AKI + CKD
Sunday, 23 October 2022
00:53
AKI
Defined as a:
Rise in creatinine >26 within 48h
Wise in creatinine >1.5 x baseline within 7 days
Urine output <0.5mL/kg/h for >6hrs
Staging: highest creatinine rise or longest period of oliguria?
Stage Serum creatinine Urine output
1 >26.5 or 1.5-1.9 x baseline <0.5ml/kg/h for 6-12h
2 2.0-2.9 x baseline <0.5ml/kg/h for >12h
3 >353.6 or >3.0 x baseline or <0.3ml/kg/h for >24h or anuria
dialysis for >12h
Risk factors:
Pre-existing CKD
Age
Male sec
Comorbidity
Causes:
Sepsis
Major surgery
Cardiogenic shock
Drugs
Hepatorenal syndrome
Obstruction
Aetiology:
Where? Pathology Example
Pre-renal Reduced Haemorrhage
vascular Cardiogenic shock, MI
volume Sepsis
(hypovolaemia) Drugs (NSAIDs, ACE-I,
Reduced ARB, hepatorenal
cardiac output syndrome)
Systemic
vasodilation
Renal
vasoconstrictio
n
Renal Glomerular Glomerulonephritis,
, Interstitial ATN
Vessels Drug reaction,
infection, infiltration
Vasculitis, HUS, TTP,
DIC
Post- Within renal Stone, renal tract
renal tract malignancy, stricture,
Extrinsic clot
compression Pelvic malignancy
Prostatic hypertrophy,
retroperitoneal
fibrosis
Management:
Diagnose and treat underlying pathology
o Pre-renal - correct volume depletion and/or increase renal perfusion
via circulatory/cardia support
o Renal - refer for biopsy and treatment of intrinsic renal disease
o Post-renal - catheter, nephrostomy or urological intervention
Common to all aetiologies is the need to manage fluid balance, acidosis,
hyperkalaemia, and recognition of need for renal replacement
o Fluid balance
Hypovolaemia
Give 500ml crystalloid stat
Reassess
Further 250-500ml bolus' if shocked
Hypervolaemia
Oxygen if required
Fluid restriction
Diuretics - only in symptomatic fluid overload
RRT - AKI with fluid overload + oliguria/anuria
o Acidosis
RRT?
o Hyperkalaemia
Presents with: tall 'tented' T waves, increased PR,
small/absent P wave, widened QRS complex, Sine wave
pattern, asystole
Treat K+ > 6.5mmol/L or if ECG changes are present
Stabilising the IV Calcium gluconate
membrane
Shift potassium into IV
cells Insulin/Dextr
ose
Nebulised
salbutamol
Removal of potassium Oral Calcium resonium
Loop diuretics
Definitive Dialysis
, management
o Renal replacement therapy
Haemodialysis and hemofiltration
Indications:
Fluid overload unresponsive to medical treatment
Severe/ prolonged acidosis
Recurrent/ persistent hyperkalaemia despite medical
treatment
Uraemia e.g. pericarditis, encephalopathy
Safe to use Short term Stop due to
use nephrotoxicity
Paracetamol NSAIDs Metformin
Warfarin Aminoglycosid Lithium
es
Statins ACEi Digoxin
Aspirin ARB
Clopidogrel Diuretics
Beta-
blockers
CKD:
Defined as abnormalities of kidney structure or function, present for > 3 months.
Classification:
Based of GFR, albuminuria, or by cause.
>GFR
Categor GFR Notes
y
G1 >90 Only CKD if evidence of kidney
damage:
Protein/haematuria
Pathology of
biopsy/imaging
Tubule disorder
Transplant
G2 60-89 ""
G3a 45-59 Mild-moderate reduced GFR
G3b 30-44 Moderate-severe reduced GFR
G4 15-29 Severe reduced GFR