194	R. Rajani and F.N. Kapadia

Step 13: Manage mechanical complications

•Cardiogenic shock, LV failure, and congestive heart failure should be managed with appropriate pharmacological therapy and rarely with mechanical devices (see Chaps. 20 and 21).

•Ventricular, septal, or papillary muscle rupture.

•RV infarction or ischemia may occur in up to 50% of patients with inferior wall MI.

•Suspect RV infarction in patients with inferior wall infarction, hypotension, and clear lung fields.

•In patients with inferior wall infarction, obtain an ECG with right-sided leads. Look for ST-segment elevation (>1 mm) in lead V4r.

•Nitrates, diuretics, and other vasodilators (ACE inhibitors) should be avoided because severe hypotension may result.

•Hypotension is initially treated with an IV fluid bolus.

Step 14: Consider other supportive therapy

•Sedatives and laxatives are useful in the initial stage.

•Hyperglycemia, either stress-induced or due to preexisting diabetes, should be controlled preferably at near-normal levels.

•Routine medication taken by the patient prior to the ACS should be reintroduced as appropriate.

Suggested Reading

1.Passaro D. Anti-platelet treatments in acute coronary syndrome: simplified network metaanalysis. Int J Cardiol. 2011;150(3):364–7.

2.O’Connor RE, Brady W, Brooks SC, et al. 2010 American Heart Association Guidelines for cardiopulmonary resuscitation and emergency cardiovascular care science: part 10. Circulation. 2010;122:S787–817.

Comment: an updated comprehensive guideline on acute coronary syndrome

3.Antman EM, Cohen M. The TIMI risk score for unstable angina/non-ST elevation MI: a method for prognostication and therapeutic decision making. JAMA. 2000;284(7):835–42.

The 7 TIMI risk score predictor variables were 65 years or older, at least three risk factors for coronary artery disease, prior coronary stenosis of 50% or more, ST-segment deviation on electrocardiogram at presentation, at least two anginal events in prior 24 h, use of aspirin in prior 7 days, and elevated serum cardiac marker.

Website

1.www.acc.org

A comprehensive website of American College of Cardiology

Hypertensive Urgencies	24
and Emergencies

Simran Singh and Chandrashekhar K. Ponde

A 55-year-old male patient was admitted to the emergency department with severe headache and giddiness. His blood pressure was 240/130 mmHg, pulse was 100/min regular, and sensorium was intact. He had also a left ventricular gallop, and room air oxygen saturation was 90%. Peripheral pulses were well felt. He was a known diabetic and hypertensive but was on irregular treatment.

Severe hypertensive crisis is occasionally seen in the ICU. Proper triaging, monitoring, and a balanced approach to lowering blood pressure are mandatory in these situations as overjealous reduction in pressure may lead to organ underperfusion, and undertreatment will lead to vital organ damage.

Step 1: Assess severity of hypertension and urgency of treatment

•Severe hypertension is defined when blood pressure exceeds 180/110 mmHg in the absence of symptoms beyond mild or moderate headache and without evidence of acute target organ damage.

•Hypertensive urgency is defined when blood pressure exceeds 180/110 mmHg in the presence of significant symptoms, such as severe headache or dyspnea, but has nil or only minimal acute target organ damage.

•Hypertensive emergency is defined when very high blood pressure (often >220/ 140 mmHg) is accompanied by evidence of life-threatening organ dysfunction such as cardiac, renal, retinal, or neurological.

S. Singh, M.D. (*)

Department of Medicine & Intensive Care, P.D. Hinduja National Hospital and Medical Research Centre, Mumbai, India

e-mail: [e-mail]

C.K. Ponde, M.D., D.M.

