Focus on Dialysis Mosby, chapter 47 S. Buckley, RN, MS Fall, N246 Copyright © 2010, 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc.

Transcript Focus on Dialysis Mosby, chapter 47 S. Buckley, RN, MS Fall, N246 Copyright © 2010, 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc.

Focus on Dialysis

Mosby, chapter 47 S. Buckley, RN, MS Fall, N246

Kidneys

• • •

Function: principal organs of the urinary system. Primary functions are: 1. regulate the volume and composition of extracellular fluid (ECF) 2. excrete waste products from the body

Additional functions of kidneys

• • • •

Control BP Produce erythropoietin (stimulates production of RBC’s) Activate vitamin D Regulate acid base balance (renin, angiotensen)

Why the need for dialysis?

•

Renal failure-complete or partial impairment of kidney function resulting in an inability to excrete metabolic waste products and fluid, as well as causing functional disturbances of all body systems.

Renal failure

• • •

Acute (ARF)-syndrome characerized by a rapid loss of renal function with progressive azotemia.

Mortality rate for intrarenal ARF is ~50% Chronic (CKD)-usually develops slowly over months to years and necessitates the initiation of dialysis or transplantation.

terms related to the phases of renal failure

• •

Oliguria-diminished urine output related to inadequate perfusion of kidney. U/O <400ml/day.

Uremia-condition in which renal function declines and symptoms develop. Accumulation of metabolic byproducts that are normally excreted by the kidneys

terms

• • • • • •

Anuria-absence of urine formation.

Polyuria-large volumes of urine Hematuria-blood in urine Anemia- hemoglobin (Hgb) <13 g/dl, (Occurs in most patients with CKD) Pruritis-itching or burning skin.

Urine formation

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Outcome of multistep process of filtration, reabsorption, secretion, and excretion of water, electrolytes, and metabolic waste products. Urine is result of process, but primary function is to filter the blood and maintain the body’s internal homeostasis.

Glomerular filtration

• •

Urine formation begins at the glomerulus, where blood is filtered.

Glomerulus is semipermeable membrane the allows filtration. The hydrostatic pressure of the blood within the glomerular capillaries causes a portion of the blood to be filtered across the membrane.

Glomerular filtration rate

• •

The amount of blood filtered by the glomeruli in a given time is termed the glomerular filtration rate (GFR).

Normal GFR=125ml/min.

Creatinine clearance

• • •

Most common indicator used to analyze urinary system disorders (creatinine clearance).

Creatinine is a waste product produced by muscle breakdown. Urinary excretion is a measure of the amount of active muscle tissue in the body. Value range-85-135ml/min.

BUN and creatinine

• •

BUN-blood urea nitrogen-commonly used test. Concentration of urea in blood, breakdown of amino acids (regulated by rate of kidney excretion) Normal finding-10-30mg/dl

Chronic and acute kidney disease

• •

Occurs when kidneys are no longer able to clean toxins and waste from blood.

Symptoms of failure: changes in urination, edema, weakness, fatigue, ammonia breath, flank pain, itching, n & V.

Prevalence of CKD

• • • • • •

16.8% of U.S. population (CDC, 2004) Greater among people with diabetes (40.2%) Non-Hispanic African Americans (19.9%) Mexican Americans (18.7%.) Native Americans (3x white pop, ~45%!!!).

•

The average annual incidence rate of dialysis was 12 times greater in persons with diabetes (130 per 100 000) vs without diabetes (11 per 100 000). By 1999–2000, diabetic patients comprised 51% of the incident dialysis population. The average annual prevalence rate was 10 times greater in the diabetic cohort. Patients with diabetes had more co morbidities at the start of dialysis and poorer 3 year survival (55 vs 68%; P<0.0001).

