Hypertensive Emergencies

Question 1

Hypertensive crisis

Answer 1

severe, abrupt increase in arterial blood pressure is associated with
impending or progressive hypertension-mediated organ
damage (HMOD)

Question 2

Hypertension-mediated organ
damage (HMOD)

Answer 2

Resp- Pulmonary Oedema
CVS- Shear stress on vascular walls leading to conditions such as aortic dissection, high afterload leading to increased myocardial O2 demand and MI
Neuro- Retinopathy and encephalopathy
Haem- Coagulation and platelet activation leading to microthrombi formation
Renal- AKI
Gastro- Abdominal pain and vomiting

Question 3

Investigations in hypertensive emergencies

Answer 3

ECG, troponin, BNP, ECHO
CXR
CT Angiogram
FBC, Coag, Bilirubin, LDG
Fundoscopy
Renal function, urine dip
Pregnancy Test

Question 4

Causes of Hypertensive Emergencies

Answer 4

• Essential HTN
• Renovascular atherosclerosis
• OSA
• Cushing, Hyperaldosteronism, Hyperthyroidism, Phaeochromocytoma
• Acute Intoxication- Cocaine, Amphetamines, PCP
• Withdrawal- opioids, BZD
• MAOI and tyrosine
• Takotsubo’s cardiomyopathy
• SAH
• Pain, anxiety, accidental awareness
• High ICP
• Seizures, Serotonin syndrome, GBS, autonomic dysreflexia

Question 5

Treatment aims for hypertensive emergencies

Answer 5

• Treat underlying cause and stop any causative agents
• <25% reduction in BP in 1st hour
• <160/100 in 2-6 hours
• Normalisation of BP by 24 hours
• Arterial line monitoring and IV infusions are preferable to prevent overshoot

Question 6

Hypertensive Emergencies- B-blockers
Acute Aortic Syndromes, PET, SAH

Answer 6

Esmolol and Labetalol, onset 1-10mins, can cause bronchoconstriction, bradycardia and reduced ionotropy.
Esmolol dose 0.5-1mg/kg then infusion 50-300mcg/kg/min
Labetalol dose 0.25-0.5m/kg then infusion of 0.4-3mg/kg/hr

Question 7

Hypertensive Emergencies- Dihydropyridine Ca Channel Blockers
Acute Cardiogenic Pulmonary Oedema

Answer 7

Clevidipine and Nircadapine, onset 2-15min, can cause reduced inotropy, reflex tachycardia, headaches, perihperal oedema.
Clevidipine 1-2mg/hr
Nrcadapine 5mg/hr

Question 8

Hypertensive Emergencies- Other Calcium Antagonists
PET & Eclampsia

Answer 8

Magnesium, onset <1min. Flushing, warmth, weakness, N+V, conduction issues.
Dose 4g over 15mins then 1g/hr for 24 hours

Question 9

Hypertensive Emergencies- Nitric Oxide Prodrugs
Acute Coronary Syndromes

Answer 9

SNP & GTN, onset 1-5mins, SNP cyanide toxicity, coronary steal, tachycardia, raised ICP and headaches, tachyphalaxis, shunt causing hypoxia.
SNP - 0.3-10mcg/kg/min
GTN- 5-200mcg/min

Question 10

Hypertensive Emergencies- a-blockers
Phaeochromocytoma

Answer 10

Phentolamine and urapidil (a1 only) Onset 1-5mins, brady and tachycardia, angina.
Phentolamine 50-300mcg/kg/min

Question 11

Hypertensive Emergencies- Peripheral dopamine agonist

Answer 11

Fenoldopam. Onset 5-15mins. Chest pain, headache, nausea, hypokalaemia. 0.1mcg/kg/min

Question 12

Blood pressure targets- Acute Ischaemic Stroke

Answer 12

<185/105

Question 13

Blood pressure targets- Acute intracerebral haemorrhage

Answer 13

If sys >220 then aim <180
If sys 150-220 then aim 130-150

Question 14

Blood pressure targets- Aneurysmal SAH Unprotected

Answer 14

Sys 160-180

Question 15

Blood pressure targets- Polytrauma or Major Bleeding

Answer 15

Polytrauma- MAP <80
Major Bleeding sys 80-90 or MAP 50-60
If traumatic brain injury MAP >80

Question 16

Blood pressure targets- Post-CABG

Answer 16

<140/85

Question 17

Blood pressure targets- Post descending aorta surgery

Answer 17

MAP 90-100

Question 18

Blood pressure targets- Carotid Endarectomy

Answer 18

Sys<160 or within 20% of pre-op value