Hypertensive Emergencies

Objectives

To outline the management of patients presenting to deployed medical facilities with hypertensive emergencies. 

Scope

This guideline intends to cover the initial investigations and management of patients presenting to the deployed medical treatment facilities with new uncontrolled hypertension. It includes the definition of hypertensive emergencies, management, and onward care.  

Audience

This guideline is intended for the use of registered healthcare professionals fulfilling a general role in forward medical locations or in an Emergency Department on deployed operations. 

Initial Assessment & Management

Definitions:  

Clinical manifestations of acute hypertension- mediated organ damage: 

• Eye signs: Grade 3-4 hypertensive retinopathy (flame haemorrhages, cotton wool spots, +/- papilloedema) 

• Brain imaging - Haemorrhagic/ ischaemic stroke 

• Acute coronary syndrome  

• Heart failure 

• Acute renal failure  

Clinical presentation: 

Highly variable, may include- 

• Severe generalised headaches, lethargy, nausea, vomiting, confusion, seizures 

• Visual field defects 

• Chest pain 

• Features of heart failure feature 

Initial Management 

Observations

Heart rate, BP (in both arms, correct cuff size), O2 saturations 

Recheck BP to confirm severe hypertension  

Address confounding factors e.g. pain/ anxiety 

Focused history of drugs use e.g. cocaine/amphetamines  

Examination

Cardiovascular exam (murmurs or signs of heart failure) 

Neurological exam  

Fundoscopy looking for eye signs above

Investigations

12-Lead ECG – LVH by voltage criteria, signs of ischaemia  

Urine dip - blood & protein  

Key Message:  Pregnancy test for all women childbearing age.  Consider pre-eclampsia or eclampsia if positive (management not covered in this guideline) 

Treatment

Acute severe hypertension/ Hypertensive urgency:  

• Reduce BP over days to weeks - managed with oral medication at R1 - At time of publication there may be no available pharmacological options at Role 1, necessitating urgent evacuation to the correct MTF. 

Acute severe hypertension with EYE SIGNS ONLY: 

• Reduce BP within days, generally with oral therapies, aiming for gradual reduction to reach target BP within weeks.  

• BP lowering target example: Aim to reduce BP <200/120 mmHg over 24 hours, then to <160/100 mmHg over a week and then to <140/90mmHg within 6–12 weeks 

• Consider management at R1 with regular reviews and Aeromed to UK  

Hypertensive emergency: 

• Likely to require IV therapy – consider early transfer to R2 – R3 

• See specific management below 

Advanced Assessment & Management

At all times patients should be moved to the correct MTF so that they can receive optimal monitoring and management according to clinical presentation/ severity 

Investigations:  

Bloods - Full blood count, U+E’s, cardiac enzymes, thyroid function (as available) 

Chest x-ray – if suspicion of heart failure or aortic dissection  

Echocardiogram – if suspicion of heart failure or aortic dissection  

CT aorta – if suspicion of aortic dissection and to exclude coarctation  

CT brain – if reduced GCS to exclude intracranial haemorrhage 

Treatment: 

The management of hypertensive emergency is specific to the clinical manifestation of hypertension- mediated organ damage (see below). 

Key message/Warning: Careful risk/ benefit assessment for excessive and rapid reduction in BP which can also result in life threatening end organ damage   

Hypertensive encephalopathy: 

Aim to reduce initial MAP by 20-25% within the first hour 

After initial BP lowering, maintain MAP for the next 2-6 hours to ensure well tolerated 

If tolerated gradual reduction to 160/110 over the next 48 hours 

Aortic dissection: 

Aim systolic BP reduction to 120mmHg and heart rate reduction to 60bpm (impulse reduction therapy) 

Haemorrhagic stroke: 

Consider rapid blood pressure lowering in acute intracerebral haemorrhage IF presenting within 6 hours of symptom onset AND systolic BP between 150-220mmHg. Most haematoma expansion occurs in the first 6 hours, so the risk of a reduction in cerebral perfusion is considered to be outweighed by the risk of haematoma expansion.  

Target systolic BP of ≤ 140mmHg, ensuring no drop greater than 60mmHg within 1 hour  

Patients presenting AFTER 6 hours OR initial systolic BP> 220mmHg the benefit for reduction is less clear cut.

If SBP >220mmHg: reasonable to cautiously reduce to a target of around 180mmHg, acknowledging that this is a fine risk/benefit judgement.

If SBP <200mmHg: Maintain current BP unless ongoing neurological decline or imaging suggestive of ongoing contrast extravasation suggests ongoing haematoma expansion. 

Exclusion criteria for rapid BP lowering: 

• Have an underlying structural cause (e.g. tumour, AV malformation or aneurysm) 

• Have a GCS score < 6 (as this is likely caused by a high ICP and altered autoregulation. Its likely that a drop in perfusion pressure will do more harm than good) 

• Are going to have early neurosurgery to evacuate the haematoma (injury due to haematoma related pressure will shortly be removed, so dropping perfusion pressure likely to lead to more harm) 

• Massive haematoma with poor prognosis (reduction in haematoma expansion will have relatively little impact on ICP, so MAP drop will likely just reduce perfusion with minimal impact on intracranial pressure).   

Ischemic stroke  

Routine antihypertensive treatment not required due to risk of reducing cerebral blood flow unless in the following scenarios:  

• BP is greater than >220/120 mmHg – reduce MAP by 10–15% within 24 h to reduce risk of haemorrhagic transformation 

• BP ≤ 220/120 AND thrombolysis is indicated: Thrombolysis unable to proceed unless BP ≤ 185/110 mmHg due to haemorrhagic transformation risk. 

Acute coronary syndrome: 

Prioritise re-vascularisation therapy and adequate analgesia (see STEMI guidelines). Routine immediate reduction in BP not recommended.  

Pulmonary oedema: 

Target MAP reduction of 15-25% while monitoring for features of end-organ hypoperfusion like chest pain, confusion/drop in GCS 

Glyceryl tri-nitrate first line IV antihypertensive +/- IV furosemide  

IV antihypertensive regimes:  

IV Labetalol - 10-20mg IV Bolus, can be repeated every 5 minutes. Total dose should not exceed 200mg  

OR 

Infusion: Dilute to 1mg/ml in 5% Glucose. Start infusion at 2mg/minute and titrate to response usually 1-6mg/minute  

IV Glyceryl trinitrate (GTN) - Start at 10micrograms/min (0.6ml/hour) and increase by 0.3-0.6ml/hr every 30min until target BP is achieved 

ONWARD CARE 

Once BP within target range consider Aeromed out of theatre – liaise with AECC for safe timelines 

All will require follow up and management with RMO in firmbase +/- secondary care specialist input