Peritoneal Dialysis

Kidney A&P

I.  Kidneys

  A. Location - back of the abdominal cavity. The right kidney is lower than the left due to the liver

B. Size   approx. same size

as your fist

4" long (12cm) 1-1/2" thick    (3cm) 2-1/2“ wide (6 cm) weighs:1/3 lb (150 gm) 

C. Layers

1. Cortex- outermost layer (85% nephrons)

shorter cortical nephrons (excretory/regulatory)

2. Medulla- middle layer (15% nephrons) longer juxtamedullary

nephrons (concentration and dilution of urine)

3. Pelvis- inner layer (collecting system- urine)

D. Blood flow through the Kidneys

Heart pumps approx.1.2 liter blood/min to the kidneys via the renal artery. Blood then travels through a series of smallerarteries and then enters the glomeruli. Some of thefluid is filtered out of each glomerulus and thenmoves into Bowman's capsule. The filtrate thenmoves through the tubules where most ofThe sugar, water, and minerals are reabsorbed back into the blood vessels. The filtrate then goes into the renal pelvis.

E. Nephrons Functional units of the kidney. Approximately one million in the cortex and medulla of each kidney

CorticalNephron

JuxtamedularyNephron

1. Glomerulus  filters blood approx.1200 ml/min (1/4 cardiac output) 

2. Bowman's Capsule surrounds the glomerulus and collects the filtrate

distal convoluted tubule

efferent arteriole- blood out

afferent arteriole- blood in

3. Juxtaglomerular Apparatus

macula densa and

juxtaglomerular cells

(1) systemic BP and volume control via therenin-angiotensin system

(2) local control of the (GFR) by nitric oxide production

(3) the production of erythropoietin in response to decrease in O2.

4. Tubules

   Proximal Convoluted- where 60%-70% filtrate containing water, glucose, nutrients, amino acids & ions from the glomerulus is re-absorbed into the capillaries.

    Loop of Henley- concentration of urine occurs (descending) water excreted

(ascending) Na+, K+, Cl- excreted

Distal Convoluted Tubulesregulation electrolytes, H2O and pH(aldosterone- Na+) (ADH- water)

Collecting ducts- water and urea are absorbed or excreted, then empty into the calyces. ADH-water Equilibrium-urea

F. Major Functions

1. Remove water, urea, creatinine, and uric acid (components of urine)

2. Maintain electrolyte balance

3. Maintain acid/base balance by removing or retaining H+ / HCO3 ions

4. Regulate blood pressure by initiating renin / angiotensin response

5. Release erythropoietin to help maintain RBC production

6. Detoxification & elimination of toxins, drugs, and their metabolites

Peritoneal Dialysis

Renal Failure

I I . Renal Failure 

   A. Acute vs. Chronic

Renal Failure

Definition

Etiologies

Prognosis

Acute Chronic

Sudden cessation of renal function with associated oliguria

infections, antibiotics, extensive burns, poisoning, shock, MI, surgery

Often reversible

Slow irreversible decrease of renal function - ESRD

diabetes, hypertension

glomerulonephritis pyelonephritis

dialysis or transplantation

B. Types

1. Pre-Renal

a) Definition Any condition that impairs renal blood flow. Nephrons remain intact but decreased blood supply causes a drop in the glomerular filtration rate which results in decreased urine output

b) Causes

cardiac disorders- arrhythmias, chf, cardiac tamponade, MI

vasodilatation- sepsis, anaphylaxis, medications, OD

hypovolemia- hemorrhage, third spacing, shock, diuretics diabetes insipidus, burns, dehydration, vomiting, diarrhea, cirrhosis

vascular- thrombus, stenosis, surgical clamping (AAA repair)

2. Renal (Intra-Renal)

  a) Definition direct damage to the kidneys

b) Causes

Pyelonephritis - infection of the kidneys from UTI (E.coli)

Glomerulonephritis - antigen/antibody complexes (strep throat)

Systemic lupus - connective tissue disorder

Hereditary lesions - polycystic kidneys

Acute Tubular Necrosis - anesthesia, radiographic dyes, lasix, vancomycin, corticosteroids, Amphotericin-B, ibuprophen, rhabdomyolysis, prolonged pre-renal causes

3. Post-Renal

a) Definition obstruction of the

urinary system

b) Causes prostatic hypertrophy, renal calculi, tumors, blood clots, pregnancy

C. Stages of Chronic Renal Failure     (normal GFR is 125 mL/min/1.73 m2)

• STAGE 1 Kidney damage with normal GFR ( ≥90)

• STAGE 2 Mild decrease in GFR (60-89)

• STAGE 3 Moderate decrease in GFR (30-59)

• STAGE 4 Severe decrease in GFR (15-29)

• STAGE 5 Kidney failure (GFR <15)

Glomerular Filtration Rate

Serum Creatinine (mg/dl)

Age

Male/Female

African American

GFR (mL/min/1.73 m2) = 186 x (Scr)-1.154 x (Age)-0.203 x (0.742 if female) x (1.212 if African-

American)

D. Symptoms

1. weakness, fatigue 2. drowsiness, confusion 3. restless legs 4. itching 5. dry flaky skin 6. loss of appetite 7. metallic taste 8. nausea/vomiting

9. edema, puffiness around eyes 10. shortness of breath 11. high blood pressure 12. muscle cramping13. decreased sexual interest 14. decreased urinary frequency 15. amenorrhea16. testicular atrophy

Symptoms (continued)

E. Complications As renal function declines, the end products of protein

metabolism accumulate in the blood and adversely affect every system in the body.

