RENAL FAILURE AND RENAL REPLACEMENT THERAPY

ByNalukenge Caroline and

Nsubuga Meddie MBChB V

CHRONIC KIDNEY DISEASE (CKD)• CKD ; a spectrum of different pathophysiologic

processes associated with abnormal kidney function, and a progressive decline in glomerular filtration rate (GFR).

• chronic renal failure applies to the process of continuing significant irreversible reduction in nephron number, and typically corresponds to CKD stages 3–5.

• End-stage renal disease; a stage of CKD where the accumulation of toxins, fluid, and electrolytes normally excreted by the kidneys results in the uremic syndrome.

STAGES OF CHRONIC RENAL DISEASEStage Description GFR

(ml/min/1.73m2)

Action

1 Kidney damage with normal or

high GFR

≥90 Investigate, e.g. haematuria and

proteinuria 2 Kidney damage

with slightly low GFR

60-89 Renoprotection-blood pressure control, dietary

modifications3 Moderately low

GFR30-59

4 Severe low GFR 15-29 Prepare for renal replacement therapy (if

appropriate)5 Kidney failure < 15 or dialysis

Risk factors for CKD• hypertension• diabetes mellitus• autoimmune disease such as SLE, vasculitis• older age• African ancestry• family history of renal disease• previous episode of acute renal failure & the presence of

proteinuria• structural abnormalities of the urinary tract.• Congenital; Polycystic kidney disease, Alport’s syndrome.• Glomerular diseases eg IgA nephropathy• Renal artery stenosis

Pathophysiology of CKD2 mechanisms; initiating mechanisms specific to the underlying etiology

(e.g., immune complexes and mediators of inflammation or toxin exposure)

a set of progressive mechanisms, involving hyperfiltration and hypertrophy of the remaining viable nephrons, eventually sclerosis & dropout of the remaining nephrons.

• The responses to reduction in nephron number are

mediated by vasoactive hormones, cytokines, and growth factors.

Clinical PresentationNB: Uraemia refers to clinical symptoms & signs of

RF due to loss of the excretory, metabolic and endocrine functions of the kidney.

• asymptomatic until GFR falls below 30 ml/minute

• may present as a raised blood urea and creatinine found during routine examination, often accompanied by HTN, proteinuria or anaemia.

Clinical Presentation cont’d• Nocturia• tiredness or breathlessness• Weakness• Kussmaul's breathing• anorexia and nausea• hiccoughs• pruritus• vomiting• muscular twitching• fits, drowsiness and coma ensue.

Clinical Presentation cont’d

PHYSICAL EXAMINATION;• Wasted• Yellow complexion• Pallor• Features of cardiac

tamponade• Brown line

pigmentation of nails• Excoriations

• Ecchymoses• Increased RR & depth• P. neuropathy• Absent reflexes• Reduced sensation• Paraesthesias• Restless legs

Diagnosis and management

• Proper history(causes/risk factors, symptoms, complications)

• Physical examination• INVESTIGATIONS- CBC - Urinalysis; protein- RFTs - LFTs (albumin)- Calcium and phosphate levels- PTH- Hepatitis(B & C) and HIV serology- Others tailored to underlying cause

ManagementIf diagnosis is not known• Immunoglobulins and protein electrophoresis • Urinary Bence Jones protein • Complement • ANA: and dsDNA if ANA is positive • ENA: if a connective tissue disorder is suspected • Rheumatoid factor • ANCA: in all possible inflammatory renal disease • Anti-GBM: in all possible inflammatory renal

disease

Management

• Imaging- Renal U/S ( kidneys, symmetry, size, renal masses,

evidence of obstruction)- Renal artery imaging: if renovascular disease is

suspected… doppler U/S- Voiding cystogram; reflux nephropathy- ??? Radiographic contrast imaging not recommended- Chest X-ray; heart size, pulmonary oedema- ECG; if > 40 years or there are risk factors for cardiac

disease

Mngt cont’d• Role of renal biopsy in CKD-mainly indicated in early stage CKD to establish

etiology in absence of clinical dx.Contraindications• bilaterally small kidneys• uncontrolled hypertension• active urinary tract infection• bleeding diathesis• morbid obesity. NB; bleeding time should be measured, and, if

increased, desmopressin should be administered immediately prior to the procedure.

Treatment• Identify the underlying renal disease , by

history, examination, testing of biochemistry, immunology, radiology and biopsy

• Look for reversible factors which are making renal function worse

• Attempt to prevent further renal damage. • Attempt to limit the adverse effects of the loss

of renal function. • Institute renal replacement therapy (dialysis,

transplantation

Treatment cont’d

a) Slowing the Progression of CKD- Protein Restriction: reduces uremia & also protein-

mediated hyperfiltration- Reducing Intraglomerular Hypertension and

Proteinuria; ACEIs and ARBs

b) Managing Other Complications of CKD- Anaemia; Recombinant human erythropoietin- Fluid and electrolyte balance ; fluid intake plus

sodium supplementation

Treatment- Acidosis; IV fluids, sodium bicarbonate- Infection; Antibiotics- Bleeding; Adequate dialysis- Renal osteodystrophy; Hypocalcaemia is corrected by

giving 1α-hydroxylated synthetic analogues of vitamin D.

