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Objectives
Anatomy Function Chronic Renal Failure (CRF)
Causes Symptoms
Dialysis
Anatomy and Physiology
The Kidneys Hilum Medulla Pyramids Papilla Renal Pelvis
Anatomy
2 Kidneys 2 Ureters Bladder Urethra
Kidney Function
Detoxify blood Increase calcium absorption
calcitriol Stimulate RBC production
erythropoietin Regulate blood pressure and
electrolyte balance renin
Formation of Urine Glomerular Filtration
GFR Reabsorption and Secretion
Simple diffusion and osmosis Facilitated diffusion
Active transport
Azotemia: elevated blood urea nitrogen not from an intrinsic renal disease
Oliguria: urine output less than 500cc/24hr.
Nonoliguria: urine output greater than 500cc/24hr.
Anuria:urine output less than 50cc/24hr.
Acute Versus Chronic Acute
sudden onset rapid reduction in urine output Usually reversible Tubular cell death and regeneration
Chronic Progressive Not reversible Nephron loss
75% of function can be lost before its noticeable
ARF versus CRF
NeuropathyRenal osteodystrophySmall size KidneyPast history of CKDBroad cast
Chronic renal failure
Chronic renal failure: slowly progressive and non- reversible loss of kidney function
Uraemia: metabolic outcome of chronic renal failure
End-stage renal disease: requirement for renal replacement therapy
ETIOLOGY
Diabetes mellitus (28%) Hypertension (25%) Glomerulonephritis (21%) Polycystic Kidney Diease (4%) Other (23%): Obstruction, infection,
etc.
Progression of chronic renal failure
Factors causing progression sustaining primary disease systemic hypertension Intraglomerular hypertension Proteinuria Nephrocalcinosis Dyslipidaemia Imbalance between renal energy demands
and supply
Slowing the Progression of Chronic Renal Failure
Control BP to <130 /80 Diet Anaemia Calcium and Phosphate Dyslipidaemia Obesity Smoking Cessation
Old Chinese saying.……
Good doctor relieve disease
Better doctor cure disease
Superior doctor prevent disease
Symptoms of chronic renal failure
Many are symptom free until 2/3 of renal mass lost. Often no physical examination findings or history. Several common modes of presentation:
progressive lethargy, anorexia, (and later vomiting)
hypertension, and /or heart failure unexplained anaemia serendipitous findings on
biochemistry
The Medical Burden Of Chronic Renal Failure
Prevention of ESRD may prevent other co-morbid conditions from developing
In particular, there is a high prevalence of Cardiovascular diseases in patients with Chronic kidney disease
CHRONIC RENAL FAILURE:CLINICAL MANIFESTATIONS
Sodium and water retention Hyperkalemia Metabolic Acidosis Mineral and Bone metabolism Cardiovascular and Pulmonary Disorders Hematologic Abnormalities Neuromuscular Abnormalities Gastrointestinal Abnormalities Endocrine Abnormalities Dermatologic Abnormalities
Sodium and Volume Balance
Sodium and water retention: CHF, Hypertension, ascites, edema
Enhanced sensitivity to extra-renal sodium and water loss vomiting, diarrhea, fever, sweating Symptoms: dry mouth, dizziness, tachycardia,
etc. Recommendations
Avoid excess salt and water intake Diuretics or dialysis
Potassium Balance
Hyperkalemia (GFR below 5 mL/min) GFRs >5 mL/min: compensatory
aldosterone-mediated K transport in the DCT
K-sparing diuretics, ACEis, beta-blockers impair Aldosterone-mediated actions
Exacerbation of hyperkalenia: Exogenous factors: K-rich diet, etc. Endogenous factors: infection, trauma, etc.
Hyperkalemia & EKG K > 5.5 -6 Tall, peaked T’s Wide QRS Prolong PR Diminished P Prolonged QT QRS-T merge – sine
wave
Hyperkalemia Symptoms Weakness Lethargy Muscle cramps Paresthesias Hypoactive DTRs Dysrhythmias
Metabolic Acidosis
Decreased acid excretion and ability to maintain physiologic buffering capacity:
GFR < 20 mL/min: transient moderate acidosis
Treat with oral sodium bicarbonate Increased susceptibility to acidosis
Mineral and Bone
Bone disease (Figure 16-6) from: Decreased Ca absorption from the gut Over-production of PTH Altered Vitamin D metabolism Chronic metabolic acidosis
Cardiovascular and Pulmonary Abnormalities
Volume and salt overload CHF and pulmonary edema Hypertension
Hyperreninemia: Hypertension Pericarditis: Remic toxin accumulation Accelerated atherosclerosis: linked to
factors above and metabolic abnormalities (Ca alterations, hyperlipidemia)
Hematological Abnormalities
Anemia: lack of erythropoietin production Bone marrow suppression:
uremic poisons: leukocyte suppression - infection
bone marrow fibrosis: elevated PTH an aluminum toxicity from dialysis
Increased bruising, blood loss (surgery) and hemorrhage
Lab Abnormalities: Prolonged bleeding time, abnormal platelet aggregation
Neuromuscular Abnormalites
CNS Abnormalities: Mild-Moderate: Sleep disorders, impaired
concentration and memory, irritability Severe: Asterixis, myoclonus, stupor,
seizures and coma Peripheral neuropathies:
“restless legs” syndrome Hemodialysis-related neuropathies
Gastrointestinal Abnormalities
Peptic Ulcer disease: Secondary hyperparathyrodism?
