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Hypertensive Emergencies Alyssa Morris, R3 March 5, 2009 Thanks to Dr Gant!

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Presentation on theme: "Hypertensive Emergencies Alyssa Morris, R3 March 5, 2009 Thanks to Dr Gant!"— Presentation transcript:

1 Hypertensive Emergencies Alyssa Morris, R3 March 5, 2009 Thanks to Dr Gant!

2 Definitions Hypertensive Emergency Hypertensive Emergency Acute, life threatening, usually a BP> 180/120 Acute, life threatening, usually a BP> 180/120 Target organ damage Target organ damage Hypertensive Urgency Hypertensive Urgency Asymptomatic, severe HTN, usually >180/120 Asymptomatic, severe HTN, usually >180/120 NO target organ damage NO target organ damage

3 Hypertensive Emergencies Neurological Neurological Hypertensive Encephalopathy Hypertensive Encephalopathy CVA CVA SAH SAH ICH ICH Cardiovascular Cardiovascular MI/ischemia MI/ischemia Acute LV dysfxn Acute LV dysfxn Ao dissection Ao dissection Pulmonary Acute edema Other Acute renal failure/insufficiency Retinopathy Eclampsia MAHA

4 Components of BP BP= CO x SVR CO= HR x SV Think of the components as: CO= heart CO= heart BP= arteries BP= arteries SVR= arterioles SVR= arterioles

5 CPP=MAP-ICP

6

7 CASE 1

8 Hypertensive Encephalopathy Uncommon syndrome Uncommon syndrome Acute and reversible Acute and reversible Results from an abrupt, sustained rise of BP that exceeds the limits of cerebral autoregulation of the small resistance arteries in the brain Results from an abrupt, sustained rise of BP that exceeds the limits of cerebral autoregulation of the small resistance arteries in the brain Arises from “breakthrough” hyperperfusion and leakage of fluid thru BBB Arises from “breakthrough” hyperperfusion and leakage of fluid thru BBB

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10 Clinical Presentation Severe h/a Severe h/a Drowsiness Drowsiness ALOC ALOC Vomitting Vomitting Seizures Seizures Focal neuro deficits Focal neuro deficits Blindness Blindness

11 Tx Various recommendations Various recommendations 25% over 3-4hrs 25% over 3-4hrs 10% in first hour, 15% in next 2-3 hours 10% in first hour, 15% in next 2-3 hours *will not be able to perfuse brain if you drop it too fast or too much

12 CPP=MAP-ICP

13 Drug Options VASODILATORS VASODILATORS Nitroprusside Nitroprusside Nitroglycerin Nitroglycerin Fenoldopam Fenoldopam Hydralazine Hydralazine BETA BLOCKERS BETA BLOCKERS Labetalol Labetalol Esmolol Esmolol CALCIUM CHANNEL BLOCKERS Enalaprilat/enalipril ALPHA BLOCKERS Phentolamine Clonidine

14 Nitroprusside Potent smooth muscle relaxing agent Potent smooth muscle relaxing agent Reduces both preload and afterload Reduces both preload and afterload Rate of onset rapid, duration very short Rate of onset rapid, duration very short Also a cerebral vasodilator Also a cerebral vasodilator Can increase ICP secondary to increased cerebral blood flow Can increase ICP secondary to increased cerebral blood flow Unstable in UV light, therefore wrapped in tinfoil Unstable in UV light, therefore wrapped in tinfoil Infusion at ug/kg/min -then increase by 0.5mcg/kg/min Infusion at ug/kg/min -then increase by 0.5mcg/kg/min Max of 10 mcg/kg/min Max of 10 mcg/kg/min

15 Nitroglycerine 1) Activates guanylate cyclase 2) Accumulation of cGMP 3) Sequestration of Ca into SR 4) Relaxation of Vascular smooth muscle  Dose dependent  Low dose: venodilator (preload)  High dose: veno and arteriodilator (afterload)  Therefore, usually reduce BP by reducing preload and CO  Start with 10-20ug/min infusion  Titrate up 5-10ug/minQ3-5min

16 Hydralazine Direct arteriolar vasodilator Direct arteriolar vasodilator Used to be used as first line in pregnancy htv emergencies Used to be used as first line in pregnancy htv emergencies Starting dose is 5mg IV Starting dose is 5mg IV Repeat doses of 5-10mg IV every 20 mins to maintain desired BP Repeat doses of 5-10mg IV every 20 mins to maintain desired BP Complications: Complications: Marked hypotension Marked hypotension Reflex tachycardia (can give angina) Reflex tachycardia (can give angina) Flushing and nausea Flushing and nausea H/a H/a

17 Labetalol Selective α-1 blocker and nonselective β-blocker Selective α-1 blocker and nonselective β-blocker α:β blockade ratio between 1:3 and 1:7 α:β blockade ratio between 1:3 and 1:7 Not a significant drop in CO like other βB Not a significant drop in CO like other βB Does not affect cerebral blood flow or renal fxn Does not affect cerebral blood flow or renal fxn BP starts to fall in 5-10m, max effect at 30m BP starts to fall in 5-10m, max effect at 30m How much do you guys give? How much do you guys give?

