Moderate arterial hypertension

Systolic arterial pressure (SAP) ≥140 mmHg or a diastolic arterial pressure (DAP) ≥90 mmHg.

Severe acute hypertension

Systolic arterial pressure [SAP] >180 mmHg and/or diastolic arterial pressure [DAP] >110 mmHg with, new or worsening end-organ dysfunction, requiring hospitalization.

Hypertensive emergencies

Severe hypertension associated with acute, life-threatening target-organ injuries.

Hypertensive urgencies

SAP > 180 mmHg and DBP > 120 mmHg but are not associated with imminent acute end-organ injury.

Organ system

Causes

Decompensated essential hypertension

Discontinuation of antihypertensive drugs

Secondary causes

CNS

Pain, Anxiety and stress, Delirium, Withdrawal symptoms,

Intracranial hypertension.

Respiratory system

Respiratory distress, Hypoxemia, Hypercarbia

Renal system

Urinary retention, Renal failure,

Hypervolemia.

Metabolic

Hypoglycemia,

Steroid administration,

Pheochromocytoma, Cushing’s syndrome,

Intoxication,

Substance abuse and overdose.

Organ system

Types of injury

Cardiovascular

Myocardial ischemia /infarction.

Unstable angina.

Heart failure and pulmonary edema.

Aortic dissection.

Central nervous system

Transient ischemic attack.

Stroke.

Acute encephalopathy.

Cerebral edema.

Retinal hemorrhages.

Renal

Acute renal failure.

Microhematuria.

Proteinuria.

Electrocardiogram (ECG): ST, T wave changes, evidence of left ventricular hypertrophy.

Complete blood count/ peripheral blood smear: anemia, evidence of hemolysis.

Urea, creatinine and lipid profile.

Cardiac enzymes, Brain natriuretic peptide (BNP).

Urinalysis with microscopic examination: hematuria and proteinuria.

Chest radiography: cardiomegaly and pulmonary congestion.

Thyroid function test.

Non-contrast computed tomography of the head (if neurological findings are abnormal).

Echocardiogram: left ventricular dysfunction, valve abnormalities, wall motion abnormalities.

Renal artery imaging (if renal artery stenosis is suspected)

Other evaluations are guided by clinical presentation such as for pheochromocytoma; urinary VMA/ metanephrines /5-HIAA.

Plasma cortisol and dexamethasone suppression test: Cushing’s syndrome.

Within minutes to 1 hour -lower mean arterial BP by 15-25% or diastolic pressure by 10 – 15% or approximately 110 mmHg.

Within the next 2-6 hours - further reduce the BP to 160 mmHg systolic and 100-110 mmHg diastolic.

Over the next 24 to 48 hours - Normal BP may be targeted.

Intensive care unit admission and intra-arterial monitoring.

Intravenous antihypertensive agents.

Blood pressure control can be slower over several hours (24-72 hrs.)

Oral medication with rapid onset of action occasionally intravenous agents.

Drugs

IV dose

Main side effects

Main clinical indications

Metoprolol (selective β₁ blocker)

5mg every 3 min over 1-30 min.

Max dose: 15 mg.

Infusion: not recommended.

Hypotension,

Heart failure,

Heart block,

Dizziness,

Fatigue,

Depression,

Bronchospasm,

Diarrhea,

Pruritis,

Rash.

Cardiac ischemic syndrome with arterial hypertension with normal heart function.

Labetalol

(α₁β₁β₂ blocker)

Bolus: 20-80 mg every 10 min.

Max dose: 300 mg.

Infusion: 0.5-2 mg/min.

Nausea,

Scalp tingling,

Bronchospasm,

Dizziness,

Heart block,

Orthostatic hypotension.

Most hypertensive emergencies

Hypertension in neuro-critically ill patient.

Pregnancy

Caution in heart failure.

Esmolol

(Selective β₁ blocker)

Bolus: 500 μg/kg (over 1min).

Max dose: 300 μg/kg/min.

Infusion: 50-300 μg/kg/min.

Arterial hypotension,

Bronchospasm,

Heart block.

Hypertensive emergencies with normal or high cardiac output.

Aortic dissection.

Nitroprusside (nitric oxide donor)

Bolus: not recommended.

Max dose: 300 μg/kg/min (<1hr).

Infusion: 0.25 – 4 μg/kg/min.

Hypotension,

Tachycardia,

Headache,

Cyanide and thiocyanide intoxication,

Nausea,

Flushing,

Vomiting,

Muscle spasm,

Pulmonary shunt.

Hypertensive emergencies especially Aortic dissection

Caution in renal and hepatic failure

Nitroglycerine (nitric oxide donor with predominant venular action)

Bolus: not recommended.

Max dose: 300 μg/ min.

Infusion: 5-300 μg/min.

Hypotension,

Headache,

Dizziness,

Vomiting,

Tachyphylaxis,

Meth-hemoglobinemia.

Hypertensive emergencies especially associated with an acute coronary syndrome, volume overload or pulmonary edema.

Furosemide

(diuretics)

Bolus: 20-40 mg.

Max dose: 200 mg/dose or 160 mg/h.

Infusion: 10 – 40 mg/h.

Hypokalemia,

Hypovolemic,

Hypotension,

Metabolic alkalosis,

Ototoxicity,

Thrombocytopenia,

Pancreatitis,

Interstitial nephritis,

Hyperglycemia,

Hyperuricemia,

Hypertensive emergencies associated with hypervolemia and/or heart failure.

Diltiazem

(Ca channel blocker)

Bolus: 0.25 mg/kg over 2 min.

