Blood transfusion and ABG

Question 1

what are the indications for red blood cell transfusion (4)

Answer 1

Hb <70: Target 70 to 90 post transfusion

Hb <80 and symptomatic: Target 80 to 100 post transfusion

Hb<80 in ACS: Target 90-100 post transfusion

Suspected major haemorrhage with signs of shock

Question 2

samples for blood transfusions go in what colour bottles

Answer 2

pink

Question 3

antibodies

what does a group and save check

Answer 3

checks ABO group and for anti A and B antibodies
takes 30 mins
uesful for elective surgeries, if unlikely to bleed and will speed up cross match

Question 4

what is a cross match

Answer 4

same as GandS but donor samples check with patient samples for potential reactions
occurs in 60-90 mins
taken if severe bleeding

Question 5

how long can blood be out of the fridge before it must be returned

Answer 5

30mins

Question 6

how long can blood be out the fridge before the transfusion must be completed

Answer 6

4 hours

Question 7

when do you consider iron replacement

Answer 7

Consider if low MCV and low ferritin
stable post op pt

Question 8

when is transxaemic acid used

Answer 8

Antifibrinolytic used in bleeding patients (major trauma, PV, epistaxis)

Question 9

what is in the major haemorrhage protocol two packs

Answer 9

Once major haemorrhage protocol is activated via 2222 the blood bank will continually
supply the major haemorrhage pack. What’s in it?

Pack A:

4 units RBC and 4 units FFP

Pack B:

4 units RBC, 4 units FFP and 1 unit platelets

Pack B is continually replaced until the lab is stood down

Question 10

when to give platelets (4)

Answer 10

Used in bleeding patients or those undergoing procedures with counts <50

Clinically significant bleeding and platelets <30

Platelets <100 with major haemorrhage or bleeding into CNS or eyes

Consider prophylactic use if having invasive surgery and count <50

Question 11

FFP is used in bleeding pt what is it

Answer 11

Centrifuged plasma that contains clotting factors and albumin

Question 12

when do you give FFP

Answer 12

Significant bleeding WITHOUT major haemorrhage AND abnormal coagulation

Consider FFP if abnormal coagulation and having invasive surgery

Question 13

cryoprecipitate is used in DIC what is in it

Answer 13

Similar to FFP but high levels of factor VIII, fibrinogen and von Willebrand Factor

Question 14

when to give cryoprecipitate (2)

Answer 14

Significant bleeding AND fibrinogen <1.5g/L

Consider prophylactic cryo if fibrinogen <1 and having invasive surgery

Question 15

by what age to blood antibodies develop

Answer 15

12months

Question 16

how long does metbaolic ocmpensation tke

Answer 16

3 days minimum
These can help identify chronicity:

Respiratory acidosis without metabolic compensation has occurred within the past 3 days

Question 17

causes of resp alkalosis

Answer 17

Hyperventilation

Panic attack

Salicylate poisoning

alitude and preg

Question 18

causes of metabolic alkalosis

Answer 18

Prolonged vomiting

diuretics
hypokalamia
cushings

Gastrointestinal loss of H+ ions (e.g. vomiting, diarrhoea)
Renal loss of H+ ions (e.g. loop and thiazide diuretics, heart failure, nephrotic syndrome, cirrhosis, Conn’s syndrome)
Iatrogenic (e.g. addition of excess alkali such as milk-alkali syndrome)

Question 19

metabolic acidosis normal anion gap

Answer 19

gastrointestinal bicarbonate loss:
prolonged diarrhoea: may also result in hypokalaemia

renal tubular acidosis

drugs: e.g. acetazolamide

ammonium chloride injection

Addison’s disease

Question 20

respiratory acidosis causes

Answer 20

Hypoventilation

Asthma

Pneumonia

COPD

CNS depressants - benzos and opiates

Guillain-Barre: paralysis leads to an inability to adequately ventilate

Question 21

absolute contraindications to doing an ABG

Answer 21

peripheral vascular disease in the limb
cellulitis surrounding the site
arteriovenous fistula
relative : impaired coagulation (e.g. anticoagulation therapy, liver disease, low platelets <50).

Question 22

raised anion gap metabolic acidosis cx

Answer 22

lactate:shock, sepsis, hypoxia
ketones: DKA , alcohol
urate: renal failure
acid poisoning: salicylates, methanol

Question 23

normal anion gap

Answer 23

10-18

Question 24

high base excess idnicates what

Answer 24

A high base excess (> +2mmol/L) indicates that there is a higher than normal amount of HCO3– in the blood, which may be due to a primary metabolic alkalosis or a compensated respiratory acidosis.

Question 25

low base excess indicates what

Answer 25

A low base excess (< -2mmol/L) indicates that there is a lower than normal amount of HCO3– in the blood, suggesting either a primary metabolic acidosis or a compensated respiratory alkalosis.

Question 26

what does a mixed resp and metabolic alkalosis caused by

Answer 26

A mixed respiratory and metabolic alkalosis would have the following characteristics on an ABG:

↑ pH
↓ CO2
↑ HCO3–
Causes of mixed respiratory and metabolic alkalosis:

Liver cirrhosis in addition to diuretic use
Hyperemesis gravidarum
Excessive ventilation in COPD