1、Case Based Presentation: Hypertension in the ICU,By Noemie Chessex and colleagues UBC,Case,A 19-year-old man presents to ED with episodic headaches that resolved spontaneously. In the last week, the headaches have become much more severe and frequent, occurring almost daily, and are accompanied by t
2、hrobbing chest pain, sweating, dizziness and palpitations.,Case,On arrival in ED, the pt is complaining of a severe headache, BP is 235/135 mm Hg, HR 90. He has profuse sweating and is complaining of dizziness and chest pain. ECG shows non-specific ST depressions.,Question 1,Define hypertensive urge
3、ncy and hypertension emergency. What are some clinical findings associated with hypertensive emergenices? (Ibrahim),Definitions: Hypertensive Crisis (Severe Htn),Hypertensive Urgency: SBP 180 or DBP110 w/o TOD Hypertensive Emergency (Malignant Htn): SBP 180 or DBP110 (esp 120) or accelerated htn wt
4、TOD TODs: Brain: Hypertensive encephalopathy/edema, ICH, ischemic stroke Retina: Grade IV retinopathy (papilledema) CVS: ACS, Acute pulmonary edema, CHF, Aortic dissection Kidneys: accelerated nephrosclerosis, nephritic syndrome Blood: MAHA, HELLP Pregnancy: HELLP, Ecclampsia,Clinical Findings,Of pr
5、edisposing disease Thyrotoxicosis/Thyroid storm, Hypothyroidism/Myxedema, goiter HPT: hypercalcemia (psychosis, constipation, inc QTc, cataract, nephrocalcinosis, N-DI, dystrophic calcifications of soft tissue (X-ray) Cushings: Cushinoid Conns: hypokalemic metabolic alkalosis Pheochromocytoma: persp
6、iration, palpitation, pain (chest, h/a, AP), labile pressure (+/- orthostatic hypotension), pallor RAS: Renal bruits OSA/Pickwikian Syndrome: Obesity wt think/short neck, day time somnolence, apnea attacks Pregnancy: HELLP, Ecclampsia (edema, protienuria, sz, inc DTR),Clinical Findings,Of Complicati
7、ons/TOD Brain: H/A, N/V, meningism, FND, delirium, decreased LOC, seizures, coma Retina: blurred vision, papilledema (IV) +/- cotton wool exudate, flame shape hg, AV nipping and silver wiring (G I-III in chronic Htn) CVS: chest pain, ACS (MR, ECG, trop), CHF, pulse/BP bi limbs deficit (AD, also of C
8、OA), AI (AD) Kidneys: active sediment, proteinuria, hematuria, tubular casts.,Question 2,What is the differential diagnosis of hypertensive emergencies/urgencies? What work up would you order for this patient? (Todd),Hypertensive Emergency/Urgency: Differential Diagnosis,Untreated or suboptimally tr
9、eated essential hypertension (most common) Renal parenchymal disease Including microvascular thrombosis TTp, HUS, vasculitis, acute glomerulonephritis Renal vascular disease (Renal artery stenosis) Pregnancy Induced Hypertension/Pre-eclampsia/Eclampsa Endocrine: Pheochromocytoma (or exogenous catech
10、olamines) Cushings syndrome Renin-secreting tumors,Drugs Sympathomimetic consumption/overdose (SPH/RCH) Cocaine/crack Amphetamines PCP Witdrawal from antihypertensive Rx MAOI interactions,Others,Autonomic hyper-reactivity Guillan-Barre Autonomic dysreflexia Porphyria Elevated ICP,Investigations,Book
11、 for history and physical examination Need for resuscitation (LOC, arrhythmias, pulmonary edema, seizures, tearing chest pain, etc) History of HTN (and detailed history of Rx, compliance and course of care as available), drug use, pregnancy (and pregnancy hx), systemic vascular disease, etc.,Investi
12、gations,Previous difficulty managing BP, or flares of symptoms (pheo cant be that rare if weve seen 2 spectacular cases within a year) Medications including OTC and recreational drugs,Investigations, continued,Physical exam: Vital signs HR as well as BP, to guide therapy Arterial line, particularly
13、if IV medications are used Neuro (LOC/encephalopathy, seizures, focal deficits) Cardiovascular (heart failure, volume status, arrhythmias) Respiratory (pulmonary edema) Abdominal exam Systolic/diastolic bruits, palpable aneurysmmasses occupying the entire epigastrium and invading the liver and aorta
14、 (hey, you never know),Investigations, continued,CBC ( Hemolytic anemia) Lytes, renal indices (renal failure as cause or consequence of hypertension) -hcg If Hx unclear, urine for cocaine or amphetamine metabolites,Investigations, continued,Chest X-ray (pulmonary edema) ECG ( Myocardial ischemia or
15、clues to chronicity, such chamber enlargement and strain patterns.) Echocardiogram (systolic/diastolic function, hypertrophy, chamber size),Investigations, continued,CT Brain: intracranial hemorrhage, tumor, posterior leukoencephalopathy CT Abdomen/Pelvis If contrast is possible (renal failure), thi
16、s can be used to assess renal arteries as well as look at adrenals and extra-adrenal masses CT Chest if aortic dissection is a concern,Here it is: Internal medicine-type stuff,Plasma renin and aldosterone Urine metanephrines (24-hr collection) Serum metanephrines would be nice, if you could find a l