Max dose: 15 mg/h.

Infusion: 5 – 15 mg/h.

Bradycardia,

AV block,

Hypotension,

Cardiac failure,

Peripheral edema,

Headache,

Constipation,

Hepatic toxicity.

Hypertensive emergencies associated with normal heart function and tachyarrhythmia.

Hydralazine (arteriolar vasodilator)

Bolus: 10-20 mg every 4-6 h.

Max dose: 40 mg/dose.

Infusion: not recommended.

Hypotension,

Tachycardia,

Headache,

Facial flushing,

Angina pectoris,

Vomiting,

Paradoxical hypertension.

Lupus-like syndrome.

Hypertensive emergencies esp. severe hypertension in pregnancy.

Drugs

IV dose

Main side effects

Main clinical indications

Dexmedetomidine

(Central α₂ receptor agonist)

Bolus: 1 μg/kg/min over 10 min.

Max dose: 1.5 μg/kg/h.

Infusion: 0.2-0.7 μg/kg/h.

Hypotension,

Bradycardia,

Fever,

Nausea,

Vomiting,

Hypoxia,

Anemia,

Hypertensive emergencies associated with hyperactive delirium or withdrawal syndrome,

Methyldopa

(Central α₂ receptor agonist)

Bolus: 250-100mg 6-8hrly.

Max dose: 1000mg 6hrly.

Infusion: not recommended.

Peripheral edema,

Fever, depression,

Sedation,

Dry mouth, bradycardia,

Hepatitis, Hemolytic Anemia,

Lupus-like

Syndrome

Hypertensive emergencies, particularly

in pregnant patients.

Use limited by

adverse effects.

Enalaprilat

(ACE inhibitor)

Bolus: 1.25-5 mg every 6 h.

Max dose: 5 mg every 6h.

Infusion not recommended.

Headache,

Hypotension,

Worsening of renal function,

Hyperkalemia, Angioedema,

Cough,

Agranulocytosis.

Hypertensive emergencies associated left ventricular dysfunction; caution in hypovolemia.

Pregnancy-induced hypertension

● Drug of choice: labetalol, nifedipine, amlodipine, methyldopa, hydralazine, and magnesium sulfate.

● Angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, direct renin inhibitors, and sodium nitroprusside are contraindicated.

Acute Aortic dissection

● Drug of choice: Esmolol.

● Rapid and immediate reduction of blood pressure within 5 to 10 min are needed for patients with acute aortic dissection.

● The target blood pressure goal in these patients is a systolic blood pressure below 120 mmHg.

● If the blood pressure remains elevated after beta-blockade, a vasodilator such as intravenous nitroglycerin or nitroprusside may be administered.

Adrenergic crisis: (Pheochromocytoma or by a hyperadrenergic state caused by the use of cocaine, amphetamines, phencyclidine, or monoamine oxidase inhibitors or by abrupt cessation of clonidine)

Drug of choice: α blockers like phentolamine and addition β blocker is added if required.

Acute pulmonary edema

Drug of choice: Intravenous nitroglycerin.

Beta blockers are contraindicated.

Acute myocardial infarction or unstable angina pectoris

Drug of choice intravenous: Esmolol.

Intravenous nitroglycerin may also be administered if needed. The target blood pressure is less than 140/90 mmHg in patients with acute myocardial infarction or unstable angina pectoris who are hemodynamically stable.

Acute renal failure

Drug of choice: nitroglycerine, nitroprusside, labetalol

Newer drugs: clevidipine, fenoldopam, and nicardipine.

Post-operative hypertension

Drugs of choice: esmolol, nitroglycerin, and nicardipine.

Neurological hypertensive emergencies

Drug of choice: labetalol, esmolol, and ca channel blockers.

Nitroglycerine, Na nitroprusside should be avoided.

IV injection: 20mg labetalol (4mL) undiluted over 2 minutes.

Repeat every 10 minutes (titrated to blood pressure) to a maximum of 4 doses (80 mg = 16mL).

If 2 bolus doses are insufficient to control blood pressure, consider IV therapy via infusion.

IV infusion: Preparation :5mg/ml (each ampoule contains 4 ml=20 mg).

Draw 2 ampule of 8 ml labetalol (i.e., 40 mg) and start at 2 ml/h (10 mg/h).

Titrate to stabilize blood pressure by adjusting (doubling, maintaining or halving) the infusion as required every15 to 30 minutes to a maximum dose of 80 mL/hour (160 mg/hour).

Weight (kg)

Nitroglycerine /SNP Dose: mcg/kg/min

0.1

0.5

1

2

5

8

10

5

0.06

0.3

0.6

1.2

3

4.8

6

10

0.12

0.6

1.2

2.4

6

9.6

12

15

0.18

0.9

1.8

3.6

9

14.4

18

20

0.24

1.2

2.4

4.8

12

19.2

24

25

0.3

1.5

3

6

15

24

30

30

0.36

1.8

3.6

7.2

18

28.8

36

35

0.42

2.1

4.2

8.4

21

33.6

42

40

0.48

2.4

4.8

9.6

24

38.4

48

45

0.54

2.7

5.4

10.8

27

43.2

54

50

0.6

3

6

12

30

48

60

55

0.66

3.3

6.6

13.2

33

52.8

66

60

0.72

3.6

7.2

14.4

36

57.6

72

65

0.78

3.9

7.8

15.6

39

62.4

78

70

0.84

4.2

8.4

16.8

42

67.2

84

75

0.9

4.5

9

18

45

72

90