Chronic Kidney Disease Definition of CKD - PowerPoint Presentation

Slide1

Chronic Kidney Disease

Definition of CKD

Structural

or functional abnormalities of the kidneys for

>

3 months

from early to late-stage disease,

Chronic Kidney Disease

as

manifested by either:

1. Kidney

damage, with or without decreased GFR, as

defined

by

• pathologic abnormalities

•

markers

of kidney damage, including abnormalities in the composition of the blood or urine or abnormalities in imaging tests

Chronic Kidney Disease

2. GFR <60 ml/min/1.73 m2, with or without kidney damage

• Estimated glomerular filtration rates (

eGFR

) range from 90 mL/minute/1.73 m2 in the early stages to 15 mL/minute/1.73 m2 in the late stages of disease is known as end-stage renal disease (ESRD).

• Complications include fluid and electrolyte abnormalities, anemia, cardiovascular disease, hyperparathyroidism, bone disease, and malnutrition.

Chronic Kidney Disease

Patients with ESRD require

renal replacement therapy

in the form of dialysis or transplantation to sustain life.

The prevalence of chronic kidney disease (CKD)

increases with age and is greater in females

and some ethnic populations.

CKD is classified according to

severity from 1 to 5

, where 5 is the most advanced and 1 the least.

Chronic Kidney Disease

The

renin-angiotensin-aldosterone system (RAAS)

Most

of the renal effects of this system are through

regulating

intraglomerular

pressures and salt and water balance.

First, In patients with CKD, intra-renal pressures are often low and sympathetic

overactivity

is common; lead to increased renin secretion.

.

Chronic Kidney Disease

This can occur with normal or elevated systemic blood pressure. this promote production of the mineralocorticoid hormone aldosterone, and promotes antidiuretic hormone (ADH) release,

In

combination, these lead to salt and fluid retention, high intravascular volumes, hypertension and

oedema

.

Chronic Kidney Disease

Second, a direct vasoconstrictor and promotes systemic and (preferential) renal hypertension on the efferent glomerular arteriole.

Vasoconstriction at this site is mediated by a high density of angiotensin II receptors. When these receptors are ligated by angiotensin II, there is increased intra- glomerular pressures.

Chronic Kidney Disease

Whilst this leads to an overall increase in GFR in the short-term, over a longer period glomerular hypertension promotes accelerated glomerular scarring and worsening CKD.

Chronic Kidney Disease

In addition there is a local immune modulatory role for this system. Both resident (e.g. tubular epithelial) cells and inflammatory (monocytes and macrophages) cells, they express the angiotensin II receptor and activation through this receptor leads to an enhanced inflammatory and fibrotic phenotype of the cell.

Chronic Kidney Disease

Measurement of renal function

Serum

creatinine

This

becomes important in advanced CKD (stages 4 and 5) and limits the value of measuring serum

creatinine

to determine renal function in advanced CKD

Chronic Kidney Disease

Glomerular filtration rate equation

Eight

eGFR

equations were validated for the MDRD(Modification of Diet in Renal Disease Study)

equation

eGFR

(mL/min/1.73m2) = 186 x [serum

creatinine

(

μmol

/L)/88.4]–1.154 x [age]–0.203 x [0.742 if female] x [1.212 if African-American

]

Chronic Kidney Disease

Creatinine

clearance

Measurements of

creatinine

clearance (

ClCr

) require accurate collection of 24 h urine samples with a serum

creatinine

sample midway through this period.

Fig. 18.3

Creatinine

clearance calculation

Chronic Kidney Disease

Cockroft

–

Gault

equation

The

Cockroft

–

Gault

equation uses weight, sex and age to estimate

creatinine

clearance and was derived using average population data

Fig

. 18.4 The

Cockroft

–

Gault

formula.

Chronic Kidney Disease

Estimates of glomerular filtration rate in

paediatric

patients

Using

the Schwartz formula or the

Counahan

– Barratt method which both rely upon inclusion of the height of the child in estimating

creatinine

clearance, since height correlates with muscle mass.

Chronic Kidney Disease

Urea

Urea

is also used in the assessment of renal function despite a

variable production rate and diurnal fluctuation in response to the protein content

of the diet

it may also be

elevated by dehydration

or an

increase in protein catabolism

such as that accompanying

gastro-intestinal

haemorrhage

,

severe infection, trauma (including surgery) and high-dose steroid therapy.

Serum urea levels are, therefore, an

unreliable measure

of renal function, but can be used as an indicator of the patient's general condition and state of hydration

.

Chronic Kidney Disease

Stages

of Chronic Kidney Disease

Chronic Kidney Disease

Significance of CKD

CKD

is of

progression to end-stage

renal disease, and a strong association with

accelerated cardiovascular disease

, similar in

diabetics.

Patients with CKD

1–3 are frequently asymptomatic

.

The reduction of GFR is insufficient to

cause

uraemic

symptoms

and any minor abnormalities in the urine such as

proteinuria or

haematuria

.

Chronic Kidney Disease

There is association with

high blood pressure

which may be the cause or a consequence of renal damage. as it allows early modification of cardiovascular risk factors

Patients with CKD

stages 4 and 5

require specialist management of the complications of CKD such as

anaemia

and bone disease

, whilst many will be undergoing preparation for renal replacement therapy.

Chronic Kidney Disease

Causes of CKD

Ischaemic

nephropathy

has traditionally

Vascular diseases

(renal artery disease, hypertension,

microangiopathy

) been referred to under perfusion of the kidneys

Diabetes mellitus

(

Diabetic Kidney Disease

) is the most common metabolic disease that leads to CKD, whilst the predominant lesion is glomerular and referred to as diabetic nephropathy.

Chronic Kidney Disease

All types of

chronic glomerulonephritis

(GN) or

Glomerular diseases

(autoimmune diseases, systemic infections, drugs,

neoplasia

) cause about 15% of cases of advanced CKD.

Lower urinary tract disease

or

Tubulointerstitial

diseases

(urinary tract infection, stones, obstruction, drug toxicity) they represent 5–10% of all cases of CKD

.

Chronic Kidney Disease

Hereditary/congenital diseases

/

Cystic diseases

(polycystic kidney disease) they represent 5% of CKD cases

CKD to be unknown

and this is the case in around 30% of patients who typically present with small kidneys and unremarkable immunological investigations.