Dr Maged Abulmagd,MD,EDICConsultant intensivist,EBGH

Hypertensive

Crisis

Hypertensive Crisis

• Hypertensive UrgencySBP >180 or DBP>110 w/o TOD

• Hypertensive Emergency SBP >180 or DBP>110 (esp >120) +TODs

• What is the primary reason for hypertensive emergencies in the USA today?

1. A-Renovascular Disease2. B-Pheochromocytoma3. C-Non-adherence to anti-hypertensive

medication4. D-Hyperaldosteronism5. E-Erythropoeitin

The commonest cause of hypertensive emergency in 2011 is undiagnosed,untreated,or undertreated essential hypertension

Epidemiology

Hypertensive emergencies are common

50 million hypertensive Americans

500,000 hypertensive emergencies/year

Higher in the elderly and African Americans

Incidence in men 2 times higher than in women

Urgency

• Rapid reduction in BP >>>> significant morbidity; organ hypoperfusion– Ischemia– Infarction

• Lower gradually over 24 – 48 hours

• Oral medications • pressure induced natriuresis>>> volume

repleting

Emergency

• Reduce DBP by 10 – 15%, or to ~ 110 mm Hg over 30 – 60 minutes

• Aortic Dissection– Rapid lowering over 5 – 10 minutes– SBP < 120 and MAP < 80

Threshold BP

There is no specific BP where hypertensive emergencies occur

Organ dysfunction is rare with diastolic BPs < 120 mm Hg

Encephalopathy will occur at lower BPs in pregnancy and in children

Vaughan and Delanty Lancet 2000; 356:411

Cerebral Autoregulation

Questions

• Define hypertensive urgency and hypertension emergency?

• What are clinical findings associated with hypertensive emergenices?

Question

• What is the most common complaint in hypertensive emergency?

1. Neurologic defect

2. Gross Hematuria

3. Chest pain

4. Headache

5. Epistaxis

Clinical Presentation

Frequency of signs and symptoms Chest Pain 27%

Dyspnea 22%

Neuro defect 21%

Zampaglione et al (Hypertension 27:144, 1996)

Clinical Findings

• Predisposing disease– Thyrotoxicosis/Thyroid storm, Hypothyroidism/Myxedema, goiter– HPT: hypercalcemia (psychosis, constipation,cataract,

nephrocalcinosis, N-DI, dystrophic calcifications of soft tissue (X-ray)

– Cushing’s: Cushinoid– Conn’s: hypokalemic metabolic alkalosis– Pheochromocytoma: perspiration, palpitation, pain (chest, AP),

labile pressure (+/- orthostatic hypotension), pallor– RAS: Renal bruits– OSA/Pickwikian Syndrome: day time somnolence, apnea attacks– Pregnancy: HELLP, Ecclampsia (edema, protienuria, sz)

Clinical Findings

• Complications/TOD– Brain: meningism, FND, delirium, decreased LOC,

seizures, coma.– Retina: blurred vision, papilledema (IV) +/- cotton

wool exudate, flame shape hg.– CVS: chest pain, ACS (MR, ECG, trop), CHF,

pulse/BP bi limbs deficit (AD).– Kidneys: active sediment, proteinuria, hematuria,

tubular casts.

A rare tumor of catecholamine-secreting chromaffin cells, 80% to 90% of which are located in the adrenal medulla.

10% to 20% are located extra-adrenal, usually throughout the sympathetic chain in the thorax, abdomen, and pelvis,are referred to as paragangliomas.

Pheochromocytoma

Hypertensive crisis is managed with intravenous nitroprusside, labetalol or phentolamine

Diagnostic tests

24-hour urine metanephrines and plasma fractionated metanephrines

Pheochromocytoma

Preeclampsia/Eclampsia

• Diastolic pressure should be reduced to 90-100 mmHg.

• Precipitous drops should be avoided as they may compromise placental circulation.

• Hydralazine and labetalol are the usual agents of choice. Nifedipine can also be used.

