Renal Flashcards
What 4 factors affect eGFR?
CAGE -
Creatinine
Age
Gender
Ethnicity
Main Drugs that can exacerbate AKI/CKD?
9 MARKS
ACE-I
Metformin - Lactic Acidosis stop GFR<30
Lithium
Gentamicin
NSAIDS
Ciclosporin
Trimethoprim - Falls exaceberation, cause Se CR++
Furosemide - Releases Na+ so can cause fluid loss
CT Contrast (Iodinated)
Indications for Urgent Dialysis?
AEIOU
A- Acidosis (Lactic, Metabolic, Uremic) - Metabolic acidosis <7.2
E- Electrolytes (Excessively high amounts) - Hyperkalemia >7mM
I - Intoxication
O - Overload (Fluid) - Pulmonary Oedema
U - Uraemia - Pericarditis, Encephalopathy
Name causes for sterile pyuria?
[8 Marks]
Partially treated UTI
Urethritis (e.g. Chlamydia)
Renal stones
Appendicitis
Renal TB
Bladder/Renal Ca
APKD
Analgesic nephropathy
Papillary necrosis
SLE?
Renal Complications + Management
Lupus nephritis can cause end-stage kidney disease.
SLE patients require regular urinalysis to rule out proteinuria.
Stage 3 (focal glomerulonephritis) + 4 (diffuse glomerulonephritis) are started on glucocorticoids + Cyclophosphamide/Mycophenolate
Stage 4 most common and severe form.
Most of bicarbonates are reabsorbed?
Proximal tubules
What’s the best way to differentiate AKI vs. CKD?
Renal US, Bloods
CKD - Smaller bilateral kidneys *
Hypocalcaemia (CKD>AKI)
- Exceptions - HIV, APKD, Amyloidosis, Diabetic Nephropathy
Normal Anion Gap Range?
8-14 mmol/L
Calc: (Na+ K) - (HCO3- + CL-)
Extent of anion gap is used to categorise causes for metabolic acidosis.
Young Female
Fever, Weight loss and Painful, Red eyes.
WHAT COULD IT BE?
TINU (Tubulointerstitial nephritis with uveitis)
Urinalysis is positive for leukocytes and protein.
Acute Interstitial Nephritis
Causes
Presentation
Investigations
Drugs - Abx (Penicillin, aminoglycosides), NSAIDS, Rifampicin, allopurinol, furosemide, PPIs, Diuretics
Systemic disease - SLE, sarcoidosis, and Sjögren’s syndrome
Infection
Fever, rash, arthralgia, eosinophilia, hypertension
mild renal impairment. Typically present with delayed (2-40 days) picture
Investigations - Urinalysis (sterile pyuria, white cell casts)
Histology: marked interstitial oedema and interstitial infiltrate in the connective tissue between renal tubules
AIN - causes an ‘allergic’ type picture consisting usually of raised urinary WCC, IgE, and eosinophils, alongside impaired renal function
What are the complications of an AV fistula?
Infection
Thrombosis - Absence of a bruit
Aneurysm
Stenosis - Acute limb pain
Vascular access steal syndrome - AV fistula causes ischaemia leading to symptoms
- Pallor
- Diminished pulses (Distal to fistula) , Reduced wrist-brachial BP
- Pain distal to fistula
- Necrosis
What Diagnostic criteria classifies an AKI?
Rise in creatinine of >= 26µmol/L in 48 hours
> = 50% rise in creatinine over 7 days (X1.5 Baseline)
Fall in urine output to <0.5ml/kg/hour for more than 6 hours / 8 hours in children
> = 25% fall in eGFR in children / young adults in 7 days.
Stages of AKI (acute renal failure)
KDIGO Criteria
(Kidney Disease: Improving Global Outcomes)
Stage 1 - Standard AKI
Increase in creatinine to 1.5-1.9 times baseline /
Increase in creatinine by ≥26.5 µmol/L /
Reduction in urine output to <0.5 mL/kg/hour for ≥ 6 hours
Stage 2 - Moderate AKI
Increase in creatinine to 2.0 to 2.9 times baseline/
Reduction in urine output to <0.5 mL/kg/hour for ≥12 hours
Stage 3 - Severe AKI
Increase in creatinine to ≥ 3.0 times baseline/
Increase in creatinine to ≥354 µmol/L/
Reduction in urine output to <0.3 mL/kg/hour for ≥24 hours/
The initiation of kidney replacement therapy (Dialysis/Renal Transplantation)
Patients <18 years, decrease in eGFR to <35
What situations should referral to nephrology occur for an AKI?
Renal transplant
Stage 3 AKI
CKD stage 4 or 5
ITU patient with unknown cause of AKI
Inadequate response to treatment
Vasculitis/ glomerulonephritis/ tubulointerstitial nephritis/ myeloma
Complications of AKI / Uraemia
Fluid Overload (Pulmonary oedema)
suspected AKI secondary to urinary obstruction
Complications of an AKI?
Electrolyte Disturbances - Hyperkalemia - Risk of arrhythmias, HyperPHOS , HypoCA,
Metabolic acidosis
Anaemia
Bleeding - Platelet dysfunction
Infection - WBC dysfunction
Uremic encephalopathy
Pericarditis
Fluid overload
Stress GI Ulcers
Complications of Uraemia?
Gout
CKD
Uric Acid Stones
What are the common risk factors for developing an AKI?
[10 Marks]
Age >65 years
CKD - eGFR < 60
Diabetes
Heart failure
Liver disease
Emergency surgery - risk of sepsis/hypovolaemia
Intraperitoneal surgery
Nephrotoxic drugs
Use of iodinated contrast agents within the past week
History of acute kidney injury
Extra - Rise in molecules that the kidney normal excretes/maintains a careful balance of - e.g. potassium, urea and creatinine
What is the most effective form of Kidney/Renal replacement therapy?
Transplant
Peritoneal dialysis
What Investigations should all patients presenting with an AKI have?
Urinalysis
Renal US - Within 24Hrs
Bloods - U+E, FBC, etc…
Management for AKI?
Largely supportive
Careful fluid balance - Maintain adequate perfusion and not to reduce fluid overload
Stop all nephrotoxic drugs
Close monitoring of electrolytes
If fluid overload (Loop diuretics)
How much protein does +1 Urine dipstick equal to?
Proteinuria
+1 = 30mg/dL
+3 = 300mg/dL
Explain how peritoneal dialysis works?
Administering dialysis fluid into the peritoneal cavity.
Waste solutes diffuse into the dialysate across the peritoneum (Acts as a semi-permeable membrane).
Ultrafiltration (draws water in from the peritoneal cavity) occurs by the addition of osmotic agents to the dialysate (typically 1.5% glucose solution).
Complications of peritoneal dialysis?
Peritoneal dialysis peritonitis (Staph. Epidermis)
Abdo pain, fever, cloudy dialysis bag- (sent for culture)
Intraperitoneal + systemic abx needed.
Catheter malfunction
Obesity (absorption of glucose from dialysis fluid)
Hernias
Explain how Haemodialysis works?
Counter-current flow is created.
Blood and dialysis fluid flow on opposite sides of the semi-permeable membrane. Solute transfer occurs by diffusion.