17、ab that would do them in a timely fashion,Question 3,How quickly should the BP be lowered in Hypertensive urgencies and emergencies? What is the effect of HTN on autoregulation of CBF? Are there any conditions where you would choose not to lower their BP? (Omar),Cerebral Autoregulation,How quickly s
18、hould the BP be lowered in Hypertensive urgencies and emergencies?,Urgency,Rapid reduction in BP may associated with significant morbidity; organ hypoperfusion Ischemia Infarction Lower gradually over 24 48 hours Oral medications are advisable Patients may have pressure induced natriuresis consider
19、volume repleting to prevent precipitous drops,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,Are there any conditions where you would choose not to lower their BP?,CVAs,Save the penumbra! But maybe the penumbra
20、 does not want to be saved,CVAs,Ischemic CVA Protective physiologic response to maintain CPP Impaired auto-regulation Some evidence for induced HTN Treat if: Thrombolysis (SBP/DBP 220, DBP 120 (critical point at which sphincter tone becomes unbearable),CVAs,Hemorrhagic CVA Controversial topic No evi
21、dence 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,ATACH,Antihypertensive Treatment in Acute Cerebral Hemorrhage 60 patients Reduction in BP us
22、ing Nicardipine 170 200, 140-170, 110-140 mm Hg No difference in any outcome measures Neuro deterioration Adverse events,INTERACT,Intensive BP reduction in acute cerebral hemorrhage 404 patients with ICH Intensive BP Tx SBP 140 vs 180 Marginal decrease in hematoma growth, but no differences in any c
23、linical outcome,Question 4,Please describe the various agents that can be used in hypertensive emergencies. (Marios),Agents used in hypertensive emergencies,Optimal characteristics of drugs used in hypertensive emergencies,Easily titratable: Fast onset Sort duration of actionMinimal reflex activatio
24、n of counterregulatory systems (sympathetic, RAAS)Devoid of side-effects or drug interactionsLack of tolerance or tachyphylaxis,Pharmacodynamic characteristics of antihypertensive drugs,Nitroprusside,The prototype of a short-acting easy-to-titrate arteriolar and venous vasodilator.Most common advers
25、e 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 non-enzymatically through combination with hemoglobin to prod
26、uce cyanomethemoglobin.A mitochondrial enzyme in the liver (rhodanase), catalyzes the reaction of cyanide with thiosulphate to produce thiocyanateThyocyanate is then excreted in the urineSo hepatic insufficiency leads to cyanide accumulation whereas renal insufficiency leads to thiocyanate accumulat
27、ion,Nitroprusside,Cyanide toxicity manifests as lactic acidosis, confusion, and hemodynamic instability.Other signs include abdominal pain, delirium, headache, nausea, muscle spasms and restlessness.Cyanide toxicity is best prevented by avoiding large doses (3mcg/kg/min) of nitroprusside for greater
28、 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 -blocker with associated -blocking activity, in a 7 to 1 ratio in i.v. formulation.Reduces peripheral vascular resitance wi
29、th mild reduction in heart rate while maintaining cardiac output.Contraindicated in reactive airway disease or second to third degree heart block.Should be used with caution in patients with second to thir degree heart block.,Nitroglycerin,A venous and coronary artery dilator.Can dilate systemic art
30、eries at higher doses.Indicated in patients with acute coronary syndromes; has also been 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
31、 coronary vasodilating effects.No negative inotropic or a-v conduction effects.Used in perioperative hypertension and eclampsia/preeclampsia.,Esmolol,Short-acting cardioselective -blocker that can be used in perioperative hypertension and tachycardia.If no other agents are used , a prolonged esmolol
32、 infusion is a relatively expensive means of blood pressure control,Phentolamine,Periphral -blocker indicated for management of hypertensive emergencies associated with chatecholamine excess such as pheo, maoi interaction, antihypertensive withdrawal syndrome, and cocaine abuse.Can cause tachycardia
33、, hypotension, vomiting, flushing, and angina.,Enalaprilat,The IV formulation and active metabolite of enalapril. 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 a
34、rtery 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/eclampsiaSide effects include tachycardia, and increased CO/myocarial oxygen consumption.Should therefore not be used in ao
35、rtic dissection or myocardial ischemia.,Pheochromocytoma,Phentolamine has classically been the drug of choice for pheo, but labetalol and nitroprusside are also effective.,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-bloc
36、ker and an easily titratable vasodilator if necessary.A vasodilator should not be used alone as this can increase shear force. Labetalol is a good agent as it provides both beta blockade and vasodilatation as one agent.,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.,
