Doctor123.org

Hypertensive Emergencies

- Urinalysis and renal function tests (red blood cell casts, hematuria, proteinuria are common) - Drug screen - Blood count and smear may indicate microangiopathic hemolytic anemia or thrombocytopenia. - Serum electrolytes, which may indicate hypokalemic alkalosis; calcium, glucose - Cardiac enzymes if concerned for myocardial ischemia - Chest radiograph - May show pulmonary edema and cardiomegaly due to CHF - Mediastinal widening and blunting of the aortic knob consistent with aortic aneurysm (potential rupture) - If CNS symptoms, order CT scan or MRI of the head. - If chest, abdominal, or back pain, consider CT angiography or MRA for suspected aortic dissection.

para>Elderly patients may experience isolated systolic HTN due to decreased baroreceptor sensitivity.

Pediatric Considerations

  • Usually associated with renal disease
  • May present with abdominal pain
  • Preferred agents for children include labetalol, nicardipine, and nitroprusside.

Pregnancy Considerations

DIAGNOSIS

Clinical presentation varies depending on organ system affected.

HISTORY

  • Headache
  • Altered mental status
  • Nausea, vomiting
  • Neurologic disturbance
  • Shortness of breath, dyspnea, orthopnea
  • Chest pain
  • Abdominal pain
  • Epistaxis

PHYSICAL EXAM

  • HTN
  • Focal neurologic deficits, stupor, coma
  • Retinopathy: Funduscopic exam may reveal papilledema, exudates, or hemorrhages.
  • Pulmonary edema
  • Hemorrhage, thrombosis, embolus
  • Renal or abdominal bruit
  • Unequal BP or pulses in the extremities

DIFFERENTIAL DIAGNOSIS

  • Myocardial infarction or angina pectoris
  • Aortic dissection
  • CHF
  • Stroke
  • Other CNS pathology (e.g., encephalopathy)
  • Acute pulmonary edema
  • Renal failure

DIAGNOSTIC TESTS & INTERPRETATION

Initial Tests (lab, imaging)

  • Urinalysis and renal function tests (red blood cell casts, hematuria, proteinuria are common)
  • Drug screen
  • Blood count and smear may indicate microangiopathic hemolytic anemia or thrombocytopenia.
  • Serum electrolytes, which may indicate hypokalemic alkalosis; calcium, glucose
  • Cardiac enzymes if concerned for myocardial ischemia
  • Chest radiographMay show pulmonary edema and cardiomegaly due to CHFMediastinal widening and blunting of the aortic knob consistent with aortic aneurysm (potential rupture)If CNS symptoms, order CT scan or MRI of the head.If chest, abdominal, or back pain, consider CT angiography or MRA for suspected aortic dissection.

Follow-Up Tests & Special Considerations

  • Subsequent workup for pheochromocytoma in selected patients
  • Workup for hyperaldosteronism (hypernatremia, hypokalemia, elevated HCO3, and decreased Ca++) and for renal artery stenosis may be indicated in selected patients, especially young patients who may have fibromuscular dysplasia.

Diagnostic Procedures/Other

  • ECG may reveal ischemia or left ventricular hypertrophy.
  • The BP should be measured with an appropriately sized cuff, with ≥2 readings from both arms; then average readings.

Test Interpretation

Extreme BP elevations can overwhelm autoregulatory mechanisms for organ blood flow, resulting in damage to arteriolar and capillary beds. This process produces organ hemorrhages and edema.

TREATMENT

GENERAL MEASURES

If ongoing end-organ damage is thought to be secondary to hypertensive state, prompt treatment with IV medication is indicated. Monitor patient closely so rapid fall in BP can be avoided.

MEDICATION

A 2008 Cochrane Review (2) noted no randomized clinical trials show reduction in mortality from recommended treatments and no clear basis for recommending one drug over another. These treatments do reduce BP in these circumstances, and evidence levels reflect their effectiveness. A single randomized trial and review article compared IV nicardipine with labetalol, suggesting nicardipine more reliably reaches target BP with similar rate of overshoot or need for additional rescue medication (3,4).

