Kidney blog

Kidney disease is often detected by lab test done by your primary care physician. 

Labs such as urine tests, blood work evaluate your kidney function, electrolytes and acid base status. 

Some times, patients may present with advanced kidney disease and needing dialysis in the hospital or at other times, kidney disease may be incidentally detected on a lab test or imaging study done for another reason. 

Primary care physicians and other specialists such as cardiologists refer to kidney specialists (aka nephrologists) to further evaluate and treat kidney disease. 

Kidney doctors (nephrologists) detect, treat and manage kidney disease, and high blood pressure. 

Your primary care tells you that you need to see a nephrologist (the kidney doctor) and you are not sure what to expect and what is going on.

Most often, your primary care noticed a lab abnormality: a creatinine that is too high for you or a sodium that is too low, other electrolyte or acid base irregularities  or perhaps urine test that showed protein or blood.

A kidney doctor is trained to evaluate these conditions to first figure out the reason for the problem or diagnose the problem, and if the problem is known, then try to treat it or prevent it from getting worse. 

Labs tests called basic metabolic panel (BMP), comprehensive metabolic panel (CMP) are routinely ordered to evaluate kidney, liver and electrolytes. 

Lab abnormalities such as high creatinine would indicate kidney function.  

Higher the creatinine worse the kidney function and this is evaluated by a formula by labs called GFR that estimates kidney function.  

Trend in BUN and creatinine over the years would give information on your kidney health over the years. For example, if your kidney function was normal a month ago, and is now significantly higher, that would mean acute kidney injury. 

On the other hand, if your creatinine had been 1.5 mg/dL for several years then that would usually indicate chronic kidney disease.

It is important to get lab tests before your appointment, preferably a week prior to the appointment if you have time, or at least 48-72 hours before your kidney doctor's appointment. 

It would also be helpful to get any prior labs you may have.

Typical imaging (pictures) that is ordered is a kidney bladder ultrasound to get baseline pictures of your kidneys and make sure there is no blockage in your kidneys. 

Ultrasound is the first step and can help determine if kidney size is preserved or if there is evidence of scarring on the kidneys.

Another test called a CT scan kidney is ordered to evaluate kidney stones and other abnormalities.

Based on kidney ultrasound, further testing may be necessary 

Kidney stones can present with severe back pain radiating towards the groin. The so called loin to groin pain typical of kidney (renal) colic. 

This pain is acute or sudden and severe and  may start out as lingering pain that is most often associated with myriad of back pain reasons. 

Back pain is most often musculoskeletal. However, best to get evaluated by your provider to determine reason for the pain.

Nephrologists (kidney doctors) manage recurrent kidney stones by analyzing 24 hour urine chemistry and kidney stone analysis to determine type of kidney stone. 

Prevention of recurrent kidney stones involved comprehensive approach of hydration, dietary changes and medications based on your urine chemistry 

Kidney cysts can be simple or complex. 

Simple kidney cysts are small pockets of fluid that can be found incidentally on a kidney ultrasound. 

These simple cysts are typically benign or non cancerous. 

Complex cysts are collections of fluid and may have other components and compartments that make them complex. These cysts could be benign in most cases however then would need further evaluation to make sure there is no malignant or cancerous lesion. 

Kidney tumors are broadly divided into benign (non cancerous) and malignant (cancerous). 

Most typical benign tumors in the kidney are angiomyolipomas. These tumors are composed on angio (blood vessels), myo (muscle) and lipo (fat)

Most typical malignant tumors in the kidney are renal cell carcinomas or sarcomas. These would need aggressive approach to management and treatment involving urologist,  surgical and medical oncologists (cancer specialists)

Nephrologists (kidney doctors) are internists with specialty training dedicated to study of fluid electrolyte balance,  kidney disease, hypertension and dialysis. 

The word nephrology (study of the nephron or functional unit of the kidney that makes urine). 

Nephrology training involves 2-3 years of fellowship training after completing internal medicine residency training for 3 years. 

Urologists are surgeons who specialize in surgical aspects of kidney, prostate, bladder, kidney stone removal and men's health such as erectile dysfunction.