• Hyperphosphataemia is controlled by dietary restriction of foods with high phosphate content (milk, cheese, eggs) and the use of phosphate-binding drugs administered with food

c) Renal replacement therapy

OBJECTIVES

Describe treatment options for renal replacement therapy

• Describe treatment options for renal replacement therapy

• Understand the general principles of dialysis modalities & compare their outcomes

• Importance of residual renal function

of dialysis modalities & compare th

PURPOSES OF DIALYSIS

1. Removes excess fluids and waste products.2. Restores chemical and electrolyte balance

HEMODIALYSIS‑ one of several renal replacement therapies used for the treatment of renal failure. HD involves the extracorporeal (outside of the body) passage of the client’s blood through a semi permeable membrane that serves as an artificial kidney.

Indications for Renal Replacement Therapy

• Hyperkalemia• Metabolic acidosis• Fluid overload (recurrent CHF

admissions)• Uremic pericarditis (rub)• Other non specific uremic symptoms:

anorexia and nausea, impaired nutritional status, increased sleepiness, and decreased energy level, attentiveness, and cognitive tasking, …

GENERAL GUIDELINE REQUIREMENTS FOR APPROPRIATE CLIENT SELECTION

1. Presence of fatal, irreversible renal failure when other therapies are unacceptable or ineffective.

2. Absence of illnesses that would prevent or seriously complicate HD.

3. Expectation of rehabilitation.

4. The client’s acceptance of the regimen.

Components of HemodialysisDialyzer or artificial kidney

Dialyzer has 4 components: Blood compartment, Dialysate compartment, Semipermeable membrane, enclosed structure to support the membrane.

Dialysate – made up of clear H2O & chemicals. Compositions may be altered according to patient’s needs for treatment of electrolyte imbalance. Warmed to 37.8 C = to 100 F to increase efficiency of diffusion. Prevent decrease in pt’s blood temperature.

Vascular access routes – AV fistula, AV Graft, Dual Lumen Cathater, AV Shunt.

Hemodialysis machine

Hemodialysis machine

PROCEDURE

The principles of HD are based on the passive transfer of toxins, which is accomplished by diffusion.

When HD is initiated, blood and dialysate flow in opposite directions from their respective sides of an enclosed semi permeable membrane.

The dialysate is a balanced mix of electrolytes and water that closely resembles human plasma. On the other side of the membrane is the client’s blood, which contains metabolic waste products, excess water, and excess electrolytes.

Cont…

During HD, the waste products move from the blood into the dialysate because of the difference in their concentrations (diffusion). Excess water is also removed from the blood into the dialysate (osmosis). Electrolytes can move in either direction, as needed, and take some fluid with them. Potassium and sodium typically move out of the plasma. This process continues as the blood and the dialysate are circulated past the membrane for a preset length of time.Duration and frequency of HD treatment depends on the amount of metabolic waste to be cleared, and the amount of fluid to be removed.

COMPLICATIONS OF HEMODIALYSIS

Dialysis disequilibrium syndrome- the cause is

unknown but maybe due to rapid decrease in

blood urea nitrogen levels during HD. These change can cause cerebral edema- leads to increase intracranial pressure. Infection- transmitted by blood transfusion are

another serious complication associated with long term HD.

Hepatitis Infection- in clients with chronic renal failure.

Best Practice for Caring for the client Undergoing Hemodialysis

Weigh the client before and after dialysis.

Know the client’s dry weight.

Discuss with physician whether any of the

client’s medications should be withheld until after

dialysis.

Be aware of events that occurred during the

dialysis treatment.

Cont…Measure blood pressure, pulse

rate, respirations, and temp.

Assess for symptoms of orthostatic hypotension.

Assess the vascular access site.

Observe for bleeding

Assess the client’s level of

consciousness and assess for

headache, nausea, and vomiting.

COMPLICATIONS OF AV FISTULAE OR SYNTHETIC AV GRAFT

Stenosis‑the most frequent cause of

permanent peripheral hemodialysis access

failure is vascular stenosis.

Thrombosis‑ this complication is more

common in synthetic AV grafts than native AV

fistulae.

Failure of maturation‑ a native AV fistula

requires 1 to 4 months to mature; if blood flow

is diminished by stenosis or multiple outflow

veins, maturation will be impaired.

Cont..Infection‑ a leading cause of

complications and death in dialysis

patient. Typical S/S of an infected dialysis

access include local erythema, induration,

tenderness, and purulent drainage from

incision sites.

Ischemic steal syndrome‑ diverting blood

flow from the distal extremity through the

hemodialysis access may cause pain and

ischemia in some patients, esp.diabetic

and elderly patient.

