CNN flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Normal GFR

In a healthy adult, GFR averages about 125 mL/min/1.73 m2, producing roughly 180 L of ultrafiltrate daily; about 99% is reabsorbed, leaving 1-2 L of urine.

Erythropoietin production site

Peritubular interstitial fibroblast-like cells in the renal cortex sense hypoxia and secrete erythropoietin, which stimulates erythroid progenitor proliferation; loss of these cells in CKD causes normocytic normochromic anemia.

Nephrotic syndrome criteria

Defined by proteinuria greater than 3.5 g per day, hypoalbuminemia, edema, and hyperlipidemia; it reflects glomerular podocyte injury and carries high risk of thrombosis and infection.

CKD G5 definition

Kidney failure is defined as an eGFR below 15 mL/min/1.73 m2; many patients require kidney replacement therapy, although some are managed conservatively with symptom control.

Vitamin D activation

The proximal tubule enzyme 1-alpha-hydroxylase converts 25-hydroxyvitamin D to active 1,25-dihydroxyvitamin D; declining kidney function lowers this conversion and reduces intestinal calcium absorption.

Red blood cell casts

Hemoglobin-containing casts formed within tubules indicate glomerular bleeding; their presence in urine sediment strongly suggests glomerulonephritis rather than a lower urinary tract source.

Anion gap formula

Anion gap equals sodium minus the sum of chloride and bicarbonate, with a normal range of about 8-12 mEq/L; an elevated gap suggests unmeasured acids such as uremic toxins or ketoacids.

Cockcroft-Gault creatinine clearance

Estimated creatinine clearance equals (140 minus age) times weight in kg, divided by 72 times serum creatinine, multiplied by 0.85 for women; widely used to adjust drug doses.

BUN-to-creatinine ratio

A ratio above 20:1 suggests a prerenal state or upper GI bleeding; a ratio of 10-20:1 is typical of intrinsic kidney disease, though urea generation varies with diet and catabolism.

Fractional excretion of sodium

FENa below 1% indicates sodium-avid prerenal physiology and above 2% suggests intrinsic tubular injury; values are unreliable in patients taking diuretics or with underlying CKD.

Kt/V adequacy target

For thrice-weekly hemodialysis, single-pool Kt/V should be at least 1.2 per treatment, reflecting delivered dialyzer clearance multiplied by time and divided by urea distribution volume.

Urea reduction ratio

URR equals pre-dialysis BUN minus post-dialysis BUN, divided by pre-dialysis BUN, times 100; a value of 65% or higher indicates adequate hemodialysis clearance.

Hyperkalemia ECG progression

Progressive hyperkalemia produces peaked T waves, then PR prolongation and loss of P waves, then QRS widening and a sine wave pattern; cardiac arrest can occur without warning.

Race-free eGFR 2021

The 2021 CKD-EPI creatinine equation omits the race coefficient and is the recommended estimating equation in the United States; a cystatin C-based eGFR confirms results when creatinine is unreliable.

AV fistula rule of sixes

A mature arteriovenous fistula should have blood flow greater than 600 mL/min, a diameter of at least 0.6 cm, and a depth no greater than 0.6 cm; maturation takes about 6-8 weeks.

Peritonitis effluent criteria

Peritoneal dialysis peritonitis is diagnosed when effluent is cloudy and contains more than 100 white cells per mm3 with at least 50% polymorphonuclear cells, often with pain and fever.

Dialysis disequilibrium syndrome

Rapid urea removal during early dialysis creates an osmotic gradient that draws water into brain cells; prevention uses shorter, slower first sessions with lower blood flow.

Air embolism during dialysis

Stop the blood pump, clamp the lines, place the patient in Trendelenburg position on the left side, and give 100% oxygen; air in the right ventricle can obstruct pulmonary outflow.

Hyperacute rejection

Hyperacute rejection occurs within minutes to hours after transplant from preformed antibodies against donor antigens; the graft becomes cyanotic and nonfunctioning and must be removed.

Tacrolimus and grapefruit

Grapefruit and grapefruit juice inhibit intestinal CYP3A4 and raise tacrolimus blood levels; patients should avoid them and report tremor, headache, or rising creatinine.

Ultrafiltration rate limit

Ultrafiltration rate generally should not exceed 13 mL/kg/hour, and some guidelines recommend 10 mL/kg/hour; higher rates increase intradialytic hypotension, myocardial stunning, and mortality.

Phosphorus binder timing

Phosphate binders must be taken with meals or within minutes of eating to bind dietary phosphate in the gut; taken between meals, they are largely ineffective.

Fluid restriction estimate

A common allowance is 500-1000 mL per day plus the previous day's urine output; daily weight gain above 1 kg or interdialytic gain above 2-3 kg suggests excess intake.

Fistula thrill assessment

Patients should palpate the thrill and auscultate the bruit daily; absence of thrill, new pain, coolness, or bleeding requires immediate contact with the dialysis team.

Salt substitute hazard

Salt substitutes contain potassium chloride and can cause dangerous hyperkalemia in kidney disease; patients should season food with herbs and spices instead.

Teach-back technique

The patient explains instructions in their own words so the educator can confirm understanding; it detects gaps and is more effective than asking whether the patient understands.

Peritoneal dialysis exit-site care

The catheter exit site is cleaned with an antiseptic, kept dry, and covered per protocol; redness, drainage, or tenderness may signal exit-site infection and needs prompt evaluation.

AAMI water chlorine testing

Per AAMI standards, dialysis water must be tested for chlorine and chloramine before each shift and after carbon filter changes, because these oxidants cause hemolysis and anemia.

Catheter bloodstream infection prevention

Central venous catheters carry the highest infection risk; minimize their use, perform hand hygiene, use chlorhexidine antisepsis, and apply sterile dressings with each connection.

Conditions for Coverage

CMS Conditions for Coverage are the federal minimum health and safety requirements that ESRD facilities must meet to participate in Medicare, covering infection control, water quality, and patient care.

National Patient Safety Goals

Joint Commission goals applied to dialysis include identifying patients correctly, improving staff communication, using medicines safely, and preventing infection; compliance is surveyed and scored.

Hand hygiene moments

Hand hygiene is required before patient contact, before aseptic tasks, after body fluid exposure, after patient contact, and after touching patient surroundings.