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Sometimes Less is More

A 64-year-old male presented to emergency room (ER), with complaints of shortness of breath for one day. He had a past medical history of hypertension, end stage renal disease on hemodialysis (HD), and grade I obesity. He reported that he missed his last HD session, which was two days prior to presentation. He denied any chest pain, palpitations, cough, or fever. Patient further mentioned that he was able to walk >10 blocks without any chest pain or shortness of breath until a couple days ago. In the ER, examining physician documented presence of a systolic ejection murmur heard best at the second right intercostal space and bilateral rales, 1+ pedal edema; jugular venous distention of 4cm. Urgent transthoracic echocardiogram (TTE) was ordered by ER physician to further investigate the aortic stenosis (AS) murmur. TTE showed aortic valve area 0.98cm2, mean gradient 32mmHg, aortic jet velocity 3.5m/s; mild left ventricle (LV) concentric hypertrophy with grade 1 diastolic dysfunction, and LV ejection fraction of 60-65%. Subsequently, patient was admitted to cardiac telemetry and primary team consulted renal and cardiothoracic (CT) team for HD and for aortic valve replacement (AVR), respectively.

CT surgery team requested cardiology consult as a part of pre-operative assessment for possible surgical AVR. Physical examination by the attending cardiologist was remarkable for II/VI mid-systolic peaking crescendo-decrescendo murmur with normal carotid pulse upstrokes. Cardiac catheterization was recommended for further evaluation as there was discrepancy between the findings on noninvasive testing and physical examination regarding severity of the AS. Cardiac catheterization revealed non obstructive coronary artery disease (30% stenosis of mid RCA) and moderate AS (aortic valve area 1.38cm2, mean gradient 28mmHg, aortic jet velocity 3.3m/s). During recovery period patient developed hematoma at access site (right groin), which was managed conservatively but resulted in prolongation of his hospital stay by 48 hours. In the meantime, the patient underwent hemodialysis and had symptomatic relief in his dyspnea. He was discharged home to follow up with his outpatient hemodialysis center.

 

Perspective:

This gentleman presented to ER with complain of shortness of breath after missing a HD session. Although, not incorrect, the systolic murmur heard by ED physician led to a cascade of downstream testing. In fact, the ‘benign’ ‘non-invasive’ testing ordered as a part of comprehensive work-up led to a delay for patient getting the HD session. Physical examination is an essential part of accurate assessment of a patient’s disease process. However, our daily practice has been increasingly occupied by ‘tunneled vision’ of things.

Aortic stenosis (AS) is one of the most common valvular diseases associated with systolic murmur in the elderly population1. An essential part of physical exam of AS is assessing the severity. Munt et al, found significant correlation of physical exam findings like grade of murmur and timing of murmur peak with severity of AS2. Further, delay in carotid upstroke and decreased amplitude was well associated with increasing grade of AS severity as measured by aortic valve area (AVA). Although, one may argue that physical exam is limited by observer expertise and inter-observed variability3, echocardiographic parameters have their own pitfalls. The AVA measurement depends on accurate evaluation of LVOT diameter, which has a variability rate of 5-8% thus providing a significant potential for error4. Further, co-existing LV dysfunction or valvular jets (e.g. MR, AR) can interfere with precise interpretation of echocardiographic parameters.

In summary, the patient should have received urgent HD on presentation. The work up for systolic murmur would have been more appropriate on an outpatient basis. This particular scenario also brings into picture the rising health care costs in the United States, contributed by both additional testing and prolonged hospitalizations. Overall, it is worth concluding that careful physical examination and assessment of the patient is foremost to efficient and ‘do not harm’ philosophy of medicine.

 

References:

1) Osnabrugge R, Mylotte D, Head SJ, Van Mieghem NM, et al. Aortic Stenosis in the Elderly Disease Prevalence and Number of Candidates for Transcatheter Aortic Valve Replacement: A Meta-Analysis and Modeling Study. J Am Coll Cardiol. 2013;62(11):1002-1012.

2) Munt B, Legget ME, Kraft CD, Miyake-Hull CY, et al. Physical examination in valvular aortic stenosis: Correlation with stenosis severity and prediction of clinical outcome. Am Heart J 1999;137:298-306.

3) Stout KK, Otto CM. Quantification of Valvular Aortic Stenosis. ACC current journal review Mar/Apr 2003.

4) Baumgartner H, Hung J, Bermejo J, Chambers JB, et al. Echocardiographic assessment of valve stenosis: EAE/ASE recommendations for clinical practice.

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FAQs about Dialysis Patients

We’ve just started a new academic year, so now’s a good time to review some uncertainties and myths surrounding the care of dialysis patients.

