects 30-50yr olds
10% found in children
Rare: 0.05% of general population, 0.1-0.6% in hypertensive patients
Can affect all ages
1 in 3 can be genetic
- Von Hippel-Lindau disease
- Neurofibromatosis (I)
- MEN type 2
- Hereditary paraganglioma syndrome
Rule of 10’s
- ~10% are extra-adrenal
- ~10% are bilateral
- ~10% are malignant
- ~10% are found in children
- ~10% are familial
- ~10% are not associated with hypertension
- ~10% contain calcification

Presentation

Signs and Symptoms

Hypertension
Constipation
Dizziness
Nausea
Tremors
SOB
Palpitations
Headache
Pallor
Sweating
Abdominal pain
Vomiting
Weight loss
Anxiety

Pathophysiology

Catecholamine-secreting tumour
Derived from chromaffin cells

Triggers

Manual pressure
Massage
Beta-blockers
Physical activity
Emotional stress
Childbirth
Tyramine-rich foods (cheese, red wine, chocolate)

Diagnosis

The work-up for a phaeochromocytoma is extensive. We’ve popped a link to An Endocrine Society Clinical Practice Guideline published in the Journal of Clinical Endocrinology and Metabolism in 2014 for you to explore it further.

But pardon the pun… ESSENTIALLY

Biochemistry
- Plasma free metanephrines
- Urinary fractionated metanephrines (24hour collection)
  - Metanephrine is a metabolite of adrenaline and noradrenaline
Radiology
- CT initially
- MR more suitable for metastatic disease
Genetic testing
- Recommended in all patients

Management

Symptomatic management of any end organ dysfunction
Removal of causative mass
Important to optimise patient’s physiology prior to surgery (alpha blockade)

References

Page last updated:

08/03/2021

S1E13: Hypertensive Emergency | Wellbeing around Exam Time | Medical Student EM focus