16 - Hypertension and Renal Artery Stenosis Flashcards
What do the kidneys do?
- Filter waste
- Hormone production (Vit D, erythropoetin)
- BP control
- Electrolyte balance
- Water balance
What happens when the kidneys fail?
- Electrolyte imbalances (phos gets high, potassium high, calcium low)
- Anemia
- Blood pressure irregularities
- Meds hang around
Describe the relationship between hypertension and renal disease
- Hypertension leads to renal disease
- Renal disease leads to hypertension
Give an example of a HTN case
60 y/o male known HTN, hasn’t been treating HTN, BP 220/110 “feels funny”
- EKG left ventricular hypertrophy due to long-term HTN
- Cr 16 (nml .6-1.2 – dialysis about 5)
- Kidneys have failed
- BP almost impossible to move because kidneys were not responding to meds
- Sent to DSM – found likely autoimmune renal issue
Describe the prevalence of HTN in the US
- 1 in 3 US adults have hypertension
- > 1 in 2 adults over 60 have hypertension
With our culture, this will only increase
- Increasing body weight
- Decreasing activity levels (
What are the JNC 8 recommendations?
** KNOW FOR EXAM **
Recommendation
> or = 60 years (18 years with CKD (18 years with diabetes (
What do you need to do if you have a hypertensive patient?
- Need to assess risk factors, co-morbidities and secondary causes – and start treatment
What are the risk factors for hypertension?
- Age
- Smoking
- DM
- High lipids
- Inactivity/weight
- Family history
- Race
What are the secondary causes of hypertension?
- Sleep apnea
- Primary hyperaldosteronism (low K, htn resistant)
- CRF
- Thyroid
- Renal vascular disease
- Pheochromocytoma
- Cushings or steroid therapy
What is the “new thing” that we look for in hypertensive patients?
- Primary Hyperaldosteronism – Diagnose with a high aldosterone/renin ratio – their K will often be low
- Consider in patients with resistant hypertension and a low potassium
When should you suspect a secondary cause?
- Age extremes (very young or old)
- Severity
- Lack of family history
- Does not respond to treatment
- Sleep apnea
What tests should be run when you are diagnosed with hypertension?
- EKG
- UA
- BMP
- TSH
- H&H
- Ca
- Cholesterol
This would help you to rule out
Describe the lifestyle changes that can make a difference
- Wt reduction of 10 kg (5-20 mm)
- Na restriction (2-8 mm)
- Physical activity (4-9 mm)
- Low fat/high veggie diet (8-14)
** Weight reduction is found to be the MOST effective **
Describe the Calcium Channel Blockers (CCBs) for the treatment of HTN
Not used much anymore
- Decreases calcium influx into smooth and cardiac cells
- Edema
- Arrhythmias
- Some lead to CHF
Not as popular as previously was; CHF plus no decrease in mortality
Short term CCB not recommended anymore
Describe beta blockers for the treatment of HTN
- Beta blockers – antagonizes beta adrenergic receptors
- Dizzy/syncope
- Fatigue
- Low HR***
- Impotence
- Makes working out difficult
Very effective; always used in MI or CAD
Describe the ACE inhibitors
Used in DM (regardless of BP) CHF and post MI – many beneficial effects
- Decreases all CV causes of death in DM II
- Think increases flexibility of vessels
- Causes cardiac remodeling (repair)
What are the side effects of ACE inhibitors?
- Increases K
- Angioedema (.2%, Asians/Blacks 3-4X more likely)
- Cough (>8%)
- Increase Creatinine
Describe the increase in creatinine
- Can increase 30% before stop or big w/u
- Small increase means intraglomular pressure has been reduced
Describe the treatment of HTN with thiazides
Thiazides - inhibits NaCl reabsorption
Side effects
- K/Na reduction
- Renal damage
- Increased glucose, Ca+
Back in favor; cheap, few side effects, decreases mortality.
Will see more Chlorthiadone (same dose as HCTZ)
Further describe the JNC 8 recommendations for medications
General nonblack population (thiazides, CCB, ACEi or ARB)
General black population (thiazides or CCB initially)
Chronic kidney disease
(treatment should include ACEi or ARB)
Up-titrate or add therapy after 1 month if BP goal is not met
- Do NOT use ACEi and ARB together
- If 3 or more drugs are needed, refer to hypertension specialist
Describe the use of ARBs in the use of treating HTN
- Block angiotensin II at the receptor
- Many similar effects as ACE – not as well studied
- Pt not to be on both ACE and ARB
What other medication can be used for HTN?
Clonidine
– alpha 2 agonist (centrally acting)
– fast acting, pts can titrate
– can have rebound
Describe polypharmacy for HTN
- The large majority of people require 2 or 3 or more meds.
- If >160/100 to start, just start 2 meds
What is the “take away”
- Beta Blockers are NOT first line (unless post MI)
- Whites – start almost anything else (Thiazides, ACE/ARB, CCB)
- Blacks – avoid ACE (know why - chance of angioedema is 3-4x higher than whites)
- Diabetics/CRF – ACE
- Post MI/CVA – beta blocker/ACE
- CHF – Beta Blocker + ACE, plus thiazide plus spiranolactone
Describe hypertensive emergencies
- “malignant hypertension”
- Any increase in BP that results in acute end organ damage
Still want to lower BP SLOWLY
What type of organ damage do we see?
- Encephalopathy, stroke, chf, aortic dissection, MI, ARF
- Nosebleed
What is a hypertensive urgency?
- > 180 or >110
- No symptoms or vague symptoms
- Disagreement in how urgent treatment needs to be; what is their normal?
- Tricky to treat in ER – do you start them on something at d/c? What if incidental finding?
- Titinilli (ER Text) says d/c and lower over 24-48 hrs
- You can send them home and have them come back the next day for a BP check
What do you need to remember about treating HTN?
Shouldn’t drop BP too quickly
Describe renal artery stenosis
- When renal arteries are constricted to the point that the kidneys have a decreased blood flow.
- Kidney thinks body is hypovolemic and secretes renin which increases BP
What should you suspect renal artery stenosis?
- Doesn’t respond to treatment
- Intermittent claudication
- Sudden worsening of HTN
- Image abnormality
- ACE leads to worsening creatinine
What is the risk for renal artery stenosis?
- HTN
- Obesity
- Vascular disease of any kind
- Age
- Smoking
- Anything that increases risk of vascular problems anywhere else
What causes renal artery stenosis?
- Usually caused by atherosclerosis (older)
- Also due to fibromuscular dysplasia (younger)
- Problems occur at 70% blockage
What happens to the kidneys if renal artery stenosis is uncontrolled?
- Affected kidney gets small, ischemic (Ischemic nephropathy)
- Other kidney gets injured from the increased BP (hypertensive nephrosclerosis)
What is the treatment for renal artery stenosis?
- Angioplasty – often wont last
- Stent – sometimes wont last
- Bypass
- Nephrectomy if affected kidney very damaged
What is fibromuscular dysplasia?
- A specific type RAS
- Angiopathy of medium sized vessels; mainly seen in women of childbearing age.
- Seems to increase just before menopause
- Genetic link as well
- Symptoms occur where artery occluded (brain, periphery – kidneys mainly)
- Rare – less than 1% of population
How do you treat fibromuscular dysplasia?
Angioplasty or stent