• ACE inhibitors should not be used due to adverse fetal effects.

Acute Post Operative Hypertension

Frequent in post-operative state (20-75%)Hyper-responsiveness to surgical trauma

Increased stress hormonesActivation of RAA

Hypothermia, hypoxia, carbon dioxide retention, bladder distention

Acute Post Operative Hypertension

Prevention Preoperative antihypertensives Hold diuretics

Treatment • Control pain and anxiety• While NPO use nicardipine, esmolol or

labetolol• Resume oral medications when possible

CARDIOVASCULAR SYSTEM

Cardiac failure

Pulmonary edema

Myocardial ischemia, or Myocardial infarction

Aortic dissection

Aortic dissection

• Goal is to reduce the shear force, and therefore the dP/dt.

• Goal is an SBP of 100-110 achieved with a beta-blocker and an easily titratable vasodilator if necessary.

• A vasodilator should not be used alone

All initial treatment is medical

Decrease pulse rate and BPGoal is systolic 100-120 mmHg & HR 50-60Esmolol & Nitroprusside combinationLabetolol single agent

Ascending require medical stabilization & then surgery Descending require medical stabilization & monitoring

Aortic dissection

Renal Artery Stenosis

What people should be screened for renal artery stenosis?

1-Patients who have uncontrolled blood pressure despite 3 or more medications at maximal dosages

2--people who are younger than 35 or older than 65 who develop sudden or new onset hypertension

Renal Artery Stenosis

The diagnosis is made with ultrasound dopplers to check blood flow rates

Arteriograms are more accurate, but only show an anatomic blockage, and don't help with functional testing

A diagnosis of exclusion. Cerebral oedema may be present on a CT scan but haemorrhage or infarction are absent.

Immediate blood pressure reduction is

mandatory.

Hypertensive Encephalopathy

CVA’s

• Ischemic CVA– Protective physiologic response to maintain

CPP– Impaired auto-regulation– Some evidence for induced HTN– Treat if:

• Thrombolysis (SBP/DBP < 185/110)• End organ damage• SBP > 220, DBP >120 .

CVA’s

• Hemorrhagic CVA– No evidence HTN leads to increased size

of ICH, but there is an association– Evidence suggests lowering BP rapidly

leads to increased mortality– Maintain SBP < 200, DBP < 130– Lowering MAP ~ 15% does not seem to

reduce CBP

Hypertensive Retinopathy

Fundoscopy used to be considered a definitive tool in diagnosing HTN encephalopathy.

Usefull in recognizing acute EOD as in HTN encephalopathy.

Absence of retinal exudates, hemorrhages, or papilledema does not exclude the diagnoses.

HPT Retinopathy

Reversible posterior leukoencephalopathy syndrome

A clinical radiographic syndrome of heterogeneous etiologies.

Characterized by

Headaches

Altered consciousness

Visual disturbances

Seizures

A/W hypertensive encephalopathy, eclampsia, and the use of cytotoxic and immunosuppressant .

It is related to disordered cerebral autoregulation and endothelial dysfunction

Reversible posterior leukoencephalopathy syndrome

Profile of an ideal IV Profile of an ideal IV antihypertensiveantihypertensive

Preserves GFR and renal blood flowFew or no drug reactionsLittle or no potential for exacerbation of co-morbid conditionsRapid onset and offset of actionMinimal hypotension “overshoot”Minimal need for continuous BP monitoring and frequent dose titrationNo acute toleranceEase of use and convenienceSafe and no toxic metabolitesMultiple formulations for short and long term useMinimal symphathetic activation

Case Based Presentation:Hypertension in the ICU

Nitroprusside

• A short-acting easy-to-titrate arteriolar and venous vasodilator.

• Most common adverse effect is hypotension which can be treated by reducing dosage and administering fluids if needed (lasts 1-2 min)

• Other adverse effects include reflex tachycardia and cyanide/thiocyanate toxicity

Nitroprusside• Nitroprusside is metabolized through combination

with hemoglobin to produce cyanomethemoglobin.

