Renal Ix Mx

Question 1

Acute kidney injury (AKI)

ix for aki with unknown aetiology?

what drugs should be stopped in an aki?

what are the 3 stages of aki?

Answer 1

Ix:

NICE recognise any of the following criteria to diagnose AKI in adults:

↑ creatinine > 26µmol/L in 48 hours
↑ creatinine > 50% in 7 days
↓ urine output < 0.5ml/kg/hr for more than 6 hours

An ultrasound is required in the investigation of all patients presenting with an AKI of unknown aetiology

NSAIDs should be stopped in AKI except aspirin at cardio-protective dose

ACEi/ARB’s should be with held in an AKI

Stage 1 AKI = Increase in creatinine 1.5-1.9 times, or reduction in urine output <0.5 mL/kg/hr for ≥ 6 hours

Stage 2 AKI = serum creatinine of 2-2.9 from baseline or reduction in urine output for 12 hours or more (< 0.5 ml/kg/hr).

Stage 3 AKI = serum creatinine to 3x or higher from baseline or reduction in urine output for 24 hours or more (< 0.3 ml/kg/hr).

Give fluids before and after surgery to prevent contrast induced AKI!

Question 2

Benign prostatic hyperplasia

Answer 2

Ix = urine dip, U+E’s, PSA if there are any obstructive symptoms

Mx = alpha-1 antagonists

e.g. tamsulosin, alfuzosin
decrease smooth muscle tone of the prostate and bladder

2nd = 5 alpha-reductase inhibitors e.g. finasteride

Surgery = TransUrethral Resection of the Prostate (TURP)

Question 3

Bladder cancer

key finding of Ix?

Answer 3

Ix = USS

The obstruction to urine outflow causes urine to
accumulate within the bladder and then create a back-pressure upon the
kidneys resulting in bilateral hydronephrosis

Question 4

Chronic kidney disease (CKD)

differentiator from aki?

Answer 4

Ix = eGFR stages 1,2,3a,3b,4,5 >90>60>45>30>15>x

IMPORTANT: Patients should only be diagnosed with CKD stage1 or 2 if there are markers of kidney disease including proteinuria, haematuria, electrolyte abnormalities or structural abnormalities detected

small kidneys* + hypocalcaemia differentiates ckd from aki

Mx = 1st line = reduced dietary intake of phosphate
2nd = phosphate binders (sevelamer)
3rd = vitamin D: alfacalcidol, calcitriol
parathyroidectomy may be needed in some cases

Anaemia in CKD: correct iron deficiency before starting erythropoiesis-stimulating agents

If the pt is taking metformin, it should be stopped when eGFR is less than 30 and used with caution when less than 45 mmol/mol

*apart from;

HIV-neuropathy
PCKD
amyloidosis
diabetic neuropathy (early)

Question 5

Epididymitis and orchitis

Epididymo-orchitis describes an infection of the epididymis +/- testes resulting in pain and swelling.

It is most commonly caused by local spread of infections from the genital tract (such as Chlamydia trachomatis and Neisseria gonorrhoeae, typically seen in sexually active younger adults) or the bladder (E. coli, typically seen in older adults with a low-risk sexual history).

what are the features?

Answer 5

Sx = UNILATERAL testicular pain and swelling

Ix = STI check or MSU (M+C)

Mx = STI = IM cef + oral doxy
MSU = oral ofloxacin

Question 6

Glomerulonephritis

Answer 6

IX = Renal biopsy/electron microscopy - thick basement membrane with subepithelial deposits. This creates a ‘spike and dome’ appearance

Mx = ACEi/ARB, severe = immunosuppress (corticosteroid+cyclophosphamide)

Question 7

Hydrocoele

Question 8

Hydronephrosis (hydrostatic dilation of the renal pelvis and calyces as a result of obstruction to urine flow downstream)

Answer 8

Ix = USS

Mx = remove obstruction, acute/chronic = nephrostomy/stent (+ab’s)

nephrostomy is quicker, stent is more definitive

Stomy is speedy

Question 9

Nephrotic syndrome

Answer 9

Nephrotic syndrome is associated with a hypercoagulable state due to loss of antithrombin III via the kidneys

Question 10

Polycystic kidney disease

haematuria, recurrent urinary tract infections, abdominal pain and feeling of ‘fullness’ in the flanks

Answer 10

Ix = USS

(in patients with positive family history)
two cysts, unilateral or bilateral, if aged < 30 years
two cysts in both kidneys if aged 30-59 years
four cysts in both kidneys if aged > 60 years

Mx = tolvaptan (vasopressin receptor 2 antagonist)

Question 11

Prostate cancer

Answer 11

Ix = PSA, multi-parametric MRI, TRUS-guided biopsy

Mx = localised = watch/remove/radiotherapy, localised-advanced=hormonal, remove, radio, metastatic = GnRH agonist (goserelin) + 3wks of antiandrogen

Question 12

Renal artery stenosis

drug cause of RAS?