ALERT

  • The general goal is to lower mean arterial pressure (MAP) by ~20% or reduce diastolic pressure to 100 to 110 mm Hg (13.3 to 14.6 kPa) over 1 hour.
  • Lower BP ≤ 20% in the first hour; then, if stable, lower to 160/100 to 110 over the next 2 to 6 hours
  • MAP is ~1/3 of the sum of twice the diastolic pressure plus the systolic pressure.

First Line

  • IV unless otherwise indicatedNicardipine: 4 to 15 mg/hr (4,5,6)[B]Labetalol (Normodyne, Trandate): bolus 20 to 80 mg q10-15min infusion 0.5 to 2 mg/min (4,5)[A]Nitroglycerin (NTG): infusion 5 to 100 μg/min (5,6,7)[A]NTG 0.4 mg SL tablet: Repeat q5min if needed. Consider IV infusion after 3 doses (6)[B].Phentolamine (Regitine): Bolus 5 to 10 mg q5-15min (6,7)[A]Esmolol: 0.05 to 0.3 mg/kg/min (5,6,7)[A]Enalapril: 0.625 to 1.25 mg (6,7)[B]
  • Drug(s) used depends on end organs affected and patient's clinical status.Hypertensive encephalopathy: nicardipine, labetalol, esmolol, or enalaprilat (6,8)[A]CNS events: nicardipine, labetalol. In ischemic stroke, withhold treatment unless systolic >220 mm Hg or diastolic >120 mm Hg, except when needed for treating concomitant cardiovascular disease or pulmonary edema (6,7,8)[A]. In patients with intracerebral hemorrhage and systolic BP 150 to 220 mm Hg, acutely lowering to a systolic of 140 mm Hg is probably safe.Subarachnoid hemorrhage: nicardipine, labetalol, or esmolol (6,7,8)[A]Myocardial ischemia: nitroglycerin infusion, or labetalol, or esmolol (6,7)[A]CHF: nitroglycerin infusion, or enalaprilat or nicardipine with a loop diuretic (5,6,8)[A]Aortic dissection: nitroprusside plus β-blocker: esmolol or labetalol, plus nicardipine/clevidipine, or nitroglycerin infusion (6,7,8)[A]Renal failure: nicardipine or fenoldopam; consider dialysis (6,7,8)[A].Pheochromocytoma: phentolamine, or labetalol, or nitroprusside infusion (4)[A]Antihypertensive withdrawal: Labetalol or phentolamine (6)[A]Interactions between MAOIs and foods or drugs: phentolamine or labetalol (6)[B]Eclampsia/preeclampsia: labetalol or nicardipine (6,7,8)[A]

Second Line

  • Nitroprusside (Nipride, Nitropress): infusion 0.5 to 10.0 μg/kg/min; contraindicated in pregnancy (6,7)[A]
  • Clevidipine: Start 1 to 2 mg/hr, double q90sec until near goal, then smaller increases q5-10min. May be a good alternate choice for patients with signs/symptoms of acute heart failure (6)[A]
  • Fenoldopam (Corlopam): 0.1 μg/kg/min IV initial dose. Increase by 0.1 μg/kg/min q15min to desired effect. Maximum dose 1.6 μg/kg/min.
  • Hydralazine: bolus 5 to 15 mg; used frequently in pregnancy- second line due to unpredictability of response (6,7)[A]

SURGERY/OTHER PROCEDURES

An arterial catheter may be used to monitor BP; advantage over noninvasive monitoring not clearly proven (7)[C]

COMPLEMENTARY & ALTERNATIVE MEDICINE

Comfortable environment, which may lower the BP

INPATIENT CONSIDERATIONS

Admission Criteria/Initial Stabilization

In general, lower the BP no more than 20% in the first hour; then, if stable, lower to 160/100 to 110 in the next 2 to 6 hours.

  • All patients with true hypertensive emergencies should be hospitalized.
  • Associated end-organ effects may require specific treatment (e.g., acute myocardial infarction).

IV Fluids

Fluid restriction may be appropriate for associated pathology, such as pulmonary edema.

Nursing

Bed rest

Discharge Criteria

Patient should be stabilized on PO antihypertensives as appropriate (9,10)[A].

