Oliguria and Anuria Hot Case

GENERAL APPROACH

Type of renal failure

• Acute (usually multi-factorial)
• Chronic (e.g. dialysis dependent) or
• Acute on Chronic (e.g. post-renal transplant)

Causes

• Pre-renal – hypovolemia, any cause of shock, sepsis, renovascular disease
• Intra-renal – nephrotoxins, urine for casts + protein, sepsis, rhabdomyolysis, nephritic/nephrotic syndromes
• Post-renal – catheter blocked, pelvic rim surgery, blocked ureters, intraabdominal pressure, hydronephrosis

INTRODUCTION

CUBICLE

• CRRT or IHD
• bags of dialysate fluid – lactate or bicarbonate buffer
• TMP
• settings
• anticoagulation strategy and filter life-spans

INFUSIONS

• inotropes/vasopressors to maintain organ perfusion
• N-acetylcysteine for imaging/ procedures with contrast
• sodium bicarbonate for metabolic acidosis
• systemic anticoagulation (for RRT or other indication)

VENTILATOR

• oxygen requirement (fluid overload with pulmonary oedema)
• PEEP

MONITOR

• CVP (number, waveform)
• renal perfusion pressure (MAP-CVP)
• ECG (signs of hyperkalaemia)
• arterial trace (pressure)

EQUIPMENT

• dialysis access — catheter (check previous insertion sites e.g. dressings), AV fistula, Tenckhoff peritoneal dialysis catheter
• IDC or lack of (colour, volume, no bag suggests chronic renal failure)
• recent intra-abdominal pressures (manometer attached to IDC)
• IABP (low position may cause oliguria)

QUESTION SPECIFIC EXAMINATION

• hands -> head -> chest -> abdo -> feet -> back

-> cardiovascular
-> respiratory
-> abdominal (kidneys, organomegaly, distension)
-> compartments
-> end-organ perfusion

• neurological

-> paralysed
-> quick examination
-> unconscious
-> conscious

Questions

• urine output over last 8 hours?
• urine dipstick and microscopy?
• paired serum and urinary electrolytes?
• has IDC been flushed recently?
• recent exposure to nephrotoxic agents?

RELEVANT INVESTIGATIONS

• CXR (APO, check IABP isn’t too low)
• ABG (metabolic and electrolyte derangements)
• pregnancy test (eclampsia?)
• urea and creatinine
• compartment pressures? (if suspect limb or abdominal compartment syndrome)

OPENING STATEMENT

• = “Multi-factorial” and list headings of causes -> clinical signs associated with list
• “There is evidence of ESRF…”

DISCUSSION

Renal disorders

• CCC — Acute Kidney Injury and RIFLE Criteria and AKIN Classification
• CCC — Rhabdomyolysis
• CCC — Contrast-induced nephropathy
• CCC — Hepatorenal syndrome
• CCC — End-stage Renal Failure
• CCC — Renal transplant patient
• CCC — Renal disease biomarkers

RRT

• CCC — Indications, timing and patient selection for RRT
• CCC — RRT terminology and nomenclature
• CCC — CRRT Circuits
• CCC — IHD vs SLEDD vs CVVH
• CCC — Prevention of RRT circuit clotting
• CCC — Regional citrate anticoagulation
• CCC — Dose of RRT
• CCC — Summary of RRT Types
• CCC — RRT prescription
• CCC — Hemoperfusion