Anti Hypertensive Agents and removal by Hemodialysis

Here is a list of common anti hypertensive agents used in ESRD and clearance via HD. In general, ACEI are removed in variable amounts, ARBs and aldo antagonists are not. Beta blockers are variable. CCB are variable but in general not that removed.

Class			%Removal with hemodialysis
Angiotensin converting enzyme inhibitors
Captopril			Yes
Benazepril			20–50%
Enalapril			35%
Fosinopril			<10%
Lisinopril			50%
Quinapril    Ramipril			<10%( limited data) <30%
Angiotensin receptor blockers
Losartan			None
Candesartan			None
Eprosartan			None
Telmisartan			None
Valsartan			None
Irbesartan			None
Aldosterone antagonists
Spironolactonea			None
Eplerenoneb			None
Renin inhibitor
Aliskiren			?
β-Blockers and combined α- and β-blockers
Atenolol			75%
Metoprolol			High
Metoprolol XL			High
Propranolol			<5%
Carvedilol			None
Carvedilol CR			None
Labetalol			<1%
Calcium channel blockers
Amlodipine			None
Diltiazem			<30%
Nifedipine			Low
Nicardipine			?
Felodipine			No
Verapamil			Low
Alpha-adrenergic blockers
Doxazosinc			None
Terazosin			None
Prazosin			?
Other
Clonidine			<5%
Hydralazine			None
Isosorbide dinitrate			Yes
Minoxidil			Partially

Concept Map: Diagnostic Approach to Hypomagnesemia

Concept Map: Hypocalcemia

Case 92: Answer and Discussion

The prevalence of non dipping of blood pressure increases with loss of renal function.

— Kenar Jhaveri (@kdjhaveri) September 27, 2018

Nondipping is more prevalent in CKD than in non-CKD patients or patients with essential HTN.  The prevalence of non dipping does increase as GFR declines. The prevalence of  reverse-dippers also increases progressively as stage of CKD progresses.

Reference: https://www.ncbi.nlm.nih.gov/pubmed/23595357
 

Topic Discussion: CABG( off pump vs on pump) and AKI

CABG induced AKI is fairly common.  Traditionally CABG is performed with bypass machine. Last decade has noted a surge in doing CABG via an off pump method. So you can get a CABG either off PUMP vs on PUMP.  If the pump is the problem and being on the bypass machine is what leads to the AKI, off PUMP CABG should have less AKI?

What is the data?

In 2010, a meta-analysis published in CJASN showed that off-pump CABG may be associated with a lower incidence of postoperative AKI but may not affect dialysis requirement, a serious complication of cardiac surgery. However, the different definitions of AKI used in individual trials and methodological concerns preclude definitive conclusions.

Then in 2014, Garg’s group from Canada did a large study looking at this question in the CORONARY study group in JAMA. They found that the use of off-pump compared with on-pump CABG surgery reduced the risk of postoperative acute kidney injury, without evidence of better preserved kidney function with off-pump CABG surgery at 1 year.

Another meta-analysis in 2015 from the Mayo clinic group showed a beneficial effect of off‐pump CABG on the incidence of AKI. However, this meta‐analysis does not show benefits of the need of dialysis or survival among patients undergoing off‐pump CABG.

In 2017, an Asian study published in Medicine found that among the 3 surgical methods( off pump, on pump with arrest heart, on pump with beating heart), off pump surgery resulted in lower AKI incidence. The short term outcome, including kidney function, of on pump beating heart surgery is similar to that of the off pump group.

The reasons that are proposed for higher AKI in on-pump CABG patients include renal hypoperfusion, hypotension, inflammation and oxidant stress. Compared to on-pump surgery, off pump surgery has potential benefits of reduced AKI risk and reduced cerebral dysfunction and reduced ICU stay and reduced mortality.

However, KDIGO guideline suggests that “off pump CABG not be selected for the purpose of reducing perioperative AKI or need for dialysis.”

Crystals in the urine Quiz Flash cards

Topic Discussion: Hormonal levels with various RAAS blockade medications

Class of RAAS agent	Renin level	Plasma renin activity	Ang II level	Aldosterone level
Renin inhibitor	Elevated	Low	Low	Low
ACEI inhibitor*	Elevated	Elevated	Low	Low
ARB*	Elevated	Elevated	Elevated	Low
Aldo receptor blocker	Elevated	Elevated	Elevated	Elevated

* after being on ACEI/ARB for long periods, due to aldosterone breakthrough, aldosterone levels could be high in some cases.