Written Prep - Renal Flashcards
Dialysis
What are the causes of ESRF
- Diabetic nephropathy (85%)
- Glomerulonephritis (20%)
(IgA nephropathy is MOST COMMON GN) - Hypertension
- PCKD
- Reflux nephropathy
Dialysis
- Indications for dialysis
- Pericarditis (STRONGEST INDICATION due to risk of tamponade)
- Uraemic SYMPTOMS
(IDEAL Study 2010: NO BENEFIT to early vs late if asymptomatic) - Refractory hyperkalaemia
- Refractory fluid overload
- Bleeding diathesis
- Refractory metabolic acidosis
Dialysis
- Markers of Effective Dialysis
Urea Reduction Ratio is the PRIMARY marker of adequacy
(Aim for URR >70%)
Other Markers:
- beta2 microglobulin
(Marker of ‘middle molecule’ clearance)
(Removal enhanced with LONGER and HAEMO filtration)
- Phosphate
Dialysis
- HIGHER FREQUENCY of haemodialysis is associated with: (4)
- Improved hypertension control
- Hyperphosphataemia
- Reduced LV mass
- Improved self-reported health
Dialysis:
- Complications of HDx (4)
1) Hypotension
2) High output HF (**may need AV ligation)
3) Muscle cramps during dialysis
4) Anaphylactoid reaction to dialyser
Dialysis:
- Risk Factors for HYPOTENSION during HDx (3)
1) Excessive ultrafiltration with inadequate compensating vascular filling or impaired vasoactive or autonomic response
2) Overzealous antihypertensives
3) Reduced cardiac reserve
Dialysis:
What drives solute/fluid removal?
PD: hypertonicity
HDx: concentration
Dialysis:
Complications of peritoneal dialysis (4)
1) PD peritonitis
2) Non-peritonitis catheter associated infections (“tunnel infection”)
3) Hypoproteinaemia
4) Hyperglycaemia and Weight gain
Dialysis:
PD Peritonitis - diagnosis and micro
= peritoneal leukocytes with >50% neutrophils
50% gram positive 15% gram negative 20% culture negative 4% polymocrobial 2% fungal
Dialysis:
PD Peritonitis Treatment
If polymicrobial or fungal: URGENT TENKHOFF REMOVAL OR LAPAROTOMY
Intraperitoneal ABx to cover gram pos and neg
- 1st and 4th gen cephs +/- vanc
Dialysis:
What does recurrent PD Peritonitis lead to?
Sclerosing peritonitis
CKD:
Pathophysiology
1st: Hyperfiltration and Hypertrophy
–> increased pressure and flow
THEN:
- glom architecture distortion
- Abnormal podocyte function
- Disruption of filtration barrier
EVENTUALLY:
Sclerosis and loss of nephron mass
CKD:
Over time kidneys become shrunk EXCEPT IN:
Norma size:
- Diabetes in EARLY STAGE
- Amyloidosis
- HIV
Bigger size:
PCKD
Risk Factors for CKD:
Childhood (2)
Genetic (4)
Personal (6)
CHILDHOOD:
- small for gestational birth weight
- childhood obesity
GENETIC:
- African
- FHx of CKD
- APOL1 gene for NONDIABETIC CKD
PERSONAL:
- Hx AKI
- Hypertension
- Diabetes
- Autoimmune disease
- Advanced age
- Abnormal genitourinary anatomy
CKD:
Is Hypertension or Sugar control more important as a risk factor?
Hypertension
Bakris 2000
CKD:
What is the normal GFR decline?
GFR peaks at 120mL/min in 3rd decade
Declines at 1mL/year
At age 70 = 70mL/min
CKD:
Value of MDRD and CKD-EPI calculations for GFR
- validated in CKD ONLY
- validated in Caucasians ONLY
- NOT validated in pregnancy or BMI extremes
At GFR >60mL it UNDERESTIMATES
CKD:
Variables included in MDRD
Serum Cr
Age
Ethnicity
Gender
Sometimes included:
Urea
Albumin
CKD:
Use of eGFR for prognosis:
CANUSA Study: for every 250mL decrease in urine output –> 36% mortality
NECOSAD Study: for every 0.5mL/min decrease in GFR –> 12% mortality
What is the most common complication of ESSENTIAL Hypertension?
Reduced nephron mass
CKD:
Mech for Metabolic Acidosis
CKD can usually still acidity urine BUT with LESS AMMONIA PRODUCTION
(So cannot excrete the same amount of H+)
Also, hyperkalaemia reduces ammonia production
CKD:
Role of Oral Bicarbonate for Metabolic Acidosis
- corrects acidosis
- recommended if bicarb <20
- SOME evidence it slows CKD progression