Dialysis

• • •

Movement of fluid/molecules across a semipermeable membrane from one compartment to another Used to correct fluid/electrolyte imbalances and to remove waste products in renal failure Treat drug overdoses

Dialysis (Cont’d)

•

Two methods of dialysis available



Peritoneal dialysis (PD)



Hemodialysis (HD)

Dialysis (Cont’d)

• •

Begun when patient’s uremia can no longer be adequately managed conservatively Initiated when GFR (or creatinine clearance) <15 ml/min

Dialysis (Cont’d)

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Certain uremic complications also indicate a need



Encephalopathy, pericarditis

General Principles of Dialysis

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Diffusion

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Movement of solutes from an area of greater concentration to an area of lesser concentration

General Principles of Dialysis (Cont’d)

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Osmosis



Movement of fluid from an area of lesser concentration to an area of greater concentration of solutes

General Principles of Dialysis (Cont’d)

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Ultrafiltration



Water and fluid removal



Results when there is an osmotic gradient across the membrane

Osmosis and Diffusion Across Semipermeable Membrane

Fig. 47-7

Peritoneal Dialysis

• • •

Peritoneal access is obtained by inserting a catheter through the anterior wall Technique for catheter placement varies Usually done via surgery

Peritoneal Dialysis (Cont’d)

• • • •

After catheter inserted, skin is cleaned with antiseptic solution and sterile dressing applied Connected to sterile tubing system Secured to abdomen with tape Catheter irrigated immediately

Peritoneal Dialysis (Cont’d)

• • •

Waiting period of 7 to 14 days preferable 2 to 4 weeks after implantation, exit site should be clean, dry, and free of redness/tenderness Once site is healed, patient may shower and pat dry

Tenckhoff Catheter

Fig. 47-8

Fig. 47-9 A-C and Fig. 47-10

Peritoneal Dialysis

Dialysis Solutions and Cycles

• • •

Available in 1- or 2-L plastic bags with glucose concentrations of 1.5%, 2.5%, and 4.25% Electrolyte composition similar to plasma Solution warmed to body temperature

Peritoneal Dialysis Dialysis Solutions and Cycles (Cont’d)

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Three phases of PD cycle

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Called an exchange

• •

Inflow (fill) Dwell (equilibration)

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Drain

Peritoneal Dialysis Dialysis Solutions and Cycles (Cont’d)

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Inflow

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Prescribed amount of solution infused through established catheter over



about 10 minutes After solution infused, inflow clamp closed to prevent air from entering tubing

Peritoneal Dialysis Dialysis Solutions and Cycles (Cont’d)

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Dwell

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Diffusion and osmosis occur between patient’s blood and peritoneal cavity



Duration of time varies depending on method

Fig. 47-12

Peritoneal Dialysis Dialysis Solutions and Cycles (Cont’d)

•

Drain



15 to 30 minutes



May be facilitated by gently massaging abdomen or changing position

Peritoneal Dialysis

Systems

• •

Automated peritoneal dialysis (APD)



Cycler delivers the dialysate

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Times and controls fill, dwell, and drain Continuous ambulatory peritoneal dialysis (CAPD)



Manual exchange

Peritoneal Dialysis

Complications

• • • • •

Exit site infection Peritonitis Abdominal pain Outflow problems Hernias

Peritoneal Dialysis Complications (Cont’d)

• • • •

Lower back problems Bleeding Pulmonary complications Protein loss

Peritoneal Dialysis Complications (Cont’d)

• • •

Carbohydrate and lipid abnormalities Encapsulating sclerosing peritonitis Loss of ultrafiltration

Peritoneal Dialysis

Effectiveness and Adaptation

• • • • •

Short training program Independence Ease of traveling Fewer dietary restrictions Greater mobility than with HD

Hemodialysis

Vascular Access Sites

•

Obtaining vascular access is one of most difficult problems



Types of access include

• • •

Shunts Internal arteriovenous fistulas and grafts Temporary vascular access

Vascular Access for Hemodialysis

Fig. 47-13

Hemodialysis

Dialyzers

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Long plastic cartridge that contains thousands of parallel hollow tubes or fibers Fibers are the semipermeable membrane

Hemodialysis System

Fig. 47-16

Hemodialysis

Procedure

• • •

Two needles placed in fistula or graft Needle closer to fistula or red catheter lumen pulls blood from patient and sends to dialyzer Blood returned from dialyzer to patient through second needle or blue catheter

Hemodialysis

Procedure (Cont’d)

• • • •

Dialyzer/blood lines primed with saline solution to eliminate air Heparin added to blood as it flows to dialyzer Terminated by flushing dialyzer with saline to remove all blood Needles removed and firm pressure applied