Answer 12

Ix = aldos:renin ratio is normal as both are high

After starting an ACE inhibitor, significant renal impairment may occur if the patient has undiagnosed bilateral renal artery stenosis

Mx = anti-hypertneisves (BB, CCB’s, diuretics)

Question 13

Renal cell carcinoma

Classic triad?

Answer 13

Ix = CT-CAP

Mx = nephrectomy

The classic triad of renal cell carcinoma is flank pain, flank mass and haematuria; however, this is only present in roughly 10-15% of patients and often suggests advanced disease.

A varicocele which, while not uncommon in the healthy male population, may be associated with a renal cell carcinoma. If a varicocele is discovered, it is a potential indication for renal USS.

Question 14

Rhabdomyolysis

Answer 14

Ix = Creatine kinase

Mx = IV fluids (to maintain good urine output)

urinary alkalinization is sometimes used

Question 15

Testicular cancer

Answer 15

Ix = USS

Mx = orchidectomy

Question 16

Testicular torsion

Answer 16

Mx = urgent surgical exploration
if a torted testis is identified then both testis should be fixed as the condition of bell clapper testis is often bilateral.

Question 17

Urinary tract calculi

Answer 17

Ix = CT-KUB

Mx = <0.5cm = wawa, <2cm = lithtripsy, (pregnant = uterscopy), staghorn = nephrolithotomy

Question 18

Urinary tract infection

Severe infections can
result in sepsis, hypovolaemia and collapse!

Answer 18

Ix = urine dip, mc&s, always culture if haematuria is present*

Mx:

F = 3days trimeth/nitro
M = 7days trimeth/nitro

catheter w asymptomatic bacteraemia = nothing, symptomatic = 7 days

pregnant female;

symptomatic: 1st = nitrofurantoin, 2nd = amox/ceph

asymptomatic = nitrofurantoin (should be avoided near term), amoxicillin or cefalexin

*pyuria(pus/neutrophils in urine) in the absence of a positive culture, otherwise
called a ‘sterile pyuria’ = TB!

Question 19

Varicocoele

Answer 19

Ix = USS w doppler

Mx = usually conservative, surgery if very painful

Question 20

Renal colic mx?

Answer 20

NSAIDS

Question 21

Renal stones

Answer 21

Ix: USS

Raised leukocytes but no nitrates = stones!

Leukocytes are raised in inflammatory processes

Question 22

analgesic nephropathy ( due to chronic NSAID use)

Answer 22

ix = ct scan

Question 23

Investigating areas of kidney obstruction? catheter obstruction?

Answer 23

Antegrade pyelography = obstruction within the kidney

Retrograde pyelography = obstructions via a catheter

Question 24

Acute hyperuricaemic nephropathy

Answer 24

Acute hyperuricaemic nephropathy is a common finding in patients
suffering from hyperuricaemia.

This is a common occurrence in patients with
increased cell turnover, such as myeloproliferative disorders or following
chemotherapy.

Uric acid crystallizes within the renal system causing
obstructions which can manifest as flank pain, oliguria, hypertension, oedema
and uraemic symptoms.

Question 25

Acute tubular necrosis

What is it?

Answer 25

Acute tubulointerstitial nephritis = a drug hypersensitivity reaction,
usually due to penicillin or NSAID medication.

Patients typically present with:

fever,
skin rashes
joint pain
eosinophilia

Question 26

Diabetic nephropathy

Answer 26

ix = proteinuria

Detection of microalbumin
in the urine has been shown to be a good marker for identifying
patients most likely at risk of further renal damage

Question 27

Most common cause of peritonitis associated with peritoneal dialysis?

Answer 27

Staphylococcus epidermidis

Question 28

Maintenance fluids?
Post-surgery bolus rate?

Answer 28

25-30 ml/kg/day of water

Approximately 1 mmol/kg/day of potassium, sodium and chloride

Post surgery;

If the pt requires 2500ml/day

Rate: 2500 / 24 = 93.75 ml/hr.

Initially prescribe 500 ml and then reassess the patients fluid status and ability to drink.

So prescribe 500 ml at a rate of 100 ml/hr.

Question 29

Hypokalameia

Answer 29

Ix:

Features
muscle weakness, hypotonia
hypokalaemia predisposes patients to digoxin toxicity - care should be taken if patients are also on diuretics

ECG features;
U waves
small or absent T waves
prolonged PR interval
ST depression

Mx:

Mild to moderate hypokalaemia 2.5 - 3.4 mmol/l = oral potassium provided the patient is not symptomatic and there are no ECG changes.

Severe hypokalaemia (<2.5mmol/l) or symptomatic hypokalaemia should be managed with IV replacement.

The patient should be managed in an area where cardiac monitoring can take place. If there are no contraindications to fluid therapy (e.g. volume overload, heart failure) potassium should be diluted to low concentrations as higher concentrations can be phlebitic.

The infusion rate should not exceed 20mmol/hr

Question 30

Haematuria Ix

Answer 30

First exclude UTI (Mc&S)

then investigate cancer?