mmol/l Typical RRT patient levels: 20 35

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1 Penticton Regional Hospital Renal Program: Hemodialysis Interpretive Guide for Hemodialysis Patients Bloodwork TEST DEFINITION ACCEPTED CREATININE Creatinine is a catabolic product of umol/l * Cr creatine, which is used in muscle contraction. It is a relatively stable Typical RRT range product & only elevates in renal of patient levels: insufficiency Each patient will have his/her own established level. We often begin RRT before the kidneys have reached complete end stage function, therefore, creatinine may rise as the kidney function continues to decline. Watch the trend. If it is rising, the patient may need a longer HD run or a different dialyzer; other values may rise in tandem (e.g. K, urea). UREA Ur (sometimes BUN) Urea is the end product of protein metabolism and is excreted by the kidneys. Urea is a good small molecule marker because its level correlates well with the nutritional state of the patient and with protein catabolism. Hence, urea is the choice waste product in determining dialysis adequacy (Kt/V modeling) mmol/l Typical RRT patient levels: Urea is affected by the patient s diet. In patients with minimal or no kidney function, adequate protein in the diet is reflected by urea values of mmol/l. Watch the trend. Poor dietary protein intake is indicated by low urea values (< 20). If it is rising, the patient may be losing more kidney function or may be getting more dietary protein. Values > 35 may require diet counseling or adjustments in dialysis parameters. Adequate dietary protein is less obvious using urea as the indicator when the patient has significant residual kidney function. Observing urea with albumin is more helpful in this instance. SODIUM Na+ Sodium is the major cation in the extracellular space. The sodium content of the blood is a result of a balance between dietary sodium intake and renal excretion mmol/l Should be within normal limits. Sodium is affected by how much salt is in our food. Fluid retention will also change sodium levels. Levels can determine if the patient is drinking too

2 SODIUM (continued) much by habit (hypothalamus thirst influence) or by need of sodium intake (physiological response water follows salt). Examples: SeNa 126 in a patient with low fluid gains indicates volume overload GW needs. SeNa 126 with a high fluid gain indicates drinking high volumes from habit. Counsel fluid restriction. SeNa 145 in low fluid gains or high fluid gains indicates high sodium in the diet. Counsel salt intake. SeNa 145 with low or no fluid gain may also indicate dehydration. GW assessment; fluid loss assessment. POTASSIUM K+ Potassium is a major cation within the cell. Dietary sources are the usual source of elevated K+ in renal patients. Remember: serious cell injury (eg. massive bruising, heart attack) may also result in elevated K mmol/l Should be within normal limits. Changes in the heart rhythm can happen if the potassium level is too high or too low or reduced too quickly. SUDDEN DEATH can occur as a result of high serum K+ levels. Renal patients may develop tolerance to slightly elevated K levels. A classic symptom of K+ is c/o weak, rubbery legs. Stat bloodwork should be done. Any K+ > 5.5 or a change in the patient s trend should be reviewed with the Nephrologist and the Dietitian. Levels trending upward may be diet related or indicate a decline in residual kidney function. Occasionally low K+ values need to be followed. Low values are at risk for becoming lower still under the influence of HD.

3 POTASSIUM (continued) Dialysis concentrate bath guidelines should be used when K+ studies are done and in conjunction with review during rounds. CARBON DIOXODE CO2 CALCIUM Ca++ Ca++, PO4, and PTH are interrelated and always reviewed together. PHOSPHORUS PO4 CO2 content of the blood primarily reflects the bicarbonate level. It will increase in metabolic alkalosis and decrease in metabolic acidosis. Ca++ is a mineral in the body that is used primarily with phosphorus in bone metabolism. Calcium exerts a sedative effect on nerve cells and assists in muscle contraction. Phosphorus is an important constituent of all body tissues and has a wide range of vital functions: formation of energy storing substances such as ATP, metabolism of carbohydrates, protein and fat, acid-base maintenance. Phosphorus is critical to normal nerve, and muscle function and provides structural support to bones and teeth. Phosphorus binders (calcium agents) are taken with meals to bind PO4 with Ca++ in the gut to form an insoluble salt which is then mmol/l Should be within normal limits. Nephrologists need to know if the CO2 levels are out of range. CO2 levels can be managed during HD using the bicarbonate setting ( ms/cm on the Integra). Low CO2s are more common in renal failure mmol/l Abnormalities in serum levels begin early in renal insufficiency. Long-term effects include bone disease & metastatic tissue calcification. Values less than 2.00 and greater than 2.70 must be followed up immediately with the physician; otherwise note need for review in Nephrologist binder or review during rounds mmol/l Phosphorus and calcium work together under the direction of the PTH. Diet changes and phosphorus binders are needed to keep the balance between calcium and phosphorus levels healthy. In addition to long-term bone disease increased serum phosphorus levels induce itch, can cause conjunctivitis, metastatic tissue calcification, corneal haziness, irregular HR, and papular eruptions. A serum level in the 1.0 to 1.8 range is desired for RRT patients. PO4 with Ca++ may indicate the phosphorus binder requires adjustment or that the patient may be skipping doses.