• Thyocyanate is then excreted in the urine

• Hepatic insufficiency leads to cyanide accumulation

• renal insufficiency leads to thiocyanate accumulation

Nitroprusside

• Cyanide toxicity manifests as lactic acidosis, confusion, and hemodynamic instability.

• Cyanide toxicity is prevented by avoiding large doses (>3mcg/kg/min) for greater than 72h, especially in patients with hepatic or renal dysfunction.

• Maximal doses of 10 mcg/kg/min should not be administered for more than 10 minutes

Labetalol

• A non-selective β-blocker with associated α-blocking activity, in a 7 to 1 ratio in i.v. formulation.

• Contraindicated in reactive airway disease or second to third degree heart block.

• Caution in patients with second to thir degree heart block.

Nitroglycerin

• A venous and coronary artery dilator.

• Indicated in acute coronary syndromes; has also used in perioperative hypertension.

• Side effects include headache, nausea, bradycardia, hypotension, and methemoglobinemia.

• Prlonged use may cause tachyphylaxis.

Nicardipine• A dihydropyridine CCB with systemic

and coronary vasodilating effects.

• No negative inotropic or a-v conduction effects.

• Used in perioperative hypertension and eclampsia/preeclampsia.

Esmolol

• Short-acting cardioselective β-blocker that can be used in perioperative hypertension and tachycardia.

• A prolonged esmolol infusion is a relatively expensive means of blood pressure control

Enalaprilat

• Its long duration of action and variable response, do not make it an ideal candidate for hypertensive emergencies.

• Contraindicated during preganancy, and in renal failure, esp. in renal artery stenosis.

Hydralazine

• An arteriolar vasodilator.

• Difficult to use due to its variable magnitude and rate of response.

• Improves placental blood flow so good for preeclampsia/eclampsia

• Should therefore not be used in aortic dissection or myocardial ischemia.

Rhoney and Peacock. Am J Health-Syst Pharm. 2009; 66:1343-52.

Specific Indications

A 76-year-old male is admitted to the ICU for recovery after lung volume reduction surgery for severe emphysema. He is alert and his BP is 168/96 mmHg. All of the following are appropriate EXCEPT?

A. Assess for pain

B. Start an antihypertensive treatment with a β-blocker

C. Reassess the patient later since there is no end-organ damage

D. Fundoscopic examination is not indicated for the transient, postoperative, acute hypertensive episode

E. Recommend the consultation of a hypertensive specialist once the patient is transferred to the ward if the blood pressure remains high

Which of the following is correct in regard to measurement of blood pressure in severe hypertension?

A. Automated oscillometric monitors are adequate for blood pressure measurement in the critically ill patient

B. A blood pressure cuff that is too small for the patient may result in a falsely decreased blood pressure measurement

C. Hypothermia causes hypotension; it does not increase blood pressure

D. Intra-arterial pressure monitoring provides the most accurate blood pressure measurement

E. A blood pressure cuff that is wrapped too loosely on the arm may result in a falsely low blood pressure

An acute hypertensive episode (190/110 mmHg), in a known hypertensive patient, is associated with acute congestive heart failure (HR 95/min). All of the following are true EXCEPT

A. Is a medical emergency requiring IV antihypertensive therapy

B. Is a medical urgency requiring oral antihypertensive therapy

C. Could be appropriately treated with a labetalol infusion

D. Requires caution with diuretics in case of diastolic dysfunction

E. Is most likely due to diastolic dysfunction

SummarySummary

HPT crisis - serious condition - associated with EOD, if left untreated

High mortality - untreatedMain causes – non-compliance and poorly

controlled chronic hypertension.Urgency vs emergencyTreatment should be tailored to the

individual’s condition HPT urgency – initial goal max 25% drop in

MAP in first hoursPrecipitous drop just as bad –continuous

monitoring essential