Department of Cardiology, P.D. Hinduja National Hospital and Medical Research Centre, Mumbai, India

R. Chawla and S. Todi (eds.), ICU Protocols: A stepwise approach,	195
DOI 10.1007/978-81-322-0535-7_24, © Springer India 2012

196	S. Singh and C.K. Ponde
Table 24.1 Target organ damage
Cardiovascular	Myocardial infarction
	Unstable angina
	Aortic dissection
	Left ventricular failure
Central nervous system	Cerebral edema
	Altered mental status (hypertensive
	encephalopathy)
	Intracerebral or subarachnoid bleeding
	Cerebral infarct or transient ischemic attack
Renal	Microhematuria
	Proteinuria
	Acute renal failure
Ophthalmologic	Retinal hemorrhages or exudates
	Papilledema

Step 2: Assess target organ involvement

•Perform focused history and physical examination

•History—duration and severity of hypertension and previous BP records

•Relevant symptoms:

–Headache and chest pain

–Dyspnea, edema, and acute fatigue

–Epistaxis

–Seizure

–Change in the level of consciousness

–Palpitation, diaphoresis, and tremors suggestive of pheochromocytoma

–Weight gain and thinning of skin suggestive of Cushing’s syndrome

•History of comorbid conditions—diabetes, smoking, hyperlipidemia, and chronic kidney disease:

–History of adherence to any prescribed antihypertensive medication is necessary

–Recent use of OCP (oral contraceptive pill), MAOI (monoamine oxidase inhibitors), nonsteroidal anti-inflammatory drug, cyclosporine, steroids, over- the-counter medicines, and herbal remedies

–Use of alcohol, cocaine, amphetamine, and phencyclidine

•Physical examination:

–Feel all peripheral pulses

–Measure the blood pressure using appropriate technique

–Measure the blood pressure in both arms and at least one leg if pedal pulses are diminished

–Carry out fundoscopy to look for papilledema and hypertension retinopathy

–Other systems examination—look for pedal edema, assess jugular venous pressure, and auscultate for abdominal bruits, crepitations and gallop, and basal crepitations

–Check the mental status

•Look for target organ damage (Table 24.1).

24 Hypertensive Urgencies and Emergencies	197

Step 3: Send relevant investigations

•Initial evaluation

–Electrocardiogram—ST, T wave changes, evidence of left ventricular hypertrophy

–Hematocrit, white blood cell count, and peripheral blood smear—anemia, evidence of hemolysis

–Urea and creatinine

–Urinalysis with microscopic examination—hematuria and proteinuria

–Chest radiograph—cardiomegaly and pulmonary congestion

–Thyroid function tests

–Noncontrast computed tomography of the head (if neurologic findings are abnormal)

–Echocardiogram (left ventricular dysfunction, valve abnormalities, wall motion abnormalities)

–Lipid profile

•Tests to be done once the patient stabilizes

–Renal artery imaging (if renal stenosis is suspected)

–Other evaluations as guided by clinical presentation, namely, urinary VMA/ metanephrines/5-HIAA-phochromocytoma

–Plasma cortisol and dexamethasone suppression test—Cushing’s syndrome

Step 4: Understand treatment goals

•Hypertensive urgency

–Immediate goal—lower blood pressure within 24–72 h

–Treatment setting—clinical discretion is required

–Medications—oral medications with rapid onset of action; occasionally intravenously

•Hypertensive emergency

–Immediate goal—lower BP by 15–25% within 2 h, 25% within 12 h, 30% within 48 h

–Treatment setting—intensive care unit and intra-arterial monitoring

–Medications—intravenous

Step 5: Get familiar with drugs used in hypertensive urgencies and emergencies (Tables 24.2 and 24.3)

Table 24.2 Drugs for hypertensive urgencies
Agent	Dose	Onset of action	Comment
Captopril	12.5–25 mg PO	15–60 min	Can precipitate acute renal failure
			in patients with bilateral renal
			artery stenosis
Nifedipine (extended	10–20 mg PO	20 min	Avoid short-acting or sublingual
release)			nifedipine due to risk of sudden
			hypotension, stroke, cardiac event
Labetalol	200–400 mg PO	20–120 min	Heart failure, bradycardia,
			bronchospasm
			(continued)

