acid-base

Question 1

how is the anion gap calculated

Answer 1

(sodium + potassium) - (bicarb + chlorine)

Question 2

what is a normal anion gap

Answer 2

8-14

Question 3

what can cause a normal anion gap (hyperchloraemic met acidosis)

Answer 3

diarrhoea, renal tubular acidosis, acetazolemide, addisons

Question 4

what can cause a raised anion gap met acidosis

Answer 4

lactate (shock, hypoxia) // ketones eg DKA, alcohol // renal failure // paracetamol overuse // uric poisoning eg salicylates, methanol

Question 5

bloods partially compensated met acidosis

Answer 5

(lungs compensate by blowing of CO2) Low Co2, raised [H], low HCO3

Question 6

causes metabolic alkalosis

Answer 6

vomitting or aspiration // diuretics // hypokalaemia // hyperaldosteronism // cushings

Question 7

bloods partially compensated metabolic alkalosis

Answer 7

raised CO2, low [H], raised HCO3

Question 8

causes resp acidosis

Answer 8

COPD // asthma // neuromuscular weakness // obesity hypoventilation // benzos, opiates

Question 9

bloods partially compensated resp acidosis

Answer 9

raised CO2, raised [H], raised HCO3

Question 10

causes resp alkalosis

Answer 10

anxiety –> hyperventilation // PE // sacilyte poisoning // CNS eg stroke, SAH // altitude // pregnancu

Question 11

bloods partially compensated resp alkalosis

Answer 11

low CO2, low [H], low HCO3

Question 12

what does salicylate overdose lead too

Answer 12

early resk alkalosis –> metabolic acidosis

Question 13

symptoms salicylate overdose

Answer 13

hyperventilation // tinnitus // tired, sweaty, fever, N+V // glucose // seizures

Question 14

mx salicylate overdose

Answer 14

charcoal, IV socium bicarb, haemodialysis

Question 15

indications haemodialysis salicylate overdose

Answer 15

> 700mg // resistant met acidosis // renal failure // pulm oedema // seizure or coma

Question 16

what can cause hyperkalaemia

Answer 16

AKI // meds // met acidosis // addisons // rhabdo // blood transfusion

Question 17

what meds can cause hyperkallaemia

Answer 17

ACEi, ARBs, spirinolacte, circlosporin, heparin

Question 18

ECG hyperkalaemia

Answer 18

tented T wave, loss of p wave, broad QRS, sinusoidal wave, V fib

Question 19

staging hyperkalaemia

Answer 19

mild 5.5-5.9 // moderate 6-6.4 // severe >6,5

Question 20

mx options hyperkalaemia (3)

Answer 20

IV calcium gluconate // salbulatol or insulin + dextrose // remove K eg calcium enema, loop diuretic, dialysis

Question 21

effect of calcium gluconate

Answer 21

does not lower K levels

Question 22

mechanism of salbutamol or insulin+dextrose

Answer 22

moves K from ECF –> ICF

Question 23

what is emergency mx for hyperkalaemia

Answer 23

IV calcium gluconate + insulin/dextrose IV

Question 24

indications emergency treatment hyperkalaemia

Answer 24

> 6.5 or ECG changes

Question 25

what type of acid-base imbalance does renal tubular acidosis cause

Answer 25

hypercholaraemic metabolic acidosis (normal anion gap)

Question 26

what is type 1 RTA

Answer 26

distal - cannot secrete H+ into urine in distal tubule

Question 27

complications RTA type 1

Answer 27

nephrocalcinosis, renal stones

Question 28

causes RTA 1

Answer 28

RA, SLE, sjorgens

Question 29

what is RTA type 2

Answer 29

decreased HCO3 absorption in proximal tubule

Question 30

complications RTA type 2

Answer 30

osteomalacia

Question 31

causes RTA 2

Answer 31

faconi, wilsons, tetracyclines, acetazolamide, topiramate

Question 32

what is type 3 RTA

Answer 32

mixed - carbonic anhydrase II deficiency

Question 33

what is type 4 RTA

Answer 33

reduced aldosterone --> reduced ammonium excretion (proximal tube)

Question 34

what causes type 4 RTA

Answer 34

hypoaldosteronism, diabetes

Question 35

which RTAs are hyper vs hypo kalaemic

Answer 35

type 1-3 = hypo // type 4 = hyper

Question 36

symptoms faconi

Answer 36

type 2 RTA // polyuria // phosphates, amino acids, glucose in urine // osteomalacia