4 PHOSPHORUS (continued) eliminated via the gastrointestinal route. Calcium agents taken between meals acts as a calcium supplement. PO4 with Ca++ may indicate constipation; that ingestion of phosphorus binders is mistimed; or that a Vit D analog is in use. PO4 with Ca++ may indicate the patient is taking too many phosphorus binders or that a Vit D analog medication is in use. PARATHYROID HORMONE ipth or PTH assessed q3m or as ordered PTH is a hormone made by the parathyroid glands located in the neck. PTH is released in response to low serum calcium. It increases resorption of bone (movement of Ca++ and PO4 out of the bone); activates vitamin D, which increases the absorption of calcium from the GI tract; and stimulates the kidneys to conserve calcium and excrete phosphorus pmol/l 2 3 x normal value for RRT patients PTH often elevates as kidney function declines. It is the master control for the balancing act between calcium and phosphorus. RRT patients are best maintained at PTH values between PTH is assessed every 3 months or as individually ordered. PTH is treated with a Vit D analog but because the Ca++ usually rises in response to the medication, the treatment depends on the serum Ca++ being within normal limits. MAGNESIUM Mg Mg is an abundant cation located in the bone (50-60%), ECF (1%) and within cells (remainder). Magnesium triggers the sodiumpotassium pump, aids transmission of neuromuscular activity and works with the release and action of PTH mmol/l Should be within normal limits, and isn t usually a concern for HD patients. However: Mg levels may be due to a state of malnourishment, excessive GI loss (vomiting, diarrhea), or alcoholism. Patient may become symptomatic with levels <0.40 mmol/l. Hypomagnesemia symptoms include: apathy, leg cramps, insomnia, confusion, and N&V. Review monthly: MgSO4 additive to the acid bath may be required.

5 AP is an enzyme distributed largely U/L Should be within normal limits. in the liver, biliary tract epithelium, and bone. ALKALINE PHOSPHATASE Alk Phos or AP or ALP An AP level is a non-specific indicator of bone activity: healing fracture, new bone growth normal and abnormal are examples. AP may be a result of some medications such as allopurinol and antibiotics. AP is reviewed monthly or as ordered. Elevated levels are not diagnostic. URIC ACID Urate, UA or U/A Uric Acid is a nitrogenous compound that is a product of purine (DNA building block) catabolism. It is mostly excreted by the kidneys thus an accumulation of uric acid may lead to gout umol/l Should be within normal limits. Gout is a painful complication of chronic kidney disease and is treated with medications such as allopurinol and in acute episodes, colchicine. Uric acid is monitored every 6 months or as ordered. HEMOGLOBIN Hgb Anemia management in RRT requires balance between Hgb, Se Fe Sat n & Ferritin in order for supplemental erythropoietin to work efficiently. A substance in your blood that carries oxygen from the lungs to all the tissues in your body. Factoid: Some conditions, such as SLE or Wegener s Granulomatosis, may be a factor in EPO resistance g/l is optimal for RRT patients in the absence of CAD; where CAD is present Normal high serum values are thought to put the RRT patient at increased risk for cardiac disease, stroke, and vascular access dysfunction. Physician/Nurse review may include: hgb: r/o anemia secondary to GI bleeding (stool for OB may order scope if positive). May require packed cell transfusion. hgb: r/o deficient stores of B12 & folate (replacement vitamin therapy) hgb: EPO if iron saturation >20% and Ferritin < 500 hgb: supplemental iron medication if iron saturation < 20% and Ferritin < 500. EPO possible.

6 HEMOGLOBIN (continued) Note-if Ferritin > 500, anemia treatment with iron supplementation may or may not occur (grey zone) IRON Saturation Fe Sat n aka Transferrin Saturation Iron and erythropoietin work closely together to counteract anemia. Free serum iron binds to a globulin protein called transferrin and is carried to the bone marrow for incorporation into hemoglobin. hgb: EPO is or placed on hold; phlebotomy may be ordered See attached algorithm for the Management of Anemia (guidelines provided by BC PRA) 20 50% Supplemental iron medication is often required for RRT patients. rbc production is deficient when iron sat s are less than 20% FERRITIN Ferr Ferritin, the major iron storage protein, is normally present in the serum in concentrations directly related to iron storage ug/l >150 but < 500 for RRT patients Ferritin levels are often elevated in patients receiving intravenous iron therapy. It is a challenge with HD patients to keep Ferritin levels within a ug/l range. Increased levels may be a sign of iron excess as a result of iron supplementation, or may indicate conditions such as hemochromocytosis. A limitation with measuring ferritin is that levels can also be elevated in conditions not reflecting iron stores such as inflammation, infections, metastatic ca, & lymphomas. There is no way to identify the actual cause of elevated ferritin by its test alone. Iron and ferritin values are always assessed together. The physician may choose to order iron supplements in patients with elevated ferritin, or hold iron products until the ferritin levels drift down to normal. In these cases, the hgb is often the

