Hypertensive crisis
 |
Resident Survival Guide |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Aarti Narayan, M.B.B.S [2]
Synonyms and keywords: Hypertensive emergency; hypertensive urgency; severe hypertension
Overview
Hypertensive crisis is a term used to describe a severe elevation in the blood pressure which may or may not be associated with end-organ damage.[1] Noncompliance with antihypertensive medications is the most common cause of hypertensive crisis.[2] Hypertensive crisis includes both hypertensive emergency and hypertensive urgency. Hypertensive urgency is the severe elevation in the blood pressure without any evidence of acute end-organ damage. Hypertensive emergency mostly falls into stage 2 of hypertension. It is usually the severe elevation in the blood pressure (systolic blood pressure >180 mm Hg, or diastolic blood pressure >120 mm Hg) complicated by acute end-organ dysfunction, such as hypertensive encephalopathy, eclampsia, dissecting aortic aneurysm, acute left ventricular failure with pulmonary edema, acute myocardial infarction, acute renal failure, or symptomatic microangiopathic hemolytic anemia.[3] The treatment of hypertensive urgency requires a gradual reduction in blood pressure over 24 to 48 hours. In hypertensive emergency, the treatment should be targeted to reduce the blood pressure by not more than 25% within the first hour; when blood pressure is stable, it should be reduced to 160/100-110 mmHg within the next 2 to 6 hours.[3]
Classification
Hypertensive crisis can be further classified as hypertensive urgency and hypertensive emergency based on either the absence or presence of acute end-organ damage.[1]
| Hypertensive crisis Acute elevation of blood pressure - Systolic blood pressure >180 mm Hg, or - Diastolic blood pressure >120 mm Hg | |||||||||||||||
| Hypertensive emergency Evidence of end organ damage | Hypertensive urgency No evidence of end organ damage | ||||||||||||||
Hypertensive Urgency
Hypertensive urgency is an acute severe elevation in the blood pressure without any evidence of acute end-organ damage.
Hypertensive Emergency
Hypertensive emergency mostly falls into stage 2 of hypertension (systolic blood pressure greater >160 mm Hg or diastolic blood pressure >100 mm Hg). It is usually an acute severe elevation in the blood pressure (systolic blood pressure >180 mm Hg, or diastolic blood pressure >120 mm Hg) complicated by acute end-organ dysfunction, such as hypertensive encephalopathy, eclampsia, dissecting aortic aneurysm, acute left ventricular failure with pulmonary edema, acute myocardial infarction, acute renal failure, or symptomatic microangiopathic hemolytic anemia.[3]
Causes
Life Threatening Causes
Hypertensive crisis is a life-threatening condition and must be treated as such irrespective of the cause.
Common Causes
- Antihypertensive medications withdrawal ( beta blockers, clonidine)
- Noncompliance with antihypertensive medications[2]
- Pheochromocytoma
- Side effects of monoamine oxidase inhibitors
- Stimulants (cocaine, methamphetamine, phencyclidine)
- Phenylephrine
Causes by Organ System
| Cardiovascular | No underlying causes |
| Chemical/Poisoning | No underlying causes |
| Dental | No underlying causes |
| Dermatologic | No underlying causes |
| Drug Side Effect | Axitinib, Naphazoline , Sorafenib |
| Ear Nose Throat | No underlying causes |
| Endocrine | No underlying causes |
| Environmental | No underlying causes |
| Gastroenterologic | No underlying causes |
| Genetic | No underlying causes |
| Hematologic | No underlying causes |
| Iatrogenic | No underlying causes |
| Infectious Disease | No underlying causes |
| Musculoskeletal/Orthopedic | No underlying causes |
| Neurologic | No underlying causes |
| Nutritional/Metabolic | No underlying causes |
| Obstetric/Gynecologic | No underlying causes |
| Oncologic | No underlying causes |
| Ophthalmologic | No underlying causes |
| Overdose/Toxicity | No underlying causes |
| Psychiatric | No underlying causes |
| Pulmonary | No underlying causes |
| Renal/Electrolyte | No underlying causes |
