AKI Flashcards
(22 cards)
where in the glomeruli is most of the filtrate reabsorbed?
- 80% is reabsorbed in the proximal tubule
what is a stage 1 AKI
<0.5 ml/kh/hr urine output
>6 hrs- 8hrs for children and young people
1.5-2x increase in serum creatinine
what is a stage 2 AKI?
<0.5 ml/kh/hr urine output
>12 hrs
2-3x increase in serum creatinine
what is a stage 3 AKI?
Less than 0.3 ml/kg/hour for 24 hours or anuria for 12 hours
>3x increase in serum creatinine
what is the normal creatine range?
60 - 100 micromoles/Litre
what is oliguria
Oliguria
<0.5ml/Kg/Hour urine output
Usually <500ml/24 hours in adults
what is anuria
Anuria
Officially would mean no urine output
Softly defined as <100ml/24 hours
what are the 4 phases of an AKI?
Onset phase- (hrs -days)
Oliguric/Anuric phase- (8-14 days)
Polyuric/Diuretic phase (7-14 days)
Recovery phase (months -1yr)
what electrolyte disturbance makes AKI a medical emergency?
hyperkalaemia
K+ > 6.0 = bad
K+ > 6.5 = medical emergency
what ECG changes can be seen with hyperkalaemia?
- reduced p wave and widened QRS
- tented T waves
- sine wave pattern pre cardiac arrest
why do px get fluid overload with AKI?
If your patient is oliguric/anuric – they won’t be able to get rid of this excess water
Symptoms:
Breathlessness
Orthopnea
Limb swelling
why can fluid overload in AKI be dangerous?
The danger = pulmonary oedema -> severe tissue hypoxia
what are the 4 main indications for dialysis?
- refractory hyperkalaemia
- pulmonary oedema
- refractory acid base disturbance
- uraemic complications such as coma and pericarditis
what are examples of prerenal causes that are likely to cause AKI?
these are v likely
Bleeding Septic shock Dehydration Myocardial Infarction Iatrogenic? Renal artery stenosis
what are renal causes of AKI-?
renal causes are unlikely
Direct toxic effects
Drugs
Calcium and other metals
Overproduction leading to blockage of the tubules
Rhabdomyolysis, myeloma,
Inflammation in the kidney
GN, interstitial nephrits, ATN
post renal causes of AKI?
- these are relatively likely
Stones Ureteric/Urethral strictures BPH Prostate Cancer Urinary Retention e.g. neurogenic, constipation
what are chronic background risk factors for AKI?
Elderly CKD Cardiac Failure Liver disease Diabetes Vascular disease Background nephrotoxic medications
what are acute risks to AKI?
S Sepsis and Hypoperfusion
T Toxins
O Obstruction
P Parenchyma
what are 4 Ms to predict/prevent AKI?
Monitor
Obs/NEWS, regular blood tests, fluid balance charts, pathology alerts
Maintain Circulation
Hydration, resuscitation, oxygenation
Minimise Kidney Insults
Nephrotoxic meds, surgery, contrast, hospital acquired infection
Manage the acute illness
Sepsis, heart failure, liver failure
what are red flags in AKI history?
Haemoptysis Rashes Joint pain/swelling ENT – crusting of nose/acute hearing impairment Significant acute limb swelling Noticable urine frothiness Jaundice
what do you give to stabilise cardiac membrane during hyperkalaemia?
Administer intravenous calcium gluconate (10mls of 10% solution) if there are hyperkalaemia associated ECG changes present.
This should help to stabilise the myocardium temporarily for 30-60 minutes and reduce the risk of fatal arrhythmia.
what treatment for hyperkalaemia pushes potassium back into the cells?
Administer an insulin-glucose intravenous infusion (typically 10 units of soluble insulin are added to 25g of glucose).
Insulin helps to shift potassium from the extracellular to the intracellular compartment, whilst the glucose helps to maintain capillary blood glucose levels.
Salbutamol is often used as adjuvant therapy for hyperkalaemia.
It promotes the movement of potassium into cells and therefore out of the serum.
The onset of action is approximately 15 – 30 minutes
The duration of effect is approximately 2 hours