Hey the patient is on chronic dialysis = total kidney failure, therefore iodinated CT contrast is A-Okay?
It depends.
Residual kidney function (the patient still has urine output) means better outcomes in terms of survival, nutrition, quality of life and better control of electrolytes and anemia. The kidneys work 24/7 to clear toxins and volume, and are better than dialysis at clearing middle molecules like phosphorus and protein-bound uremic toxins.
So if the dialysis patient still makes urine, avoid nephrotoxins including iodinated CT contrast unless there is strong medical necessity. Protect those kidneys!

Well we really need to give the CT contrast, so we’ll just coordinate dialysis afterward and that will save the day right?
Evidence is mixed but suggests that dialyzing out IV contrast is ineffective. You sucker punched the kidneys, and there’s no take-backsies.
However if there is concern that the amount of contrast led to volume overload and is compromising lung function – dialysis can remove volume and help with that.

How about MRI gadolinium contrast? Is the answer also “it depends”?
Gadolinium = never ok! Nephrogenic systemic fibrosis. Rare, but BAD. Look it up.

The nephrologist threw a fit when I asked for a PICC line for IV antibiotics. Why is she so loco?
Please recite daily: NO PICC LINES IN DIALYSIS PATIENTS. This also applies to predialysis patients with advanced chronic kidney disease who are heading toward dialysis dependence.
To do dialysis requires a dialysis access. For hemodialysis patients, the preferred access is an arm arteriovenous fistula (AVF). For peritoneal dialysis patients, peritoneal membrane failure eventually occurs and they will have to switch to hemodialysis. PICC lines cause vein trauma thus predisposing to future AVF failure. Along the same lines, radial artery approach for left heart cath should be avoided in patients with advanced chronic kidney disease.
Switch to PO antibiotics if possible. Or pick IV antibiotics that can be given during dialysis (cefazolin, vancomycin, cefepime are examples). If prolonged IV access is absolutely necessary, a small-bore internal jugular tunneled catheter (like a Hickman) can be considered.
There will be exceptions based on an individual patient’s clinical situation and life expectancy – please discuss with your favorite nephrologist!

The dialysis diet is low sodium, low phosphorus, low potassium. My patient is diabetic so she can’t even have carbs. Can she eat anything??
We’re not saying zero. Daily limits are sodium 2 gm, potassium 2 gm, phosphorus 800 mg. The dialysis diet is complex – that’s why every dialysis unit has dedicated dietician(s).
She should eat a lot of protein. Dialysis is a catabolic treatment and patients are encouraged to eat high protein diets (1.2-1.5 g/kg/day) to avoid protein calorie malnutrition.

Are all renal supplement drinks good for all kidney disease patients?
No! The supplement drinks that are for dialysis patients (Nepro, Novasource) are HIGH protein (see above, dialysis patients are recommended to eat a lot of protein). These are NOT good for predialysis patients with advanced chronic kidney disease, who need to be on LOW protein diet which may be beneficial in slowing progression of kidney failure. An example of a low-protein supplement for predialysis patients is Suplena Carb Steady.

My patient is on chronic hemodialysis and does not have a clinic follow up scheduled with his nephrologist. What is this craziness?
Most hemodialysis patients are in-center (they go for scheduled dialysis treatments at a dialysis unit, typically 3 days per week) and their nephrologist will round on them at the dialysis center. So they don’t need a separate clinic appointment.
Patients who do home dialysis will see their nephrologist in clinic once per month.

My hemodialysis patient was started on a blood thinner. Do I need to let the nephrologist know?
Please ALWAYS let the nephrologist know when a dialysis patient is started on warfarin or apixaban. (Apixaban is currently the only FDA-approved direct oral anticoagulant for dialysis patients.) Heparin is often used in the dialyzer circuit to prevent clotting. If a patient is started on anticoagulation, heparin may be held since the oral anticoagulant may be sufficient.
From a big picture standpoint, the use of anticoagulation in dialysis remains controversial (see my prior blog).

Ok we decided anticoagulation is no longer needed (or maybe the patient self-discontinued her apixaban… true story). Everything ok now?
On the flip side, if oral anticoagulation is stopped, please notify the nephrologist so that heparin can be re-introduced. If a dialyzer circuit clots and blood cannot be returned to the patient, this is equivalent to losing a half unit of blood.

Wei Ling Lau Headshot
 
Wei Ling Lau, MD FASN is Assistant Professor in Nephrology at University of California-Irvine. She is currently funded by an AHA Innovative Research Grant, and has been a speaker for CardioRenal University and the American Society of Nephrology. Follow her on Twitter @Kidneys1st.