condition part 1 Flashcards
definition for AKI
a significant deterioration in renal function occurring over hours-days
KDIGo definition
- inc in SCr by > 03.mg within 48 hours
- inc in SCr to >1.5 times baseline
- urine volume <0.5ml/Kg for 6 hours
what are the different stages of AKi
Stage 1
- SCr 1.5-1.9 times baseline or >0.3mh inc
- Urine - <0.54ml/kg for 6-12 hrs
Stage 2
- SCr 2-2.9 times baseline
- urine < 0.5ml/kg for > 12hrs
Stage 3
- 3 times baseline or inc >4.0mg or initiation of renal replacement therapy
- urine - <0.3ml/kg for > 24hrs or anuria for > 12hrs
how common is AKI
affect 18% of hospital patients in the UK
incidence of hospital-acquired AKI has Inc
incidence of commnity-acquired AKI on admission to hospital is 3-5% in the UK
who is affected the most by AKi
elderly and hospitalised pt
causes of AKI
pre-renal (40-70% of cases)
- due to renal hypotensions
- hypovolaemia
- hypotension
- sepsis (systemic vasodilation)
- congestive cardiac failure
- liver cirrhosis
- renal artery stenosis
- NSAIDs
- ACEi (interfere with blood flow)
Intrinsic ( 10-50%)
- due to damages in the kidney
- tubular - acute tubular necrosis, nephrotoxins eg drugs, radiological contrasts, heavy metal poisoning, HB in haemolysis, myoglubinuria in rhabdomyolysis, crystal and protein (Ig)
- glomerular - glomerulonephritis, autoimmune conditions (SLE, HSP)
- interstitial - acute interstitial nephritis (drugs, infection, autoimmune)
- vascular - vasculitis, malignant hypertension, thrombus, cholesterol emboli, large vessels occlusion
post-renal (10-25%)
- due to urinary tract obstruction
- luminal - stones, clots, sloughed papillae
- mural - malignancy ( ureteric, bladder, prostate)
- extra-luminal - malignancy in the pelvic
- retroperitoneal fibrosis
RF for AKi
>65yrs HF Liver disease CKD past history of AKI diabetes poor fluid intake inc fluid loss -diarrhoea, bleeding Oliguria (production of abnormal small amount of urine) haematological malignanacy - urinary symtoms spesis nephrotoxic drugs
symptoms of AKI
usually result of underlying causes, but could be
- oliguria/anuria
- polyuria
- N+V
- dehydration
- confusion
- palpitations - cardiac arrhythmia due to altered K+ level
- rash/bruising - vascular disease
signs on exam for AKI
HTN skin turgor - dec with dehydration and inc in oedema raised JVP palpable bladder postural hypotension pulmonary and peripheral oedema
differenital for AKI
CKD
acute on chronic renal failure
investigation for AKI
ABCDE - C - check BP, JVP, skin turgor, cap refill, urine poutput, check urgent K+ and ECG
history - looking for RF
examination - full systemic examination, abdo masses, renal bruits, rashes
urinalysis - leukocytes and nitrites indicating infection, blood and protein indicating glomerular disease, send culture for infection
bloods - FBC, U+E, creatinine, LFT, clotting, ESR, CRP
- creatine kinase - (rhabdomyolysis), ABG, blood film and renal immunology
imaging - renal USS, CTKUB, CXR
need to variefy if pt has CKD or actually AKI
mangement for AKI
general measure
- euvolaemia - correct any fluid imbalance (avoid potassium containing fluids unless hypokalaemic
- stop nephrotoxic drugs
- stop exacerbating factors - hypovolaemia, sepsis, high BP
monitor
- consider transfer to ICU.HDU
- hourly obs
- daily fluid balance and weight chart
- daily U+Es
nutrition - aim for normal calorie intake, consider NG tube if intake is poor
treating underlying causes
- pre-renal - fluids for volume depletion, antibiotics for sepsis, ICU referral if in shock
- intrinsic - refere to nephrology
- post-renal - cather for obstruction
- refer to urology for cystoscopy/stents/nephrostomy
managing complications
- hyperkalaemia - IV calcium gluconate over 2 mins for cardioprotectivity, IV insulin and glucose stimulates intracellular uptake of K+ to buy time to lower K+
- pulmonary oedema - high flow O2, IV flurosemide, venous vasodilator
- uraemia - dialysis maybe if severe of complication eg encephalopathy
- acidaemia - dialysis maybe or IV bicarb
Renal replacement therapy
- haemodialysis - requires patient to be haemodynamically stable, allows good clearance of solutes in short periods
haemofiltration - slower at clearing solutes, less significant shift so BP likely to drop
indication for acute dialysis - refractory pulmonary oedema, perisistnet hyperkalaemia, severe meabolic acidosis, uraemic encephalopathy, uraemic pericarditis
definition of CKD
presence of kidney damage or dec in kidney function for 3 months or more or
GFR <60 for 3 months or more with or without evidence of kidney damage or
GFR > 60 for 3 months or more together with evidence of kidney damage
what are the different stage of CKD