198			S. Singh and C.K. Ponde
Table 24.2	(continued)
Agent	Dose	Onset of action	Comment
Clonidine	0.1–0.2 mg PO	30–60 min	Rebound hypertension due to
			abrupt withdrawal
Prazosin	1–2 mg PO	2–4 h	First-dose hypotension, syncope,
			tachycardia
Amlodipine	5–10 mg	30–50 min	Headache, tachycardia, flushing

Table 24.3 Drugs for hypertensive emergencies

Sodium nitroprusside

Dose: 0.25–10 mcg/Kg/min IV infusion

Onset/duration of action after discontinuation: seconds/2–3 min Comments

Arterial and venodilator with rapid onset and offset of action Preferred agents for most hypertensive emergencies

Titrate to goal BP

Infusion bag and delivery set must be light resistant or covered Nausea, vomiting, muscle twitching on prolonged use (>24–48 h)

Thiocyanate/cyanide intoxication, metabolic acidosis in patients with renal impairment Thiocyanate level >10 mg/dL should be avoided

Nitroglycerine

Dose: 5–100 mcg/min IV infusion

Onset/duration of action after discontinuation: 2–5 min/5–15 min

Comments

Mostly venodilator with modest arterial dilation

Headache, tachycardia, flushing, vomiting

Develops tolerance with prolonged use

Methemoglobinemia

Useful in emergencies with cardiac failure or ischemia

Labetalol

Dose: 10–80 mg IV bolus every 10 min to a maximum dose of 300 mg

Infusion: 0.5–2 mg/min

Onset/duration of action after discontinuation: 5–10 min/3–6 h

Comments

Combined a- and b-blockade

Bradycardia, bronchospasm

Avoid in congestive heart failure (CHF), bronchial asthma

Commonly used in pregnancy-induced hypertension

Enalapril

Dose: 1.25 mg every 6 h

Onset/duration of action after discontinuation: 15–30 min/6–12 h

Comments

Mainly afterload reduction

Contraindicated in pregnancy, renal artery stenosis

Useful in patients with CHF

(continued)

24 Hypertensive Urgencies and Emergencies	199

Table 24.3 (continued)

Esmolol

Dose: 500 mcg/Kg IV bolus can be repeated after 5 min

Infusion: 50–200 mcg/Kg/min

Onset/duration of action after discontinuation: 1–5 min/15–30 min

Comments

Avoid in patients with heart block, CHF, asthma

Short-acting cardioselective b-blocker

Bradycardia, CHF, heart block, may precipitate bronchospasm

Hydralazine

Dose: 10–20 mg IV bolus may be repeated every 30 min till goal BP is reached or unacceptable tachycardia develops

Onset/duration of action after discontinuation: 10–30 min/2–4 h Comments

Direct arteriolar vasodilator Reflex tachycardia, flushing

Avoid in patients with increased ICP, ischemic heart disease, and aortic dissection (without b-blockade)

Phentolamine

Dose: 5–15 mg IV bolus, repeat every 5–15 min

Infusion: 0.2–5 mg/min

Onset/duration of action after discontinuation: 1–2 min/10–30 min

Comments

Pure a-blockade

Reflex tachycardia, orthostatic hypotension

Used in syndromes with excess catecholamine (pheochromocytoma)

Nicardipine

Dose: 5 mg/h IV infusion; titrate up by 2.5 mg/h every 20 min up to maximum dose of 15 mg/h

Onset/duration of action after discontinuation: 15–30 min/1–4 h Comments

Dihydropyridine calcium channel blocker Reflex tachycardia

Avoid in acute heart failure

Useful in subarachnoid hemorrhage

Fenoldopam

0.1 mcg/Kg/min IV infusion, titrate up every 15 min to a maximum of 0.8 mcg/Kg/min Onset/duration of action after discontinuation: 3–5 min/30 min

Comments

Selective peripheral dopamine-1 receptor agonist Arterial vasodilator

Improves renal perfusion, useful in patients with hypertensive emergencies with renal failure

Contraindicated in glaucoma