Medicine: Renal Flashcards
The A-F of what the kidney does
Acidosis Anaemia Bones Clearance Drugs Electrolytes Fluids
What are the consequences of kidney failure based off it’s functions?
Acidotic Anaemic HypoCa High PTH Uraemia HyperK Hypervolaemia
Nephrotic Syndrome
Proteinuria
Low Albumin
Oedema
Dyslipidaemia
Nephritic Syndrome
Haematuria
HTN
AKI
Which hyperparathyroidism do you get?
Secondary: dec Ca + inc Pi
What is the clearance rate of the kidneys?
100mL/min = 144L/day
How do you measure clearance?
Urea - made by liver in response to nitrogen clearance
Creatinine - made by muscle in response to turnover
We use CKD-EPI and Cockcroft Gault calcs to find the eGFR from the creatinine
If you see someone w a high creatinine and you’re not sure why, what can you do?
Check for diabetes and HTN -> failing this see a nephrologist
Hx + Exam
Hx: CKD Sx? DM? IHD? SLE? Childhood UTIs? Stones? Drug Hx? FHx? Travel Hx?
Exam: BP, urinalysis, bloods, imaging, biopsy
What are causes of false pos haematuria?
Myoglobin + Beetroot
How do you quantify proteinuria?
Protein:Creatinine Ratio has now surpassed the 24h urine collection
Significant >100mg/mmol (1g/day)
Nephrotic >300mg/mmol (3g/day)
What can be seen in urine microscopy?
Crystals: ca oxalate, struvite, urate
Casts: red (GN), white (PN), muddy (ATN)
+ RBCs, WBCs, Bacteria
What are the indications for kidney biopsy? (3)
Unexplained injury w normal size
Histology likely to influence tx or offer prognostic info
Info concerning activity and potential reversibility of a prev identified lesion would be useful
What are the causes of an AKI?
Pre-Renal: red blood flow ?sepsis ?shock
Intrinsic: nephrotic + nephritic ?IgA ?lupus
Obstruction: urological ?stones ?malignancy ?prostate
What is a crescent a sign off?
V aggressive nephritis
Obs to assess fluid balance
Overload: raised JVP, pulm oedema, sacral/peripheral oedema
Deplete: dry mucous membranes, red skin turgor, sunken eyes, inc CRT, tachycardic, hypotensive
CKD Stage v GFR
1: >90
2: 60-89
3a: 45-59
3b: 30-44
4: 15-29
5: <15
What are the target BP for CKD pts?
If no proteinuria <130/80
If w proteinuria <125/75
When do you start getting sx of renal disease? And what are those sx?
Stage 5
Sx: pericardial effusion, N+V, weakness, lethargy, confusion
Mx of CKD
Slow Progress: ACEi/ARB, glycaemic control, lifestyle
Tx Comps: bicarbonate, iron, EPO, vit D sups if deficient or analogue if inc PTH, dietary restriction of 3P’s (potassium, phosphate, protein)
ESRF: dialysis w CVD risk measures + transplantation
What are the general functions of each part of the nephron?
PCT - electrolytes
Ascending Limb - fluid concentration
DCT - fine tuning both
What/Where/Why does the kidney secrete?
EPO, interstitial fibroblasts, dec oxygen delivery
1α-hydroxylase, PCT, low plasma calcium
Renin, juxtaglomerular cells, low blood pressure
What condition should you NOT use ACEi in?
Renal Artery Stenosis
How has synthetic EPO revolutionised renal care?
Before we were reliant on transfusions which inc risk of HIV/Hep C + sensitise for future transplants
Why do we get acidotic?
Production of ammonia +/or dec production or loss of bicarbonate
Which ion tends to be elevated in acidosis?
Potassium
OsmolaLity vs OsmolaRity
If they don’t equal there’s an osmolar gap
OsmolaLity: measured ie 275-295 mOsmol/kg
OsmolaRity: calculated ie 2(Na+K) + Urea + Glucose
Mx of HyperK
Recognise it’s a medical emerg >5.5mM so A-E approach
You want a baseline ECG, cardiac monitor, senior support STAT
You give 10mL 10% IV calcium gluconate, 50mL 50% dextrose w 10U insulin infusion, consider dialysis
Liaise w ICU + then once stable ix possible causes: drug chart, U+Es, short synacthen test
What is the long term mx for hyperK?
Tbc
Workup for an AKI
Tbc
What are the important considerations when starting a drug?
?Nephrotoxic
?Renally Excreted
?Correct Dose
Who can support you if you’re unsure about a drug?
Check BNF + liaise w pharmacist, senior nurse, reg
What is the best stain for overall assessment of glomerular structure?
Periodic Acid Schiff: stains mesangial matrix and basement membranes
What is the definition of oliguria?
<0.5mL/kg/hr
What are the secondary causes of nephrotic syndrome?
DM SLE Amyloid Myeloma PET
What does the histology show in nephrotic syndrome caused by DM?
- Diffuse glomerular basement membrane thickening
- Kimmelstiel Wilson Nodules
- Advanced Glomerulosclerosis
What are the most common causes of AKI?
STOP: sepsis/dehydration, toxins, obstruction, parenchymal kidney disease - blood cultures, hydration status, review drug chat and OTC hx, US, if all neg discuss biopsy w renal
What are the most common causes of CKD?
- Diabetic
- IgA
- Reno-Vascular
- Glomerulonephritides
What are the endocrine functions of the kidneys?
Erythropoietin
1α-OHase
Renin
Sx of CKD
Acidotic - Nausea + Vomiting Anaemic - Pale, SOB, Tired HypoCa - Spasms + Numb Uraemic - Jaundice + Pruritis HyperK - Palps + Cardiac Arrest Oedema - Pulm, Pedal, Ascites
What are the indications for emergency dialysis?
Work through all the vowels: acidosis (pH<7.1), electrolyte imbalance (K+>6.5), intoxication, overload refractory to diuretics, uraemic pericarditis or encephalopathy