Haemostasis Flashcards

1
Q

Physiologic haemostasis occurs in three interrelated phases: initiation, amplification, and propagation.

A

T

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2
Q

Regarding physiologic haemostasis, initiation refers to platelet aggregation and activation.

A

F

This is true for amplification.

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3
Q

Regarding physiologic haemostasis, propagation refers to thrombin formation.

A

F

This is true for initiation.

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4
Q

Regarding physiologic haemostasis, amplification refers to fibrin formation and clot stabilisation.

A

F

This is true for propagation.

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5
Q

In general, anticoagulation prescribed for secondary thrombotic prophylaxis should not be discontinued for dermatologic surgery procedures.

A

T

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6
Q

Optimizing anaesthesia, and alleviating anxiety and situational hypertension, will significantly reduce the risk of perioperative bleeding.

A

T

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7
Q

Clonidine 0.1mg orally can be used with patient who have anxiety accompanied by situational hypertension and its antihypertensive effects last for 2 -4 hours

A

F
All correct, except lasts for 12 hours
provides antihypertensive, sedative, and anxiolytic effects

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8
Q

Clonidine should be given the day before surgery

A

F

60 mins

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9
Q

Clonidine should be avoided in patients with a preop systolic pressure less tha 100 mmHg

A

T

also avoid if pulse less than 60

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10
Q

Oral midazolam 5-10mg will provide rapid anxiolosis (within 20mins) but can cause significant haemodynamic compromise

A

F

Has no haemodynamic effects

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11
Q

Physical haemostatics include gelatine sponge, oxidised cellulose, microfibrillor collagen haemostat

A

T

They act as a physical mesh onto which coagulation can occur

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12
Q

Aluminum chloride and trichloroacetic acid are most likely to leave pigment particles which may stain the skin

A

F

Least likely, unlike silver nitrate or ferric sulphate

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13
Q

Adjuncts to haemostasis include silver nitrate, ferric sulphate (Monsels solution), aluminium chloride or 35% trichloroacetic acid

A

T

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14
Q

Electrosurgery and suture ligation for haemostasis should be precise to minimize excessive collateral tissue injury.

A

T

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15
Q

Haemostasis is defined as the arrest of bleeding through physiologic or surgical intervention.

A

T

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16
Q

The final haemostatic plug derives 20% of its strength from platelets and 80% from the fibrin network.

A

F

55% from platelets, 45% from fibrin.

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17
Q

Von Willebrand disease is the most common inherited bleeding disorder.

A

T

Affects up to 1% of the population.

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18
Q

Herbs and medication supplements that affect haemostasis include feverfew, fish oil, garlic, ginger, ginkgo, ginseng, dong quai root, bilberry, chondroitin and vitamin E.

A

T

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19
Q

The mild anticoagulation effect of vitamin E may be significantly increased when taken with aspirin and garlic.

A

T

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20
Q

To maximise the vasoconstrictive effects of adrenaline, at least 5 minutes should pass before the first incision.

A

F

15 mins.

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21
Q

Adrenaline should be avoided at acral sites, especially the fingers and toes, due to the risk of ischaemic necrosis or injury

A

F

22
Q

It is safe to perform ring blocks in patients with peripheral vascular disease, diabetes mellitus or vasospastic/thrombotic conditions

A

F

23
Q

Tourniquet use without sedation should be limited to 60 minutes or less

A

T

24
Q

Of the topical haemostatics, aluminium chloride is the least likely to leave pigment particles

A

T

25
Q

Continuous-wave carbon dioxide laser is a valuable tool for haemostasis, capable of sealing blood vessels of 0.5mm diameter

A

T

26
Q

Laser haemostasis is best applied to fast capillary bleeding

A

F

Slow – otherwise it’s difficult to get a dry field.

27
Q

Nd:YAG laser can be used as the sole instrument for haemostasis

A

F

Avoid dt its diffuse and deep destruction.

28
Q

Bipolar electrocoagulation is safest for pts with implantable debrillators because the current is isolated between the two tips of the bipolar forcepts and there is no distal dispersion of energy.

A

T

29
Q

Bipolar electrocoagulation causes three times more tissue necrosis than equivalent current through a unipolar electrode.

A

F

Three times less.

30
Q

Charring and collateral tissue damage is greater with electrocoagulation than with electrodesiccation and electrofulguration.

A

F

Other way around.

31
Q

A ‘wet’ surgical field (presence of blood) disperses electric current and causes excess charring.

A

T

32
Q

The ‘dabbing’ method, rather than the ‘roll back’ method, is best for precise electrocoagulation.

A

F

‘roll back’ is best.

33
Q

Vessels greater than 2mm diameter should generally be ligated.

A

T

34
Q

A double imbricating suture (consisting of 2 modified external purse string sutures applied peripheral to the area of excision) is a useful technique to control bleeding

A

T

35
Q

The dorsal nasal artery, inferior and superior labial artery, angular artery and superficial temporal artery are most vulnerable to injury in cutaneous reconstruction.

A

T

36
Q

New onset of painful swelling within a previously stable and asymptomatic wound is an expanding haematoma until proven otherwise.

A

T

37
Q

Expanding haematomas do not require intervention.

A

F

38
Q

Evacuation of a haematoma is not always necessary, especially if it is small, stable and not compromising tissue viability.

A

T

39
Q

Haematomas evolve through four stages – early development, gelatinous phase, organisation, liquefaction.

A

T

40
Q

People with Von Willebrands disease may also have abnormalities in Factor VII

A

F

factor VIII

41
Q

Moderate thrombocytopenia (50 000–100 000) should not affect hemostasis in cutaneous surgery

A

T
even 20-50,000 ok as long a sno signs of bleeding an dnot planning a flap or anything major
If below 20,000 dont operate

42
Q

the risk of bleeding is considered to be greater with antiaggregants than with anticoagulants

A

T

43
Q

It is safe to operate if the INR is over 3.0

A

F

usually dont operate in this instance

44
Q

Sustained systolic hypertension above 180 mmHg is dangerous and may lead to myocardial infarction or stroke as well as bleeding

A

T

45
Q

Pt fasting prior to surgery helps prevent complications

A

F
more risk of hypoglycaeia and light headedness
fasting often skip their usual meds
ensure they have eaten and drunk if surgery under local only

46
Q

CO2 laser in continuous waveform setting can be used for haemostasis

A

T

47
Q

Active drains use positive pressure created by removing air from the collection device manually or mechanically

A

F
negative pressure
all else true

48
Q

The risk of postoperative bleeding is greatest in the first 24 h, and especially within the first several hours

A

T

cold packs, elevation, rest and compression all help prevent bleeding

49
Q

After surgery involving extensive skin undermining and mobilization, if patients cannot remain hospitalized, it is good practice to keep them in an observation cubicle for 1–2 h

A

T
so they can be monitored for bleeding and can accentuate the pressure that the dressing may exert, either with patients compressing the treated area with their body – in the case of the trunk – or with the patient’s own hand in the case of facial lesions

50
Q

In the case of ambulatory patients, it is advisable to assess them 2–4 h after surgery

A

T

to assess for bleeding/haematoma and for pain management

51
Q

Expanding hematomas require intervention and are medical emergencies in periorbital and cervical locations

A

T