7 FERRITIN (continued) deciding factor. RETICULOCYTES retics A reticulocyte is an immature rbc. It indicates bone marrow function and evaluates erythropoietin activity. 0.5% - 2% based on absolute retic count Although done monthly, reticulocyte values are of heightened interest when EPO is first initiated or when changes are made in EPO dosing. A standard initiation dose of EPO is 4000 u 3 x weekly. We expect to see reticulocyte production rise from the baseline value. If it remains unchanged or rises minimally, the physician may increase the EPO dosing. WHITE BLOOD CELLS wbc WHITE BLOOD CELLS (continued) PLATELETS Plts White blood cells fight off infections. Platelets adhere to each other and initiate the clotting cascade when damaged endothelium is encountered ˆ9/L Should be within normal limits. If wbc, assess patient for active or quiet sources of infection. Temp of 37.5 or higher &/or chills/rigor should be followed with a blood culture. Urgent review is required in the presence of symptoms. If wbc chronic, review on non-urgent basis. wbc may occur if using a cellulose-based membrane for HD. Usually, wbc recovery occurs within the first hour of HD. Post cbc may be indicated in this case. wbc occurs with chemotherapy consider dialyzing patient in isolation, encourage use of mask while patient in-centre ˆ9/L Should be within normal range. Thrombocytopenia occurs when plts <100,000. Prolonged bleeding may occur when plts < 40,000. Spontaneous bleeding is a serious danger when plts <20,000.

8 PLATELETS (continued) Thrombocytosis occurs when plts >400,000 and may occur as a compensatory response to severe hemorrhage. Polycythemia vera and leukemia are other possible reasons for elevated plts. ALBUMIN alb CHOLESTEROL Cho HD patients have cholesterol panels done on an annual basis (includes LDL, HDL and triglycerides). TRIGLYCERIDE trig A protein in your blood that measures your nutritional state. It also helps to keep the amount of fluid in body cells balanced. Cholesterol is required for the production of steroids, bile acids and cellular membranes. Because cholesterol is the main lipid involved in arteriosclerotic disease, high levels of free and bound LDLs (low density lipoproteins) are associated with increased cardiovascular disease. Triglycerides are required for fat storage. Values outside normal range should be reviewed. Extreme low and high values should be reviewed urgently g/l RRT patients generally have difficulty ingesting adequate protein amounts. Supplements are supplied when RRT patients meet criteria. Very low values lead to 3 rd spacing fluid retention which is difficult to correct with hemodialysis alone. Values are generally considered non-urgent but important. Assess according to patient trend. Steady decline indicates anorexia and may require medication intervention (Megace) if nutrition supplement unhelpful. If albumin is low, pre urea is likely to be low as well mmol/l Cholesterol values may be normal as kidney function declines; however, cardiovascular disease is prevalent in the elderly renal population. Inappropriate cholesterol panel values can result in heart and blood vessel damage. Diet changes and pills may be needed to keep levels safe. Cholesterol panel results are primarily followed by the Nephrologist and by the Dietitian mmol/l May be normal or too high as kidney function declines. It can be lowered with diet, exercise, weight loss, and or medication. Part of the CHO panel.

9 HEPATITIS B ANTIBODY A positive titre indicates contact > 10 miu/ml HBsAB with the disease and subsequent indicates protection immunity development, or that the vaccination series was administered. Further hepatitis studies determine if contagious hepatitis disease exists or if active infection is present (Hep B surface core antibody and Hep B surface antigen) The full Hep B screen is done upon admission to the hemodialysis unit. After establishing the patient s Hep B status, the patient is recognized as infectious and is no longer tested, or is monitored with periodic antigen or antibody tests to confirm benign status. Vaccination protection is offered and provided to all RRT patients requiring immunity to Hepatitis B. Conversion to positive protection requires more than double the vaccine for patients with renal disease. Follow the vaccination algorithm for the dosing schedule. 24 hour URINE for UREA & VOLUME Assessed every 3 months, or as ordered, to determine residual kidney function levels. No normal values. Ranges from Zero urine output to several litres daily. Highly individual. Urine output may decrease over time, in which case the patient s presenting fluid gains will increase unless dietary adjustments are made. RRT patients with urine output often have less difficulty managing serum potassium and fluid issues. Blood urea may be lower than 20 mmol/l if urine output represents significant residual kidney function. * All lab values stated are congruent with the PRH LAB department. References: Diagnostic and Laboratory Test Reference; Pagana; 1992; Mosby Fluids, Electrolytes, and Acid-Base Balance; Horne & Swearingen; 1993; Mosby Renal Nursing; Smith; 1997; Baillière Tindall Prepared by Laurie Bates, RN, CNeph (C) Updated Oct-2007