Renal

Question 1

How much cardiac output is directed towards the kidneys

Answer 1

25%

Question 2

Where are kidneys located

Answer 2

Retroperitineal

Question 3

Describe kidney anatomy

Answer 3

Outer - renal cortex
> renal medulla
Renal pelvis (middle)

Ureters > bladder > urethra

Question 4

How many nephrons per kidney

Answer 4

1 million

Question 5

Describe nephron anatomy

Answer 5

Afferent (to) and efferent (away) arteroles
Into glomelerus via bowman’s > PCT (urea excrete, reabsorb organic compounds) >
Loop of henle descending(water reabsorption) & ascending (NO water - NA&CL excrete)
Distal convoluted tubule (optional electrolyte control based on hormones)

Question 6

Normal Glomerular filtration rate (GFR)

Answer 6

> 90

Question 7

What is filtered in the glomelerus

Answer 7

Almost plasma without red cells or proteins
(Slag of the nephron - absorbs anything as ‘filtrate’ before its specifics are reabsorbed or excreted via tubules

Question 8

Difference between osmolarity and osmolality

Answer 8

Osmolality - solutes per kg
Osmolarity - solutes per litre

Question 9

Describe types of AKI with examples

Answer 9

Pre renal: Decreased renal flow (absolute or relative fluid loss - distributive or haemorrhage)

Intra renal:
Acute tubular necrosis
Acute interstitial nephritis
Glomeleronephritis
Rabdo

Post renal:
Obstruction to outflow (kidney stone, BPH)

Question 10

Diagnosing AKI? And stages

Answer 10

Rise in creatinine
Fall in urine output

Recall stages
1- 1.5-1.9 above baseline (or over 26mmol/L) /0.5ml/kg/hr 6hrs
2. 2-2.9 above baseline / 0.5ml/kg/hr 12 hours
3 3> baseline / <0.3ml/kg/hr for 25 hours or anuria > 12 hours

Question 11

Management of AKI

Answer 11

Optimise haemodynamics
Correct K+ / electrolytes
Identify /treat cause (pre, int, post)
Medication review
Filter
Prevent reoccurrence

Question 12

Normal serum potassium

Answer 12

3.5-5
Severe > 6.5

Question 13

Causes of high or low potassium

Answer 13

Kidney disease, addisonian, acidosis, medication (nsaids, digoxin), salt intake, diarrhoea and vomiting, low magnesium (low k)

Question 14

Management of hyperkalemia

Answer 14

Stop all K supplements
Protect heart (ecg changes) = calcium
Move K in cells = insulin/glucose infusion (10 units actrapid & 250ml 10% -15 mins)
SLB nebuliser
Bicarb acidosis
Excrete K = treat cause, RRT, lokelma, loop diuretics

Question 15

Management of hypokalemia and symptoms

Answer 15

Check cause - insulin infusion, alkalosis, salbutamol

Symptoms: cramps, constipation
>3 PO Sando K
< 3 KCL IV 40mmol / litre saline over 6 hours
ECG monitoring
Check mag level

Question 16

Causes of hypokalemia

Answer 16

GI loss, renal loss (diuresis/ filter), medication (diuretics), alkalosis, refeeding syndrome, insulin, hypo magnesium

Question 17

Indications for renal replacement therapy

Answer 17

AEIOU - refractory

A- acidosis (metabolic)
E- electrolyte (hyperk- refractory)
I- intoxication - salicylates, lithium, methanol, ethylene glycol, theophyline
O- overload (fluid)
U- uremia (severe- encephalopathy, pericarditis, nausea/ vomiting)

Question 18

Describe RAS

Answer 18

Low renal blood flow releases
Renin which converts to Angiotensin 1 by angiotensinogin
Angiotensin converting enzyme (ACE) converted 1>2
Angiotensin 2 causes vasoconstriction

4 mechanisms:
1 ^sympathetic tone vasoconstrict
2 petuitaey gland = release ADH ^H20
3 tubules na/cl uptake increase H20
4 adrenal cortex releases aldosterone water retention ENAC channels

Question 19

Describe atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP)

Answer 19

Released from stretched atrial and ventricles from increase workload / high blood pressure

Inhibits RAS /4 factors

Modulates / suppresses blood pressure

Question 20

Describe auto regulation

Answer 20

Kidneys ability to autoregulate renal blood flow despite blood pressure changes between 80-200 systolic
Uses hormones

Question 21

Hormones to manage renal blood flow

Answer 21

Prostaglandin - efferent & afferent arterioles to dilate (fight/flight)
Dopamine - constricts skin & muscle vessels but dilates renal /cardiac vessels
Anti diuretic hormone (ADH/ vasopressin) - peptide hormone from posterior pituitary
Aldosterone- released by adrenal
Erythropoesis- EPO Hormone produced in kidney causes red cell production (CKD pts have EPO injections to stop anemia)

Question 22

Hyponatraemia symptoms

Answer 22

Lethargy, headache, confusion, fitting, coma

Question 23

Causes of hyponatraemia

Answer 23

Hypervolemic: CHF, liver disease, kidney disease
Euvolemic: drugs (SSRI), SIADH, polydipsia
(Plasma & urine osmolality)
Hypovolemic: Drugs (diuretics), endocrine, severe diarrhoea/vomiting, sweating, third spacing

Question 24

Treatment of hyponatraemia

Answer 24

If severe: Hypertonic saline for treatment control.
Correct slowly, not more than 10mmol in first 24 hours and 8mmol following 24hours.
Risk of pontine demyelenstion

Question 25

Causes of hypernatraemia

Answer 25

Dehydration (diarrhoea, DI, DKA, sweating, diuretics)

Question 26

Causes of SIADH

Question 27

Causes of SIADH