| Rheumatology/Immunology/Allergy | No underlying causes |
| Sexual | No underlying causes |
| Trauma | No underlying causes |
| Urologic | No underlying causes |
| Miscellaneous | No underlying causes |
Causes in Alphabetical Order
- List the causes of the disease in alphabetical order. You may need to list across the page, as seen here
Treatment
The management of hypertensive crisis differs based on the presence of end-organ damage and on the level of blood pressure. In case of absence of end-organ damage and SBP above 160 and DBP above 110, then the patient is suffering from hypertensive urgency. In such cases the goal is to decrease the blood pressure gradually over 24-48 hours using oral antihypertensive drugs. Rapid decrease in the BP is very dangerous as this may precipitate organ hypo perfusion as (Brain, heart or Kidneys) causing ischemia and infarction. For those with end-organ damage and SBP >179 and DBP >119, the patient is suffering from hypertensive emergency. These patients should be admitted to the ICU and receive parenteral antihypertensive medications to avoid fluctuating drug levels from the oral or intramuscular routes. The immediate goal is to decrease the DBP by 10-15 % or to approximately 110 mm Hg in the first 30-60 minutes, then when blood pressure is stable, reduce to 160/100-110 mmHg within the next 2-6 hours. Start the treatment with short acting IV antihypertensive drugs depending on the type of the end-organ damage. Keep close monitoring to the blood pressure and in severely ill patients intra-arterial blood pressure monitoring is used. Once the blood pressure is stable we shift to oral antihypertensive drugs. When the patient is stable and the blood pressure is well tolerated, reduce the blood pressure to normal within 24-48 hours.
Several classes of antihypertensive agents are recommended and the choice for the antihypertensive agent depends on the cause for the hypertensive crisis, the severity of elevated blood pressure and the patients usual blood pressure before the hypertensive crisis. In most cases, the administration of an intravenous sodium nitroprusside injection which has an almost immediate antihypertensive effect is suitable but in many cases not readily available. In less urgent cases, oral agents like captopril, clonidine, labetalol, prazosin, which have all a delayed onset of action by several minutes compared to sodium nitroprusside, can also be used.
It is also important that the blood pressure is lowered not too abruptly, but smoothly. The diagnosis of a hypertensive emergency is not only based on the absolute level of blood pressure, but also on the individual regular level of blood pressure before the hypertensive crisis. Individuals with a history of chronic hypertension may not tolerate a "normal" blood pressure.
Hypertensive Emergency as a Specific Term
The term hypertensive emergency is primarily used as a specific term for a hypertensive crisis with a diastolic blood pressure of 120 mm Hg and above plus end organ damage (brain, cardiovascular, renal) (as described above) in contrast to hypertensive urgency where as yet no end organ damage has developed. The former requires immediate lowering of blood pressure such as with sodium nitroprusside infusions (NOT injections) while urgencies (about 3/4 of cases with diastolic blood pressure of 120 mm Hg and above) can be treated with parenteral administration (NOT oral) of labetalol or some calcium channel blockers. The former use of oral nifedipine, a calcium channel antagonist, has been strongly discouraged or banned because it is not absorbed in a controlled and reproducible fashion and has led to serious and fatal hypotensive problems.
Hypertensive Emergency as a Generic Term
Sometimes, although not very often, the term hypertensive emergency is also used as a generic term, comprising both hypertensive emergency as a specific term for a serious and urgent condition of elevated blood pressure and hypertensive urgency as a specific term of a less serious and less urgent condition (the terminology hypertensive crisis is usually used in this sense).
