FN: Acute Kidney Injury Flashcards
Definition
Significant decline in renal function over hrs or days manifesting as an abrupt and sustained raise in SE U and CR
Causes
Pre-renal and ATN account for 80%
Renal causes
ATN:
- ischaemia: shock, HTN, HUS, TTP
- Direct nephrotoxins: drugs, contrast, Hb
Acute TIN: drug hypersensitivity
Nephritic syndrome
Post-renal
SNIPPIN Stone Neoplasm Inflammation: stricture Prostatic hypertrophy Posterior urethral valves Infection: TB, schisto Neuro: post-op, neuropathy
Presentation
Uraemia/Azotaemia Acidosis Hyperkalaemia Fluid overload: 1. Oedema, inc. pulmonary 2. Raised BP (or decreased) 3. S3 gallop 4. Raised JVP
Chronic features
Hx of comorbidity: DM, HTN
Long duration of symptoms
Previously abnormal bloods (GP records)
Clinical assessment
Acute or chronic
Volume depleted
GU tract obstruction
RAre cause
Volume depleted? signs
Postural hypotension
Reduced JVP
Raised Pulse
Poor skin turgor, dry mucus membranes
GU tract obstruction?
Suprapubic discomfort Palpable bladder Enlarge prostate Catheter Complete anuria (rare in ARF)
Rare cause
Assoc. with proteinuria ± haematuria
Vasculitis: rash, arthralgia, nosebleed
Investigations
bloods
ABG
GN screen
Urine
ECG
CXR
Renal US
Bloods shows
FBC U+E LFT Glucose Clotting Ca ESR
ABG
Hypoxia (oedema), acidosis, raised K+
GN screen
if cause unclear
Urine
Dip
MCS
Chemistry (U+E, PCR, osmolality, BJP)
ECG show
Hyperkalaemia
CXR
Pulmonary oedema
Renal US
Renal size
Hydronephrosis
NB urine osmolality
In pre-renal failure, urine is concentrate and NA is reabsorbed - raised osmolality, Na
Classification
RIFLE classification
Treatment general
- Identify and Rx pre-renal or post-renal causes
- Urgent US
- Rx exacerbating factors e.g. sepsis
- Give PPis
- Stop nephrotoxins: NSAIDS, ACEi, gent, nac
- Stop metformin if Cr >150mM
Monitoring
Catheterise and monitor UO
Consider CVP
Fluid balance
Wt.
Hyperkalaemia features
Peaked T waves Flattened P waves Raised PR interval Widened QRS Sine-wave pattern - VF
Management of Hyperkalaemia
- 10ml 10% calcium gluconate
- 100ml 20% glucose + 10u insulin (Actrarapid)
- Salbutamol 5mg nebuliser
- Calcium resonium 15g PO or 30g PR
- Haemogiltration (usually needed if anuric)