Dialysis is a process of cleaning your blood with a machine when your kidneys fail to maintain cleaning toxins in your body, and keeping your body in balance with electrolytes and acid base. 

There are two types of dialysis : hemodialysis and peritoneal dialysis. The most common form of dialysis is in center hemodialysis which means dialysis provided in a free standing dialysis unit. There are several dialysis units in Orange County and it is best to choose one close to you or one that you are most comfortable with.  

Other forms of dialysis are 

HOME HEMODIALYSIS and PERITONEAL DIALYSIS which would need training by the patient and preferably a family member or caregiver in order to provide optimal care.  

Kidney doctors supervise dialysis treatments at your individual facilities and dialysis is performed by dialysis unit staff. 

In-center hemodialysis is most commonly done three times a week Monday-Wednesday-Friday or Tuesday-Thursday-Saturday

There are several shifts available throughout the day some shifts starting as early as 4:30 AM.

Each session is 3.5 to 4 hours per treatment and is variable based on your labs and fluid electrolyte status.

 Not every patient has the same dialysis treatment prescription.  

Some may need extra treatments based on their fluid electrolyte balance. 

It is best to discuss with your nephrologist about your dialysis

 Hemodialysis access:  for long term dialysis 

What is dialysis access?

Dialysis access is either a port called a dialysis catheter or a shunt called AV (arteriovenous) fistula or a graft called AV graft. 

The most ideal access is AV fistula. It involves connecting your own artery and vein in your arm  by a surgeon, typically a vascular surgeon.

How long does it take for AV fistula to mature or ready for use for dialysis?

2-3 months or longer. Some times, the surgeon may have to revise the fistula or do additional procedure called transposition to allow better access and maturation.

Advantages of AV fistula: 

1.  Minimal to no risk of infection, since the connection is within your body. 

2. Better dialysis clearance compared to catheter 

Disadvantages of AV fistula:  

1. Some patients may see poor maturation and development. 

2. May need multiple procedures prior to being used 

Next best is AV graft.  AV graft involves connecting your artery and vein with a graft which looks like a tube connector. 

How long does it take AV graft to use?

Typically 2 weeks

Advantages of AV graft:

1.  Lower risk of infection compared to dialysis catheter. 

2.  Can be used sooner than AV fistula 

3. May be the only option for those who has poor AV fistula maturation or poor circulation 

Disadvantages of AV graft:  

Has some risk of infection given graft is a foreign body 

Least favorite access but most widely used access:  Tunneled dialysis catheter 

Advantages of tunneled dialysis catheter 

1.  Immediate use of dialysis access hence widely used for new start dialysis 

2. May be the only access for those with poor blood circulation and failed AV fistula maturation and when Av graft is not an option

Disadvantages of tunneled dialysis catheter: 

1.  High risk for infection

2.  If infected may have to take it out and place new catheters 

3.  Difficult to shower with and have to be very careful with handling to avoid infections

Vascular surgeons place AV fistulas and AV grafts. 

Referral to vascular surgeon would first involve vein mapping 

(ultrasound guided mapping or visualizing your veins) to get the best anatomical location for placement of your access. 

The other role for vascular surgeons in dialysis patients is to help with angioplasty or de-clotting (unblocking)  Av fistulas (done by Interventional Radiology as well), removal of infected grafts, and bleeding or non functioning issues with AV fistula.

Kidney doctors refer to vascular surgeons in patients with advanced chronic kidney disease (advanced Stage IV and V)

Since AV fistula takes 2-3 months for it to be ready for use, better to place a fistula and start dialysis instead of a dialysis catheter. 

FOR MORE INFORMATION; 

REFER TO FISTULA FIRST CATHETER LAST INITIATIVE 

www.esrdncc.org

AV (arteriovenous) Fistulas are placed at 

1. The wrist (radiocephalic fistula):  A connection between radial artery and cephalic vein 

2.  Upper arm  (brachiobasilic fistula):  A connection between brachial artery and cephalic vein 

3. Forearm (brachiocephalic fistula): A connection between brachial artery and cephalic vein