Intravenous Antihypertensive Drugs
Shown below is a table of the IV antihypertensive drugs and their appropriate doses.[3]
| Drug | Dose |
|---|---|
| Clevidipine | 1 to 2 mg/h as IV infusion, max 16 mg/h |
| Enalaprilat | 1.25–5 mg every 6 hrs IV |
| Fenoldopam | 0.1–0.3 µg/kg per min IV infusion |
| Hydralazine | 10–20 mg IV |
| Nicardipine | 5–15 mg/h IV |
| Nitroglycerin | 5–100 µg/min as IV infusion |
| Nitroprusside | 0.25–10 µg/kg/min as IV infusion |
| Esmolol | 250–500 µg/kg/min IV bolus, then 50–100 µg/kg/min by infusion May repeat bolus after 5 min or increase infusion to 300 µg/min |
| Labetalol | 20–80 mg IV bolus every 10 min 0.5–2.0 mg/min IV infusion |
| Phentolamine | 5–15 mg IV bolus |
Oral Antihypertensive Drugs
Shown below is a table of the oral antihypertensive drugs and their appropriate doses.[3]
| Drug | Dose |
|---|---|
| Captopril | 12.5 to 25 mg PO or SL, repeat as needed. max dose - 50 mg PO |
| Clonidine | 0.1-0.2 mg PO x 1, then 0.05 to 0.1 mg/1-2 hrs. Max dose - 0.6 to 0.7 mg |
| Labetalol | 200 mg PO, then 200 mg/hr until desired effect. Max dose - 1200 mg |
- Other agents to consider include:
- PO frusemide 20mg (repeat as necessary)
- PO nifedipine SR 30mg, single dose
- PO felodipine 5 mg, single dose
Management of Specific Hypertensive Emergencies
| Hypertensive emergencies | Preferred agents |
|---|---|
| Aortic dissection | Labetalol, or nicardipine + esmolol, or nitroprusside + esmolol or nitroprusside + IV metoprolol Note: Administer beta blocker to control the heart rate before initiating a vasodilator e.g. nitroprusside
|
| Acute pulmonary edema / systolic dysfunction | Nitroglycerin + (Nicardipine or, fenoldopam, or nitroprusside) + loop diuretic |
| Acute pulmonary edema / diastolic dysfunction | Low-dose Nitroglycerin + (esmolol, metoprolol, labetalol, or verapamil) + loop diuretic |
| Acute coronary syndrome | Nitroglycerin + (labetalol or esmolol) |
| Hypertensive emergency with acute or chronic renal failure | Nicardipine or fenoldopam |
| Hypertensive encephalopathy | Nicardipine, labetalol, fenoldopam Note: the blood pressure should not be lowered by more than 25% |
| Pre-eclampsia / eclampsia | Labetalol or nicardipine |
| Sympathetic crisis / cocaine overdose | Benzodiazepine + (verapamil, diltiazem, or nicardipine) Note: Beta blockers should NOT be administered alone to prevent un-opposed alpha-adrenergic stimulation |
| Cerebrovascular accident | Nicardipine, labetalol, fenoldopam, or clevidipine Note: An expert's judgement is required to determine if the blood pressure should be lowered. |
| Withdrawal of antihypertensive therapy e.g. clonidine or propanolol | Re-administer the discontinued drug; phentolamine, nitroprusside, or labetalol, if necessary |
References
- ↑ 1.0 1.1 "The fifth report of the Joint National Committee on Detection, Evaluation, and Treatment of High Blood Pressure (JNC V)". Arch Intern Med. 153 (2): 154–83. 1993. PMID 8422206. Unknown parameter
|month=ignored (help) - ↑ 2.0 2.1 Stewart, DL.; Feinstein, SE.; Colgan, R. (2006). "Hypertensive urgencies and emergencies". Prim Care. 33 (3): 613–23, v. doi:10.1016/j.pop.2006.06.001. PMID 17088151. Unknown parameter
|month=ignored (help) - ↑ 3.0 3.1 3.2 3.3 3.4 Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL; et al. (2003). "The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report". JAMA. 289 (19): 2560–72. doi:10.1001/jama.289.19.2560. PMID 12748199.
- ↑ Chobanian, AV.; Bakris, GL.; Black, HR.; Cushman, WC.; Green, LA.; Izzo, JL.; Jones, DW.; Materson, BJ.; Oparil, S. (2003). "The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report". JAMA. 289 (19): 2560–72. doi:10.1001/jama.289.19.2560. PMID 12748199. Unknown parameter
|month=ignored (help)