Pseudoaneurysm‑ also called false

aneurysm or pulsating hematoma

TYPES OF VASCULAR ACCESS FOR HEMODIALYSIS

Permanent AV fistular –forearm for 2-4 months or more

Av graft- forearm for 1-2 weeks Dualumen HD – subclavian vein –

immediately post operatively and after x-ray confirmation of placement

Temporary HD catheter (dual or triple)- subclavian, internal jugular or femoral vein- immediately after insertion and x-ray confirmation

AV shunt (relatively uncommon)-forearm- immediately after insertion

PERITONIAL DIALYSIS

Peritoneal dialysis (PD) takes place within the

peritoneal cavity. PD is slower than hemodialysis,

However , and more time is needed for the same

effect to be obtained.

TYPES OF PERITONEAL DIALYSIS

CAPD- Continuous Ambulatory Peritoneal Dialysis

MBCAPD‑ Multiple‑Bag CAPD

APD‑ Automated Peritoneal Dialysis

IPD‑ Intermittent Peritoneal Dialysis

CCPD‑ Continuous Cycle peritoneal Dialysis

PROCEDURE AND PROCESS The surgical insertion of a siliconized rubber

(Sillastic) catheter into the abdominal cavity is

required to allow the infusion of dialyzing fluid

(dialysate) is infused according to the physician

order, 1 to 2L of dialysate is infused by gravity (fill)

into the peritoneal space over a 10 to 20 minutes

period, according to the client’s tolerance. The fluid dwells in the cavity for a specified time

ordered by the physician. The fluid then flows out of the body (drain)

by gravity into a drainage bag.

Con’t of process and procedure

The peritoneal outflow contains the dialysate in

addition to the excess water, electrolytes

and nitrogenous waste products that have

accumulated in the body.

The Three Phases of the process:

1. Infusion or fill.

2. Dwell

3. Outflow or drain.

Cont.. PD occurs through diffusion and osmosis

across the Semipermeable peritoneal

membrane and adjacent capillaries.

The peritoneal membrane is large and porous.

it allows solutes, which carry fluid with

them to move by an osmotic gradient from

an area of higher concentration in the body

(blood) to an area of lower concentration in

the dialyzing fluid.

Complications of CAPD

PERITONITIS‑the major complication of PD. The

most common cause of peritonitis is contamination

of the connection site during an exchange. The

infection of peritoneum is manifested by cloudy

dialysate outflow (effluent), fever, rebound

abdominal tenderness, abdominal pain, general

malaise, nausea, and vomiting.

Cont..

Cloudy or opaque effluent is the earliest sign of

peritonitis. The best treatment of peritonitis is

prevention.

The nurse must maintain meticulous sterile

technique when caring for the PD catheter

and when hooking up or clamping off

dialysate bags.

Con’t

Pain- pain during inflow of dialysate is common

during the first few exchanges because of

peritoneal irritation; however, it disappear after a

week or two. Cold dialysate aggravates

discomfort. Thus the dialysate bags should be

warmed before instillation by use of a heating pad

to wrap the bag or use of warming chamber.

Con’t Microwave oven are not recommended for

the warming of dialysate because of their

unpredictable warming patterns and

temperatures.

Exit Site and Tunnel infections- the normal

exit site from a PD catheter should be clean,

dry, and with out pain or evidence of

inflammation.

Con’t

Insufficient flow of the Dialysate- Constipation is

the primary cause of inflow or outflow problems.

To prevent constipation, the physician orders a

bowel preparation before placing the PD catheter.

The nurse ensures that the drainage bag is lower

than the client abdomen. The nurse inspects the

connection tubing and PD system for kinking or

twisting and rechecks to make sure that clamps

are open.

Con’t

Dialysate Leakage- when dialysis is initiated,

small volumes of dialysate are used. It may

take clients 1 to 2 weeks to tolerate a full 2-L

exchange without leakage around the catheter

site.

Other Complication- The nurse notes any

change in the color of the outflow.

NURSING CARE DURING PERITONEAL DIALYSIS

Evaluate baseline vital signs

The client is weigh, always on the same scale, before

the beginning of the procedure or at least every 24

hours while receiving the treatment.

Baseline laboratory value determination, such as

electrolyte and glucose levels,

Con’t

During PD, the nurse continually monitors the

client. For the first

exchanges, record the values every 15

minutes. Ongoing assessment for

respiratory distress, pain or discomfort.

Abdominal dressing around the catheter exit

site is checked frequently for wetness.

Monitor for dwell time.

NURSING CARE CON’T

For hourly exchanges, dwell time usually ranges from 20 to 40

Minutes. Blood glucose assessment is necessary, due to

Glucose absorption occur in some patient.

The outflow is recorded accurately after each exchange.

Con’t

Visual inspection of the outflow bag and daily

weights may be sufficient to note the

adequacy of the return. If drainage return is

brown, a bowel perforation must be

suspected. If drainage return is the same

color as urine and has the same glucose

concentration, a possible bladder perforation

should be investigated. If drainage is cloudy

or opaque, an infection is suspected.