Uremic gastroenteritis: mucosal alterations
Uremic Fetor: bad breath (ammonia) Non-Specific abnormalities:
anorexia, nausea, vomiting, diverticulosis, hiccoughs
Endocrine Abnormalities
Insulin: Prolonged half-life due to reduced clearance (metabolism)
Amenorrhea and pregnancy failure: low estrogen levels
Impotence, oligospermia and geminal cell dysplasia: Low testosterone levels
Dermatologic Abnormalities
Pallor: anemia Skin color changes: accumulation
of pigments Ecchymoses and hematomas:
clotting abnormalities Pruritus and Excoriations: Ca
deposits from secondary hyperparathyroidism
Conclusion – chronic renal failure
Progressive chronic disease leading to end-state renal failure
Different primary disease can cause chronic renal failure
Diabetic nephropathy is a frequent cause for chronic renal failure
Symptoms can be very different and depend on primary disease and stage of chronic renal failure
Stages of renal failure can be associated with a progressive decrease of GFR
The consequences are complex according to the different function of the kidney and involve many organ systems
Pre-Dialysis Treatment 1. Maintain normal electrolytes a. Potassium, calcium, phosphate are major
electrolytes affected in CRF b. ACE inhibitors may be acceptable in many
patients with creatinine >3.0mg/dL c. ACE inhibitors may slow the progression of
diabetic and non-diabetic renal disease [13] d. Reduce or discontinue other renal toxins
(including NSAIDS) e. Diuretics (eg. furosemide) may help
maintain potassium in normal range f. Renal diet including high calcium and low
phosphate
1. Reduce protein intake to <0.6gm/kg body weight
a. Appears to slow progression of diabetic and non-diabetic kideny disease
b. In type 1 diabetes mellitus, protein restriction reduced levels of albuminuria
c. Low protein diet did not slow progression in children with CRF
1. Underlying Disease
a. Diabetic nephropathy should be treated with ACE inhibitors until creatinine >2.5-3mg/dL
b. Hypertension should be aggressively treated (ACE inhibitors are preferred)
Dialysis
½ of patients with CRF eventually require dialysis
Diffuse harmful waste out of body Control BP Keep safe level of chemicals in body 2 types
Hemodialysis Peritoneal dialysis
Hemodialysis1. Indications a. Uremia - azotemia with symptoms and/or signs b. Severe Hyperkalemia c. Volume Overload - usually with congestive heart
failure (pulmonary edema) d. Toxin Removal - ethylene glycol poisoning,
theophylline overdose, etc. e. An arterio-venous fistula in the arm is created
surgically f. Catheters are inserted into the fistula for blood flow
to dialysis machine
Hemodialysis
3-4 times a week Takes 2-4 hours Machine filters
blood and returns it to body
1. Procedure for Chronic Hemodialysis a. Blood is run through a semi-permeable
filter membrane bathed in dialysate b. Composition of the dialysate is altered to
adjust electrolyte parameters c. Electrolytes and some toxins pass through
filter d. By controlling flow rates (pressures),
patient's intravascular volume can be reduced
e. Most chronic hemodialysis patients receive 3 hours dialysis 3 days per week
1. Efficacy a. Some acids, BUN and creatinine are
reduced b. Phosphate is dialyzed, but quickly
released from bone c. Very effective at reducing
intravascular volume/potassium d. Once dialysis is initiated, kidney
function is often reducede. Not all uremic toxins are removed
and patients generally do not feel "normal"
f. Response of anemia to erythropoietin is often suboptimal with hemodialysis
1. Chronic Hemodialysis Medications a. Anti-hypertensives - labetolol, CCB, ACE
inhibitors b. Eythropoietin (Epogen®) for anemia in
~80% dialysis ptsc. Vitamin D Analogs - calcitriol given
intravenously d. Calcium carbonate or acetate to
phosphate and PTHe. RenaGel, a non-adsorbed phosphate
binder, is being developed for hyperphosphatemia
f. DDAVP may be effective for patients with symptomatic platelet problems
Types of Access Temporary site AV fistula
Surgeon constructs by combining an artery and a vein
3 to 6 months to mature AV graft
Man-made tube inserted by a surgeon to connect artery and vein
2 to 6 weeks to mature
Temporary Catheter
AV Fistula & Graft
Chronic Renal Failure
Long-Term Management Renal Dialysis
Hemodialysis Common
complications
What This Means For You
No BP on same arm as fistula Protect arm from injury Control obvious hemorrhage
Bleeding will be arterial Maintain direct pressure
No IV on same arm as fistula A thrill will be felt – this is normal
Access Problems
AV graft thrombosis AV fistula or graft bleeding AV graft infection Steal Phenomenon
Early post-op Ischemic distally Apply small amount of pressure to
reverse symptoms
Peritoneal Dialysis
Abdominal lining filters blood 3 types
Continuous ambulatory Continuous cyclical Intermittent
Considerations
Make sure the dressing remains intact Do not push or pull on the catheter Do not disconnect any of the
catheters Always transport the patient and
bags/catheters as one piece Never inject anything into catheter
Dialysis Related Problems
Lightheaded –give fluids Hypotension Dysrhythmias Disequilibration Syndrome
At end of early sessions Confusion, tremor, seizure Due to decrease concentration of blood
versus brain leading to cerebral edema