Blood Pressure. Michelle Bertram- Nephrology- OBH

Transcription

1 Blood Pressure Michelle Bertram- Nephrology- OBH

2 Hypertension- how common? 29-30% white adults 46-51% uncontrolled

3 Diagnosis Two or more properly measured BP s after an initial screen NICE guidelines also require home BP monitoring for dx Normal BP <120/80 Prehypertension /80-89 Stage 1 HTn /90-99 Stage 2 HTn 160/100 Target BP <140/90 If diabetic <130/80 If > 70 years <150/90

4 Measuring BP Two feet on ground Back supported Arm resting on desk For each that you get wrong- adds 2mmHg BP BP s on legs- need at least 10-20mmHg added to reading

5 Definitions HTn based on home readings 24hr ave > 135/85 Daytime BP >140/90 Night time BP > 125/75

6 Hypertensive Emergency Malignant HTn HTn + retinal exudates, haemorrhage or papilloedema Usually diastolic BP >120 can be as low as 100 if prev normotensive Hypertensive Urgency Diastolic BP >120 in asymptomatic pt

7 Approach to patient Evaluate for end-organ damage Start treatment! Re-evalute BP over 3-6 visits spaced over weeks to months Consider ambulatory BP monitoring or home measures

8 White Coat HTn 20-25% stage 1 hypertensives More common in elderly Less likely if diastolic 105mmHg Dx confirmed w ambulatory readings

9 Masked HTn Normal office readings but hypertensive at home Up to 0.06% population, perhaps higher Associated with cardiovascular risk

10 History Last known normal BP Course of BP Past treatments- side FX Drugs that may cause HTn Oestrogens, illicit, corticosteroids Other CVRF Smoking DM, lipids, inactivity Diet Sodium, alcohol, fats Sxs OSA Family hx HTn/ premature CV death/ Familial dz- pheo/renal/dm/gout Symptoms of 2 nd disease Pheo sxs Symptoms of target organ damage h/ache/ weakness or blindness/ visual change/ CP/ SOB/ claudication

11 Tests EUC/ Hb/ lipids/ fasting BGL ECG Microalbuminuria Echo Secondary causes if young

12 Why treat? 20-25% RR reduction CCF & MI 30-40% reduction in risk CVA

13 Non-pharmacological Rx Salt restriction 50mmol/day (regular 200umol/day) 4.8/2.5mmHg reduction in BP Weight Loss 0.5-2mmHg for every 1kg LOW DASH diet Fruits, veies, low-fat dairy- 11.4/5.4mmHg drop DASH + low salt further 2.2/1mmHg drop Exercise Regular aerobic exercise 5-15mmHg reduction Alcohol >3 drinks for men, >2 drinks women- reduced ETOH- reduction in BP 3.3/2mmHg

14 Drug Therapy First line agents Thiazides ACEi/ARB CaChBl- long acting dihydropyridine Beta blockers now out of fashion

15 Drug efficacy All will produce good anti-htn effect in 30-50% patients Wide inter-patient variability If poor response to first agent stop that agent and try another If initial BP consistently 20/10 over target you will need to start two agents together Recommendation CaChBl + long acting ACEi/ARB

16 Drug choice May be other indications for a specific agent Younger patients (50year or younger) Respond best to ACEi or ARBs (beta blockers) Older patients & Black patients Respond best to thiazides or long acting CaChBl Probably because of reduced baseline plasma renin activity

17 Sequential monotherapy As dose of Rx increases the additive antihypertensive effect is attenuated and side effects become a problem If poor response limit the mediaction trial to one step up in dose and if target not acheievd switch to a different agent

18 Non-BP indications for specific agents ACEi LV dysf(x)/ STEMI/ proteinuric CKD ARB Same as ACEi except- severe HTn + ECG evidence of LVH (LIFE trial) (just that ACEi not studied) Thiazides ALLHAT trial- benefit with Chlorthalidone Vs amlodipine and lisinopril in reduction CV events in pts >55yrs with one or more other RF CaChBl- nil Beta blockers Post MI/ CCF/ rate control/ anti-anginal Otherwise NOT recommended as a first line agent- inferior protection vs stroke, in pts over 60 atenolol may slightly increase mortality Alpha blockers Doxazosin arm in ALLHAT terminated early- increased risk of heart failure & CV events