1 - >90, normal or inc GFR with other evidence of renal damages
2 - 60-89, slight dec GFR with other evidence of renal damage
3A&B - A(45-59) & B (30-44) with moderate dec GFR +/- evidence of renal damage
4- 15-29, severe dec GFR +/- evidence of renal damage
5 - <15, established renal failure (ERF)/End stage renal disease (ESRD)
evidence of renal damage = proteinuria, haematuria, evidence of disease
how common is CKD
8.8% of UK population have symtpomatic CKD
who is affected the most by CKD
4x more common in African-American deut to increase prevalence of HTN
CKD due to atherosclerotic renal disease more common in elderly
>70% of all CKD are due to DM, atherosclerosis and HTN
what are some screening questions for CKD
duration of symptoms
drugs eg NSAIDs, analgesia, herbal remedies
previous medial and surgical history -chemo, multisystem disease such as SLE, malaria
previous occasions on which urinalysis (urea and creatinine) might have been performed
causes for CKD
congenital and inherited - PCKD, medullary cystic disease, tuberous sclerosis, oxalosis, cystinosis, congenital obstructive uropathy
glomerular disease - primary glomerulonephritis incl focal glmoerulosclerosis, secondary glomerular disease ((systemic lupus, polyangitis, Wegener’s granulomatosis, amyloidosis, diabetic glomerulosclerosis, accelerated HTN, haemolytic uraemic syndrome,
vascular disease - hypertensive nephrosclerosis (inc BP), reno-vascular disease, smale and medium-sized vessel vasculitis, DM
tubulointersitial disease - Tubulointerstitial nephritis – idiopathic, due to drugs (especially nephrotoxic analgesics), immunology related, reflux nephropathy, tuberculosis
Urinary tract obstruction - calculus disease, prostatic disease, pelvic tumours, retroperitoneal fibrosis
RF for CKD
DM, age > 60, recurrent UTIs, urinary obstruction, systemic illness that affects the kidneys
symptoms for CKD
early CKD often asymptomatic
when urea is >40ml
- malaise, loss of energy
loss appetite/anorexia
insomnia
nocturia/polyuria (loss of concentrating ability)
-N+V and diarrhoea
- metallic taste
- paraesthesiae due to neuropathy
-restless legs snydrome (overwhelming need to frequently alter position of lower limbs)
bone pain due to metabolic bone disease
paraesthesiae and tetany due to hypocalcaemia
symptoms due to salt and water retention - peripheral or pulmonary oedema
symptoms due to anaemia
amenorrhoea in women, erectile dysfunction in men
oliguria
[urea] > 60mmol/L = more severe uraemic symptoms and CNS involvement eg mental slowing, confusion, clouding of consciousness, seizures, myoclonic twitching, encephalopathy, coma
Urine output is not a useful guide to kidney function as though GFR decreases => oliguria; tubular resorption is also less so high vols of urine may still result
signs on exam for CKD
short stature (if CKD in childhood)
pallor due to anaemia or yellow pigmentation (uraemic syndrome)
bruising or purpura
inc photosensitivity prigmentation
brown discolouration of nails
scratch marks due to uraemic puritis
signs of fluid overload eg pleural effusion
pericardial friction rub
mitral regurgitation due to overload or annular calcification
glove and stocking peripheral sensory loss
high BP
impalpable kidneys unless enlarged due to PCKD, tumours or obstruction
signs of an underlying condition that has lead to CKD
- cutaneous vasculitis lesion in systemic vasculitides
- retinopathy in DM
- evidence of peripheral vascular disease
- evidence of spina bifida or other causes of neruogenic bladder
- should assess hydration status (JVP and skin turgor, BP lying and standing)
differential for CKD
AKI
investigation for CKD
bloods - FBC (Hb dec), eosinophilia (vasculitis, allergic tubulointerstitial nephritis), fragmented RBC +/- thrombocytopenia (accelerated HTN, haemolytic uraemic syndrome)
ESR inc
Uand E inc - inc PTH
immnunology - autoantibody screening in SLE, antibodies to HBV,HCV,HIV
urinalysis
urine microscpy, culture and sensitivity
- WCC (infection)
- eosinophiluria 0 allergic tubulointersititial nephritis
- casts - Granular casts formed from abnormal cells within the tubular lumen, and indicate active renal disease. Red-cell casts are highly suggestive of glomerulonephritis.
radiology - USSm AXR, CT (retroperitoneal fibrosis), MRI and IV urography
renal biopsy
bone scan and DXR
treatment for CKD
transplant ultimate choice, RRT
monitoring - ultimately need ed dialysis
reduce use of drug that are excreted in the kidney - heparin, lithium, digoxin, ehtnambutol, cephalosporins, sulfmethoxazole, procainaminde, tetracycline, opiates
definition of hydronephrosis
aseptic distension and dilation of the renal pelvis and calyces usually caused by urinary tract obstruction
