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Information ⬇

Author(s): David Sprigings and John B. Chambers

Severe hypertension is arbitrarily defined as a systolic blood pressure of >180 mmHg, and/or a diastolic blood pressure of >120 mmHg. Acute management is determined by the clinical context and the presence and type of organ damage.

Intravenous therapy has specific indications, but is potentially dangerous, as an abrupt reduction in blood pressure may cause cerebral, myocardial and renal ischaemia.

Priorities ⬆ ⬇

Outline

Establish the context and comorbidities by focused clinical assessment and investigation (Tables 55.1 and 55.2).

Management of severe hypertension in specific situations is discussed below. If IV therapy is indicated, transfer the patient to CCU, HDU or ITU for arterial blood pressure monitoring and general care.

Acute Aortic Dissection!!navigator!!

  • Make sure adequate analgesia has been given, as pain will contribute to hypertension.
  • Put in an arterial line to allow continuous BP monitoring, and a bladder catheter to monitor urine output.
  • Start labetalol IV (Table 55.3). Give a bolus of 20 mg over 2 min, followed by an infusion of 1–6 mg/min, increasing the infusion rate every 10 min as needed to achieve target systolic BP.
  • Target systolic BP is 100–120 mmHg within 20–30 min, providing urine output remains >30 mL/h, and there is no other clinical evidence of organ ischaemia.
  • If target BP is not achieved with labetalol 6 mg/min, add a nitrate infusion (Table 55.3).
  • Start or increase oral therapy.
  • See Chapter 50 for further management of aortic dissection.

Acute Ischaemic Stroke!!navigator!!

  • See Chapter 65 for the assessment of the patient with ischaemic stroke.
  • If the patient is a candidate for thrombolysis: start antihypertensive therapy if BP is ≥185/110 mmHg.
  • If the patient is not a candidate for thrombolysis, start therapy if BP is ≥220/120 mmHg.
  • Give labetalol 10 mg IV bolus over 1 min, followed by an infusion of 1–8 mg/min, increasing the infusion rate every 10 min as needed to achieve target BP.
  • Target BP is <185/110 mmHg. If BP is not maintained at or below this target, do not give thrombolysis.
  • If target BP is not achieved with labetalol 8 mg/min, add a nicardipine infusion (Table 55.3) at 5 mg/h, and increased the infusion rate by 2.5 mg/h every 10 min to a maximum of 15 mg/h.
  • Target BP is <185/110 mmHg. If BP is not maintained at or below this target, do not give thrombolysis.
  • Monitor BP every 15 min for 2 hours from the start of thrombolytic therapy, then every 30 minutes for 6h, and then every hour for 16h.
  • Start or increase oral therapy.

Acute Haemorrhagic Stroke!!navigator!!

  • If the patient presents within 6h of the onset of intracerebral haemorrhage, with systolic BP >150 mmHg, start antihypertensive therapy.
  • Target systolic BP is 140 mmHg within 6 h and maintained for at least 7 days.
  • Give labetalol or nicardipine by infusion (as for acute ischaemic stroke).
  • Start or increase oral therapy.

Subarachnoid Haemorrhage!!navigator!!

  • Make sure adequate analgesia has been given.
  • If systolic BP is >160 mmHg, start antihypertensive therapy.
  • Target systolic BP is <160 mmHg.
  • Give labetalol or nicardipine by infusion (as for acute ischaemic stroke).
  • See Chapter 67 for further management of subarachnoid haemorrhage.

Hypertensive Encephalopathy!!navigator!!

  • This is rare. Hypertensive encephalopathy is due to cerebral oedema resulting from hyperperfusion, as a consequence of severe hypertension, with failure of autoregulation of cerebral blood flow. Clinical features are summarized in Table 55.3.
  • It may be difficult to distinguish clinically between hypertensive encephalopathy, subarachnoid haemorrhage and stroke. Hypertensive encephalopathy is favoured by the gradual onset of symptoms and the absence (or late appearance) of focal neurological signs. CT should be done to exclude other diagnoses. In hypertensive encephalopathy, neurological status improves with lowering of blood pressure.
  • Target BP is 10–20% lower than initial BP after 1h of therapy, and 25% lower after 24h.
  • Give nicardipine by infusion.
  • Start or increase oral therapy.

Acute Heart Failure!!navigator!!

  • Treat with a nitrate infusion plus a loop diuretic IV (e.g. furosemide 20–40 mg initially).
  • See Chapters 47 and 48 for further management of acute pulmonary oedema and acute heart failure.

Acute Coronary Syndrome!!navigator!!

  • Make sure adequate analgesia has been given.
  • Treat with a nitrate infusion plus esmolol IV (Table 55.3).
  • See Chapters 45 and 46 for further management of acute coronary syndromes.

Phaeochromocytoma Hypertensive Crisis!!navigator!!

  • See Chapter 94.
  • Treat with phentolamine IV (Table 55.3). Seek expert advice from an endocrinologist.

Suspected Pre-Eclampsia/Eclampsia: Pregnancy or Within Three Months of Giving Birth!!navigator!!

  • The diagnosis of pre-eclampsia/eclampsia is discussed in Chapter 32.
  • Seek urgent advice from an obstetrician.
  • Target BP is 130–150/80–100 mmHg.
  • Give labetalol 20 mg IV bolus over 2 min, followed by an infusion of 1–2 mg/min.
  • If there is pulmonary oedema, add nitrate IV.

Cocaine-Induced Hypertension!!navigator!!

  • Sedation with a benzodiazepine is the preferred initial treatment for cocaine-induced hypertension.
  • Target diastolic BP is 100–105 mmHg within 2–6 hours.
  • Blood pressure will fall as cocaine is metabolized. If treatment in addition to benzodiazepine is needed, use phentolamine IV.

Other Patients!!navigator!!

  1. Admit for investigation and management if there are any of the following features:

    Recheck the blood pressure after the patient has rested for 30 min in a quiet room.

  2. Start or increase oral therapy. Aim to reduce BP to ≤160/100mmHg over the first 24h:
    • Initial therapy for the patient who is not already receiving anti-hypertensive therapy is given in Table 55.5.
    • Nifedipine MR should be co-administered with amlodipine for the first three days of treatment with amlodipine (as amlodipine has a large volume of distribution, and is therefore of limited efficacy during this period).
    • For patients already on treatment, check compliance, prescribe usual treatment at increased dose if appropriate, or add an agent from another class. If the patient is already taking an ACE-inhibitor or angiotensin-receptor blocker, a calcium channel blocker and a thiazide, consider adding spironolactone 25–50 mg daily.

  3. What is causing severe hypertension?

    Causes of secondary hypertension, and clues to specific diagnoses, are summarized in Table 55.6.

  4. Seek advice from a nephrologist if there is:
    • Acute kidney injury or chronic kidney disease
    • Evidence of acute glomerulonephritis or vasculitis (2+ or more proteinuria and/or red cell casts in the urine)
    • Suspected renal artery stenosis
    • Suspected scleroderma renal crisis (see Table 25.1)

Further Reading ⬆

James PA, Oparil S, Carter BL, et al. (2014) 2014 Evidence-Based Guideline for the management of high blood pressure in adults: Report from the panel members appointed to the Eighth Joint National Committee (JNC 8). JAMA 311, 507–520. DOI: 10.1001/jama.2013.284427.

Monnet X, Marik PE (2014) What's new with hypertensive crises? Intensive Care Med 41, 127–130. DOI: 10.1007/s00134-014-3546-7.

Poulter NR, Prabhakaran D, Caulfield M (2015) Hypertension. Lancet 386, 801–812.