ONGOING CARE

FOLLOW-UP RECOMMENDATIONS

Close outpatient follow-up with primary care physician is recommended to ensure ongoing control of HTN.

Patient Monitoring

  • Follow BP closely to avoid a rapid drop.
  • Begin oral therapy as soon as possible after BP control has been achieved with IV medications.
  • Ongoing BP control plus monitoring of affected organ system(s) (e.g., renal function) for evidence of continued morbidity

DIET

Low-sodium diet

PATIENT EDUCATION

  • Avoid abrupt discontinuation of antihypertensive medicines.
  • Stress importance of compliance.
  • Emphasize the lack of symptoms with HTN until organ damage occurs.

PROGNOSIS

  • BP should return to acceptable levels within 24 hours.
  • Long-term prognosis depends on extent of secondary end-organ damage in addition to ongoing BP control.

COMPLICATIONS

  • Complications depend on organ system(s) secondarily affected.
  • Abrupt or excessive lowering of BP may result in inadequate cerebral or cardiac blood flow, leading to stroke or myocardial ischemia.
  • The benefits of aggressive treatment may outweigh the risks in patients with severe HTN but no end-organ damage. No studies prove that aggressive treatment reduces the risk of long-term morbidity or mortality from hypertensive urgencies.

REFERENCES

11 Mozaffarian D, Benjamin EJ, Go AS, et al. Heart disease and stroke statistics-2016 update: a report from the American Heart Association. Circulation. 2016;133(4):e38-e360.22 Perez MI, Musini VM. Pharmacological interventions for hypertensive emergencies. Cochrane Database Syst Rev. 2008;(1):CD003653.33 Peacock WF, Varon J, Baumann BM, et al. CLUE: a randomized comparative effectiveness trial of IV nicardipine versus labetalol use in the emergency department. Crit Care. 2011;15(3):R157.44 Peacock WFIV, Hilleman DE, Levy PD, et al. A systematic review of nicardipine vs labetalol for the management of hypertensive crises. Am J Emerg Med. 2012;30(6):981-993.55 Monnet X, Marik PE. What's new in hypertensive crises? Intensive Care Med. 2015;41(1):127-130.66 Adebayo O, Rogers RL. Hypertensive emergencies in the emergency department. Emerg Med Clin North Am. 2015;33(3):539-551.77 Hoekstra JW, Qureshi A. Management of hypertension and hypertensive emergencies in the emergency department: the EMCREG-International Consensus Panel Recommendations. Ann Emerg Med. 2008;51(3)(Suppl):S1-S38.88 Marik PE, Rivera R. Hypertensive emergencies: an update. Curr Opin Crit Care. 2011;17(6):569-580.99 Morgenstern LB, Hemphill JCIII, Anderson C, et al. Guidelines for the management of spontaneous intracerebral hemorrhage: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2010;41(9):2108-2129.1010 Chobanian AV, Bakris GL, Black HR, et al. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. JAMA. 2003;289(19):2560-2572.

ADDITIONAL READING

James PA, Oparil S, Carter BL, et al. 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. 2014;311(5):507-520.

SEE ALSO

Aortic Dissection; Hypertension, Essential; Pheochromocytoma; Preeclampsia and Eclampsia (Toxemia of Pregnancy)

CODES

ICD10

I10 Essential (primary) hypertension

ICD9

  • 401.0 Malignant essential hypertension
  • 401.9 Unspecified essential hypertension

SNOMED

  • Hypertensive emergency (disorder)
  • Hypertensive disorder, systemic arterial (disorder)
  • Malignant hypertension (disorder)

CLINICAL PEARLS

  • Treatment of severe HTN (hypertensive urgency) without evidence of acute end-organ damage is controversial. In this case, treatment is in the emergency department by initiation of oral medication, with close follow-up.
  • If severe HTN and evidence of end-organ damage, slowly initiated IV treatment with close inpatient monitoring is recommended.
  • Avoid rapid prehospital lowering of BP.
  • Treatment depends on the organ systems affected.
  • Esmolol, nitroprusside, and ACE inhibitors are contraindicated in pregnancy.