19 Resistant HTn Not controlled on three agents ACE or ARB + thiazide (chlorthalidone not HCT) + CaChBl 4 th line Spironolactone (50mg max) 5 th line Vasodilating beta blocker- labetalol or carvidolol Centrally acting- clonidine/ moxonidine Vasodilators- hydralazine/ minoxidil RFA renal artery sympathetic nerves

20 Hypertension on the ward 54yo female Post renal biopsy BP 190/80- asymptomatic PMHx hypertension & CKD creat 300 On amlodipine 5mg, coversyl 10mg What do you do?

21 Options 1. Give stat 5mg amlodipine 2. Give 20mg lasix 3. Given 25mg hydralazine

22 Answer = 4 Need to reduce BP quickly to reduce bleeding risk Give 25mg hydralazine Lasix will not work given reduced GFR Amlodipine has long half life- will take too long to work

23 Other options Minoxidil 5mg Clonidine 0.2mg Methyldopa 250mg Captopril mg orally GTN patch 5mg (less easy to titrate) Always call consultant before using

24 Case 2 62yo male Presents to ED with BP 200/100 Ran out of his BP meds 4 days ago Feeling a bit funny but otherwise ok What do you do?

25 Case 2 Symptoms of end organ damage? Neuro exam including retinal exam Examine for signs of cardiac failure ECG CXR Find out what he is on & restart Check in with GP in 1-2/7

26 Case 3 73 year old on CaChBl/ ACEi/ thiazide comes to ED unwell, unable to get out of bed & dizzy History of falls BP 110/80 no postural drop. Not SOB Last year on presentation to ED with a sore throat prior to starting CaChBl her BP was 155/80 ECG normal, HR is 72,

27 What do you do? 1. Cardiac monitored bed 2. Keep her in for serial trops & ECGs 3. CT brain 4. CTPA 5. Stop her amlodipine & send her home once she can walk

28 Case 3 Patients over 65 should be treated to a target of 150/80 Elderly patients do not tolerate lower BP s Increased risk mortality & morbidity

29 Case 4 45yo dialysis patient- works as a naturopath Presents obtunded with BP 220/130 Last dialysis yesterday, not fluid overloaded On amlodipine 10mg, coversyl 10mg, irbesartan 300mg, prazosin 5mg tds, metoprolol 100mg bd What do you do?

30 CT brain Call ICU consultant Case 4 IV GTN Sodium nitroprusside IVI IV bolus hydralazine, clonidine or diazoxide

31 Case 5 56yo female with history of scleroderma BP 190/100 Platelet count 40, fragmented red cells on blood film, LDH 600, creat 400 (usually 120) Not on any BP meds, no symptoms What do you do?

32 Case 5 1. Hydralazine 5mg IV over 10 minutes 2. Captopril 6.25mg po 3. Start 5mg perindopril and 150mg irbesartan 4. Start amlodipine 5mg daily

33 Scleroderma renal crisis Answer is 3 Priority is to double block the reninangiotensin system as a priority

34 Case 5 Same naturopath HDx pt comes to clinic after discharge On coversyl 10mg bd, irbesartan 300mg, prazosin 5mg tds, metoprolol 100mg daily, amlodipine 10mg BP in lower leg 190/90 Asymptomatic

35 Options 1. Chlorthalidone 2. Moxonidine (physiotens) (centrally acting alpha blocker) 3. Clonidine 4. Minoxidil 5. Hydralazine 6. Spironolactone 7. Change metoprolol over to labetolol

36 chlorthalidone Will not work as she has no native urine output

37 Physiotens Already on prazosin which is a peripherally acting alpha blocker so probably won t work

38 Clonidine Patient is not compliant Suddenly stopping can ppt hypertensive crisis Side effects- drowsiness

39 Minoxidil Will work but causes terrible leg swelling and increased body hair

40 Spironolactone Won t work- no GFR and it s a diuretic

41 Hydralazine & Labetolol Both reasonable options