Renal Flashcards
what do the kidneys aim to maintain in body?
remove wastes and extra fluid also acid produced by cells of body and maintain healthy balance of water, salts, and minerals e.g. sodium, calcium, phosphorus and potassium in blood.
list some different things that can be used for the diagnosis/ detection of AKI/ CKD
signs
symptoms
risk factors
urine output
serum creatinine
What algorithm is endorsed by nhs england and used in labs to identify potential cases of AKI based on creatinine levels
AKI
how is an AKI warning stage test result result communicated once identified
to GP clinical systems
what is the benefit of communicating aki warning stage test results to gp clinical systems
allows primary care team to take action based on clinical judgement
list some of the different measures for renal function that may be used selectively for different patient groups depending on appropriateness
creatinine
24 hr urine collection
51 chromium edta test
cystatin c
egfr
list some different patient groups where gfr may appear BETTER than it actually is
elderly
low protein diet
amputees
muscle wasting disorders
list some populations in which gfr may appear WORSE than it actually is
high muscle mass
high protein diet
muscle breakdown
name of the equation that is used to calculate creatinine clearance
cockcroft gault
whilst creatinine clearance is not good for diagnosis what is it good for
bedside calculation and drug dosing
Modification of Diet in Renal Disease (MDRD eGFR) becomes more useful in <60ml/min function or stage 3/4 of CKD, why is is not useful at lower level
overestimates renal function
give some patient populations where mdrd egfr is useful for bedside calc and drug dosing but not diagnosis
obesity
muscle mass
fluid overload
give a brief description of CKD
abnormalities of kidney structure or function present for greater than 3 months with implications for health
why is ckd more prevalent in elderly populations
ageing process causes loss of nephrons and natural decline of renal function
UK kidney association has classified ckd as individuals with an egfr of below x on at least 2 occasions y days apart with or without markers of kidney damage
X = 60
Y = 90
list some different markers of kidney damage
albuminuria
haematuria
electrolyte abnormalities
renal histological abnormalities
structural abnormalities
kidney transplant Hx
examples of structural abnormalities detected by imaging
e.g. polycystic kidneys, reflux nephropathy
There are several causes of CKD, give examples 7
- intrinsic kidney disease conditions
- kidney infections
- polycystic kidney disease
- glomerulonephritis
- meds impacting kidneys
- obstructive kidney disease conditions
multi-system diseases involving kidneys
give examples of intrinsic kidney disease conditions that may cause CKD
ashypertension
T1,T2DM
hypercholesterolaemia
polycystic kidney disease is inherited t/f?
true… cysts develop in kidney
give examples of meds impacting kidneys –> CKD
lithium
ciclosporin
calcineurin inhibitors (such as tacrolimus)
aminoglycosides
mesalazine
ckd is classified according to what 3 things
cause
gfr
albuminuria
name a tool that is used to predict the risk of kidney failure
kfre kidney failure risk equation
the kfre tool determines a persons risk of developing kidney failure within x years
2-5
why is it important to have a tool that accurately predicts a patients risk of developing kidney failure
helps dr and patient plan best pathway of care and highlight which patients need to be referred to hospital because their disease is more severe
true or false, aki is a term used to a cover a spectrum of injury to the kidneys
true
aki is characterised by a decline in renal function over hrs or days that can result in failure to
maintain fluid, electrolyte and acid base homeostasis
in the early stages aki can be symptomless, what might some people experience in the early stages however
produce less urine than usual
what symptoms can develop rapidly in someone with aki
nausea, vomiting, diarrhoea
reduced urine output
changes to urine colour
new or worsening confusion, fatigue, drowsiness
in the context of aki what are nausea, vomiting and diarrhoea all evidence of
dehydration
list some different risk factors for aki/ renal hypoperfusion
hypotension
hypovolaemia
drugs
sepsis
haemodynamic disturbances
ischaemic aki
intense sodium and water retention
what effect does haemodynamic disturbance have on the kidneys
endothelial and epithelial injury and immune activation
during ischaemic aki what does the kidney lose
autoregulatory capacity
elderly patients and those that are taking medication deemed nephrotoxic or those that cause dehydration are at a greater or lesser risk of developing aki
greater
true or false, nsaids and cox II inhibitors do not need to be avoided in patients at high risk of AKI
false
what effect do nsaids have on the kidney that would be problematic in aki
altered haemodynamics leading to underperfusion and reduced glomerular filtration
what action should be taken towards opioid analgesics in the presence of aki
avoid long acting preparations
reduced dose and frequency
use opiates with minimal renal excretion
list some opiate options that have minimal renal excretion
fentanyl
oxycodone
hydromorphone
tramadol
what change in side effect profile would you expect if using opioid analgesics like morphine, pethidine and codeine in the presence of aki
accumulation of active metabolites, increased cns side effects and respiratory depression
what changes in side effects would you expect in patients taking pregabalin or gabapentin in the presence of aki
accumulation leading to increased cns side effects
what action should be taken towards use of pregabalin or gabapentin the case of aki
reduce dose
in aki what effect might antihypertensives including alpha beta and ca channel blockers have
hypotension may exacerbate renal hypoperfusion
what change is side effect profile occurs when using beta blockers in states of reduced renal function
risk of bradycardia
what action is required towards antihypertensive drugs in the presence of aki
consider withholding or reduce dose depending on blood pressure
what effects can acei/arbs/aliskiren have on the kidneys in aki
hypotension and hyperkalaemia
in aki withholding acei/arbs and aliskiren can be considered however in some situations continuing them may be helpful, name on situation where this may be the case
HF
what effect might loop or thiazide diuretics have on the kidneys in aki
volume depletion and acute interstitial nephritis (rare)
in aki why are loop diuretics such as furosemide and bumetanide preferred
thiazides less effect if gfr below 25 ml/min
action in presence of AKI for diuretics?