18 Esmolol Selective β-1 blocker Selective β-1 blocker Very short acting Very short acting Elimination ½ life of 9 minutes Elimination ½ life of 9 minutes No intrinsic sympathomimetic activity No intrinsic sympathomimetic activity

19 Phentolamine α-blocking agent α-blocking agent Used for the Mx of catecholamine-induced HTV crisis Used for the Mx of catecholamine-induced HTV crisis MAOI, Pheo, Cocaine MAOI, Pheo, Cocaine Immediate effect Immediate effect Effect lasts up to 15 mins Effect lasts up to 15 mins 1-5mg IV boluses 1-5mg IV boluses

20 CASE 2

21 PRES Posterior reversible encephalopathy syndrome Posterior reversible encephalopathy syndrome Pathophysiology Pathophysiology 1. Cerebral vasospasm leading to cytotoxic edema 2. Vasodilattion leading to vasogenic edema

22 CASE 3

23 HTN Mx in Ischemic Stroke Stroke. 2007;38:

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25 HTN Mx in Ischemic Stroke HTN common in 1st hours after stroke HTN common in 1st hours after stroke SBP>160 found in 60% pts with acute ischemic stroke SBP>160 found in 60% pts with acute ischemic stroke For every 10mmHg raise >180, risk of neurologic deterioration increases by 40% and risk of poor outcome by 23% For every 10mmHg raise >180, risk of neurologic deterioration increases by 40% and risk of poor outcome by 23%

26 HTN Mx in Ischemic Stroke Theoretical reasons for lowering BP in stroke Theoretical reasons for lowering BP in stroke Decrease formation of brain edema Decrease formation of brain edema Lessening risk of hemorrhagic transformation of infarction Lessening risk of hemorrhagic transformation of infarction Preventing further vascular damage Preventing further vascular damage Forestalling early recurrent stroke Forestalling early recurrent stroke BUT remember aggressive tx of BP may lead to neurologic worsening by decreasing perfusion pressure to ischemic areas of brain BUT remember aggressive tx of BP may lead to neurologic worsening by decreasing perfusion pressure to ischemic areas of brain

27 CPP=MAP-ICP

28 CASE 4

29 HTN Mx in Ischemic Stroke A lot of studies showing harm with reduction of BP A lot of studies showing harm with reduction of BP Most pts have a decrease in BP a few hours post- stroke w/o intervention Most pts have a decrease in BP a few hours post- stroke w/o intervention Oliveira-Filho et al. Neurology. 2003;61: Oliveira-Filho et al. Neurology. 2003;61: Found >90% pts had a decrease in SBP by 28% in 24hrs post-stroke with no intervention Found >90% pts had a decrease in SBP by 28% in 24hrs post-stroke with no intervention

30 Consensus Statement “ emergency administration of antihypertensive agents should be withheld unless DBP>120 and SBP>220” “ emergency administration of antihypertensive agents should be withheld unless DBP>120 and SBP>220” “reasonable goal to decrease blood pressure by 15-25% within 24 hours” “reasonable goal to decrease blood pressure by 15-25% within 24 hours” This is a case-by-case decision This is a case-by-case decision More research needs to be done More research needs to be done

31 Case 4

32 Stroke, 2007;38:

33 HTN Mx in Hemorrhagic Stroke Primary rational for reducing BP is to avoid hemorrhagic expansion from potential sites of bleeding Primary rational for reducing BP is to avoid hemorrhagic expansion from potential sites of bleeding BP is correlated with increased ICP and volume of hemorrhage BP is correlated with increased ICP and volume of hemorrhage Difficult to determine whether increased BP is a cause of hemorrhage growth or an effect of increased volumes of ICH and increased ICP Difficult to determine whether increased BP is a cause of hemorrhage growth or an effect of increased volumes of ICH and increased ICP

34 HTN Mx in Hemorrhagic Stroke Summary of studies Isolated SBP<210 is not clearly related to hemorrhagic expansion or neurologic worsening Isolated SBP<210 is not clearly related to hemorrhagic expansion or neurologic worsening Decrease in MAP by 15% does not result in decreased CBF Decrease in MAP by 15% does not result in decreased CBF Baseline BP was not associated with growth of ICH in largest prospective study Baseline BP was not associated with growth of ICH in largest prospective study Hemorrhage enlargement occurs more frequently in pts with increased SBP but it is not clear if this is an effect of increased growth of ICH with associated increase in ICP or a contributing cause to the growth of ICH Hemorrhage enlargement occurs more frequently in pts with increased SBP but it is not clear if this is an effect of increased growth of ICH with associated increase in ICP or a contributing cause to the growth of ICH Evidence supports maintaining CPP >60mmHg Evidence supports maintaining CPP >60mmHg

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36 HTN Bleeds Where do you get HTN bleeds in the brain? 1) Cerebellum 2) Pons 3) Basal ganglia 4) Thalamus

37 Case 4

38 HTN Mx in Ao Dissection Remember to check BP in legs if you are thinking dissection b/c the flap can give you falsely low BP in arms Remember to check BP in legs if you are thinking dissection b/c the flap can give you falsely low BP in arms Want to avoid shear stress and wide pulse pressures Want to avoid shear stress and wide pulse pressures Reduce the LV ejection force Reduce the LV ejection force Goal is to get SBP but just do what you can Goal is to get SBP but just do what you can Use labetalol or esmolol Use labetalol or esmolol Can use nipride after have sufficiently BB b/c will blunt the reflex tachycardia and increased SV Can use nipride after have sufficiently BB b/c will blunt the reflex tachycardia and increased SV

39 Case 6

40 Drug Summary Nitroprusside Nitroprusside ug/kg/min ug/kg/min Inc by 0.5ug/kg/min quickly Inc by 0.5ug/kg/min quickly Nitro Nitro 10-20ug/min 10-20ug/min Inc by 5-10ug/min Q3-10min Inc by 5-10ug/min Q3-10min Labetalol Labetalol 10-20mg IV Q5-10min 10-20mg IV Q5-10min Infusion at 1-2mg/min Infusion at 1-2mg/min

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