Hemodialysis

Procedure (Cont’d)

• •

Before treatment, nurse should



Complete assessment of fluid status, condition of access, temperature, skin condition During treatment, nurse should



Be alert to changes in condition

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Perform vital signs every 30 to 60 minutes

Fig. 47-17

Hemodialysis

Complications

• • • • • •

Hypotension Muscle cramps Loss of blood Hepatitis Sepsis Disequilibrium syndrome

Hemodialysis

Effectiveness and Adaptation

• • •

Cannot fully replace metabolic and hormonal functions of kidneys Can ease many of the symptoms Can prevent certain complications

Continual Renal Replacement Therapy (CRRT)

• • •

Alternative or adjunctive method for treating ARF Means by which uremic toxins and fluids are removed Acid-base status/electrolytes adjusted slowly and continuously

Continual Renal Replacement Therapy (CRRT) (Cont’d)

• • •

Can be used in conjunction with HD Contraindication



Presence of manifestations of uremia requiring rapid resolution Continued for 30 to 40 days

Continual Renal Replacement Therapy (CRRT) (Cont’d)

• • •

Hemofilter change every 24 to 48 hours Ultrafiltrate should be clear yellow Specimens may be obtained for evaluation

Continual Renal Replacement Therapy (CRRT) (Cont’d)

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Two types of CRRT



Continuous arteriovenous therapies (CAVTs)



Continuous venovenous therapies (CVVTs)

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Most commonly used

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Continuous venovenous hemofiltration

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(CVVH) Continuous venovenous hemodialysis (CVVHD)

Continual Renal Replacement Therapy (CRRT) (Cont’d)

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Continuous venovenous hemofiltration (CVVH)



Large volume of fluid removed hourly,



then replaced Fluid replacement dependent on stability/individualized needs of patient

Continual Renal Replacement Therapy (CRRT) (Cont’d)

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Continuous venovenous hemodialysis (CVVHD)



Uses dialysate

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Dialysate bags attached to distal end of hemofilter

Continual Renal Replacement Therapy (CRRT) (Cont’d)

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Continuous venovenous hemodialysis (CVVHD) (cont’d)



Fluid pumped countercurrent to blood

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flow Ideal treatment for patient who needs fluid/solute control but cannot tolerate rapid fluid shifts with HD

Continual Renal Replacement Therapy (CRRT) (Cont’d)

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Highly permeable, hollow fiber hemofilter Uses double-lumen catheter placed in femoral, jugular, or subclavian vein Removes plasma water and nonprotein solutes

Continual Renal Replacement Therapy (CRRT) (Cont’d)

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CRRT versus HD



Continuous rather than intermittent



Solute removal by convection (no



dialysate required) in addition to osmosis and diffusion Less hemodynamic instability

Continual Renal Replacement Therapy (CRRT) (Cont’d)

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CRRT versus HD (cont’d)



Does not require constant monitoring by HD nurse

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Does not require complicated HD equipment

Fig. 47-19

Chronic Kidney Disease

Gerontologic Considerations

• •

About 35% of ESRD patients are 65 years of age or older Most common diseases leading to renal failure in the older adult



Hypertension



Diabetes

Nursing Management

Evaluation

• • • • •

Maintenance of ideal body weight Acceptance of chronic disease No infections No edema Hematocrit, hemoglobin, and serum albumin levels in acceptable range

Case Study

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65-year-old female with history of progressive renal failure for 5 years

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Diagnosed with type 1 diabetes mellitus when 15 years of age

Case Study (Cont’d)

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She has diabetic retinopathy with macular degeneration

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Gives herself insulin using an insulin pen

Case Study (Cont’d)

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Lab values



BUN 72 mg/dl



Serum creatinine 7.5 mg/dl



GFR 12 ml/min

Discussion Questions 1.

What are her options for renal replacement therapy?

2.

Which one would be the best choice for her?

Focus on Dialysis Mosby, chapter 47 S. Buckley, RN, MS Fall, N246 Copyright © 2010, 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc.

Transcript Focus on Dialysis Mosby, chapter 47 S. Buckley, RN, MS Fall, N246 Copyright © 2010, 2007, 2004, 2000, Mosby, Inc., an affiliate of Elsevier Inc.