1. Hyperkalemia 2. Metabolic Acidosis 3. Pericarditis (effusion / tamponade) 4. Pulmonary Edema 5. Hypertension 6. Anemia 7. Bone disease 8. Vascular calcifications

1. Transplantation

F. Treatment Options

2. Dialysis a) hemodialysis b) CRRT (ICU) c) Peritoneal

3. No Treatment

ComplicationsTransplantation

Pain/Discomfort of Surgery

Risk of Rejection

Frequent Medical Needs

Weakened Immune System

Side Effects of Medications

Cancer (skin)

Stress

Cost

Hemodialysis

Bleeding (anticoagulation)

Clotting in dialyzer

Disequilibrium syndrome

Muscle cramping

Hypotension

Air emboli

Fever / Infection

Arrhythmias

Angina

Complications Peritoneal Dialysis

Abdominal pain / cramps Anorexia Nausea Reflux Hernias

Weight gain Peritonitis Exit site infection Dyspnea (fluid retention)

Peritoneal Dialysis

C A P D

III . Peritoneal Dialysis

A. Definition removal of fluid and waste products via a dialysis catheter located in the peritoneal cavity; space between the stomach, liver,

spleen, intestines and kidneys by: 1) diffusion 2) osmosis 3) ultrafiltration 4) convection

Ultrafiltration Occurs because of a

pressure gradient

Convection Occurs as solvent

drag. Solvent brings the solute with it.

B. Process

3.   Drain - After a specified dwell time the

fluid containing the waste and excess fluid

is drained out.

1.  Infusion- 1 to 3 liters of sterile dialysate solution is infused through the dialysis catheter into the abdominal cavity which comes into contact with the peritoneal membrane.

2.   Dwell - The membrane is semi-permeable and acts as a filter which allows waste products and excess fluid to pass from the blood stream, across the membrane and into the dialysis solution.

(however!!!)

     1- Drain -

                                      2- Infusion-

      3- Dwell -

C. Types

1. CCPD - Continuous Cycler Peritoneal Dialysis (or APD - Automated PD). Cycler is used during the night to perform up to 8 exchanges. Long dwell during the day

   2. CAPD - Continuous Ambulatory Peritoneal Dialysis 4 or 5 exchanges per day

D. Dialysate 1. Definition: Fluid containing dextrose and

electrolytes

2. Concentrations: Higher concentrations of glucose pull more fluid a) 1.5%

b) 2.5% c) 4.25%

ƒ

Recent findings have shown that it improvesthe long-dwell ultrafiltration and clearance of creatinine and urea compared to 4.25% dextrose.

EXTRANEAL is a glucose-free polymer that is indicated for a single daily exchange for the long 8-16 hour dwell during CAPD or APD.

3. Possible Additives

  a) heparin   b) insulin (added by pharmacy)

  c) antibiotics (added by pharmacy)

  d) potassium (added by pharmacy)

         Advantages

1. flexible schedule

2. less expensive than Hemodialysis

3. fairly easy to learn

4. fewer dietary restrictions

5. no needles required

6. dialysis can be done at home, on vacation or wherever you are

7. no blood loss

8. continue daily activities

          Disadvantages 

1. burn out, no days off

2. procedure must be followed exactly to prevent peritonitis

3. altered body image

4. risk of infection

5. permanent catheter access

6. larger clothing size because of fluid in the peritoneal cavity

7. some protein loss

8. storage space (supplies)

Peritoneal Dialysis

Nursing Responsibilities

IV   Nursing responsibilities

A. room environment - during bag connection, tubing change, adding meds, exit-site care for recent post ops

    1. prefer a private room (roommate approved by  MD)     2. air vent covered     3. door closed (sign on door) Procedure in Progress Do Not Enter    4. curtain pulled     5. mask on patient, roommate, staff

B. accurate I&O

C. daily weights abdomen must be empty,

weigh after first AM drain

D. exit site care (daily)

immediately post-op - do not disturb

recent post-op - ExSept

long standing - soap & water

E. phosphate binders must be given immediately before or after meals, otherwise  they are calcium supplements Examples:. PhosLo, Renagel, Ca+ carbonate (Tums)

F. sorbitol standing order. No fleets enema or MOM.

(Mg+ not removed by dialysis)

G. tubing clamps soak in hibiclens / betasept (in open position)

rinse off prior to use change solution every 24hrs.

H. IV rates watch, especially pre-op and post-op patients. Use IV Pump!

I. insulin is stable 2 hrs. in the warmer 24 hrs. out of the warmer

J. potassium is stable 1 hr after added (adheres to bag)

K. heparin should be added to the bag prior to the infusion during the current exchange. Does not cross the peritoneal membrane so does not cause systemic anticoagulation

L. Specimens C & S – aerobic & anaerobic culture bottles, 30ml extra in sterile specimen cup

Cell Count – lavender top tube

(must hand deliver specimens to the lab!)

M. Documentation

Meditech: CAPD Assess & Care (150344)