withold if volume depleted
potassium sparing diuretics such as amiloride, spironolactone and eplerenone can cause volume depletion and hyperkalaemia in aki, what action should be taken if a patient is on these drugs
stop
statins may cause aki if rhabdomylolysis is present and can generally increase the risk of developing it, what action would be taken if patient develops unexplained or persistent muscle pain
stop
diigoxin can cause hyperkalaemia and accumulate in AKI -> bradycardia, visual disturbances, mental confusion
action in presence of AKI
reduce dose
monitor L+ and drug levels
DOACS
INFECTION
DIABETES
OTHER AGENTS
…
3 categories that aki causes can be divided into
pre renal
intrinsic renal
post renal
pre renal aki is caused by reduced blood flow to the kidneys, give some causes of this
hypovolemia
reduced cardiac output
hypotension
medicines
how might loop diuretics cause pre renal aki
reduce blood pressure and circulating volume
acei and arbs and nsaids may cause pre renal aki by affecting
renal blood flow
pre renal aki can also be caused by systemic vasodilation, give a condition where this may be the case
sepsis
which type of aki cause is due to structural damage to the kidney tissues and may be a result of persistent pre and post renal causes
Intrinsic renal (or intrarenal)
what medicines can also cause intrinsic renal aki
antibiotics
x ray contrast media
chemo
types of structural damage that result in intrinsic renal aki can be grouped into what different categories depending on the area of the kidneys that are affected
vascular
glomerular
tubular
interstitial
what is the least common cause of aki that is due to obstruction of the flow of urine out of the kidneys
post renal
give some different causes for post renal aki
renal stones
blocked catheters
enlarged prostate
genitourinary masses
Classification of AKI
NICE clinical guideline Acute kidney injuryLinks to an external site.: prevention, detection and management recommends defining acute kidney injury by any of the following criteria:
a rise in serum creatinine of 26 micromol/litre or greater within 48 hours a 50 percent or greater rise in serum creatinine known or presumed to have occurred within the past seven days
a fall in urine output to less than 0.5 mL/kg/hour for more than six hours in adults and more than eight hours in children and young people
a 25 percent or greater fall in eGFR in children and young people within the past seven days. AKI can be staged based on severity, and increasing severity of AKI correlates with higher risk of worse outcomes.
Kidney Disease: Improving Global Outcomes (KDIGO) has produced a Clinical practice guideline for acute kidney injury which includes AKI staging information. The information in the following table is taken from this guideline. There are two classification systems used in practice:
At risk patients in primary care
Diabetes Mellitus
Chronic Kidney Disease – if become acutely unwell, unable to maintain fluid intake, should contact GP to withhold medication ACE/ARB
Dementia –inability to self-care and fluid intake
Heart Failure – often have CKD and on ACE/diuretics
Maintaining optimal fluid intake
Older people
Most at risk
Dementia/frailty/risks of dehydration
Psychiatric Patients
Self-neglect - dehydration
Laxative or diuretic abuse
Recreational drugs
Paediatric Patients with CKD
Patients with Cancer
Awareness in community, management is secondary care
AKI known complication of cancer therapy – drugs/type of cancer/risks of sepsis
what is the treatment and management of aki dependent on
site
staging
presence of complicating factors
what are sick day rules
withholding nephrotoxic drugs to prevent the development of aki in patients that start vomiting, diarrhoea, fevers, sweats or shaking
aim of treatment is to manage the progression and complications of ckd and patients should be provided with information and education, what should they be encouraged to do non pharmacologically
exercise
achieve healthy weight
smoking cessation
dietary advice
The mainstay of treatment of CKD is based around the management of the multimorbidities associated with CKD,…
Complications of CKD include:
cardiovascular disease (hypertension, peripheral vascular disease and heart failure)
cardiovascular events (stroke and myocardial infarction)
anaemia or chronic disease
renal bone disease
malnutrition
neuropathy (nerve pain)
lipid abnormalities
increased risk of acute kidney injury
end-stage renal disease that requires renal replacement therapy (RRT)
risk of acidosis (to learn about acidosis, access this Lab Tests Online article Acidosis and Alkalosis)
increased risk of infection – those with CKD have been shown to be at increased risk of hospitalisation due to infections such as pneumonia, sepsis, and urinary tract infections.TIs
at end stage ckd renal replacement therapies may be more appropriate, give some examples
peritoneal dialysis, haemodialysis, kidney transplant
the main pharmacological treatments offered to those with ckd are?
blood pressure
renal bone disease
renal anaemia
preservation of kidney function
metabolic acidosis
why might patients with ckd be offered statin or oral antiplatelet therapy
secondary prevention of cvd
what is the rationale behind using an sglt2 inhibitor ckd
blocks sglt2 in kidneys
reduces pressure and inflammation
stops protein leaking into urine
reduces blood pressure and weight
so reduces damage
adding x to the current standard care for ckd has been shown to significantly reduce the risk of
having declining kidney function
end stage kidney disease
dying from causes related to kidney or cv system
dapagliflozin
name the drug that is recommended as an option for treating end stage 3 and 4 ckd with albuminuria and associated with t2dm in adults
finerenone
what 2 things have to be measured to determine if finerenone treatment can be initiated and to determine the starting dose
serum potassium and egfr
CASE STUDIES
